Tagged: Basic Research Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 1:53 pm on April 10, 2020 Permalink | Reply
    Tags: "VLASS A Survey of the Radio Sky", , , Basic Research, , ,   

    From Harvard-Smithsonian Center for Astrophysics: “VLASS, A Survey of the Radio Sky” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    Technological advances in recent years have increased the sensitivity of radio interferometers like the Karl G. Jansky Very Large Array (VLA) to the radio emission from astronomical sources in their continuum (not only in their lines) by factors of several, enabling them to see fainter and more distant objects.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    Radio interferometers obtain high spatial resolution details of astronomical sources, and the new VLA, in addition to its sensitivity and high resolution, can provide information about the polarization of the emission, enable more reliable large-scale mosaic images, and with repeating observations monitor temporal variations. Not least, a series of recent sensitive sky surveys at optical and infrared wavelengths justify completing a corresponding radio survey. When combined, these multi-wavelength all-sky surveys will permit astronomers to characterize stellar and galaxy populations in unprecedented detail.

    1
    The radio source 3C402. The greyscale background is an optical image of the field while the contours show earlier radio imaging results. The insets are new radio images from VLASS that show the previous radio source is actually two separate galaxies. VLASS; Lacy et al. 2020

    CfA astronomers Edo Berger, Atish Kamble, and Peter Williams are members of the VLASS (The Very Large Array Sky Survey) team, a large group working on a unique radio all-sky survey having all the aforementioned capabilities and able to cover all of the sky visible from the VLA location in New Mexico. VLASS science has four themes: finding otherwise hidden explosions and/or transient events, probing astrophysical magnetic fields, imaging galaxies both near and distant, and using radio wavelengths to peer through dust obscuration effects to study the Milky Way. Each theme contains numerous subtopics. Hidden explosions, for example, will probe the explosive death throes of massive stars including supernovae, their role in cosmological studies, gamma-ray bursts; signs of mergers between black holes and neutron stars will have implications for gravitational wave detections.

    VLASS observations, begun in September 2017, are expected to be completed in 2024. In a new paper [PASP], the team reviews the VLASS goals and first-look results from early observations, showing how the data successfully demonstrate the ability of the project to achieve all its proposed goals. VLASS includes an integral education and outreach component with two workshops on data visualization held in the first year to train users to produce images that are aesthetic as well as scientifically accurate. The first preliminary data and materials are now available to scientists and the public.

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 1:39 pm on April 10, 2020 Permalink | Reply
    Tags: "Center for Astrophysics Scientist and Team First to Measure Wind Speed on an Object Outside the Solar System", 2MASS J1047+21, , , Basic Research, ,   

    From Harvard-Smithsonian Center for Astrophysics: “Center for Astrophysics Scientist and Team First to Measure Wind Speed on an Object Outside the Solar System” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    April 9, 2020

    Amy Oliver
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    Fred Lawrence Whipple Observatory
    520-879-4402
    amy.oliver@cfa.harvard.edu

    1
    Artist’s conception of the atmospheric rotation of brown dwarf 2MASS J1047+21, which was measured at 1.741 hours. Credit: NRAO

    An international collaboration of scientists—with key contributions from the Center for Astrophysics | Harvard & Smithsonian—today announced the first measurement of atmospheric wind speed ever recorded outside the solar system using a novel technique.

    Researchers focused their efforts on 2MASS J1047+21, a cool brown dwarf located 33.2 light years from Earth, and clocked wind speeds at 650 meters per second, or 1,450 miles per hour. “For the first time ever, we measured the speed of the winds of a brown dwarf—too big to be a planet, too small to be a star,” said Peter K.G. Williams, Innovation Scientist for CfA and the American Astronomical Society. Williams led the radio astronomical observations that made the result possible. “The results rule out a few unusual models and prove that this new technique works and can be applied to more objects.”

    Prior to the study, scientists had only scientifically measured wind speeds within the solar system, leaving scientists to guess at the atmospheric natures of bodies beyond the solar system. “While we have long been able to directly probe the atmospheres and winds of the bodies in our own solar system, we’ve had to conjecture what they’re like in other kinds of bodies, and if there’s one thing we’ve learned from our studies of extrasolar bodies thus far, it’s that our primary conjectures often turn out to be wrong,” said Williams. “This new technique opens the way to better understanding the behavior of atmospheres that are unlike anything found in our solar system.”

    Using a combination of radio and infrared emissions, the new technique can be more broadly applied to those objects too far away for scientists to observe cloud movement in the atmosphere, like brown dwarfs and exoplanets. “Even though brown dwarfs are completely covered in clouds, they’re too far away for us to pick out individual clouds like we do on planets within our solar system, but we can still measure how long it takes for a group of clouds to do a lap around the atmosphere; as clouds come in and out of view they change the brightness of the planet,” said Williams. “This lap time depends on two things: how fast the brown dwarf itself is spinning, and how fast the wind is blowing on top of that.”

    Cloud movement alone, however, couldn’t produce an accurate measurement of atmospheric wind speeds on the brown dwarf, and researchers also looked to radio wave emissions for a measurement of the brown dwarf’s rotation beneath its atmosphere. “It turns out that in some brown dwarfs it’s possible to measure this spin rate by detecting radio waves,” said Williams. “We observed a pulse of radio waves every time the brown dwarf rotated. This is because the radio waves come from high-energy particles trapped in its magnetic field, and its magnetic field is rooted deep in its interior—just like Earth—where there’s no wind to alter the measurement. By taking the difference between the cloud lap time and the radio pulse time, we were able to determine the wind speed.”

    This work was accomplished by combining radio observations from the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) observatory and infrared observations from NASA’s Spitzer Space Telescope.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    NASA/Spitzer Infrared Telescope. No longer in service.

    The study rules out some current theoretical models of how brown dwarf atmospheres work, and Williams believes the results, published in Science, will both better constrain theoretical models for the future and guide the efforts of theorists working in exoplanetary atmospheric studies.

