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  • richardmitnick 5:06 pm on February 4, 2023 Permalink | Reply
    Tags: "The Origin of the Origin of the Universe", , , , Astrophysics, , , , , , ,   

    From Astrobites : “The Origin of the Origin of the Universe” 

    Astrobites bloc

    From Astrobites

    2.4.23
    Katherine Lee

    Title: Measurement of the Cosmic Microwave Background Spectrum by the COBE FIRAS Instrument

    Authors: J. C. Mather, E. S. Cheng, D. A. Cottingham, R. E. Eplee Jr., D. J. Fixsen, T. Hewagama, R. B. Isaacman, K. A. Jensen, S. S. Meyer, P. D. Noerdlinger, S. M. Read, L. P. Rosen, R. A. Shafer, E. L. Wright, C. L. Bennett, N. W. Boggess, M. G. Hauser, T. Kelsall, S. H. Moseley Jr., R. F. Silverberg, G. F. Smoot, R. Weiss, and D. T. Wilkinson

    First Author’s Institution: NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

    Status: published in ApJ [open access]

    Back in the mid-20th century, there were two competing theories about the origin of the Universe. Scientists, including Edwin Hubble and Georges Lemaître, had already established that space was expanding.

    ______________________________________________________________________________
    Edwin Hubble

    .


    ______________________________________________________________________________

    Some argued that if you run this expansion back in time, it implies a beginning when everything must have been compressed into a hot, dense singularity, exploding outward from that point in a “Big Bang”. Other astronomers, however, were uncomfortable with the idea that the Universe even had an origin at all. These scientists, most notably Fred Hoyle, argued instead for a cosmology in which the Universe had always existed and had always been expanding, with new galaxies springing up periodically to fill in the gaps. This picture of our Universe is referred to as the “Steady State Theory”.

    These two theories predict fundamentally different things about the background temperature of the Universe. If matter in the Universe does not originate from a single point, as in the Steady State picture, then we would expect the background radiation to be chaotic in nature; there would be no reason for different unconnected regions of spacetime to look the same as each other.

    However, if everything in the Universe comes from the same initial conditions, then everything should be roughly the same temperature. This can also be expressed as the idea that the Universe should be in thermodynamic equilibrium on large scales, and that if you measure the intensity of background radiation at all frequencies, you should see a blackbody spectrum—the characteristic spectrum of an object in equilibrium, dependent only on the object’s temperature. Thus, a key prediction of the Big Bang theory is that the temperature should be nearly constant over the entire sky, with the differences (called anisotropies) from this constant average temperature being extremely small—around one part in 100,000!

    COBE comes to the rescue

    Big Bang cosmologists in the 1960s believed that the peak of the Universe’s blackbody spectrum should be in the microwave frequency range, defined as between 300 MHz and 300 GHz. This would be expected from a massive explosion of energy at the Big Bang, the light from which would have been redshifted into the microwave range as it traveled through the expanding universe. So, if the Big Bang theory is true, we should expect to see a constant source of background radiation coming from all directions in the microwave sky: a so-called Cosmic Microwave Background, or CMB.

    The detection of this CMB radiation in 1965 by Arno Penzias and Robert Woodrow Wilson, as well as the cosmological interpretation of that detection by Robert Dicke, Jim Peebles, Peter Roll, and David Wilkinson, laid the groundwork for modern cosmology, and was the beginning of the end for the idea that the Universe had no origin.

    However, Penzias and Wilson’s discovery was not an accurate measurement of the CMB’s temperature or spectrum. No anisotropies had been detected, and there was still debate over whether or not the CMB spectrum was truly a blackbody. The goal of the Cosmic Background Explorer (COBE) satellite, launched by NASA in 1989, was to answer these lingering questions.

    COBE was split into three instruments: the Differential Microwave Radiometer (DMR), the Far-InfraRed Absolute Spectrophotometer (FIRAS), and the Diffuse Infrared Background Experiment (DIRBE). DMR measured the CMB anisotropies, while DIRBE mapped infrared radiation from foreground dust.

    2
    igure 1: A diagram of the FIRAS instrument, taken from Figure 1a of Mather et. al. (1999).

    FIRAS, meanwhile, was designed to measure the CMB spectrum. It scanned the entire sky multiple times in order to minimize errors, and measured the temperature over a wide range of frequencies between 30 and FIRAS, meanwhile, was designed to measure the CMB spectrum. It scanned the entire sky multiple times in order to minimize errors and measured the temperature over a wide range of frequencies between 30 and nearly 3000 GHz. After eliminating known sources of interference such as cosmic rays, as well as subtracting the effects of light from the Milky Way galaxy and of the Doppler shift caused by the movement of the Earth through space, these scans were then averaged together to create direct measurements of the CMB intensity at various frequencies.

    2
    Figure 2: The cosmic microwave background spectrum, as measured by FIRAS. It shows a near-perfect blackbody, with any deviations from total thermodynamic equilibrium being much too small to see. This plot is taken from Figure 4 of Fixsen et al. (1996), which notes that “uncertainties are a small fraction of the line thickness.”line thickness.”

    The authors found that the background radiation in our universe is in fact extremely close to being a perfect bThe authors of today’s paper found that the background radiation in our Universe is in fact extremely close to being a perfect blackbody! The final temperature found by FIRAS was reported by Mather et al. (1999) to be 2.725 K, with an uncertainty of just 0.002 K! This is an incredibly high-precision measurement and represents the final nail in the coffin for cosmologies other than the Big Bang. John C. Mather received the Nobel Prize in 2006 for his work as FIRAS’s project lead.

    3
    Figure 3: A comparison of the abilities of the COBE [above], WMAP, and Planck satellites to resolve tiny fluctuations in the CMB temperature, called anisotropies. Image: NASA/JPL-Caltech/ESA (Wikimedia Commons)




    Today, cosmologists use the CMB and its anisotropies to characterize the early history of the universe, find galaxy clusters in the later universe, and even look for new physics! The COBE measurements represented the dawn of a new era in cosmology, and laid the groundwork for modern CMB measurements. The science we do toToday, cosmologists use the CMB and its anisotropies to characterize the early history of the Universe, find galaxy clusters in the later Universe, and even look for new physics! Later full-sky measurements taken by the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck satellite added never-before-seen levels of precision to our ability to study the structure and content of the Universe, and future missions like LiteBIRD will continue to improve our ability to study the CMB even more closely, building on COBE’s groundbreaking data. These experiments still rely upon the CMB temperature established by FIRAS, which remains the definitive result even 23 years after its publication.

    ___________________________________________________________________
    Inflation

    In physical cosmology, cosmic inflation, cosmological inflation is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10^−36 seconds after the conjectured Big Bang singularity to some time between 10^−33 and 10^−32 seconds after the singularity. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago).

    Inflation theory was developed in the late 1970s and early 80s, with notable contributions by several theoretical physicists, including Alexei Starobinsky at Landau Institute for Theoretical Physics, Alan Guth at Cornell University, and Andrei Linde at Lebedev Physical Institute. Alexei Starobinsky, Alan Guth, and Andrei Linde won the 2014 Kavli Prize “for pioneering the theory of cosmic inflation.” It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe. Many physicists also believe that inflation explains why the universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the universe is flat, and why no magnetic monopoles have been observed.

    The detailed particle physics mechanism responsible for inflation is unknown. The basic inflationary paradigm is accepted by most physicists, as a number of inflation model predictions have been confirmed by observation; however, a substantial minority of scientists dissent from this position. The hypothetical field thought to be responsible for inflation is called the inflaton.

    In 2002 three of the original architects of the theory were recognized for their major contributions; physicists Alan Guth of M.I.T., Andrei Linde of Stanford, and Paul Steinhardt of Princeton shared the prestigious Dirac Prize “for development of the concept of inflation in cosmology”. In 2012 Guth and Linde were awarded the Breakthrough Prize in Fundamental Physics for their invention and development of inflationary cosmology.

    4
    Alan Guth, from M.I.T., who first proposed Cosmic Inflation.

    Alan Guth’s notes:
    Alan Guth’s original notes on inflation.
    ___________________________________________________________________

    Nobel Prize in Physics for 2011 Expansion of the Universe

    4 October 2011

    The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2011

    with one half to

    Saul Perlmutter
    The Supernova Cosmology Project
    The DOE’s Lawrence Berkeley National Laboratory and The University of California-Berkeley,

    and the other half jointly to

    Brian P. SchmidtThe High-z Supernova Search Team, The Australian National University, Weston Creek, Australia.

    and

    Adam G. Riess

    The High-z Supernova Search Team,The Johns Hopkins University and The Space Telescope Science Institute, Baltimore, MD.

    Written in the stars

    “Some say the world will end in fire, some say in ice…” *

    What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year’s Nobel Laureates in Physics. They have studied several dozen exploding stars, called supernovae, and discovered that the Universe is expanding at an ever-accelerating rate. The discovery came as a complete surprise even to the Laureates themselves.

    In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.

    The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

    The teams used a particular kind of supernova, called Type 1a supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected – this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

    For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.

    The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.

    *Robert Frost, Fire and Ice, 1920
    ______________________________________________________________________________

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 2:52 pm on February 4, 2023 Permalink | Reply
    Tags: "A world with no weak forces", , Astrophysics, , ,   

    From particlebites: “A world with no weak forces” 

    particlebites bloc

    From particlebites

    2.4.23
    Nirmal Raj

    Gravity, electromagnetism, strong, and weak — these are the beating hearts of the universe, the four fundamental forces. But do we really need the last one for us to exist?

    Harnik, Kribs and Perez went about building a world without weak interactions and showed that, indeed, life as we know it could emerge there. This was a counter-proof by example to a famous anthropic argument by Agrawal, Barr, Donoghue and Seckel for the puzzling tininess of the weak scale, i.e. the electroweak hierarchy problem.

    1
    Summary of the argument in hep-ph/9707380 that a tiny Higgs mass (in Planck mass units) is necessary for life to develop.

    Let’s ask first: would the Sun be there in a weakless universe? Sunshine is the product of proton fusion, and that’s the strong force. However, the reaction chain is ignited by the weak force!

    2
    image: Eric G. Blackman.

    So would no stars shine in a weakless world? Amazingly, there’s another route to trigger stellar burning: deuteron-proton fusion via the strong force! In our world, gas clouds collapsing into stars do not take this option because deuterons are very rare, with protons outnumbering them by 50,000. But we need not carry this, er, weakness into our gedanken universe. We can tune the baryon-to-photon ratio — whose origin is unknown — so that we end up with roughly as many deuterons as protons from the primordial synthesis of nuclei. Harnik et al. go on to show that, as in our universe, elements up to iron can be cooked in weakless stars, that they live for billions of years, and may explode in supernovae that disperse heavy elements into the interstellar medium.

    3
    source: hep-ph/0604027

    A “weakless” universe is arranged by elevating the electroweak scale or the Higgs vacuum expectation value (\approx 246 GeV) to, say, the Planck scale (\approx 10^{19} GeV). To get the desired nucleosynthesis, care must be taken to keep the u, d, s quarks and the electron at their usual mass by tuning the Yukawa couplings, which are technically natural.

    And let’s not forget dark matter. To make stars, one needs galaxy-like structures. And to make those, density perturbations must be gravitationally condensed by a large population of matter. In the weakless world of Harnik et al., hyperons make up some of the dark matter, but you would also need much other dark stuff such as your favourite non-WIMP.