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 12:55 pm on April 10, 2020 Permalink | Reply
    Tags: "Belle II explores new "portal" into dark matter - First results from the Belle II Experiment", Basic Research, , From KEK,   

    From KEK Inter-University Research Institute Corporation: “Belle II explores new “portal” into Dark Matter – First results from the Belle II Experiment” 

    From KEK Inter-University Research Institute Corporation

    1
    Figure 1 : A computer graphics image of a simulated event in which a Z’ boson is produced by e+e- collisions, in association with two muons (green curves and hits) and decays into invisible particles. In this figure, the Z’ boson decays into an invisible neutrino and an anti-neutrino, but it may also decay into a dark matter particle and its anti-particle. In either case, no trace is left is in the detector./© KEK, Belle II, created using Belle II in Virtual Reality developed by Zachary Duer, Tanner Upthegrove, Leo Piilonen, George Glasson, W. Jesse Barber, Samantha Spytek, Christopher Dobsonat the Virginia Tech Institute for Creativity, Arts and Technology, Virginia Tech Department of Physics, Virginia Tech School of Education.

    The Belle II international collaboration has published its first results in a paper selected as an Editors’ Suggestion in Physical Review Letters. The paper reports the first search for a new type of elementary particle that may act as a “portal” between ordinary matter and Dark Matter, which is understood to make up some 85% of the matter in the universe.

    Summary of the result

    The Belle II experiment, which operates at the SuperKEKB electron-positron collider in Tsukuba, Japan, searched for a hypothetical new particle called the Z’ that may act as a “portal” between ordinary matter and Dark Matter. Belle II data collected in 2018 shows no evidence of the Z’, setting new limits on the properties of such a particle.

    Belle II KEK High Energy Accelerator Research Organization Tsukuba, Japan

    The SuperKEKB electron-positron collider in Tsukuba, Japan

    Cosmological observations in recent years provide strong evidence that only 15% of the mass of the matter of the universe is known to us, while the remaining 85% is composed of some still undetected and mysterious particles known as Dark Matter*. A great deal of effort in the international particle physics community, including the Belle II experiment, is now focused on finding evidence of Dark Matter particles.

    A Z’ boson is one of the proposed theoretical candidates that might connect dark matter with the ordinary world. If it exists, it could be produced in electron-positron collisions at SuperKEKB and subsequently decay to invisible Dark Matter particles (Figure 1). Discovery of a Z’ boson might solve important open issues in particle physics related to the behavior of Dark Matter and resolve some anomalies observed in other experiments that cannot be explained by the reigning theory of particle physics (the Standard Model).

    2
    Figure 2 : Mass of the Z’ candidates (data points) compared to the expected background events (histograms) on a semi-logarithmic scale. Although the Dark Matter particles cannot be directly observed at Belle II, mass of the candidates could be determined from the energies and momenta of the other particles produced in the electron-positron collision simultaneously with the Z’ candidate. The presence of a Z’ would show up as a sharp excess of data over the background. No such structure is visible here./This figure is taken from Fig. 2 of the paper: I. Adachi et al, (Belle II Collaboration), Phys. Rev. Lett. 124, 141801 (2020), DOI:10.1103/PhysRevLett.124.141801 published under the Creative Commons Attribution 4.0 International license.

    Theoretical models and detailed simulations predict that Belle II could detect a clear signal that Z’ particles are being produced in electron-positron collisions by searching for an excess of events containing a pair of two oppositely charged muons (heavy cousins of electrons). So far, the data show no such signal (Figure 2). Further searches in a much larger data set yet to be collected by Belle II will either reveal a feebly interacting Z’ boson—or rule it out.

    This first physics result was obtained by analyzing a small data sample collected during the commissioning of SuperKEKB in 2018. Since 2019, SuperKEKB and Belle II have been collecting data in full operation mode, while steadily improving the performance of these sophisticated machines [*1]. Eventually, the experiment will acquire 180,000 times more data than used in the first published analysis. With a data sample of this unprecedented size, Belle II will perform many studies related to dark matter, searches for new particles, and precision measurements that will help elucidate the fundamental laws of Nature.

    Note added: The data used for this analysis were recorded in 2018. Currently, because of the COVID-19 pandemic, all international travel to KEK is suspended, but the accelerator and experiment continue to operate thanks to the extraordinary dedication of KEK staff and Belle II members stationed at KEK as well as international cooperation through remote internet connections.

    [*1]: The operation of the SuperKEKB accelerator and the Belle II experiment was conducted step-by-step: in “Phase 1” from February to June 2016, commissioning of the accelerator was carried out without the Belle II detector. In “Phase 2” from March to June 2018, the Belle II detector was positioned in the interaction region of the electron and positron beams, and the “first collision” was observed. Then, the vertex detector to measure particle decay points was installed at the center of the Belle II detector. The “Phase 3” operation started in March 2019 to acquire data with the fully instrumented Belle II detector.

    *Dark Matter Background

    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, did most of the work on Dark Matter.

    Fritz Zwicky from http:// palomarskies.blogspot.com

    Coma cluster via NASA/ESA Hubble

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


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu

    The Vera C. Rubin Observatory currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    LSST Data Journey, Illustration by Sandbox Studio, Chicago with Ana Kova

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    KEK-Accelerator Laboratory

    KEK, the High Energy Accelerator Research Organization, is one of the world’s leading accelerator science research laboratories, using high-energy particle beams and synchrotron light sources to probe the fundamental properties of matter. With state-of-the-art infrastructure, KEK is advancing our understanding of the universe that surrounds us, its mechanisms and their control. Our mission is:

    • To make discoveries that address the most compelling questions in a wide range of fields, including particle physics, nuclear physics, materials science, and life science. We at KEK strive to make the most effective use of the funds entrusted by Japanese citizens for the benefit of all, by adding to knowledge and improving the technology that protects the environment and serves the economy, academia, and public health; and

    • To act as an Inter-University Research Institute Corporation, a center of excellence that promotes academic research by fulfilling the needs of researchers in universities across the country and by cooperating extensively with researchers abroad; and

    • To promote national and international collaborative research activities by providing advanced research facilities and opportunities. KEK is committed to be in the forefront of accelerator science in Asia-Oceania, and to cooperate closely with other institutions, especially with Asian laboratories.

    Established in 1997 in a reorganization of the Institute of Nuclear Study, University of Tokyo (established in 1955), the National Laboratory for High Energy Physics (established in 1971), and the Meson Science Laboratory of the University of Tokyo (established in 1988), KEK serves as a center of excellence for domestic and foreign researchers, providing a wide variety of research opportunities. In addition to the activities at the Tsukuba Campus, KEK is now jointly operating a high-intensity proton accelerator facility (J-PARC) in Tokai village, together with the Japan Atomic Energy Agency (JAEA). Over 600 scientists, engineers, students and staff perform research activities on the Tsukuba and Tokai campuses. KEK attracts nearly 100,000 national and international researchers every year (total man-days), and provides excellent research facilities and opportunities to many students and post-doctoral fellows each year.