    If you believe in the string landscape, a weakless world isn’t just a hypothetical. Someone somewhere might be speculating about a habitable universe with a fourth fundamental force, explaining to their bemused colleagues: “It’s kinda like the strong force, only weak…”

    4

    Bibliography

    Viable range of the mass scale of the standard model
    V. Agrawal, S. M. Barr, J. F. Donoghue, D. Seckel, Phys.Rev.D 57 (1998) 5480-5492.

    A Universe without weak interactions
    R. Harnik, G. D. Kribs, G. Perez, Phys.Rev.D 74 (2006) 035006

    Further reading

    Gedanken Worlds without Higgs: QCD-Induced Electroweak Symmetry Breaking
    C. Quigg, R. Shrock, Phys.Rev.D 79 (2009) 096002

    The Multiverse and Particle Physics
    J. F. Donoghue, Ann.Rev.Nucl.Part.Sci. 66 (2016)

    The eighteen arbitrary parameters of the standard model in your everyday life
    R. N. Cahn, Rev. Mod. Phys. 68, 951 (1996)

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    What is ParticleBites?
    ParticleBites is an online particle physics journal club written by graduate students and postdocs. Each post presents an interesting paper in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.

    The papers are accessible on the arXiv preprint server. Most of our posts are based on papers from hep-ph (high energy phenomenology) and hep-ex (high energy experiment).

    Why read ParticleBites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. With each brief ParticleBite, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in particle physics.

    Who writes ParticleBites?

    ParticleBites is written and edited by graduate students and postdocs working in high energy physics. Feel free to contact us if you’re interested in applying to write for ParticleBites.

    ParticleBites was founded in 2013 by Flip Tanedo following the Communicating Science (ComSciCon) 2013 workshop.

    2
    Flip Tanedo UCI Chancellor’s ADVANCE postdoctoral scholar in theoretical physics. As of July 2016, I will be an assistant professor of physics at the University of California, Riverside

    It is now organized and directed by Flip and Julia Gonski, with ongoing guidance from Nathan Sanders.

     
  • richardmitnick 2:21 pm on February 4, 2023 Permalink | Reply
    Tags: "Serendipitous detection of a rapidly accreting black hole in the early Universe", , Astrophysics, , , , eRosita Russian German space X-ray telescope, The MPG Institute for Extraterrestrial Physics [MPG Institut für Extraterrestrische Physik](DE)   

    From The MPG Institute for Extraterrestrial Physics [MPG Institut für Extraterrestrische Physik](DE): “Serendipitous detection of a rapidly accreting black hole in the early Universe” 

    From The MPG Institute for Extraterrestrial Physics [MPG Institut für Extraterrestrische Physik](DE)

    1.31.23

    Wolf, Julien
    phd student
    Tel +49 89 30000-3879
    Fax +49 89 30000-3569
    jwolf@mpe.mpg.de

    Salvato, Mara
    Senior Scientist
    Tel +49 89 30000-3815
    Fax +49 89 30000-3569
    mara@mpe.mpg.de

    Nandra, Kirpal
    director
    Tel +49 89 30000-3401
    Fax +49 89 30000-3569
    knandra@mpe.mpg.de

    eROSITA telescope finds an X-ray bright, optically faint quasar accreting material at an extremely high rate only about 800 million years after the big bang.

    Analyzing data from the eROSITA Final Equatorial-Depth Survey, astronomers at MPE have found a faint X-ray source identified with a very distant supermassive black hole that is accreting material at an extremely high rate. This quasar, at a redshift of z=6.56, is much more luminous in X-rays than expected. This is the most distant blind X-ray detection to date, from an object whose radiation was emitted almost 13 billion years ago and allows the scientists to investigate the growth of black holes in the early Universe.

    Supermassive black holes at the centres of galaxies can be detected out to great distances – but only if they accrete matter, which heats up and shines brightly, causing it to become an “active galactic nucleus” (AGN). These “quasars” or quasi-stellar objects then outshine the rest of their galaxy, but at large distances, they nevertheless are difficult to detect and extremely rare. To date, only about 50 quasars with redshift z>5.7, when the Universe was less than one billion years old, have been detected in X-rays.

    2
    A new, faint X-ray source (right) was found in the eROSITA Final Equatorial-Depth Survey (eFEDS). Using optical follow-up observations (left top), the eROSITA team identified this as a quasar at a redshift of z=6.56. Quasars are powered by a central supermassive black hole, accreting material at a high rate. This is the most distant blind X-ray detection to date and allows the scientists to investigate the growth of black holes in the early Universe. Collage: MPE/Cluster Origins.

    Analyzing X-ray data of the eROSITA Final Equatorial-Depth Survey (eFEDS), which were taken during the Performance Verification Phase of the eROSITA telescope in 2019, the eROSITA team found a new point source. In collaboration with colleagues using the Subaru telescope, they identified the X-ray emission with a previously known quasar J0921+0007 at a redshift of 6.56, which was initially discovered by a team searching for distant sources with the Subaru telescope.


    Dedicated follow-up observations at infrared wavelengths showed that the black hole has 250 million solar masses, a relatively low mass for a supermassive black hole at this distance. Chandra follow-up observations confirmed the high X-ray luminosity measured by eROSITA, indicating a very high accretion rate.

    “We did not expect to find such a low-mass AGN already in our very first mini-survey with eROSITA”, says Julien Wolf, who searches for the most distant supermassive black holes in eROSITA data as part of his Ph.D. at the Max Planck Institute for Extraterrestrial Physics (MPE). “It is the most distant serendipitous X-ray detection to date and its properties are rather atypical for quasars at such high redshifts: it is intrinsically faint in visible light but very luminous in X-rays.”

    The quasar detected by eROSITA shows properties, which are similar to so-called narrow-line Seyfert-1 galaxies, a particular class of active galaxies in the local Universe. They are associated with supermassive black holes below 100 million solar masses, accreting matter at a high rate, and could be younger than their higher mass siblings.

    “Hunting for rare objects like this needs deep multi-wavelength data complementing the large X-ray survey area. Luckily, most of the sky is mapped at optical and infrared wavelengths, although the Subaru data in eFEDS area are especially deep,” emphasises Mara Salvato, eROSITA spokesperson.

    3
    X-ray image cutouts in the region of J0921+0007. The eROSITA/eFEDS image is on the left, the high-resolution Chandra image is on the right. © MPE

    While the bulk of active galaxies detected at high redshifts (i.e. large distances) host black holes with masses of one to ten billion solar masses, there must also be many with less massive black holes. These, however, need to accrete matter at a very high rate to shine brightly enough so that they can be detected at all.

    In addition to this source, the team had earlier found another luminous and similarly distant quasar in the same field. “eROSITA is uniquely suited to performing a census of rare X-ray objects like these powerful high-redshift quasars,” states Kirpal Nandra, director of high-energy physics at MPE. “This is now the second example we’ve found in eFEDS when we expected to find none”.

    The early eROSITA data are just a foretaste of what’s to come. Based on these early detections, the scientists expect to find hundreds more examples with the eROSITA all-sky survey. In an effort to find this elusive population of yet unknown distant quasars, the group has developed a large programme exploring the eROSITA all-sky survey. This dedicated survey has already led to the discovery of five new X-ray luminous quasars at z>5.6, which will be presented in a future publication. Simultaneously, a Russian team of researchers have also reported the first eROSITA high-redshift detections in the northern hemisphere.

    Objects like these are currently our best way of understanding early black hole formation. If the surprising eFEDS detections are confirmed in the larger dataset, it could represent a challenge for some evolutionary models.

    Astronomy & Astrophysics

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    For their astrophysical research, The MPG Institute for Extraterrestrial Physics [MPG Institut für Extraterrestrische Physik]( DE) scientists measure the radiation of far away objects in different wavelenths areas: from millimetere/sub-millimetre and infared all the way to X-ray and gamma-ray wavelengths. These methods span more than twelve decades of the electromagnetic spectrum.

    The research topics pursued at MPE range from the physics of cosmic plasmas and of stars to the physics and chemistry of interstellar matter, from star formation and nucleosynthesis to extragalactic astrophysics and cosmology. The interaction with observers and experimentalists in the institute not only leads to better consolidated efforts but also helps to identify new, promising research areas early on.

    The structural development of the institute mainly has been directed by the desire to work on cutting-edge experimental, astrophysical topics using instruments developed in-house. This includes individual detectors, spectrometers and cameras but also telescopes and integrated, complete payloads. Therefore the engineering and workshop areas are especially important for the close interlink between scientific and technical aspects.

    The scientific work is done in four major research areas that are supervised by one of the directors:

    Center for Astrochemical Studies (CAS)
    High-Energy Astrophysics
    Infrared/Submillimeter Astronomy
    Optical & Interpretative Astronomy

    Within these areas scientists lead individual experiments and research projects organized in about 25 project teams.

    MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.] (DE)is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.

    According to its primary goal, the MPG Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014) MPG Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.

    The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

    The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

    History

    The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

    The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

    The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

    MPG Institutes and research groups

    The MPG Society consists of over 80 research institutes. In addition, the society funds a number of Max Planck Research Groups (MPRG) and International Max Planck Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
    The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University (US) focusing on neuroscience.
    The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.

    Internally, MPG Institutes are organized into research departments headed by directors such that each MPI has several directors, a position roughly comparable to anything from full professor to department head at a university. Other core members include Junior and Senior Research Fellows.

    In addition, there are several associated institutes:

    International Max Planck Research Schools

    International Max Planck Research Schools

    Together with the Association of Universities and other Education Institutions in Germany, the Max Planck Society established numerous International Max Planck Research Schools (IMPRS) to promote junior scientists:

    • Cologne Graduate School of Ageing Research, Cologne
    • International Max Planck Research School for Intelligent Systems, at the Max Planck Institute for Intelligent Systems located in Tübingen and Stuttgart
    • International Max Planck Research School on Adapting Behavior in a Fundamentally Uncertain World (Uncertainty School), at the Max Planck Institutes for Economics, for Human Development, and/or Research on Collective Goods
    • International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering, Magdeburg
    • International Max Planck Research School for Astronomy and Cosmic Physics, Heidelberg at the MPI for Astronomy
    • International Max Planck Research School for Astrophysics, Garching at the MPI for Astrophysics
    • International Max Planck Research School for Complex Surfaces in Material Sciences, Berlin
    • International Max Planck Research School for Computer Science, Saarbrücken
    • International Max Planck Research School for Earth System Modeling, Hamburg
    • International Max Planck Research School for Elementary Particle Physics, Munich, at the MPI for Physics
    • International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Marburg at the Max Planck Institute for Terrestrial Microbiology
    • International Max Planck Research School for Evolutionary Biology, Plön at the Max Planck Institute for Evolutionary Biology
    • International Max Planck Research School “From Molecules to Organisms”, Tübingen at the Max Planck Institute for Developmental Biology
    • International Max Planck Research School for Global Biogeochemical Cycles, Jena at the Max Planck Institute for Biogeochemistry
    • International Max Planck Research School on Gravitational Wave Astronomy, Hannover and Potsdam MPI for Gravitational Physics
    • International Max Planck Research School for Heart and Lung Research, Bad Nauheim at the Max Planck Institute for Heart and Lung Research
    • International Max Planck Research School for Infectious Diseases and Immunity, Berlin at the Max Planck Institute for Infection Biology
    • International Max Planck Research School for Language Sciences, Nijmegen
    • International Max Planck Research School for Neurosciences, Göttingen
    • International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen
    • International Max Planck Research School for Marine Microbiology (MarMic), joint program of the Max Planck Institute for Marine Microbiology in Bremen, the University of Bremen, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, and the Jacobs University Bremen
    • International Max Planck Research School for Maritime Affairs, Hamburg
    • International Max Planck Research School for Molecular and Cellular Biology, Freiburg
    • International Max Planck Research School for Molecular and Cellular Life Sciences, Munich
    • International Max Planck Research School for Molecular Biology, Göttingen
    • International Max Planck Research School for Molecular Cell Biology and Bioengineering, Dresden
    • International Max Planck Research School Molecular Biomedicine, program combined with the ‘Graduate Programm Cell Dynamics And Disease’ at the University of Münster and the Max Planck Institute for Molecular Biomedicine
    • International Max Planck Research School on Multiscale Bio-Systems, Potsdam
    • International Max Planck Research School for Organismal Biology, at the University of Konstanz and the Max Planck Institute for Ornithology
    • International Max Planck Research School on Reactive Structure Analysis for Chemical Reactions (IMPRS RECHARGE), Mülheim an der Ruhr, at the Max Planck Institute for Chemical Energy Conversion
    • International Max Planck Research School for Science and Technology of Nano-Systems, Halle at Max Planck Institute of Microstructure Physics
    • International Max Planck Research School for Solar System Science at the University of Göttingen hosted by MPI for Solar System Research
    • International Max Planck Research School for Astronomy and Astrophysics, Bonn, at the MPI for Radio Astronomy (formerly the International Max Planck Research School for Radio and Infrared Astronomy)
    • International Max Planck Research School for the Social and Political Constitution of the Economy, Cologne
    • International Max Planck Research School for Surface and Interface Engineering in Advanced Materials, Düsseldorf at Max Planck Institute for Iron Research GmbH
    • International Max Planck Research School for Ultrafast Imaging and Structural Dynamics, Hamburg

    Max Planck Schools

    • Max Planck School of Cognition
    • Max Planck School Matter to Life
    • Max Planck School of Photonics

    Max Planck Center

    • The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
    • The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

    Max Planck Institutes

    Among others:
    • Max Planck Institute for Neurobiology of Behavior – caesar, Bonn
    • Max Planck Institute for Aeronomics in Katlenburg-Lindau was renamed to Max Planck Institute for Solar System Research in 2004;
    • Max Planck Institute for Biology in Tübingen was closed in 2005;
    • Max Planck Institute for Cell Biology in Ladenburg b. Heidelberg was closed in 2003;
    • Max Planck Institute for Economics in Jena was renamed to the Max Planck Institute for the Science of Human History in 2014;
    • Max Planck Institute for Ionospheric Research in Katlenburg-Lindau was renamed to Max Planck Institute for Aeronomics in 1958;
    • Max Planck Institute for Metals Research, Stuttgart
    • Max Planck Institute of Oceanic Biology in Wilhelmshaven was renamed to Max Planck Institute of Cell Biology in 1968 and moved to Ladenburg 1977;
    • Max Planck Institute for Psychological Research in Munich merged into the Max Planck Institute for Human Cognitive and Brain Sciences in 2004;
    • Max Planck Institute for Protein and Leather Research in Regensburg moved to Munich 1957 and was united with the Max Planck Institute for Biochemistry in 1977;
    • Max Planck Institute for Virus Research in Tübingen was renamed as Max Planck Institute for Developmental Biology in 1985;
    • Max Planck Institute for the Study of the Scientific-Technical World in Starnberg (from 1970 until 1981 (closed)) directed by Carl Friedrich von Weizsäcker and Jürgen Habermas.
    • Max Planck Institute for Behavioral Physiology
    • Max Planck Institute of Experimental Endocrinology
    • Max Planck Institute for Foreign and International Social Law
    • Max Planck Institute for Physics and Astrophysics
    • Max Planck Research Unit for Enzymology of Protein Folding
    • Max Planck Institute for Biology of Ageing

     
  • richardmitnick 12:56 pm on February 4, 2023 Permalink | Reply
    Tags: "3 new studies indicate a conflict at the heart of cosmology", "The Big Think", , Astrophysics, , , , ,   

    From “The Big Think” : “3 new studies indicate a conflict at the heart of cosmology” 

    From “The Big Think”

    2.1.23
    Don Lincoln

    The Universe isn’t as “clumpy” as we think it should be.

    1
    Credit: NASA.

    Key Takeaways

    Telescopes are essentially time machines. As we examine galaxies that are at greater and greater distances from the Earth, we are looking further and further back in time. A new series of studies that examine the “clumpiness” of the Universe indicates that there might be a conflict at the heart of cosmology. The Big Bang theory is still sound, but it may need to be tweaked.

    A series of three scientific papers describing the expansion history of the Universe is telling a confusing tale, with predictions and measurements slightly disagreeing.

    While this disagreement isn’t considered a fatal disproof of modern cosmology, it could be a hint that our theories need to be revised.

    PRD “Joint analysis of DES Year 3 data and CMB lensing from SPT and Planck I: Construction of CMB Lensing Maps and Modeling Choices”
    PRD “Joint analysis of DES Year 3 data and CMB lensing from SPT and Planck II: Cross-correlation measurements and cosmological constraints”
    PRD “Joint analysis of DES Year 3 data and CMB lensing from SPT and Planck III: Combined cosmological constraints”

    Creation stories, both ancient and modern

    Understanding exactly how the world around us came into existence is a question that has bothered humanity for millennia. All around the world, people have devised stories — from the ancient Greek legend of the creation of the Earth and other primordial entities from Chaos (as first written down by Hesiod) to the Hopi creation myth (which describes a series of different kinds of creatures being created, eventually ending up as humans).

    In modern times, there are still competing creation stories, but there is one that is grounded in empiricism and the scientific method: the idea that about 13.8 billion years ago, the Universe began in a much smaller and hotter compressed state, and it has been expanding ever since then. This idea is colloquially called the “Big Bang,” although different writers use the term to mean slightly different things. Some use it to refer to the exact moment at which the Universe came into existence and began to expand, while others use it to refer to all moments after the beginning. For those writers, the Big Bang is still ongoing, as the expansion of the Universe continues.

    The beauty of this scientific explanation is that it can be tested. Astronomers rely on the fact that light has a finite speed, which means that it takes time for light to cross the cosmos. For example, the light we see as the Sun shining was emitted eight minutes before we see it. Light from the nearest star took about four years to get to Earth, and light from elsewhere in the cosmos can take billions of years to arrive.

    The telescope as a time machine

    Effectively, this means that telescopes are time machines. By looking at more and more distant galaxies, astronomers are able to see what the Universe looked like in the distant past. By stitching together observations of galaxies at different distances from the Earth, astronomers can unravel the evolution of the cosmos.

    The recent measurements use two different telescopes to study the structure of the Universe at different cosmic epochs. One facility, called the South Pole Telescope (SPT), looks at the earliest possible light, emitted a mere 380,000 years after the Universe began.

    At that time, the Universe was 0.003% its current age. If we consider the current cosmos to be equivalent to a 50-year-old person, the SPT looks at the Universe when it was a mere 12 hours old.

    The second facility is called the Dark Energy Survey (DES).
    ___________________________________________________________________
    The Dark Energy Survey

    Dark Energy Camera [DECam] built at The DOE’s Fermi National Accelerator Laboratory.

    NOIRLab National Optical Astronomy Observatory Cerro Tololo Inter-American Observatory (CL) Victor M Blanco 4m Telescope which houses the Dark-Energy-Camera – DECam at Cerro Tololo, Chile at an altitude of 7200 feet.

    NOIRLabNSF NOIRLab NOAO Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.

    The Dark Energy Survey is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. The Dark Energy Survey began searching the Southern skies on August 31, 2013.

    According to Albert Einstein’s Theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up.

    Nobel Prize in Physics for 2011 Expansion of the Universe

    4 October 2011

    The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2011

    with one half to

    Saul Perlmutter
    The Supernova Cosmology Project
    The DOE’s Lawrence Berkeley National Laboratory and The University of California-Berkeley,

    and the other half jointly to

    Brian P. Schmidt
    The High-z Supernova Search Team,
    The Australian National University, Weston Creek, Australia.

    and

    Adam G. Riess
    The High-z Supernova Search Team,The Johns Hopkins University and
    The Space Telescope Science Institute, Baltimore, MD.
    Written in the stars

    “Some say the world will end in fire, some say in ice…” *

    What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year’s Nobel Laureates in Physics. They have studied several dozen exploding stars, called supernovae, and discovered that the Universe is expanding at an ever-accelerating rate. The discovery came as a complete surprise even to the Laureates themselves.

    In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.

    The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

    The teams used a particular kind of supernova, called Type 1a supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected – this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

    For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.

    The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.

    *Robert Frost, Fire and Ice, 1920
    ___________________________________________________________________
    To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called Dark Energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or Albert Einstein’s Theory of General Relativity must be replaced by a new theory of gravity on cosmic scales.

    The Dark Energy Survey is designed to probe the origin of the accelerating universe and help uncover the nature of Dark Energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the Dark Energy Survey collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.
    ___________________________________________________________________
    This is a very powerful telescope located on a mountain top in Chile. Over the years, it has surveyed about 1/8 of the sky and photographed over 300 million galaxies, many of which are so dim, they are about one-millionth as bright as the dimmest stars visible to the human eye. This telescope can image galaxies from the current day to as far back as eight billion years ago. Continuing with the analogy of a 50-year-old individual, DES can take pictures of the Universe starting when it was 21 years old up until the present. (Full disclosure: Researchers at Fermilab, where I also work, carried out this study — but I did not participate in this research.)

    As light from distant galaxies travels to Earth, it can be distorted by galaxies that are closer to us. By using these tiny distortions, astronomers have developed a very precise map of the distribution of matter in the cosmos. This map includes both ordinary matter, of which stars and galaxies are the most familiar examples, and dark matter, which is a hypothesized form of matter that neither absorbs nor emits light. Dark matter is only observed through its gravitational effect on other objects and is thought to be five times more prevalent than ordinary matter.
    __________________________________
    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., and Vera Rubin a Woman in STEM, denied the Nobel, some 30 years later, did most of the work on Dark Matter.

    Fritz Zwicky.

    Coma cluster via NASA/ESA Hubble, the original example of Dark Matter discovered during observations by Fritz Zwicky and confirmed 30 years later by Vera Rubin.

    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.

    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.

    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).

    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970.

    Vera Rubin measuring spectra, worked on Dark Matter(Emilio Segre Visual Archives AIP SPL).

    Dark Matter Research

    Super Cryogenic Dark Matter Search from DOE’s SLAC National Accelerator Laboratory at Stanford University at SNOLAB (Vale Inco Mine, Sudbury, Canada).

    LBNL LZ Dark Matter Experiment xenon detector at Sanford Underground Research Facility Credit: Matt Kapust.


    DAMA at Gran Sasso uses sodium iodide housed in copper to hunt for dark matter LNGS-INFN.

    Yale HAYSTAC axion dark matter experiment at Yale’s Wright Lab.

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB (CA) deep in Sudbury’s Creighton Mine.

    The LBNL LZ Dark Matter Experiment Dark Matter project at SURF, Lead, SD.

    DAMA-LIBRA Dark Matter experiment at the Italian National Institute for Nuclear Physics’ (INFN’s) Gran Sasso National Laboratories (LNGS) located in the Abruzzo region of central Italy.