     
  • richardmitnick 12:13 pm on April 10, 2020 Permalink | Reply
    Tags: Basic Research, , , ,   

    From Fermi National Accelerator Lab: “The cold eyes of DUNE” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    April 9, 2020
    Jerald Pinson

    How do you detect a particle that has almost no mass, feels only two of the four fundamental forces, and can travel unhindered through solid lead for an entire light-year without ever interacting with matter? This is the problem posed by neutrinos, ghostly particles that are generated in the trillions by nuclear reactions in stars, including our sun, and on Earth. Scientists can also produce neutrinos to study in controlled experiments using particle accelerators. One of the ways neutrinos can be detected is with large vats filled with liquid argon and wrapped with a complex web of integrated circuitry that can operate in temperatures colder than the average day on Neptune.

    Industry does not typically use electronics that operate at cryogenic temperatures, so particle physicists have had to engineer their own. A collaboration of several Department of Energy national labs, including Fermilab, has been developing prototypes of the electronics that will ultimately be used in the international Deep Underground Neutrino Experiment, called DUNE, hosted by Fermilab.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    SURF DUNE LBNF Caverns at Sanford Lab

    DUNE will generate an intense beam of neutrinos at Fermilab in Illinois and send it 800 miles through the Earth’s crust to detectors in South Dakota. Results from the experiment may help scientists understand why there is more matter than antimatter, an imbalance that led to the formation of our universe.

    2
    Analog-to-digital convertors built to work at cryogenic temperatures, such as the prototype pictured here, will operate inside of liquid-argon chambers in the Deep Underground Neutrino Experiment. Photo: Alber Dyer, Fermilab

    Physics and chill

    DUNE’s neutrino detectors will be massive: a total of four tanks, each as high as a four-story building, will contain a combined 70,000 tons of liquid argon and be situated in a cavern a mile beneath Earth’s surface.

    FNAL DUNE Argon tank at SURF

    Argon occurs naturally as a gas in our atmosphere, and turning it into a liquid entails chilling it to extremely cold temperatures. The atomic nuclei of liquid argon are so densely packed together that some of the famously elusive neutrinos traveling from Fermilab will interact with them, leaving behind tell-tale signs of their passing. The resulting collision produces different particles that scatter in all directions, including electrons, which physicists use to reconstruct the path of the otherwise invisible neutrino.

    A strong electric field maintained within the detector causes the free electrons to drift toward wires attached to sensitive electronics. As the electrons travel past the wires, they generate small voltage pulses that are recorded by electronics in the liquid-argon chamber. Amplifiers in the chamber then boost the signal by increasing the voltage, after which they are converted to digital data. Finally, the signals collected and digitized across the entire chamber are merged together and sent to computers outside the detector for storage and analysis.

    Challenges for chilled electronics

    The electronics in neutrino detectors work the same way as the technology we use in our everyday lives, with one major exception. The integrated circuitry in our phones, computers, cameras, cars, microwaves and other devices has been developed to operate at or around room temperature, down to about minus 40 degrees Celsius. The liquid argon in neutrino detectors, however, is cooled to around minus 200 degrees.

    “If you use electronics designed to work at room temperature, rarely do you find that they work anywhere nearly as well as those designed to operate at cryogenic temperatures,” said Fermilab scientist David Christian.

    In the past, this issue was sidestepped altogether by placing the electronic circuitry outside of the argon tanks. But when you’re measuring a limited number of electrons, even the slightest amount of electronics noise can mask the signal you’re looking for.

    The easiest way to mitigate the problem involves the same tactic you use to keep food from spoiling: Keep it cold. If all the electronics are submerged in the liquid argon, there are fewer thermal vibrations from atoms and a larger signal-to-noise ratio. Placing the electronics in the liquid-argon tank has the added benefit of decreasing the amount of wire you have to use to deliver signals to the amplifiers. If, for example, amplifiers and analog-to-digital converters are kept outside the chamber (as they are in some neutrino detectors), long wires have to connect them to the detectors on the inside.

    “If you put the electronics inside the cold chamber, you have much shorter wires and therefore lower noise,” said Carl Grace, an engineer at Lawrence Berkeley National Laboratory. “You amplify the signal and digitize it in the argon chamber. You then have a digital interface to the outside world in which noise is no longer a concern.”

    There are several design challenges these teams have had to overcome during development, not the least of which was determining how to test the durability of the devices.

    “These chips will have to operate for a minimum of 20-odd years, hopefully longer,” Grace said. “And because of the nature of the argon chambers, the electronics that get put inside of them can’t cannot be changed. They cannot be swapped out or repaired in any way.”

    Since Grace and his team don’t have 20 years in which to test their prototypes, they’ve approximated the effects of aging by increasing the amount of voltage powering the chips to simulate the wear and tear of regular, long-term operation.

    “We take the electronics, cool them down and then elevate their voltage to accelerate their aging,” Grace said. “By observing their behavior over a relatively short period of time, we can we can then estimate how long the electronics would last if they were operated at the voltages for which they were designed.”

    Resistance in circuits

    Not only do these circuits need to be built to last for decades, they also need to be made more durable in another way.

    Electronic circuitry has a certain amount of resistance to the electric current flowing through it. As electrons pass through a circuit, they interact with the vibrating atoms within the conducting material, which slows them down. But these interactions are reduced when the electronics are cooled to cryogenic temperatures, and the electrons that constitute the signal move more quickly on average.

    This is a good thing in terms of output; the integrated circuits being built for DUNE will work more efficiently when placed in the liquid argon. But, as the electrons travel faster through the circuits as temperatures drop, they can begin to do damage to the circuitry itself.

    “If electrons have a high enough kinetic energy, they can actually start ripping atoms from the crystal structure of the conducting material,” Grace said. “It’s like bullets hitting a wall. The wall starts to lose integrity over time.”

    DUNE chips are designed to mitigate this effect. The chips are fabricated using large constituent devices to minimize the amount of damage accrued, and they are used at lower voltages than normally used at room temperature. Scientists can also adjust operating parameters over time to compensate for any damage that occurs during their many years of use.

    Timeline to completion

    With preparations for the DUNE well under way and the experiment slated to begin generating data by 2027, scientists from many institutions have been hard at work developing electronic prototypes.

    Scientists at Brookhaven National Laboratory are working on perfecting the amplifier, while teams from Fermilab, Brookhaven and Berkeley labs are collaborating on the analog-to-digital converter design.

    Fermilab has also teamed up with Southern Methodist University to develop the electronic component that merges all of the data within an argon tank before it’s transmitted to electronics located outside the cold detector. Finally, researchers working on a competing design at SLAC National Accelerator Laboratory are trying to find a way to efficiently combine all three components into one integrated circuit.

    The various teams plan to submit their circuit designs this summer for review. The selected designs will be built and ultimately installed in the DUNE neutrino detectors at the Sanford Underground Neutrino Facility in South Dakota.

    SURF-Sanford Underground Research Facility, Lead, South Dakota, USA

    U.S. work on LBNF/DUNE is supported by the Department of Energy Office of Science.

    See the full here.


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 11:19 am on April 10, 2020 Permalink | Reply
    Tags: "Top Five Mercury mysteries that BepiColombo will solve", , Basic Research, ,   

    From European Space Agency – United Space in Europe: “Top Five Mercury mysteries that BepiColombo will solve” 

    ESA Space For Europe Banner

    From European Space Agency – United Space in Europe

    4.9.20

    ESA/JAXA Bepicolumbo in flight illustration Artist’s impression of BepiColombo – ESA’s first mission to Mercury. ESA’s Mercury Planetary Orbiter (MPO) will be operated from ESOC, Germany.

    Mercury is a desert world which scientists until recently considered quite uninteresting. NASA’s Mariner and MESSENGER missions, however, revealed that there is much more to the smallest and innermost planet of the Solar System than meets the eye.

    NASA Mariner 10

    NASA/Messenger satellite, ended its mission in 2015 with a dramatic, but planned, event – crashing into the surface of the planet that it had been studying for over four years.

    Despite temperatures on its surface rising up to 450°C, there seems to be water ice on Mercury. The planet also appears to have a way too large inner core for its size and a surprising chemical composition. Here are the top five Mercury mysteries that the European-Japanese BepiColombo mission might solve.

    1. Where did Mercury form?

    Only a little larger than the Moon, Mercury zooms around the Sun on an elliptical orbit every 88 days. At its closest, the planet gets to only one third of the Earth-Sun distance. Has it always been in this place? Scientists are not so sure.

    Data from NASA’s MESSENGER spacecraft, which orbited Mercury between 2011 and 2015, revealed that there is too much of the volatile chemical element potassium, as compared to the more stable radioactive thorium, in the material on the surface of Mercury.

    “Potassium evaporates very quickly in a hot environment while thorium survives even in very high temperatures,” says Johannes Benkhoff, ESA BepiColombo Project Scientist. “Planets that formed closer to the Sun therefore usually have more thorium as compared to potassium. The ratio of these elements was measured on Earth, Mars, the Moon and Venus and it seems to be correlated with the temperature at which the bodies are believed to have formed. But on Mercury we see much more potassium than we would expect.”

    In fact, the ratio of potassium to thorium on Mercury is comparable to that of Mars, which is much farther away from the Sun. Johannes admits that no existing planet formation model can properly explain this deviation. Scientists therefore started looking into the possibility that Mercury may have formed farther away from the Sun, about as far as Mars, and was thrust closer to the star by a collision with another large body. A powerful impact could also explain why Mercury has such an oversized internal core and a relatively thin outer mantel.

    1
    Mercury’s inner core appears too big for such a small planet.

    Mercury’s core, approximately 3600 km in diameter, sits inside the planet’s diameter of less than 5000 km, making up over 40% of the planet’s volume. In comparison, Earth has a diameter of about 12 700 km, but its core is only 1200 km across.

    “One theory is that this big impact in the past, in addition to possibly pushing Mercury to where it is today, also stripped away most of the crust material and left behind the dense core with only a thin outer layer,” says Johannes.

    Some even suggest that the ancient Mercury may have been the mysterious body believed to have struck Earth some 4.5 billion years ago, a collision that, according to some theories, created a large amount of debris that led to the formation of the Moon.

    How much light can BepiColombo shed on the mystery of Mercury’s formation? Johannes says that instruments such as the MERTIS Radiometer and Thermal Infrared Spectrometer, the MIXS Imaging X-ray Spectrometer and MGNS Gamma-ray and Neutron Spectrometer will provide a new level of insight into the mineralogical and elemental composition of Mercury’s surface. Orbiting closer to the planet than its predecessor MESSENGER, ESA’s Mercury Planetary Orbiter (MPO), one of the two orbiters comprising the BepiColmbo mission, will image Mercury’s surface with higher resolution and also provide better coverage of the planet’s southern hemisphere compared to MESSENGER.

    2. Is there really water on Mercury?

    2
    NASA’s mission MESSENGER, which orbited Mercury between 2011 and 2015, detected what appears to be water ice in craters around Mercury’s poles.

    With temperatures on its surface reaching up to 450°C, one wouldn’t expect to find water on Mercury, let alone ice. Surprisingly, when MESSENGER looked into some of the craters around the planet’s poles, it saw what appeared like light reflected from a mass of water ice.

    “We have strong indications that there might be water ice in these craters, but it has not been detected directly,” says Johannes. “With the instruments that we have on MPO, we hope to be able not only to measure water content directly and confirm whether there really is water but also to attempt to find out how much of it is there.”

    The notion of water ice on the scorched planet is not so absurd, Johannes adds. Mercury rotates around an axis that is perpendicular to its orbital plane. The planet is therefore not tilted like Earth. As a result, the sunrays, three times more intense than on Earth, never reach inside the polar craters, allowing them to remain constantly ice cold.

    Johannes hopes that with the ability of MPO’s instruments to identify the precise elemental composition of the surface of Mercury, scientists might even get an idea of where this ice actually came from. Scientists think the ice probably doesn’t come from Mercury directly. Its origin, however, is another mystery. Comets are the likeliest source of water on Earth, but not many are believed to have struck Mercury in the past.

    “Comets in this region are quite rare and usually end up in the Sun because of its strong gravity,” says Johannes. “The ice may have come from asteroids that have collided with Mercury throughout its evolution. Thanks to the cold temperatures in the shaded craters, the ice may have survived there for tens of millions of years.”