    DARWIN Dark Matter experiment. A design study for a next-generation, multi-ton dark matter detector in Europe at The University of Zurich [Universität Zürich](CH).

    PandaX II Dark Matter experiment at Jin-ping Underground Laboratory (CJPL) in Sichuan, China.

    Inside the Axion Dark Matter eXperiment U Washington. Credit: Mark Stone U. of Washington. Axion Dark Matter Experiment.

    3
    The University of Western Australia ORGAN Experiment’s main detector. A small copper cylinder called a “resonant cavity” traps photons generated during dark matter conversion. The cylinder is bolted to a “dilution refrigerator” which cools the experiment to very low temperatures.
    __________________________________

    Is the Big Bang incomplete?

    In order to test the Big Bang, astronomers can use measurements taken by the South Pole Telescope and use the theory to project forward to the present day. They can then take measurements from the Dark Energy Survey and compare them. If the measurements are accurate and the theory describes the cosmos, they should agree.

    And, by and large, they do — but not completely. When astronomers look at how “clumpy” the matter of the current Universe should be, purely from SPT measurements and extrapolations of theory, they find that the predictions are “clumpier” than current measurements by DES.

    This disagreement is potentially significant and could signal that the theory of the Big Bang is incomplete. Furthermore, this isn’t the first discrepancy that astronomers have encountered when they project measurements of the same primordial light imaged by the SPT to the modern day. Different research groups, using different telescopes, have found that the current Universe is expanding faster than expected from observations of the ancient light seen by the SPT, combined with Big Bang theory. This other discrepancy is called the Hubble Tension, named after American astronomer Edwin Hubble, who first realized that the Universe was expanding.

    __________________________________________________________________________________

    Edwin Hubble

    .

    __________________________________________________________________________________


    Have astronomers disproved the Big Bang?

    While the new discrepancy in predictions and measurements of the clumpiness of the Universe are preliminary, it could be that both this measurement and the Hubble Tension imply that the Big Bang theory might need some tweaking. Mind you, the discrepancies do not rise to the level of scrapping the theory entirely; however, it is the nature of the scientific method to adjust theories to account for new observations.

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 10:46 am on February 4, 2023 Permalink | Reply
    Tags: "Untangling a Knot of Galaxy Clusters", Abell 2256, Astrophysics, , , , , ,   

    From The National Aeronautics and Space Administration Chandra X-ray telescope: “Untangling a Knot of Galaxy Clusters” 

    NASA Chandra Banner

    From The National Aeronautics and Space Administration Chandra X-ray telescope

    1.30.23

    1
    Abell 2256, Labeled (Credit: X-ray: Chandra: NASA/CXC/Univ. of Bolonga/K. Rajpurohit et al.; XMM-Newton: ESA/XMM-Newton/Univ. of Bolonga/K. Rajpurohit et al.
    Radio: LOFAR: LOFAR/ASTRON; GMRT: NCRA/TIFR/GMRT; VLA: NSF/NRAO/VLA; Optical/IR: Pan-STARRS

    Astronomers have captured a spectacular, ongoing collision between at least three galaxy clusters. Data from NASA’s Chandra X-ray Observatory, ESA’s (European Space Agency’s) XMM-Newton, and a trio of radio telescopes is helping astronomers sort out what is happening in this jumbled scene.

    The European Space Agency [La Agencia Espacial Europea] [Agencia Espacial Europea][Agence spatiale européenne][Europäische Weltraumorganization](EU) XMM Newton X-ray Telescope.

    Collisions and mergers like this are the main way that galaxy clusters can grow into the gigantic cosmic edifices seen today. These also act as the largest particle accelerators in the universe.

    The giant galaxy cluster forming from this collision is Abell 2256, located 780 million light-years from Earth. This composite image of Abell 2256 combines X-rays from Chandra and XMM in blue with radio data collected by the Giant Metrewave Radio Telescope (GMRT), the Low Frequency Array (LOFAR), and the Karl G. Jansky Very Large Array (VLA) all in red, plus optical and infrared data from Pan-STARRs in white and pale yellow.

    Astronomers studying this object are trying to tease out what has led to this unusual-looking structure. Each telescope tells a different part of the story. Galaxy clusters are some of the biggest objects in the universe containing hundreds or even thousands of individual galaxies. In addition, they contain enormous reservoirs of superheated gas, with temperatures of several million degrees Fahrenheit. Only X-ray telescopes like Chandra and XMM can see this hot gas. A labeled version of the figure shows gas from two of the galaxy clusters, with the third blended too closely to separate from the others.

    The radio emission in this system arises from an even more complex set of sources. The first are the galaxies themselves, in which the radio signal is generated by particles blasting away in jets from supermassive black holes at their centers. These jets are either shooting into space in straight and narrow lines (those labeled “C” and “I” in the annotated image, using the astronomer’s naming system) or slowed down as the jets interact with gas they are running into, creating complex shapes and filaments (“A”, “B,” and “F”). Source F contains three sources, all created by a black hole in a galaxy aligning with the left-most source of this trio.

    Radio waves are also coming from huge filamentary structures (labeled “relic”), mostly located to the north of the radio-emitting galaxies, likely generated when the collision created shock waves and accelerated particles in the gas across over two million light-years. A paper analyzing this structure was published earlier this year by Kamlesh Rajpurohit from the University of Bologna in Italy in the March 2022 issue of The Astrophysical Journal [below]. This is Paper I in an ongoing series studying different aspects of this colliding galaxy cluster system.

    Finally, there is a “halo” of radio emission located near the center of the collision. Because this halo overlaps with the X-ray emission and is dimmer than the filamentary structure and the galaxies, another radio image has been produced to emphasize the faint radio emission. Paper II led by Rajpurohit, recently published in the journal Astronomy and Astrophysics [below], presents a model that the halo emission may be caused by the reacceleration of particles by rapid changes in the temperature and density of the gas as the collision and merging of the clusters proceed. This model, however, is unable to explain all the features of the radio data, highlighting the need for more theoretical study of this and similar objects.

    2
    Halo of Radio Emission (Credit: LOFAR/ASTRON)

    Paper III by Rajpurohit and collaborators will study the galaxies producing radio waves in Abell 2256. This cluster contains an unusually large number of such galaxies, possibly because the collision and merger are triggering the growth of supermassive black holes and consequent eruptions. More details about the LOFAR image of Abell 2256 will be reported in an upcoming paper by Erik Osinga.

    The full list of co-authors for papers I and II include researchers from the University of Bologna, Italy (Franco Vazza, Annalisa Bonafede, Andrea Botteon, Christopher J. Riseley, Paola Domínguez-Fernández, Chiara Stuardi, and Daniele Dallacasa); Leiden Observatory, Leiden University, the Netherlands (Erik Osinga, Reinout J. van Weeren, Timothy Shimwell, Huub Röttgering, and George Miley); Thüringer Landessternwarte, Tautenburg, Germany (Matthias Hoeft and Alexander Drabent); INAF-Istituto di Radio Astronomia, Bologna, Italy (Gianfranco Brunetti and Rossella Cassano); Hamburger Sternwarte, Germany (Denis Wittor, Marcus Brüggen, and Francesco de Gasperin); Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Italy (Marisa Brienza); Center for Astrophysics, Harvard | Smithsonian (William Forman); Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley (Sangeeta Rajpurohit); Physical Research Laboratory, Ahmedabad, India (Arvind Singh Rajpurohit); Universität Würzburg, Würzburg, Germany (Etienne Bonnassieux), and INAF–IASF Milano, Italy (Mariachiara Rossetti).

    The Astrophysical Journal 2022
    Astronomy and Astrophysics 2023

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.
    In 1976 the Chandra X-ray Observatory (called AXAF at the time) was proposed to National Aeronautics and Space Administration by Riccardo Giacconi and Harvey Tananbaum. Preliminary work began the following year at NASA’s Marshall Space Flight Center and the Harvard Smithsonian Center for Astrophysics. In the meantime, in 1978, NASA launched the first imaging X-ray telescope, Einstein (HEAO-2), into orbit. Work continued on the AXAF project throughout the 1980s and 1990s. In 1992, to reduce costs, the spacecraft was redesigned. Four of the twelve planned mirrors were eliminated, as were two of the six scientific instruments. AXAF’s planned orbit was changed to an elliptical one, reaching one third of the way to the Moon’s at its farthest point. This eliminated the possibility of improvement or repair by the space shuttle but put the observatory above the Earth’s radiation belts for most of its orbit. AXAF was assembled and tested by TRW (now Northrop Grumman Aerospace Systems) in Redondo Beach, California.

    AXAF was renamed Chandra as part of a contest held by NASA in 1998, which drew more than 6,000 submissions worldwide. The contest winners, Jatila van der Veen and Tyrel Johnson (then a high school teacher and high school student, respectively), suggested the name in honor of Nobel Prize–winning Indian-American astrophysicist Subrahmanyan Chandrasekhar. He is known for his work in determining the maximum mass of white dwarf stars, leading to greater understanding of high energy astronomical phenomena such as neutron stars and black holes. Fittingly, the name Chandra means “moon” in Sanskrit.

    Originally scheduled to be launched in December 1998, the spacecraft was delayed several months, eventually being launched on July 23, 1999, at 04:31 UTC by Space Shuttle Columbia during STS-93. Chandra was deployed from Columbia at 11:47 UTC. The Inertial Upper Stage’s first stage motor ignited at 12:48 UTC, and after burning for 125 seconds and separating, the second stage ignited at 12:51 UTC and burned for 117 seconds. At 22,753 kilograms (50,162 lb), it was the heaviest payload ever launched by the shuttle, a consequence of the two-stage Inertial Upper Stage booster rocket system needed to transport the spacecraft to its high orbit.

    Chandra has been returning data since the month after it launched. It is operated by the SAO at the Chandra X-ray Center in Cambridge, Massachusetts, with assistance from Massachusetts Institute of Technology and Northrop Grumman Space Technology. The ACIS CCDs suffered particle damage during early radiation belt passages. To prevent further damage, the instrument is now removed from the telescope’s focal plane during passages.

    Although Chandra was initially given an expected lifetime of 5 years, on September 4, 2001, NASA extended its lifetime to 10 years “based on the observatory’s outstanding results.” Physically Chandra could last much longer. A 2004 study performed at the Chandra X-ray Center indicated that the observatory could last at least 15 years.

    In July 2008, the International X-ray Observatory, a joint project between European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU), NASA and Japan Aerospace Exploration Agency (JAXA) (国立研究開発法人宇宙航空研究開発機構], was proposed as the next major X-ray observatory but was later cancelled. ESA later resurrected a downsized version of the project as the Advanced Telescope for High Energy Astrophysics (ATHENA), with a proposed launch in 2028.

    European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Athena spacecraft depiction

    On October 10, 2018, Chandra entered safe mode operations, due to a gyroscope glitch. NASA reported that all science instruments were safe. Within days, the 3-second error in data from one gyro was understood, and plans were made to return Chandra to full service. The gyroscope that experienced the glitch was placed in reserve and is otherwise healthy.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [NASA/ESA Hubble, NASA Chandra, NASA Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 8:12 am on February 4, 2023 Permalink | Reply
    Tags: "Astronomers Studied More Than 5000 Black Holes to Figure Out Why They Twinkle", , Astrophysics, , , ,   

    From “The Conversation (AU)” : “Astronomers Studied More Than 5000 Black Holes to Figure Out Why They Twinkle” 

    From “The Conversation (AU)”

    2.4.23
    Christian Wolf

    Black holes are bizarre things, even by the standards of astronomers. Their mass is so great it bends space around them so tightly that nothing can escape, even light itself.