    Although BepiColombo will not provide a definite answer, its thorough measurements of the polar areas can provide some hints about the origin of Mercury’s ice.

    3. Is Mercury dead or alive?

    Unlikely to host life, with a parched, seemingly dead surface, Mercury has always been an underdog of Solar System exploration. When the MESSENGER spacecraft finally took a close look at the planet’s surface, however, it found that there might be more going on on Mercury than one would expect.

    The mission found strange geological features, unknown from other planets, dotting the areas inside and around some of Mercury’s craters. These dents in the surface, or hollows, as the scientists call them, appear to be caused by the evaporation of material from inside Mercury.

    3
    Small dents, or hollows, in the Kertész crater of Mercury. These previously unknown geological features were discovered by NASA’s MESSENGER mission and their origin remains a mystery.

    “The interesting thing is that these hollows appear to be fairly recent,” says Johannes. “It appears that there is some volatile material coming up from the outer layer of Mercury and sublimating into the surrounding space, leaving behind these strange features.”

    Since BepiColombo will commence its survey of Mercury ten years after the end of the MESSENGER mission, the scientists hope that they might find evidence of the hollows changing, either growing or shrinking. That would mean that Mercury is still an active, living planet, and not a dead world like the Moon.

    “If we prove that these hollows are changing, that would be one of the most fantastic results we could get with BepiColombo,” says Johannes. “The process driving the creation of these hollows is totally unknown. It might be caused by the heat or by solar particles bombarding the surface of the planet. It’s something completely new and everyone is looking forward to getting more data.”

    4. Why is Mercury so dark?

    With its crater-ridden dusty surface, Mercury might seem quite similar to the Earth’s natural satellite, the Moon. At least at first glance. At closer inspection, and for reasons that scientists don’t yet understand, Mercury appears much darker. The planet reflects only about two-thirds as much light as material collected from the Moon.

    The MERTIS thermal infrared spectrometer aboard the MPO will create a detailed map of the distribution of minerals on Mercury’s surface. By providing better accuracy and resolution of the elemental composition compared to the MESSENGER data, MERTIS and other MPO instruments will help answer the question why Mercury is so dark.

    “There are various explanations as to why Mercury is as dark as it is,” says Johannes. “It’s possible that the material on its surface is similar to what we can see on other planets but the extreme heat on Mercury makes those materials appear darker. There is also a possibility that what we see on the surface is graphite, which is very dark as well. A graphite rich layer could have formed inside the planet as it was cooling down. Some of this material may have been brought to the surface during further evolution.”

    5. How come Mercury has a magnetic field?

    Not too many planets have a magnetic field. Among the rocky planets of the inner Solar System, only Mercury and Earth have one. Mars used to have a magnetic field in the past and lost it. Mercury appears too small to have one. Yet, it still does, even though it’s one hundred times weaker than the magnetic field of Earth. Scientists wonder what sustains this magnetic field despite the odds stacked against it.

    Earth’s magnetic field is generated by the fast spinning of its liquid iron core. As for Mercury, scientists used to think that the core, due to the planet’s small size, must have cooled down and solidified since the planet’s formation. Is that really the case?

    “Mercury’s core must be partially molten to explain this magnetism,” says Johannes. “We can also measure tides on the surface of Mercury, suggesting there must be liquid inside the planet. As Mercury orbits around the Sun and interacts with its gravity, we expect a bulge to form and change its size while moving around the Sun.”

    At its largest, this bulge, according to some estimates, can be up to 14 metres high. Following Mercury throughout its journey around the Sun, which takes the planet from as close as 46 million kilometres to as far as 70 million kilometres away from the Sun, BepiColombo will be able to makes precise measurements of the changes in the bulge. The data will help scientists to better estimate the size of the inner liquid core.

    Mercury’s magnetic field also appears shifted 400 kilometres to the north and not centred in the middle of the planet like that of Earth.

    The two orbiters comprising the BepiColombo mission, ESA’s MPO and the Mercury Magnetospheric Orbiter (Mio) of the Japanese Aerospace Exploration Agency (JAXA), will study Mercury’s magnetic field in greater detail than any spacecraft before and shed light on these perplexing questions. The two orbiters will travel through different areas of Mercury’s magnetosphere and on different timescales. They will measure simultaneously how the magnetic field changes over time and in space, and attempt to explain how the close proximity of the Sun and interaction with the powerful solar wind affect the magnetic field.

    Understanding Mercury’s magnetic field in a greater detail will also help astronomers gain further insight into what is going on inside the mysterious planet.

    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 European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

     
  • richardmitnick 9:59 am on April 9, 2020 Permalink | Reply
    Tags: "Black Hole Bends Light Back on Itself", A black hole that is orbited by a sun-like star; together the pair is called XTE J1550-564., , , Basic Research, , ,   

    From Caltech : “Black Hole Bends Light Back on Itself” 

    Caltech Logo

    From Caltech

    April 08, 2020

    Whitney Clavin
    (626) 395‑1944
    wclavin@caltech.edu

    New study proves a theory first predicted more than 40 years ago.

    1
    This illustration shows how some of the light coming from a disk around a black hole is bent back onto the disk itself due to the gravity of the hefty black hole. The light is then reflected back off the disk. Astronomers using data from NASA’s now-defunct Rossi X-ray Timing Explorer (RXTE) mission were able to distinguish between light that came straight from the disk and light that was reflected. The bluish material coming off the black hole is an outflowing jet of energetic particles. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)/R. Connors (Caltech)

    You may have heard that nothing escapes the gravitational grasp of a black hole, not even light. This is true in the immediate vicinity of a black hole, but a bit farther out—in disks of material that swirl around some black holes—light can escape. In fact, this is the reason actively growing black holes shine with brilliant X-rays.

    Now, a new study accepted for publication in The Astrophysical Journal offers evidence that, in fact, not all of the light streaming from a black hole’s surrounding disk easily escapes. Some of it gives in to the monstrous pull of the black hole, turns back, and then ultimately bounces off the disk and escapes.

    “We observed light coming from very close to the black hole that is trying to escape, but instead is pulled right back by the black hole like a boomerang,” says Riley Connors, lead author of the new study and a postdoctoral scholar at Caltech. “This is something that was predicted in the 1970s, but hadn’t been shown until now.”