    And yet, despite their famous blackness, some black holes are quite visible. The gas and stars these galactic vacuums devour are sucked into a glowing disc before their one-way trip into the hole, and these discs can shine more brightly than entire galaxies.

    Stranger still, these black holes twinkle.

    1
    This illustration shows a disk of hot gas swirling around a black hole. The stream of gas stretching to the right is what remains of a star that was pulled apart by the black hole. Credit: NASA/JPL-Caltech.

    The brightness of the glowing discs can fluctuate from day to day, and nobody is entirely sure why.

    We piggy-backed on NASA’s asteroid defense effort to watch more than 5,000 of the fastest-growing black holes in the sky for five years in an attempt to understand why this twinkling occurs.

    In a new paper in Nature Astronomy [below], we report our answer: a kind of turbulence driven by friction and intense gravitational and magnetic fields.

    Gigantic star-eaters

    We study supermassive black holes, the kind that sit at the centers of galaxies and are as massive as millions or billions of Suns.

    Our own galaxy, the Milky Way, has one of these giants at its center, with a mass of about four million Suns.

    For the most part, the 200 billion or so stars that make up the rest of the galaxy (including our Sun) happily orbit around the black hole at the center.

    However, things are not so peaceful in all galaxies. When pairs of galaxies pull on each other via gravity, many stars may end up tugged too close to their galaxy’s black hole. This ends badly for the stars: They are torn apart and devoured.

    We are confident this must have happened in galaxies with black holes that weigh as much as a billion Suns, because we can’t imagine how else they could have grown so large. It may also have happened in the Milky Way in the past.

    Black holes can also feed in a slower, more gentle way: by sucking in clouds of gas blown out by geriatric stars known as red giants.

    Feeding time

    In our new study, we looked closely at the feeding process among the 5,000 fastest-growing black holes in the Universe.

    In earlier studies, we discovered the black holes with the most voracious appetite. Last year, we found a black hole that eats an Earth’s-worth of stuff every second [PASA (below)]. In 2018, we found one that eats a whole Sun every 48 hours [PASA (below)].

    But we have lots of questions about their actual feeding behavior. We know material on its way into the hole spirals into a glowing “accretion disc” that can be bright enough to outshine entire galaxies. These visibly feeding black holes are called quasars.

    Most of these black holes are a long, long way away – much too far for us to see any detail of the disc. We have some images of accretion discs around nearby black holes, but they are merely breathing in some cosmic gas rather than feasting on stars.

    Five years of flickering black holes

    In our new work, we used data from NASA’s ATLAS telescope in Hawaii.


    It scans the entire sky every night (weather permitting), monitoring for asteroids approaching Earth from the outer darkness.

    These whole-sky scans also happen to provide a nightly record of the glow of hungry black holes, deep in the background. Our team put together a five-year movie of each of those black holes, showing the day-to-day changes in brightness caused by the bubbling and boiling glowing maelstrom of the accretion disc.

    The twinkling of these black holes can tell us something about accretion discs.

    In 1998, astrophysicists Steven Balbus and John Hawley proposed a theory of “magneto-rotational instabilities” that describes how magnetic fields can cause turbulence in the discs [Reviews of Modern Physics (below)]. If that is the right idea, then the discs should sizzle in regular patterns.

    They would twinkle in random patterns that unfold as the discs orbit. Larger discs orbit more slowly with a slow twinkle, while tighter and faster orbits in smaller discs twinkle more rapidly.

    But would the discs in the real world prove this simple, without any further complexities? (Whether “simple” is the right word for turbulence in an ultra-dense, out-of-control environment embedded in intense gravitational and magnetic fields where space itself is bent to breaking point is perhaps a separate question.)

    Using statistical methods, we measured how much the light emitted from our 5,000 discs flickered over time. The pattern of flickering in each one looked somewhat different.

    But when we sorted them by size, brightness, and color, we began to see intriguing patterns. We were able to determine the orbital speed of each disc – and once you set your clock to run at the disc’s speed, all the flickering patterns started to look the same.

    This universal behavior is indeed predicted by the theory of “magneto-rotational instabilities”.

    That was comforting! It means these mind-boggling maelstroms are “simple” after all.

    And it opens new possibilities. We think the remaining subtle differences between accretion discs occur because we are looking at them from different orientations.

    The next step is to examine these subtle differences more closely and see whether they hold clues to discern a black hole’s orientation. Eventually, our future measurements of black holes could be even more accurate.

    Nature Astronomy 2022
    PASA 2022
    PASA 2018
    See the above science papers for instructive material with images.
    Reviews of Modern Physics 1998

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation (AU) launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 6:38 pm on February 3, 2023 Permalink | Reply
    Tags: "New Method to Weigh Protoplanetary Disks", , Astronomers have found a way to directly measure the amount of gas in protoplanetary disks without making assumptions about the relative amounts of different gasses-a more method., Astrophysics, , ,   

    From ALMA [The Atacama Large Millimeter/submillimeter Array](CL) : “New Method to Weigh Protoplanetary Disks” 

    From ALMA [The Atacama Large Millimeter/submillimeter Array](CL)

    1.17.23 [Previously reported from NAOJ]

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory Santiago – Chile
    Phone: +56 2 2467 6258
    Cell phone: +56 9 7587 1963
    Email: valeria.foncea@alma.cl

    Daisuke Iono
    Interim EA ALMA EPO officer
    Observatory, Tokyo – Japan
    Email: d.iono@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Amy C. Oliver
    Public Information & News Manager
    National Radio Astronomical Observatory (NRAO), USA
    Phone: +1 434 242 9584
    Email: aoliver@nrao.edu

    1
    Observational image of the protoplanetary disk around TW Hydrae showing the distributions of solid particles (red), carbon monoxide (blue), and dense gas (white). Credit: T. Yoshida, T. Tsukagoshi et al. – ALMA (ESO/NAOJ/NRAO)

    Astronomers have found a way to directly measure the amount of gas in protoplanetary disks without making assumptions about the relative amounts of different types of gas, making this method more accurate and robust than previous methods.

    Planets form in protoplanetary disks of gas and dust around young stars. Scientists study protoplanetary disks by looking at their spectra, the wavelengths of radio waves emitted by disk components. Hydrogen gas is the main constituent of protoplanetary disks, but it isn’t easy to measure directly because it doesn’t emit radio waves efficiently. Carbon monoxide is often used as a proxy. Still, the hydrogen-to-carbon monoxide ratio can differ depending on the environment, leading to significant uncertainties in total mass estimates.

    A team led by Tomohiro Yoshida, a graduate student at the Graduate University for Advanced Studies in Japan, searched the Atacama Large Millimeter/submillimeter Array (ALMA) archival data for observations of the nearest protoplanetary disk around the star TW Hydrae. From this, they produced a radio image 15 times more sensitive than previous studies, allowing them to examine the wavelengths of the spectral lines and their shapes.

    From the shape of the carbon monoxide lines, the team could measure the gas pressure near the disk’s center. This pressure reveals the total mass of gas near the center without making assumptions about the hydrogen-to-carbon monoxide ratio. The team found that despite being near the end of the planet formation process, there is still enough gas in the inner region of the TW Hydrae system to make a Jupiter-sized planet.

    Yoshida, the lead author of this study, says, “We would like to apply this novel technique to other disks and investigate the amount of gas in planet-forming disks with various characteristics and at various ages to clarify the gas dissipation process and the formation process of planetary systems.”

    Additional Information

    These results appeared in The Astrophysical Journal Letters on September 22, 2022.
    See the science paper for instructive material with images.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Atacama Large Millimeter/submillimeter Array (ALMA) (CL), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large

    ALMA is a time machine!

    ALMA-In Search of our Cosmic Origins

     
  • richardmitnick 5:57 pm on February 3, 2023 Permalink | Reply
    Tags: "Outflows from Baby Star Affect Nearby Star Formation", , Astrophysics, , , , These observations have succeeded in directly imaging the impact of molecular outflows on star formation within a star forming cluster.   

    From ALMA [The Atacama Large Millimeter/submillimeter Array](CL) : “Outflows from Baby Star Affect Nearby Star Formation” 

    From ALMA [The Atacama Large Millimeter/submillimeter Array](CL)

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory Santiago – Chile
    Phone: +56 2 2467 6258
    Cell phone: +56 9 7587 1963
    Email: valeria.foncea@alma.cl

    Junko Ueda
    Public Information Officer
    NAOJ
    Email: junko.ueda@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Amy C. Oliver
    Public Information & News Manager
    National Radio Astronomical Observatory (NRAO), USA
    Phone: +1 434 242 9584
    Email: aoliver@nrao.edu

    2.3.23

    1
    Composite image of the cluster forming region, OMC-2/ FIR 3 and FIR 4, obtained with ALMA (red: carbon monoxide gas, orange: emission from the dust, blue: silicon monoxide gas). For each color, the stronger the radio wave intensity, the more whitish the color is. FIR 3 is located in the upper left of this image, while FIR 4 is located in the bottom right. The giant molecular outflow driven by the protostar in the FIR 3 region (red color) collides with the “filamentary molecular cloud” (orange color). Subsequently, outflow gas interacting with the filamentary molecular cloud is being compressed (shown in pinkish red). The outflow gas also collides with downstream dense gas (shown in orange color) where a group of baby stars is being born (green circles within the FIR 4 region). The shock layers are observed with the silicon monoxide gas (pale blue). The white bar in the lower right corner shows the scale of 4000 astronomical units (au). Credit: A. Sato et al./ALMA (ESO/NAOJ/NRAO).

    2
    Composite image of the cluster forming region, OMC-2/ FIR 3 and FIR 4, obtained with ALMA (red: carbon monoxide gas, orange: emission from the dust, blue: silicon monoxide gas). For each color, the stronger the radio wave intensity, the more whitish the color is. FIR 3 is located in the upper left of this image, while FIR 4 is located in the bottom right. The giant molecular outflow driven by the protostar in the FIR 3 region (red color) collides with the “filamentary molecular cloud” (orange color). Subsequently, outflow gas interacting with the filamentary molecular cloud is being compressed (shown in pinkish red). The outflow gas also collides with downstream dense gas (shown in orange color) where a group of baby stars is being born (green circles within the FIR 4 region). The shock layers are observed with the silicon monoxide gas (pale blue). The white bar in the lower right corner shows the scale of 4000 astronomical units (au). Credit: A. Sato et al./ALMA (ESO/NAOJ/NRAO)

    Astronomers revealed fast gas outflows from a baby star strongly colliding with nearby dense gas where a group of baby stars are being born. The result suggests that the outflow collision shakes the cradle of the baby stars, and has a significant impact on the ongoing star formation process. This study provides insight into the star formation process within cluster regions where baby stars are born simultaneously in a complex and crowded environment.

    Baby stars (protostars) form due to the collapse of dense cores of gas and dust. At the same time, some of the material is ejected by the protostar. This phenomenon is called molecular outflow and shows a bipolar and collimated structure. The extension of the molecular outflow can be more than a million times bigger than the protostar. The molecular outflow is much easier to find than the compact and embedded protostar itself, hence searching for outflows can be a powerful tool to explore the birthplaces of protostars.