    The new findings were made possible by combing through archival observations from NASA’s now-defunct Rossi X-ray Timing Explorer (RXTE) mission, which came to an end in 2012.

    NASA/ROSSI

    The researchers specifically looked at a black hole that is orbited by a sun-like star; together, the pair is called XTE J1550-564. The black hole “feeds” off this star, pulling material onto a flat structure around it called an accretion disk. By looking closely at the X-ray light coming from the disk as the light spirals toward the black hole, the team found imprints indicating that the light had been bent back toward the disk and reflected off.

    “The disk is essentially illuminating itself,” says co-author Javier Garcia, a research assistant professor of physics at Caltech. “Theorists had predicted what fraction of the light would bend back on the disk, and now, for the first time, we have confirmed those predictions.”

    The scientists say that the new results offer another indirect confirmation of Albert Einstein’s general theory of relativity, and also will help in future measurements of the spin rates of black holes, something that is still poorly understood.

    “Since black holes can potentially spin very fast, they not only bend the light but twist it,” says Connors. “These recent observations are another piece in the puzzle of trying to figure out how fast black holes spin.”

    The new study, titled, “Evidence for Returning Disk Radiation in the Black Hole X-ray Binary XTEJ1550-564,” was funded by NASA, the Alexander von Humboldt Foundation, and the Margarete von Wrangell Fellowship. Other co-authors are Thomas Dauser, Stefan Licklederer, and Jörn Wilms of The University of Erlangen-Nüremberg in Germany; Victoria Grinberg of the Universität Tübingen in Germany; James Steiner of the MIT Kavli Institute for Astrophysics and Space Research and Harvard University; Navin Sridhar of Columbia University; John Tomsick of UC Berkeley; and Fiona Harrison, the Harold A. Rosen Professor of Physics at Caltech and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy.

    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 California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 11:59 am on April 7, 2020 Permalink | Reply
    Tags: "Clemson researchers capture first-ever photographic proof of power-packed jet emerging from colliding galaxies", , , Basic Research, ,   

    From Clemson University: “Clemson researchers capture first-ever photographic proof of power-packed jet emerging from colliding galaxies” 

    From Clemson University

    April 7, 2020
    Laura Schmitt

    A team of Clemson University College of Science researchers, in collaboration with international colleagues, has reported the first definitive detection of a relativistic jet emerging from two colliding galaxies — in essence, the first photographic proof that merging galaxies can produce jets of charged particles that travel at nearly the speed of light.

    Furthermore, scientists had previously discovered that these jets could be found in elliptical-shaped galaxies, which can be formed in the merging of two spiral galaxies. Now, they have an image showing the formation of a jet from two younger, spiral-shaped galaxies.

    1
    The Seyfert 1 galaxy, TXS 2116-077, (seen on the right) collides with another spiral-shaped galaxy of similar mass, creating a relativistic jet in the TXS’s center. Both galaxies have active galactic nuclei (AGN). Image Credit: Courtesy Vaidehi Paliya

    “For the first time, we have found two spiral- or disk-shaped galaxies on path for a collision that have produced a nascent, baby jet that has just started its life at the center of one of the galaxies,” said Vaidehi Paliya, a former Clemson post-doctoral researcher and lead author of the findings reported in The Astrophysical Journal on April 7, 2020.

    The paper is titled “TXS 2116-077: A gamma-ray emitting relativistic jet hosted in a galaxy merger.” In addition to Paliya, who is now at the Deutsches Elektronen Synchrotron (DESY) in Germany, the other Clemson authors include associate professor Marco Ajello, professor Dieter Hartmann, and adjunct professor Stefano Marchesi of the department of physics and astronomy.

    The fact that the jet is so young enabled the researchers to clearly see its host.

    According to Ajello, others have already imaged galactic collisions many times. But he and his colleagues are the first to capture two galaxies merging where there is a fully formed jet pointing at us — albeit, a very young one, and thus not yet bright enough to blind us.

    “Typically, a jet emits light that is so powerful we can’t see the galaxy behind it,” Marchesi said. “It’s like trying to look at an object and someone points a bright flashlight into your eyes. All you can see is the flashlight. This jet is less powerful, so we can actually see the galaxy where it is born.”

    Jets are the most powerful astrophysical phenomena in the universe. They can emit more energy into the universe in one second than our sun will produce in its entire lifetime. That energy is in the form of radiation, such as intense radio waves, X-rays, and gamma-rays.

    “Jets are the best accelerators in the universe — far better than the super colliders we have on Earth,” said Hartmann, referring to accelerators used in high-energy physics studies.

    Jets were thought to be born from older, elliptical-shaped galaxies with an active galactic nucleus (AGN), which is a super-massive black hole that resides at its center. As a point of reference, scientists believe all galaxies have centrally located super-massive black holes, but not all of them are AGNs. For example, our Milky Way’s massive black hole is dormant.

    Scientists theorize that the AGNs grow larger by gravitationally drawing in gas and dust through a process called accretion. But not all of this matter gets accreted into the black hole. Some of the particles become accelerated and are spewed outward in narrow beams in the form of jets.

    “It’s hard to dislodge gas from the galaxy and have it reach its center,” Ajello explained. “You need something to shake the galaxy a little bit to make the gas get there. The merging or colliding of galaxies is the easiest way to move the gas, and if enough gas moves, then the super-massive black hole will become extremely bright and could potentially develop a jet.”

    Ajello believes that the team’s image captured the two galaxies, a Seyfert 1 galaxy known as TXS 2116-077 and another galaxy of similar mass, as they were colliding for the second time because of the amount of gas seen in the image.

    “Eventually, all the gas will be expelled into space, and without gas, a galaxy cannot form stars anymore,” Ajello said. “Without gas, the black hole will switch off and the galaxy will lay dormant.”

    Billions of years from now, our own Milky Way will merge with the nearby Andromeda galaxy.

    “Scientists have carried out detailed numerical simulations and predicted that this event may ultimately lead to the formation of one giant elliptical galaxy,” said Paliya. “Depending on the physical conditions, it may host a relativistic jet, but that’s in the distant future.”

    The team captured the image using one of the largest land-based telescopes in the world, the Subaru 8.2-meter optical infrared telescope located on a mountain summit in Hawaii. They performed subsequent observations with the Gran Telescopio Canarias and William Herschel Telescope on the island of La Palma off the coast of Spain, as well as with NASA’s Chandra X-Ray Observatory space telescope.