    The majority of stars form together with other stars in a crowded environment called a cluster formation. Theoretical studies predict that the outflows within the star forming cluster play an important role and can themself trigger (or at least facilitate) further star-formation activity. Alternatively, ongoing star formation could be disrupted by neighboring molecular outflows. Although star formation in a cluster environment is common, observational studies that spatially resolve the individual protostars within the cluster are still limited because the target sources are located relatively far from us. ALMA (Atacama Large Millimeter/submillimeter Array) is a powerful instrument to resolve gas and dust distributions and reveal the complex star formation processes in cluster forming regions.

    Asako Sato, a graduate student at Kyushu University in Japan, and her team used ALMA to observe the regions FIR 3 and FIR 4 in the Orion Molecular Cloud -2 (OMC-2). OMC-2 is one of the nearest cluster forming regions, located at the distance of 1400 light-years away in the constellation Orion. They investigated the spatial distribution of dust and the gaseous carbon monoxide (CO) and silicon monoxide (SiO). The dust is one of the fundamental compositions to form dense material, hence a good tracer of dense cores, where protostar formation happens. CO is the second most abundant molecule in the Universe after the hydrogen molecule. CO emits strong signals in the millimeter wavelength regime and is a good tracer of molecular outflows. Emission from SiO is used to trace powerful shocked regions. A collision such as between bipolar molecular outflows and surrounding material strips silicon (Si) atoms from dust grains, which then react with oxygen (O) to form SiO. Thanks to ALMA’s high-sensitivity, this study detected twice as many molecular outflows as compared to the previous studies in the FIR 3 and FIR 4 regions.

    The results show a giant molecular outflow driven by a protostar in the FIR 3 region strongly colliding with the FIR 4 region, where several protostars are being formed. The ALMA observations have clearly imaged shock layers between the molecular outflow and dense materials associated with the FIR 4 region. “The molecular outflow is proceeding from the upper left of the image, and colliding with the FIR 4 region in the bottom right. We clearly see two strong shock layers in SiO gas (which is denoted in blue color in Figure 2 within the FIR 4 region).” says Satoko Takahashi, an astronomer at the National Astronomical Observatory of Japan, and co-author of the paper. Moreover, the image shows that the CO gas within the outflow collides with the “filamentary molecular cloud” (Figure 2: presented in orange color) and is subsequently compressed (Figure 2: shown in pinkish red). The team also obtained evidence that dust within the filamentary molecular clouds can be heated by a collision with the molecular outflow. Finally, within the compressed clouds, the team detected fragmented dusty sources, which could be the cradles of the future star formation sites.

    With this study, it was difficult to conclude whether star formation activities within the cluster forming region, FIR 4, were triggered by the collision with the giant molecular outflow, or if the star formation within FIR 4 had already started before the collision. “Even though the two different star formation scenarios were not disentangled, the observations clearly indicated strong shocks caused by the outflow colliding with the FIR 4 region. This means the collision must have affected the star forming activities there.” Says Sato, the primary author of the paper. She also expresses her ambition to perform future observations with ALMA to answer the questions, “How protostars in the FIR 4 region will evolve and how massive stars will form can be investigated through the dynamical motions of the gas compressed by the giant bipolar molecular outflow, which could indicate the inflow of gas toward the center of the cluster or alternatively the destruction of the cradle of the cluster.”

    These observations have succeeded in directly imaging the impact of molecular outflows on star formation within a star forming cluster. Further studies will help us to understand the star formation process under the cluster forming environment.

    Additional Information

    This research was published in The Astrophysical Journal on February 2, 2023.

    Authors: Asako Sato (Kyushu University), Satoko Takahashi (NAOJ/SOKENDAI), Shun Ishii (NAOJ/SOKENDAI), Paul T. P. Ho (ASIAA/EAO), Masahiro N. Machida (Kyushu University), John Carpenter (JAO), Luis A. Zapata (UNAM), Paula Stella Teixeira (University of St Andrews), and Sumeyye Suri (University of Vienna).

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Atacama Large Millimeter/submillimeter Array (ALMA) (CL), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large

    ALMA is a time machine!

    ALMA-In Search of our Cosmic Origins

     
  • richardmitnick 1:37 pm on February 3, 2023 Permalink | Reply
    Tags: "Astronomers find rare Earth-mass rocky planet suitable for the search for signs of life", , A newly discovered exoplanet could be worth searching for signs of life., A planet that orbits its home star-the red dwarf Wolf 1069 in the habitable zone., Astrophysics, , , , Of the more than 5000 exoplanets they have discovered so far only about a dozen have an Earth-like mass and populate the habitable zone.,   

    From The MPG Institute for Astronomy [MPG Institut für Astronomie] (DE) Via “phys.org” : “Astronomers find rare Earth-mass rocky planet suitable for the search for signs of life” 

    MPG Institut für Astronomie (DE)

    From The MPG Institute for Astronomy [MPG Institut für Astronomie] (DE)

    Via

    “phys.org”

    2.3.23

    Dr. Markus Nielbock
    Press and public relations officer
    Max Planck Institute for Astronomy, Heidelberg
    +49 6221 528-134
    pr@mpia.de

    Dr. Diana Kossakowski
    Max Planck Institute for Astronomy, Heidelberg
    kossakowski@mpia.de

    Dr. Martin Kürster
    Leitung der technischen Abteilungen
    Max Planck Institute for Astronomy, Heidelberg
    +49 6221 528-214
    kuerster@mpia.de

    1
    Artist’s conception of a rocky Earth-mass exoplanet like Wolf 1069 b orbiting a red dwarf star. If the planet had retained its atmosphere, chances are high that it would feature liquid water and habitable conditions over a wide area of its dayside. Credit: Daniel Rutter/NASA/Ames Research Center.

    A newly discovered exoplanet could be worth searching for signs of life. Analyses by a team led by astronomer Diana Kossakowski of the Max Planck Institute for Astronomy describe a planet that orbits its home star-the red dwarf Wolf 1069 in the habitable zone.

    This zone includes distances around the star for which liquid water can exist on the surface of the planet. In addition, the planet named Wolf 1069 b has an Earth-like mass. Very likely, this planet is a rocky planet that may also have an atmosphere. This makes the planet one of the few promising targets to search for signs of life-friendly conditions and biosignatures.

    When astronomers search for planets outside our solar system, they are particularly interested in Earth-like planets. Of the more than 5000 exoplanets they have discovered so far only about a dozen have an Earth-like mass and populate the habitable zone, the range in a planetary system where water can maintain its liquid form on the planet’s surface. With Wolf 1069 b, the number of such exoplanets on which life could have evolved has increased by one candidate.

    A planet with eternal day and night

    Detecting such low-mass planets is still a major challenge. Diana Kossakowski and her team at the Max Planck Institute for Astronomy in Heidelberg have taken on this task. As part of the Carmenes project, an instrument was developed specifically for the search of potentially habitable worlds. The Carmenes team is using this apparatus at the Calar Alto Observatory in Spain.


    “When we analyzed the data of the star Wolf 1069, we discovered a clear, low-amplitude signal of what appears to be a planet of roughly Earth mass,” says Diana Kossakowski. “It orbits the star within 15.6 days at a distance equivalent to one-fifteenth of the separation between the Earth and the sun,” The results of the study have now been published in the journal Astronomy & Astrophysics [below].

    2
    Simulated surface temperature map of Wolf 1069 b, assuming an Earth-like atmosphere. The map is centered at point that always faces the star. The temperatures are given in Kelvin. 273.15 Kelvin corresponds to zero degree Celsius. Liquid water would be possible on the planet’s surface inside the red circle. Credit: Kossakowski et al (2023) / MPIA

    According to the study, the surface of the dwarf star is relatively cool and thus appears orange-reddish. “As a result, the so-called habitable zone is shifted inwards,” Kossakowski explains. Despite its close distance to the central star, the planet Wolf 1069 b therefore receives only about 65% of the incident radiant power of what Earth receives from the sun. These special conditions make planets around red dwarf stars like Wolf 1069 potentially friendly to life.

    In addition, they may all share a special property. Their rotation is probably tidally locked to the orbit of its host star. In other words, the star always faces the same side of the planet. So there is eternal day, while on the other side it is always night. This is also the reason why we always face the same side of the moon.

    Climate simulations for exoplanets

    If Wolf 1069 b is assumed to be a bare and rocky planet, the average temperature even on the side facing the star would be just minus 23 degrees Celsius. However, according to existing knowledge, it is quite possible that Wolf 1069 b has formed an atmosphere. Under this assumption its temperature could have increased to plus 13 degrees, as computer simulations with climate models show. Under these circumstances, water would remain liquid and life-friendly conditions could prevail, because life as we know it depends on water.

    An atmosphere is not only a precondition for the emergence of life from a climatic point of view. It would also protect Wolf 1069 b from high-energy electromagnetic radiation and particles that would destroy possible biomolecules. The radiation and particles either stem from interstellar space or from the central star. If the star’s radiation is too intense, it can also strip off a planet’s atmosphere, as it did for Mars. But as red dwarf, Wolf 1069 emits only relatively weak radiation.

    Thus, an atmosphere may have been preserved on the newly discovered planet. It is even possible that the planet has a magnetic field that protects it from charged stellar wind particles. Many rocky planets have a liquid core, which generates a magnetic field via the dynamo effect, similar to planet Earth.

    3
    Illustration that compares three exoplanet systems of red dwarf stars hosting Earth-mass planets. The green rings indicate the individual habitable zones. Credit: J. Neidel/ MPIA graphics department.

    The difficult search for Earth-mass exoplanets

    There has been immense progress in the search for exoplanets since the first of its kind was discovered 30 years ago. Still, the signatures that astronomers look for to detect planets with Earth-like masses and diameters are relatively weak and hard to extract from the data. The Carmenes team is looking for small periodic frequency shifts in the stellar spectra. These shifts are expected to arise when a companion pulls on the host star by its gravity, causing it to wobble. As a result. the frequency of the light measured on Earth changes due to the Doppler effect.

    In the case of Wolf 1069 and its newly discovered planet, these fluctuations are large enough to be measured. One of the reasons is that the mass difference between the star and planet is relatively small, causing the star to wobble around the shared center of mass more prominently than in other cases. From the periodic signal, the mass of the planet can be estimated, as well.

    Only a handful of candidates for future exoplanet characterization

    At a distance of 31 light-years, Wolf 1069 b is the sixth closest Earth-mass planet in the habitable zone around its host star. It belongs to a small group of objects, such as Proxima Centauri b and Trappist-1 e, that are candidates for biosignature searches. However, such observations are currently beyond the capabilities of astronomical research.

    “We will probably have to wait another ten years for this,” Kossakowski points out. The Extremely Large Telescope (ELT), currently under construction in Chile, may be able to study the composition of the atmospheres of those planets and possibly even detect molecular evidence of life.

    Astronomy & Astrophysics

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The MPG Institute for Astronomy campus, Heidelberg (DE)
    The MPG Institute for Astronomy [MPG Institut für Astronomie] (DE) is a research institute of The MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.] (DE). It is located in Heidelberg, Baden-Württemberg, Germany near the top of the Königstuhl, adjacent to the historic Landessternwarte Heidelberg-Königstuhl astronomical observatory. The institute primarily conducts basic research in the natural sciences in the field of astronomy.

    In addition to its own astronomical observations and astronomical research, the Institute is also actively involved in the development of observation instruments. The instruments or parts of them are manufactured in the institute’s own workshops.

    The founding of the institute in 1967 resulted from the insight that a supra-regional institute equipped with powerful telescopes was necessary in order to conduct internationally competitive astronomical research. Hans Elsässer, an astronomer, became the founding director in 1968. In February 1969, a first group of 5 employees started work in the buildings of the neighbouring Königstuhl State Observatory. The institute, which was completed in 1975, was initially dedicated to the preparation and evaluation of astronomical observations and the development of new measurement methods.

    From 1973 to 1984, it operated the Calar Alto Observatory on Calar Alto near Almería together with Spanish authorities.


    The Calar Alto Astronomical Observatory 3.5 meter Telescope, located in Almería province in Spain on Calar Alto, a 2,168-meter-high (7,113 ft) mountain in Sierra de Los Filabres(ES)

    This largest observatory on the European mainland was used equally by astronomers from both countries until 2019. On 23 May 2019, the regional government of Andalusia and the MPG signed a transfer agreement for the 50% share in the observatory. Since then, it has been owned exclusively by Spain.

    Since 2005, The MPG Institute for Astronomy has been operating the Large Binocular Telescope (LBT) together with partners from Germany, Italy and the USA and equipping it with measuring instruments.

    LBT-University of Arizona Large Binocular Telescope Interferometer, or LBTI, is a ground-based instrument connecting two 8-meter class telescopes on Mount Graham, Arizona, Altitude 3,221 m (10,568 ft.) to form the largest single-mount telescope in the world. The interferometer is designed to detect and study stars and planets outside our solar system. Credit: NASA/JPL-Caltech.

    Two scientific questions are given priority at The MPG Institute for Astronomy. One is the formation and development of stars and planets in our cosmic neighborhood. The resonating question is: Is the Sun with its inhabited planet Earth unique, or are there also conditions in the vicinity of other stars, at least the numerous sun-like ones among them, that are conducive to life? On the other hand, the area of galaxies and cosmology is about understanding the development of today’s richly structured Universe with its galaxies and stars and its emergence from the simple initial state after the Big Bang.

    The research topics at a glance:
    • Star formation and young objects, planet formation, astrobiology, interstellar matter, astrochemistry
    • Structure and evolution of the Milky Way, quasars and active galaxies, evolution of galaxies, galaxy clusters, cosmology

    Together with the Center for Astronomy at The Ruprecht Karl University of Heidelberg [Ruprecht-Karls-Universität Heidelberg](DE), the Heidelberg Institute for Theoretical Studies (HITS) and the Department of Astro- and Particle Physics of the MPI for Nuclear Physics (MPIK), the MPIA in Heidelberg is a globally renowned centre of astronomical research.

    Since 2015, the MPIA has been running the “Heidelberg Initiative for the Origins of Life” (HIFOL) together with the MPIK, the HITS, the Institute of Geosciences at Heidelberg University and the Department of Chemistry at The Ludwig Maximilians University of Munich [Ludwig-Maximilians-Universität München](DE). HIFOL brings together top researchers from astrophysics, geosciences, chemistry and the life sciences to promote, strengthen and combine scientific research towards the prerequisites for the emergence of life.

    Structure
    • Galaxies and Cosmology Department

    • Planet and Star Formation Department

    • Atmospheric Physics of Exoplanets
    • Technical Departments

    Instrumentation
    The MPIA also builds instruments or parts of them for ground-based telescopes and satellites, including the following:
    • Calar Alto Observatory (Spain)[above]
    • La Silla Observatory of the European Southern Observatory (The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europäische Südsternwarte](EU)(CL))
    European Southern Observatory(EU) La Silla Observatory 600 km north of Santiago de Chile at an altitude of 2400 metres.
    • Paranal Observatory and E-ELT (ESO)

    The Paranal Observatory pictured with Cerro Paranal in the background. The mountain is home to one of the most advanced ground-based telescopes in the world, the VLT. The VLT telescope consists of four unit telescopes with mirrors measuring 8.2 meters in diameter and work together with four smaller auxiliary telescopes to make interferometric observations. Each of the 8.2m diameter Unit Telescopes can also be used individually. With one such telescope, images of celestial objects as faint as magnitude 30 can be obtained in a one-hour exposure. This corresponds to seeing objects that are four billion (four thousand million) times fainter than what can be seen with the unaided eye.

    The European Southern Observatory(EU) ELT 39 meter telescope to be on top of Cerro Armazones in the Atacama Desert of northern Chile at an altitude of 3,060 metres (10,040 ft).

    • Large Binocular Telescope [above]
    • Infrared Space Observatory (The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU))

    ESA Infrared Space Observatory.

    • Herschel Space Observatory (ESA, The National Aeronautics and Space Agency)

    European Space Agency Herschel spacecraft active from 2009 to 2013.
    • James Webb Space Telescope (NASA, ESA.CSA)

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) James Webb Infrared Space Telescope(US) annotated, finally launched December 25, 2021, ten years late.

    The MPIA is also participating in the Gaia mission.

    European Space Agency [La Agencia Espacial Europea][Agence spatiale européenne][Europäische Weltraumorganisation](EU) GAIA satellite.

    Gaia is a space mission of The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU), in which the exact positions, distances and velocities of around one billion Milky Way stars are determined.

    The MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.](DE) is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.

    According to its primary goal, the MPG Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014) MPG Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.

    The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

    The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

    History

    The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

    The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

    The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

    MPG Institutes and research groups

    The MPG Society consists of over 80 research institutes. In addition, the society funds a number of Max Planck Research Groups (MPRG) and International Max Planck Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
    The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University (US) focusing on neuroscience.
    The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.

    Internally, MPG Institutes are organized into research departments headed by directors such that each MPI has several directors, a position roughly comparable to anything from full professor to department head at a university. Other core members include Junior and Senior Research Fellows.

    In addition, there are several associated institutes:

    International Max Planck Research Schools

    International Max Planck Research Schools

    Together with the Association of Universities and other Education Institutions in Germany, the Max Planck Society established numerous International Max Planck Research Schools (IMPRS) to promote junior scientists:

    • Cologne Graduate School of Ageing Research, Cologne
    • International Max Planck Research School for Intelligent Systems, at the Max Planck Institute for Intelligent Systems located in Tübingen and Stuttgart
    • International Max Planck Research School on Adapting Behavior in a Fundamentally Uncertain World (Uncertainty School), at the Max Planck Institutes for Economics, for Human Development, and/or Research on Collective Goods
    • International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering, Magdeburg
    • International Max Planck Research School for Astronomy and Cosmic Physics, Heidelberg at the MPI for Astronomy
    • International Max Planck Research School for Astrophysics, Garching at the MPI for Astrophysics
    • International Max Planck Research School for Complex Surfaces in Material Sciences, Berlin
    • International Max Planck Research School for Computer Science, Saarbrücken
    • International Max Planck Research School for Earth System Modeling, Hamburg
    • International Max Planck Research School for Elementary Particle Physics, Munich, at the MPI for Physics
    • International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Marburg at the Max Planck Institute for Terrestrial Microbiology
    • International Max Planck Research School for Evolutionary Biology, Plön at the Max Planck Institute for Evolutionary Biology
    • International Max Planck Research School “From Molecules to Organisms”, Tübingen at the Max Planck Institute for Developmental Biology
    • International Max Planck Research School for Global Biogeochemical Cycles, Jena at the Max Planck Institute for Biogeochemistry
    • International Max Planck Research School on Gravitational Wave Astronomy, Hannover and Potsdam MPI for Gravitational Physics
    • International Max Planck Research School for Heart and Lung Research, Bad Nauheim at the Max Planck Institute for Heart and Lung Research
    • International Max Planck Research School for Infectious Diseases and Immunity, Berlin at the Max Planck Institute for Infection Biology
    • International Max Planck Research School for Language Sciences, Nijmegen
    • International Max Planck Research School for Neurosciences, Göttingen
    • International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen
    • International Max Planck Research School for Marine Microbiology (MarMic), joint program of the Max Planck Institute for Marine Microbiology in Bremen, the University of Bremen, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, and the Jacobs University Bremen
    • International Max Planck Research School for Maritime Affairs, Hamburg
    • International Max Planck Research School for Molecular and Cellular Biology, Freiburg
    • International Max Planck Research School for Molecular and Cellular Life Sciences, Munich
    • International Max Planck Research School for Molecular Biology, Göttingen
    • International Max Planck Research School for Molecular Cell Biology and Bioengineering, Dresden
    • International Max Planck Research School Molecular Biomedicine, program combined with the ‘Graduate Programm Cell Dynamics And Disease’ at the University of Münster and the Max Planck Institute for Molecular Biomedicine
    • International Max Planck Research School on Multiscale Bio-Systems, Potsdam
    • International Max Planck Research School for Organismal Biology, at the University of Konstanz and the Max Planck Institute for Ornithology
    • International Max Planck Research School on Reactive Structure Analysis for Chemical Reactions (IMPRS RECHARGE), Mülheim an der Ruhr, at the Max Planck Institute for Chemical Energy Conversion
    • International Max Planck Research School for Science and Technology of Nano-Systems, Halle at Max Planck Institute of Microstructure Physics
    • International Max Planck Research School for Solar System Science at the University of Göttingen hosted by MPI for Solar System Research
    • International Max Planck Research School for Astronomy and Astrophysics, Bonn, at the MPI for Radio Astronomy (formerly the International Max Planck Research School for Radio and Infrared Astronomy)
    • International Max Planck Research School for the Social and Political Constitution of the Economy, Cologne
    • International Max Planck Research School for Surface and Interface Engineering in Advanced Materials, Düsseldorf at Max Planck Institute for Iron Research GmbH
    • International Max Planck Research School for Ultrafast Imaging and Structural Dynamics, Hamburg

    Max Planck Schools

    • Max Planck School of Cognition
    • Max Planck School Matter to Life
    • Max Planck School of Photonics

    Max Planck Center

    • The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
    • The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

    Max Planck Institutes

    Among others:
    • Max Planck Institute for Neurobiology of Behavior – caesar, Bonn
    • Max Planck Institute for Aeronomics in Katlenburg-Lindau was renamed to Max Planck Institute for Solar System Research in 2004;
    • Max Planck Institute for Biology in Tübingen was closed in 2005;
    • Max Planck Institute for Cell Biology in Ladenburg b. Heidelberg was closed in 2003;
    • Max Planck Institute for Economics in Jena was renamed to the Max Planck Institute for the Science of Human History in 2014;
    • Max Planck Institute for Ionospheric Research in Katlenburg-Lindau was renamed to Max Planck Institute for Aeronomics in 1958;
    • Max Planck Institute for Metals Research, Stuttgart
    • Max Planck Institute of Oceanic Biology in Wilhelmshaven was renamed to Max Planck Institute of Cell Biology in 1968 and moved to Ladenburg 1977;
    • Max Planck Institute for Psychological Research in Munich merged into the Max Planck Institute for Human Cognitive and Brain Sciences in 2004;
    • Max Planck Institute for Protein and Leather Research in Regensburg moved to Munich 1957 and was united with the Max Planck Institute for Biochemistry in 1977;
    • Max Planck Institute for Virus Research in Tübingen was renamed as Max Planck Institute for Developmental Biology in 1985;
    • Max Planck Institute for the Study of the Scientific-Technical World in Starnberg (from 1970 until 1981 (closed)) directed by Carl Friedrich von Weizsäcker and Jürgen Habermas.
    • Max Planck Institute for Behavioral Physiology
    • Max Planck Institute of Experimental Endocrinology
    • Max Planck Institute for Foreign and International Social Law
    • Max Planck Institute for Physics and Astrophysics
    • Max Planck Research Unit for Enzymology of Protein Folding
    • Max Planck Institute for Biology of Ageing

     
  • richardmitnick 11:21 am on February 3, 2023 Permalink | Reply
    Tags: "Into the Maelström", Astrophysics, , , , , ,   

    From “Centauri Dreams” At follow.it : “Into the Maelström” 

    From “Centauri Dreams”

    At

    follow.it

    2.3.23
    Paul Gilster

    The European Southern Observatory’s (ESO) GRAVITY instrument is a beam combiner in the infra-red K-band that operates as a part of the Very Large Telescope Interferometer, combining infra-red light received by four different telescopes, out of the eight operated (four 8.2 metre fixed telescopes and four 1.8 metre movable telescopes).

    The latest measurements of the stars orbiting the Milky Way’s Galactic Core Super-Massive Black Hole (SMBH), otherwise known as Sagittarius A* (pronounced as ‘Sagittarius A Star’), by the GRAVITY instrument have determined its mass and distance to new levels of accuracy:

    Ro = 8,275 parsecs (+\-) 9.3 parsecs and a mass of (in 10^6 Msol) 4.297 +\- 0.013.

    1
    Image: The galactic centre in infrared. Credit: NASA.

    In round figures, that’s 27,000 light-years and 4.3 million Solar masses. The closest that light can approach a Black Hole and still escape is the Event Horizon, which is the spherical boundary at the distance of the Schwarzschild Radius, which is a radius of 2.95325 kilometres per solar mass. Thus 4.3 million solar masses is wrapped in an Event Horizon 12.7 million kilometres in radius. In aeons to come, when the Milky Way and Messier 31 have collided and their black holes have coalesced, the combined Super Massive Black Hole (SMBH) will mass 100 million solar masses with an event horizon almost 300 million kilometres in radius.

    Into the Maelström

    Mass-energy, so Albert Einstein’s General Theory of Relativity tells us, puts dents into Space-time. Most concentrations of mass-energy, like stars, planets and galaxies, form shallow dents. Black Holes – like the future SMBH – go deeper, forming an inescapable waterfall of space-time inwards to their centres, the edge of which is the Event Horizon.

    Light follows the curvature of space-time, traveling the shortest pathways (geodesics). At the Event Horizon the available geodesics all point towards the “middle” of the Black Hole. For particles with rest mass, like atoms, dust and space-ships, geodesics can’t be followed, merely approached, so they follow different pathways just as inexorably towards the centre.

    Instead of flying radially inwards towards the future SMBH’s Centre, let’s ponder orbiting it. For most orbital distances from any Black Hole any small mass in orbit will experience nothing different to orbiting around any other large mass. Too close and you’ll experience extreme tidal forces if the black hole is small, so to avoid being torn to shreds when approaching really close a really big Black Hole is needed. The future SMBH massing 100 million solar masses with a Schwarzschild radius of 300 million kilometres has very mild Tidal Forces at the Event Horizon, though potentially significant for things as big as stars and planets.

    We have multi-year ‘movies’ of stars orbiting around our SMBH, though none as close as we will explore. Close orbits get measured in multiples of M – which is half the Schwarzschild radius. At a radius of r = 3M space-time is so curved that the geodesics form a circle around the Black Hole. Light can thus orbit indefinitely, building up to potentially extraordinary energy densities if nothing else gets in its way, forming a so-called Photon Sphere. But the centre of the Galaxy is full of dust and gas, so something is always getting in the way. Eventually even photons get so energetic they perturb each other out of the Sphere.

    For particles that don’t follow geodesics, merely approximate them, the Innermost Stable Circular Orbit (ISCO) is further out, at r = 6M. Objects here travel at half the speed of light. Other shapes of orbits can dip a bit closer in, down to r = 4M. Deeper in and motion near the Black Hole is no longer “orbital”. You must point away from the Black Hole and apply thrust or in-fall is inevitable.

    The equation of orbital motion from the ISCO radius (rI) all the way to the centre was only recently worked out in closed form for rotating and non-rotating (stationary) Black Holes. Previously numerical Relativity methods were used, complicating modelling of Accretion Disks around astrophysical Black Holes. The Equation of Motion of a test particle (i.e. very small mass) around a non-rotating Black Hole, which our future SMBH might approximate, is straightforward:

    3

    Φ is the angular distance traveled, with a range from negative infinity to zero, by convention. I’ve plotted r against Φ here:

    4

    The Red Circle at r = 3 M is the Photon Sphere and the Yellow Circle at r = 2M is the Schwarzschild Radius aka Event Horizon. In this case the plot starts at r = 5.95M with the test particle circling the Black Hole 6 times before hitting the central point. The proper time experienced by an observer spiralling into the Centre is a bit more complicated. We can parameterise x as follows to make the mathematics easier:

    5

    with ψ running from an angle π to 0. Then the Proper-Time τ of the inspiral trajectory is:

    6

    The above equation is true for any black-hole, spinning or stationary. For a stationary Black Hole, rI = 6M, so the equation simplifies to:

    7

    But what is M? It’s the “geometrized” mass of the Black Hole, which is derived by multiplying the mass by G/c2. Similarly the proper time is in units of “geometrized” time, so it needs to be divided by the speed of light, c, to convert to seconds.

    In the case of the fall from r = 5.95M to r = 0, thus ψ = (5.95/6) ∗ (π) to ψ = 0, the total time is τ = 1291.14M. In the case of our Galaxy’s SMBH a proper time of M is 493 seconds. So the inspiral time is 176.6 hours and the Event Horizon is reached with 1.32 hours to go.

    Surviving the Plunge

    Falling into a Black Hole is probably fatal. However, like any fall, it’s not gravity that’ll kill you, but the sudden stop at the end. The final destination is the concentration of mass at the very centre. As the Centre is approached the first derivative of gravitational acceleration with respect to the radial distance vectors – the tidal forces – that will be experienced will become extreme.

    Black holes are the pointy end of a spectrum of astrophysical objects. Stars exist due to their dynamic balance between the outward pressure from their fusion energy production and the inward pressure from their self gravity. When fusion energy production ends, the cores of stars begin collapsing, held above the Abyss of gravitational collapse by successive fusion energy reactions, then electron degeneracy pressure from squeezing free electrons too close together (via the Pauli Exclusion Principle), and when that isn’t enough, neutron degeneracy pressure and beyond.

    Pressure is a measure of the ‘expansive’ energy packed in a volume. Dimensionally we can see that F / m^2 (Pressure) = E / m^3 (Energy per unit volume), so that as the mutual gravitational squeeze pushes inwards on a mass of particles which are pushing back against each other thanks to the Pauli Exclusion Principle for fermions (electrons, protons, neutrons etc) that pressure increases and increases, in a feed-back loop. Too much and equilibrium is never achieved. Thanks to Special Relativity we know that energy has mass, so that Pressure adds to the inward squeeze of gravity as particles are squeezed harder together. When the Gravity Squeeze – Push-Back Pressure process self-amplifies and runs away, the mass collapses ‘infinitely’ inwards forming a Singularity. Such a Singularity cuts itself of from the rest of the Universe when it squeezes inwards past the mass’s Schwarzschild Radius:

    9

    The resulting Event Horizon defines a Black Hole, by being a ‘surface of no return’ for everything, including light. Nothing escapes from within the Event Horizon. The minimum mass to cause such an inwards collapse and form a Black Hole for a mass of fermions (i.e. the same particles that make Stars, humans and space-ships) in the present day Universe is about 3 solar masses, squished into a volume smaller than 18 kilometres across.

    Before we get to that point there are White Dwarfs and Neutron Stars – objects supported against collapse by Electron Degeneracy Pressure and Neutron Degeneracy Pressure, respectively. White Dwarfs are typically composed of carbon and oxygen – the ashes of helium fusion – and have observed masses anywhere between 0.1 and 1.3 Solar masses. Their radius is proportional to the inverse 1/3 power of their mass:

    10

    R* is a reference radius. For a cool white dwarf of 1 solar mass, the radius is about 0.8 Earth’s – 5,600 km. A space vehicle falling from infinity, on a flyby very close to such a star’s surface will rush past the lowest point of its orbit at 6,900 km/s, experiencing over 430,000 gee acceleration. In free-fall however it feels only the first derivative of that acceleration:

    11

    Which in this example is 0.15 gee per metre of radial stretching directed outwards and inwards along the direction of the radial distance to the white dwarf and a squeezing force half that directed laterally inwards from the sides. Easily resisted by small structures, like bodies and space-ships.

    Neutron stars are smaller again – typically 20 km wide for a 1.3 solar mass neutron star. A near surface flyby isn’t recommended, since the tidal forces are thus almost a million times stronger. Close proximity to a magnetic neutron star is probably lethal anyway due to the intense magnetic fields long before the tidal forces rip you to shreds. Heavier neutron stars get smaller – just like white dwarfs – until they totally collapse as a black hole.

    Black holes reverse the trend. The Event Horizon gets bigger linearly with their mass and there’s no upper limit to their mass. Our future Galactic SMBH’s Event Horizon will be 295.325 million kilometres in radius, give or take. Substituting the Schwarzschild Radius equation into the Tidal force equation gives us:

    11

    So the tidal force at the Event Horizon is 0.1 microgee per metre. The Moon could almost enter the Event Horizon peacefully…

    12

    How far into the SMBH can we, as Observers, then fall? If we can brace ourselves against 1,000 gees per metre of squeezing and stretching, then quite a long way…

    13

    Which gives a distance of 139,430 kilometres from the centre. In other words 99.953% of the way to the central Singularity.

    What wonders might we see? Quantum Gravity is yet to give a clear answer. Traditionally an imploding mass ends in the Singularity, which is a geometrical point. But quantum particles can’t be reduced to a singular point and retain quantum information. A possibility, due to the massively distorted space-time around the collapsing mass, is that ultimately the quantum particles all “bounce” after hitting Planck density and explode back outwards. To external Observers this is seen, in time-dilated fashion, as the slow-leak from the Event Horizon that is Hawking Radiation. Or, if the particles “twist” in a higher dimension, so they bounce as a new Big Bang forming another Universe. This can be seen as an emergence from a White Hole, as White Holes must keep expanding else they collapse into another Black Hole.

    None of those options are ‘healthy’ to be around as flesh-and-blood Observer, so presently surviving the plunge is in doubt.

    As we conclude, let’s check back in with Edgar Allan Poe, who knew a few things about terrifying plunges himself. In Descent into the Maelstrom, he gives us a look into what might be considered a 19th Century conception of a black hole and the journey into its bizarre interior.

    References

    Mummery, A. & Balbus, S. “Inspirals from the innermost stable circular orbit of Kerr black holes: Exact solutions and universal radial flow,” Physical Review Letters 129, 161101 (12 October 2022).
    https://doi.org/10.48550/arXiv.2209.03579

    Fragione, G. and Loeb, A., “An Upper Limit on the Spin of SgrA* Based on Stellar Orbits in Its Vicinity” (2020) ApJL 901 L32
    https://iopscience.iop.org/article/10.3847/2041-8213/abb9b4/pdf

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Tracking Research into Deep Space Exploration
    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight.
    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.


    National Aeronautics and Space Administration Galileo Spacecraft 1989-2003.
    Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

     
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