    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, Spain, sited on a volcanic peak 2,267 metres (7,438 ft) above sea level

    ING 4.2 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands, 2,396 m (7,861 ft)

    NASA/Chandra X-ray Telescope

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Ranked as the 27th best national public university by U.S. News & World Report, Clemson is dedicated to teaching, research and service. Founded in 1889, we remain committed both to world-class research and a high quality of life. In fact, 92 percent of our seniors say they’d pick Clemson again if they had it to do over.

    Clemson’s retention and graduation rates rank among the highest in the country for public universities. We’ve been named among the “Best Public College Values” by Kiplinger magazine in 2019, and The Princeton Review named us among the “Best Value Colleges” for 2020.

    Our beautiful college campus sits on 20,000 acres in the foothills of the Blue Ridge Mountains, along the shores of Lake Hartwell. And we also have research facilities and economic development hubs throughout the state of South Carolina — in Anderson, Blackville, Charleston, Columbia, Darlington, Georgetown, Greenville, Greenwood, and Pendleton.

    The research, outreach and entrepreneurial projects led by our faculty and students are driving economic development and improving quality of life in South Carolina and beyond. In fact, a recent study determined that Clemson has an annual $1.9 billion economic impact on the state.

    Just as founder Thomas Green Clemson intertwined his life with the state’s economic and educational development, the Clemson Family impacts lives daily with their teaching, research and service.
    How Clemson got its start

    University founders Thomas Green and Anna Calhoun Clemson had a lifelong interest in education, agricultural affairs and science.

    In the post-Civil War days of 1865, Thomas Clemson looked upon a South that lay in economic ruin, once remarking, “This country is in wretched condition, no money and nothing to sell. Everyone is ruined, and those that can are leaving.”

    Thomas Clemson’s death on April 6, 1888, set in motion a series of events that marked the start of a new era in higher education in South Carolina. In his will, he bequeathed the Fort Hill plantation and a considerable sum from his personal assets for the establishment of an educational institution that would teach scientific agriculture and the mechanical arts to South Carolina’s young people.

    Clemson Agricultural College formally opened as an all-male military school in July 1893 with an enrollment of 446. It remained this way until 1955 when the change was made to “civilian” status for students, and Clemson became a coeducational institution. In 1964, the college was renamed Clemson University as the state legislature formally recognized the school’s expanded academic offerings and research pursuits.

    More than a century after its opening, the University provides diverse learning, research facilities and educational opportunities not only for the people of the state — as Thomas Clemson dreamed — but for thousands of young men and women throughout the country and the world.

     
  • richardmitnick 11:21 am on April 7, 2020 Permalink | Reply
    Tags: , , , Basic Research, , SPT-CL J2106-5844- the most massive distant (farther than roughly 8 billion light-years) galaxy cluster known.   

    From AAS NOVA: ” Featured Image: A Distant Cluster Tips the Scales” 

    AASNOVA

    From AAS NOVA

    6 April 2020
    Susanna Kohler

    1

    You’re looking at SPT-CL J2106-5844, the most massive distant (farther than roughly 8 billion light-years) galaxy cluster known. This composite image (click for the full view) shows the field of the cluster, which spans a distance of roughly 3 million light-years across, in three Hubble color filters. The overlaid contours show the distribution of mass within the cluster, as recently determined by a team of scientists led by Jinhyub Kim (Yonsei University, Republic of Korea; University of California, Davis). Kim and collaborators used weak gravitational lensing — slight distortions in the shapes of background galaxies caused when their light is bent by the massive gravitational pull of this cluster — to map out the tremendous mass of SPT-CL J2106-5844.

    Weak gravitational lensing NASA/ESA Hubble

    They find this cluster weighs in at a whopping ~1 quadrillion (1015) solar masses! Studying this distant, monster cluster can help us place constraints on how the universe’s large-scale structure formed and evolved. To read more about what the authors learned, check out the article below.

    Citation

    “Precise Mass Determination of SPT-CL J2106-5844, the Most Massive Cluster at z > 1,” Jinhyub Kim et al 2019 ApJ 887 76.
    https://iopscience.iop.org/article/10.3847/1538-4357/ab521e

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 9:01 am on April 7, 2020 Permalink | Reply
    Tags: , , , Basic Research, , , , , Quasar 3C 279, , Telescopes contributing also are the Submillimeter Telescope; and the South Pole Telescope., Telescopes contributing to this result were ALMA; APEX; the IRAM 30-meter telescope; the James Clerk Maxwell Telescope; the Large Millimeter Telescope; the Submillimeter Array., The data analysis to transform raw data to an image required specific computers (or correlators) hosted by the MPIfR in Bonn and the MIT Haystack Observatory.,   

    From ALMA: “Event Horizon Telescope Images of a Black-Hole Powered Jet” 

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    From ALMA

    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

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

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

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    2
    Illustration of multiwavelength 3C 279 jet structure in April 2017. The observing epochs, arrays, and wavelengths are noted at each panel. Credit: J.Y. Kim (MPIfR), Boston University Blazar Program (VLBA and GMVA), and Event Horizon Telescope Collaboration.

    Something is Lurking in the Heart of Quasar 3C 279. One year ago, the Event Horizon Telescope (EHT) Collaboration published the first image of a black hole in the nearby radio galaxy Messier 87.

    Mesier 87*, The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    Now the collaboration has extracted new information from the EHT data of the far quasar 3C 279: they observed in the finest detail ever a relativistic jet that is believed to originate from the vicinity of a supermassive black hole. In their analysis, which was led by astronomer Jae-Young Kim from the Max Planck Institute for Radio Astronomy in Bonn, they studied the jet’s fine-scale morphology close to the jet base where highly variable gamma-ray emission is thought to originate. The technique used for observing the jet is called very long baseline interferometry (VLBI). The results are published in the coming issue of “Astronomy & Astrophysics, April 2020.

    The EHT collaboration continues extracting information from the groundbreaking data collected in its global campaign in April 2017. One target of the observations was the quasar 3C 279, a galaxy 5 billion light-years away, in the constellation Virgo that scientists classify as a quasar because a point of light at its center shines ultra-bright and flickers as massive amounts of gases and stars fall into the giant black hole there. The black hole is about one billion times the mass of the Sun, that is, 200 more massive than our Galactic Centre black hole. It is shredding the gas and stars that come near into an inferred accretion disk and we see it is squirting some of the gas back out in two fine fire-hose-like jets of plasma at velocities approaching the speed of light. This tells of enormous forces at play in the center.

    The EHT collaboration continues extracting information from the groundbreaking data collected in its global campaign in April 2017. One target of the observations was the quasar 3C 279, a galaxy 5 billion light-years away, in the constellation Virgo that scientists classify as a quasar because a point of light at its center shines ultra-bright and flickers as massive amounts of gases and stars fall into the giant black hole there. The black hole is about one billion times the mass of the Sun, that is, 200 more massive than our Galactic Centre black hole. It is shredding the gas and stars that come near into an inferred accretion disk and we see it is squirting some of the gas back out in two fine fire-hose-like jets of plasma at velocities approaching the speed of light. This tells of enormous forces at play in the center.

    The interpretation of the observations is challenging. Motions different than the jet direction, and apparently as fast as about 20 times the speed of light are difficult to reconcile with the early understanding of the source, this suggests traveling shocks or instabilities in a bent, possibly rotating jet, which also emits at high energies, such gamma-rays.

    The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope.

    The telescopes work together using a technique called very long baseline interferometry (VLBI). This synchronizes facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope. VLBI allows the EHT to achieve a resolution of 20 micro-arcseconds — equivalent to identifying an orange on Earth as seen by an astronaut from the Moon. The data analysis to transform raw data to an image required specific computers (or correlators), hosted by the MPIfR in Bonn and the MIT Haystack Observatory.

    Anton Zensus, Director at the MPIfR and Chair of the EHT Collaboration Board, stresses the achievement as a global effort: “Last year we could present the first image of the shadow of a black hole. Now we see unexpected changes in the shape of the jet in 3C 279, and we are not done yet. We are working on the analysis of data from the centre of our Galaxy in Sgr A*, and on other active galaxies such as Centaurus A, OJ 287, and NGC 1052. As we told last year: this is just the beginning.”

    Opportunities to conduct EHT observing campaigns occur once a year in early Northern springtime, but the March/April 2020 campaign had to be cancelled in response to the CoViD-19 global outbreak. In announcing the cancellation Michael Hecht, astronomer from the MIT/Haystack Observatory and EHT Deputy Project Director, concluded that: “We will now devote our full concentration to completion of scientific publications from the 2017 data and dive into the analysis of data obtained with the enhanced EHT array in 2018. We are looking forward to observations with the EHT array expanded to eleven observatories in the spring of 2021”.

    Additional Information

    The Event Horizon Telescope international collaboration announced the first-ever image of a black hole at the heart of the radio galaxy Messier 87 on April 10, 2019 by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a new instrument with the highest angular resolving power that has yet been achieved.

    The individual telescopes involved in the EHT collaboration are: the Atacama Large Millimetre Telescope (ALMA), the Atacama Pathfinder EXplorer (APEX), the Greenland Telescope (since 2018), the IRAM 30-meter Telescope, the IRAM NOEMA Observatory (expected 2021), the Kitt Peak Telescope (expected 2021), the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), and the South Pole Telescope (SPT).

    The EHT consortium consists of 13 stakeholder institutes; the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universität Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max-Planck-Institut für Radioastronomie, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

    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), 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

     
  • richardmitnick 12:53 pm on April 6, 2020 Permalink | Reply
    Tags: "Far stars firmly in sight thanks to telescope teamwork", , , , Basic Research, , Interferometry- to harness the power of multiple telescopes.   

    From Australian National University: “Far stars firmly in sight thanks to telescope teamwork” 

    ANU Australian National University Bloc

    From Australian National University

    6 April 2020

    1

    Stars far, far away could appear a lot closer when viewed through our telescopes thanks to new research from The Australian National University (ANU).

    The research has also brought the properties of nearby stars into never before seen precision, and could allow us to catch a rare glimpse of the conditions of planets orbiting them in the future.

    PhD researcher Adam Rains used a cutting-edge approach to measure the properties of 16 stars, making them clearer than ever before.

    “To put things in perspective, the measurement precision we achieved is like looking at a dollar coin 4,600 km away and measuring its diameter to the nearest 0.25 mm,” Mr Rains said.

    “We now know the temperature of these stars to a similar level of precision! For example – this is like measuring a 5,000 degree star to within 50 degrees.

    “To do this, we combined the light from multiple telescopes.”

    Mr Rains says ordinarily, features like the size and temperature of stars are very difficult to measure directly.

    “Most stars are simply too far away, and our current telescopes too small for us to study at the level of detail or resolution we have reached here,” he said.

    “The stars we looked at are relatively close in comparison. That’s why this research is so important – so much of our knowledge of stars all over the universe is built upon what we have learnt about the stars closest to us.”

    Several of the stars observed for this study have planets around them – making any information collected about them even more valuable.

    “By knowing things like how big, how hot, and how bright these stars are, we are also better able to figure out what conditions might be like on any planets orbiting them,” Mr Rains said.

    Mr Rains looked at a number of stars like Tau Ceti which have been previously observed by other astronomers, to make sure his results matched up.

    The study was carried out using a method called interferometry to harness the power of multiple telescopes.

    “Interferometry combines light from a set of separate telescopes to increase their resolution beyond any of the individual telescopes – making the whole greater than the sum of its parts,” Mr Rains said

    “Currently the biggest telescopes on the planet have mirrors about 10 metres across. Even larger telescopes are under construction, but there are practical limits on just how big they can get.

    “If you can combine the light from separate telescopes you can achieve the resolution of a much larger telescope – without actually building one. It’s like having a 130m telescope.”

    For this technique to work, you have to make sure the starlight from the telescopes arrives at the camera at exactly the same time.

    This is achieved by having ‘mirror-trains’. Mirrors are placed on carriages that move along a rail system to control when each telescope’s light hits the camera.

    “The further apart your telescopes, the longer the rail system you need, but this technique is the only one that lets us study other stars at such high resolution,” Mr Rains said.

    Mr Rains’ work was based on observations carried out at the Very Large Telescope facility in Chile, operated by the European Southern Observatory.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    The research has been published by the Monthly Notices of the Royal Astronomical Society.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ANU Campus

    ANU is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

    Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: