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  • richardmitnick 3:41 pm on January 22, 2018 Permalink | Reply
    Tags: , , , Basic Research, , , , ,   

    From CfA: “A New Bound on Axions” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    January 19, 2018

    1
    A composite image of M87 in the X-ray from Chandra (blue) and in radio emission from the Very Large Array (red-orange). Astronomers used the X-ray emission from M87 to constrain the properties of axions, putative particles suggested as dark matter candidates. X-ray NASA/CXC/KIPAC/N. Werner, E. Million et al.; Radio NRAO/AUI/NSF/F. Owen.

    NASA/Chandra Telescope

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

    An axion is a hypothetical elementary particle whose existence was postulated in order to explain why certain subatomic reactions appear to violate basic symmetry constraints, in particular symmetry in time. The 1980 Nobel Prize in Physics went for the discovery of time-asymmetric reactions. Meanwhile, during the following decades, astronomers studying the motions of galaxies and the character of the cosmic microwave background [CMB] radiation came to realize that most of the matter in the universe was not visible.

    CMB per ESA/Planck

    Cosmic Background Radiation per Planck

    ESA/Planck

    It was dubbed dark matter, and today’s best measurements find that about 84% of matter in the cosmos is dark. This component is dark not only because it does not emit light — it is not composed of atoms or their usual constituents, like electrons and protons, and its nature is mysterious. Axions have been suggested as one possible solution. Particle physicists, however, have so far not been able to detect directly axions, leaving their existence in doubt and reinvigorating the puzzles they were supposed to resolve.

    CfA astronomer Paul Nulsen and his colleagues used a novel method to investigate the nature of axions. Quantum mechanics constrain axions, if they exist, to interact with light in the presence of a magnetic field. As they propagate along a strong field, axions and photons should transmute from one to the other other in an oscillatory manner. Because the strength of any possible effect depends in part on the energy of the photons, the astronomers used the Chandra X-ray Observatory to monitor bright X-ray emission from galaxies. They observed X-rays from the nucleus of the galaxy Messier 87, which is known to have strong magnetic fields, and which (at a distance of only fifty-three million light-years) is close enough to enable precise measurements of variations in the X-ray flux. Moreover, Me3ssier 87 lies in a cluster of galaxies, the Virgo cluster, which should insure the magnetic fields extend over very large scales and also facilitate the interpretation. Not least, Messier 87 has been carefully studied for decades and its properties are relatively well known.

    The search did not find the signature of axions. It does, however, set an important new limit on the strength of the coupling between axions and photons, and is able to rule out a substantial fraction of the possible future experiments that might be undertaken to detect axions. The scientists note that their research highlights the power of X-ray astronomy to probe some basic issues in particle physics, and point to complementary research activities that can be undertaken on other bright X-ray emitting galaxies.

    Science paper:
    A New Bound on Axion-Like Particles, Journal of Cosmology and Astroparticle Physics.

    See the full article here .

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    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.

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  • richardmitnick 2:58 pm on January 22, 2018 Permalink | Reply
    Tags: "Cosmic messenger" particles, , , Basic Research, , , , KM3NeT neutrino telescope, , , , , ,   

    From Penn State: “Three types of extreme-energy space particles may have unified origin” 

    Penn State Bloc

    Pennsylvania State University

    22 January 2018
    Kohta Murase
    murase@psu.edu
    (+1) 814-863-9594

    Barbara Kennedy (PIO):
    bkk1@psu.edu,
    (+1) 814-863-4682

    [ Barbara K. Kennedy ]

    1
    This image illustrates the “multi-messenger” emission from a gigantic reservoir of cosmic rays that are accelerated by powerful jets from a supermassive black hole. Credit: Kanoko Horio.

    One of the biggest mysteries in astroparticle physics has been the origins of ultrahigh-energy cosmic rays, very high-energy neutrinos, and high-energy gamma rays. Now, a new theoretical model reveals that they all could be shot out into space after cosmic rays are accelerated by powerful jets from supermassive black holes and they travel inside clusters and groups of galaxies. It also shows that these space particles could travel inside clusters and groups of galaxies.

    The model explains the natural origins of all three types of “cosmic messenger” particles simultaneously, and is the first astrophysical model of its kind based on detailed numerical computations. A scientific paper that describes this model, produced by Penn State and University of Maryland scientists, will be published as an Advance Online Publication on the website of the journal Nature Physics on January 22, 2018.

    “Our model shows a way to understand why these three types of cosmic messenger particles have a surprisingly similar amount of power input into the universe, despite the fact that they are observed by space-based and ground-based detectors over ten orders of magnitude in individual particle energy,” said Kohta Murase, assistant professor of physics and astronomy and astrophysics at Penn State. “The fact that the measured intensities of very high-energy neutrinos, ultrahigh-energy cosmic rays, and high-energy gamma rays are roughly comparable tempted us to wonder if these extremely energetic particles have some physical connections. The new model suggests that very high-energy neutrinos and high-energy gamma rays are naturally produced via particle collisions as daughter particles of cosmic rays, and thus can inherit the comparable energy budget of their parent particles. It demonstrates that the similar energetics of the three cosmic messengers may not be a mere coincidence.”

    Ultrahigh-energy cosmic rays are the most energetic particles in the universe — each of them carries an energy that is too high to be produced even by the Large Hadron Collider, the most powerful particle accelerator in the world. Neutrinos are mysterious and ghostly particles that hardly ever interact with matter. Very high-energy neutrinos, with energy more than one million mega-electronvolts, have been detected in the IceCube neutrino observatory in Antarctica.

    U Wisconsin IceCube neutrino observatory

    U Wisconsin IceCube experiment at the South Pole



    U Wisconsin ICECUBE neutrino detector at the South Pole


    IceCube Gen-2 DeepCore PINGU


    IceCube reveals interesting high-energy neutrino events

    Gamma rays have the highest-known electromagnetic energy — those with energies more than a billion times higher than a photon of visible light have been observed by the Fermi Gamma-ray Space Telescope and other ground-based observatories.

    NASA/Fermi LAT


    NASA/Fermi Gamma Ray Space Telescope

    “Combining all information on these three types of cosmic messengers is complementary and relevant, and such a multi-messenger approach has become extremely powerful in the recent years,” Murase said.

    Murase and the first author of this new paper, Ke Fang, a postdoctoral associate at the University of Maryland, attempt to explain the latest multi-messenger data from very high-energy neutrinos, ultrahigh-energy cosmic rays, and high-energy gamma rays, based on a single but realistic astrophysical setup. They found that the multi-messenger data can be explained well by using numerical simulations to analyze the fate of these charged particles.

    “In our model, cosmic rays accelerated by powerful jets of active galactic nuclei escape through the radio lobes that are often found at the end of the jets,” Fang said. “Then we compute the cosmic-ray propagation and interaction inside galaxy clusters and groups in the presence of their environmental magnetic field. We further simulate the cosmic-ray propagation and interaction in the intergalactic magnetic fields between the source and the Earth. Finally we integrate the contributions from all sources in the universe.”

    The leading suspects in the half-century old mystery of the origin of the highest-energy cosmic particles in the universe were in galaxies called “active galactic nuclei,” which have a super-radiating core region around the central supermassive black hole. Some active galactic nuclei are accompanied by powerful relativistic jets. High-energy cosmic particles that are generated by the jets or their environments are shot out into space almost as fast as the speed of light.

    “Our work demonstrates that the ultrahigh-energy cosmic rays escaping from active galactic nuclei and their environments such as galaxy clusters and groups can explain the ultrahigh-energy cosmic-ray spectrum and composition. It also can account for some of the unexplained phenomena discovered by ground-based experiments,” Fang said. “Simultaneously, the very high-energy neutrino spectrum above one hundred million mega-electronvolts can be explained by particle collisions between cosmic rays and the gas in galaxy clusters and groups. Also, the associated gamma-ray emission coming from the galaxy clusters and intergalactic space matches the unexplained part of the diffuse high-energy gamma-ray background that is not associated with one particular type of active galactic nucleus.”

    “This model paves a way to further attempts to establish a grand-unified model of how all three of these cosmic messengers are physically connected to each other by the same class of astrophysical sources and the common mechanisms of high-energy neutrino and gamma-ray production,” Murase said. “However, there also are other possibilities, and several new mysteries need to be explained, including the neutrino data in the ten-million mega-electronvolt range recorded by the IceCube neutrino observatory in Antarctica. Therefore, further investigations based on multi-messenger approaches — combining theory with all three messenger data — are crucial to test our model.”

    The new model is expected to motivate studies of galaxy clusters and groups, as well as the development of other unified models of high-energy cosmic particles. It is expected to be tested rigorously when observations begin to be made with next-generation neutrino detectors such as IceCube-Gen2 and KM3Net, and the next-generation gamma-ray telescope, Cherenkov Telescope Array.

    Artist’s expression of the KM3NeT neutrino telescope

    HESS Cherenkov Telescope Array, located on the Cranz family farm, Göllschau, in Namibia, near the Gamsberg

    “The golden era of multi-messenger particle astrophysics started very recently,” Murase said. “Now, all information we can learn from all different types of cosmic messengers is important for revealing new knowledge about the physics of extreme-energy cosmic particles and a deeper understanding about our universe.”

    The research was partially supported by the National Science Foundation (grant No. PHY-1620777) and the Alfred P. Sloan Foundation.

    See the full article here .

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    We teach students that the real measure of success is what you do to improve the lives of others, and they learn to be hard-working leaders with a global perspective. We conduct research to improve lives. We add millions to the economy through projects in our state and beyond. We help communities by sharing our faculty expertise and research.

    Penn State lives close by no matter where you are. Our campuses are located from one side of Pennsylvania to the other. Through Penn State World Campus, students can take courses and work toward degrees online from anywhere on the globe that has Internet service.

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  • richardmitnick 2:14 pm on January 22, 2018 Permalink | Reply
    Tags: , , Basic Research, CoRoT-2b, , , McGill University   

    From McGill: “A ‘hot Jupiter’ with unusual winds” 

    McGill University

    McGill University

    Contact Information
    Contact:
    Chris Chipello
    Media Relations Office
    christopher.chipello@mcgill.ca
    Office Phone:
    O: 514-398-4201
    C:514-717-4201

    Secondary Contact Information
    Nicolas Cowan
    McGill University/ McGill Space Institute
    nicolas.cowan@mcgill.ca

    Puzzling finding raises new questions about atmospheric physics of giant planets.

    1
    Artist’s concept shows the gaseous exoplanet CoRoT-2b with a westward hot spot in orbit around its host star.
    CREDIT: NASA/JPL-Caltech/T. Pyle (IPAC).

    The hottest point on a gaseous planet near a distant star isn’t where astrophysicists expected it to be – a discovery that challenges scientists’ understanding of the many planets of this type found in solar systems outside our own.

    Unlike our familiar planet Jupiter, so-called hot Jupiters circle astonishingly close to their host star — so close that it typically takes fewer than three days to complete an orbit. And one hemisphere of these planets always faces its host star, while the other faces permanently out into the dark.

    Not surprisingly, the “day” side of the planets gets vastly hotter than the night side, and the hottest point of all tends to be the spot closest to the star. Astrophysicists theorize and observe that these planets also experience strong winds blowing eastward near their equators, which can sometimes displace the hot spot toward the east.

    In the mysterious case of exoplanet CoRoT-2b, however, the hot spot turns out to lie in the opposite direction: west of center. A research team led by astronomers at McGill University’s McGill Space Institute (MSI) and the Institute for research on exoplanets (iREx) in Montreal made the discovery using NASA’s Spitzer Space Telescope.

    NASA/Spitzer Infrared Telescope

    Their findings are reported Jan. 22 in the journal Nature Astronomy.

    Wrong-way wind

    “We’ve previously studied nine other hot Jupiter, giant planets orbiting super close to their star. In every case, they have had winds blowing to the east, as theory would predict,” says McGill astronomer Nicolas Cowan, a co-author on the study and researcher at MSI and iREx. “But now, nature has thrown us a curveball. On this planet, the wind blows the wrong way. Since it’s often the exceptions that prove the rule, we are hoping that studying this planet will help us understand what makes hot Jupiters tick.”

    CoRoT-2b, discovered a decade ago by a French-led space observatory mission, is 930 light years from Earth. While many other hot Jupiters have been detected in recent years, CoRoT-2b has continued to intrigue astronomers because of two factors: its inflated size and the puzzling spectrum of light emissions from its surface.

    “Both of these factors suggest there is something unusual happening in the atmosphere of this hot Jupiter,” says Lisa Dang, a McGill PhD student and lead author of the new study. By using Spitzer’s Infrared Array Camera to observe the planet while it completed an orbit around its host star, the researchers were able to map the planet’s surface brightness for the first time, revealing the westward hot spot.

    New questions

    The researchers offer three possible explanations for the unexpected discovery – each of which raises new questions:

    The planet could be spinning so slowly that one rotation takes longer than a full orbit of its star; this could create winds blowing toward the west rather than the east – but it would also undercut theories about planet-star gravitational interaction in such tight orbits.

    The planet’s atmosphere could be interacting with the planet’s magnetic field to modify its wind pattern; this could provide a rare opportunity to study an exoplanet’s magnetic field.

    Large clouds covering the eastern side of the planet could make it appear darker than it would otherwise – but this would undercut current models of atmospheric circulation on such planets.

    “We’ll need better data to shed light on the questions raised by our finding,” Dang says. “Fortunately, the James Webb Space Telescope, scheduled to launch next year, should be capable of tackling this problem. Armed with a mirror that has 100 times the collecting power of Spitzer’s, it should provide us with exquisite data like never before.”

    Scientists from the University of Michigan, the California Institute of Technology, Arizona State University, New York University Abu Dhabi, the University of California, Santa Cruz, and Pennsylvania State University also contributed to the study.

    See the full article here .

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    All about McGill

    With some 300 buildings, more than 38,500 students and 250,000 living alumni, and a reputation for excellence that reaches around the globe, McGill has carved out a spot among the world’s greatest universities.
    Founded in Montreal, Quebec, in 1821, McGill is a leading Canadian post-secondary institution. It has two campuses, 11 faculties, 11 professional schools, 300 programs of study and some 39,000 students, including more than 9,300 graduate students. McGill attracts students from over 150 countries around the world, its 8,200 international students making up 21 per cent of the student body.

     
  • richardmitnick 9:57 am on January 22, 2018 Permalink | Reply
    Tags: , , Basic Research, , Henrietta Swan Leavitt, Mapping the cosmos with Cepheid stars,   

    From astronomy.com: “Mapping the cosmos with Cepheid stars” 

    Astronomy magazine

    astronomy.com

    January 19, 2018
    Alison Klesman

    A young astronomer improves our ability to use a well-established law to measure distance.

    1
    RS Puppis is a bright Cepheid star – a star that pulsates regularly, changing its size and its brightness over time.
    NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration; Acknowledgment: H. Bond (STScI and Penn State University)

    Cepheid variable stars are a vital rung on the “ladder” astronomers use to determine the distance to astronomical objects. These pulsating stars, which change in brightness as they also change in physical size over time, allowed Edwin Hubble to measure the distance to the Andromeda Galaxy and determine that our Milky Way was one of what we now know are trillions of “island universes” — galaxies — scattered throughout the larger, expanding universe.

    These stars have been used as distance indicators since the early 1900s, thanks to the hard work of Henrietta Leavitt.

    3
    Henrietta Swan Leavitt, Born July 4, 1868, Died December 12, 1921; and Kate Hartman today

    And today, a young astronomer is using the Sloan Digital Sky Survey’s Apache Point Galactic Evolution Experiment (APOGEE) to make more precise measurements of Cepheid variables than ever before.

    SDSS APOGEE spectrograph

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)

    Her project, featured in a press conference during last week’s 231st Meeting of the American Astronomical Society, showed that astronomers are still striving to understand the intricacies of these stars — and how they are closer than ever before to the final piece of the puzzle.

    Why Cepheid variables are special

    Kate Hartman, an undergraduate from Pomona College working with Rachael Beaton, the NASA Hubble and Carnegie-Princeton Postdoctoral Fellow at Princeton University, was tasked with using APOGEE data to determine the amount of elements present in each Cepheid star measured. Though it may sound simple, this type of measurement is vital to ensure astronomers’ calibration of the period-luminosity relationship for Cepheid variables — called the Leavitt Law — is correct. Problems with that calibration would affect distances measured using the law, which would increase uncertainties in other types of distance measurements, as well.

    2
    A light curve showing Delta Cephei’s brightness over time. Delta Cephei is the prototype Cepheid variable star, after which the class is named.
    ThomasK Vbg (Wikipedia)

    The Leavitt Law works like this: Cepheid variables are giant stars that pulsate — physically — over the course of hours or days. As Beaton explained in a press release, “over a pulsation cycle of a Cepheid variable, the star’s properties change. Its temperature, surface gravity, and atmospheric properties can vary greatly over a fairly short time.” These stars demonstrate a clear period-luminosity relationship — a correlation between the period over which a star varies and its intrinsic brightness — that means once an astronomer has measured a Cepheid’s light curve (the variation in its light over time), they immediately know the brightness of the star. Knowing the intrinsic brightness of the star — rather than simply how bright the star appears — allows the astronomer to calculate its distance, because objects get dimmer with distance via a simple and universal law.

    This is why only certain types of stars can be used as distance indicators — without the ability to know for certain how bright a star or other object actually is, astronomers cannot use it to measure distance.

    APOGEE’s Cepheid catalog

    So then the question arises: Do variables with slightly different chemical compositions or in different chemical environments have different period-luminosity relationships? Or is the single Leavitt Law capable of letting astronomers view any Cepheid variable, anywhere, and measuring its distance in a more straightforward way? And, additionally: Are surveys like APOGEE capable of producing reliable information, such as composition, about these stars, when a single image could catch the star at any random time during its pulsation period?

    Hartman and Beaton wanted to find out. APOGEE was perfect for this job, because although it’s “optimized to study the cool, old giant-type stars found all across our galaxy,” said Beaton, “Cepheid variables … are similar in temperature, so they are well suited for APOGEE.”

    Thus, APOGEE not only provides a large catalog of Cepheids, it also provides a tool to measure their properties in the same way that other (older) stars are measured. This type of consistency lets astronomers study both young and old parts of the galaxy to better trace its evolution.

    4
    The Cepheid variable star in the Andromeda Galaxy that allowed Edwin Hubble to measure the distance to our neighboring galaxy. NASA/ESA/Hubble Heritage Team

    See the full article here .

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  • richardmitnick 7:48 am on January 22, 2018 Permalink | Reply
    Tags: , , Basic Research, , , New Study on Black Hole Magnetic Fields Has Thrown a Huge Surprise at Astronomers,   

    From Science Alert: “New Study on Black Hole Magnetic Fields Has Thrown a Huge Surprise at Astronomers” 

    ScienceAlert

    Science Alert

    22 JAN 2018
    MICHELLE STARR

    For the first time, scientists have studied the magnetic field of a black hole inside the Milky Way in multiple wavelengths – and found that it doesn’t conform to what we previously thought.

    1
    X-ray echoes during V404 Cygni’s feeding event in 2015. (Andrew Beardmore & NASA/Swift)

    NASA Neil Gehrels Swift Observatory

    According to researchers at the University of Florida and the University of Texas at San Antonio, the black hole called V404 Cygni’s magnetic field is much weaker than expected – a discovery that means we may have to rework our current models for black hole jets.

    V404 Cygni, located around 7,800 light-years away in the constellation of Cygnus, is a binary microquasar system consisting of a black hole about 9 times the mass of the Sun, and its companion star, an early red giant slightly smaller than the Sun.

    In 2015, the system flared into life, and, over the course of about a week, periodically flashed with activity as the black hole devoured material from its companion star.

    At times, it was the brightest X-ray object in the sky; but it also showed, according to NASA-Goddard’s Eleonora Troja, “exceptional variation at all wavelengths” – offering a rare opportunity to study both V404 Cygni and black hole feeding activity.

    It was this period that the team, led by Yigit Dallilar at the University of Florida, studied.

    When black holes are active, they become surrounded by a brightly glowing accretion disc, lit by the gravitational and frictional forces that heat the material as it swirls towards the black hole.

    As they consume matter, black holes expel powerful jets of plasma at near light-speed from the coronae – regions of hot, swirling gas above and below the accretion disc.

    Previous research [Astronomy] has shown that these coronae and the jets are controlled by powerful magnetic fields – and the stronger the magnetic fields close to the black hole’s event horizon, the brighter its jets.

    This is because the magnetic fields are thought to act like a synchrotron, accelerating the particles that travel through it.

    Dallilar’s team studied V404 Cygni’s 2015 feeding event across optical, infrared, X-ray and radio wavelengths, and found rapid synchrotron cooling events that allowed them to obtain a precise measurement of the magnetic field.

    Their data revealed a much weaker magnetic field than predicted by current models.

    “These models typically talk about much larger magnetic fields at the base of the jet, which many assume to be equivalent to the corona,” Dallilar told Newsweek.

    “Our results indicate that these models might be oversimplified. Specifically, there may not be a single magnetic field value for each black hole.”

    Black holes themselves don’t have magnetic poles, and therefore don’t generate magnetic fields. This means that the accretion disc corona magnetic fields are somehow generated by the space around a black hole – a process that is not well understood at this point.

    This result doesn’t mean that previous findings showing strong magnetic fields are incorrect, but it does suggest that the dynamics may be a little more complicated than previously thought.

    The team’s research did find that synchrotron processes dominated the cooling events, but could not provide data on what caused the particles to accelerate in the first place. It is, as one has come to expect from black holes, a finding that answers one question and turns up a lot more in need of further research.

    “We need to understand black holes in general,” said researcher Chris Packham of the University of Texas at San Antonio.

    “If we go back to the very earliest point in our universe, just after the big bang, there seems to have always been a strong correlation between black holes and galaxies. It seems that the birth and evolution of black holes and galaxies, our cosmic island, are intimately linked.

    “Our results are surprising and one that we’re still trying to puzzle out.”

    The research has been published in the journal Science.

    See the full article here .

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  • richardmitnick 1:36 pm on January 20, 2018 Permalink | Reply
    Tags: , , Basic Research, Core-collapse Supernova Rate Problem, , ,   

    From Gemini: “Game Over for Supernovae Hide & Seek” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    January 12, 2018

    The Core-collapse Supernova Rate Problem, or the fact that we don’t see as many core-collapse supernovae as we would expect, has a solution, thanks to research using the Gemini South telescope. The research team concludes that the majority of core collapse supernovae, exploding in luminous infrared galaxies, have previously not been found due to dust obscuration and poor spatial resolution.

    1
    SN 2013if with GeMS/GSAOI, from left to right with linear scaling: Reference image (June 2015), discovery image (April 2013) and the image subtraction. SN 2013if had a projected distance from the nucleus as small as 600 light years (200 pc), which makes it the second most nuclear CCSN discovery in a LIRG to date in the optical and near-IR after SN 2010cu.

    Core-collapse supernovae are spectacular explosions that mark the violent deaths of massive stars. An international team of astronomers, led by PhD student Erik Kool of Macquarie University in Australia, used laser guide star imaging on the Gemini South telescope to study why we don’t see as many of these core-collapse supernovae as expected.

    Gemini South Laser Guide Stars

    The study began in 2015 with the Supernova UNmasked By InfraRed detection (SUNBIRD) project which has shown that dust obscuration and limited spatial resolution can explain the small number of detections to date.

    In this, the first results of the SUNBIRD project, the team discovered three core-collapse supernovae, and one possible supernova that could not be confirmed with subsequent imaging. Remarkably, these supernovae were spotted as close as 600 light years from the bright nuclear regions of these galaxies – despite being at least 150 million light years from the Earth. “Because we observed in the near-infrared, the supernovae are less affected by dust extinction compared to optical light,” said Kool.

    According to Kool the results coming from SUNBIRD reveal that their new approach provides a powerful tool for uncovering core-collapse supernova in nuclear regions of galaxies. They also conclude that this methodology is crucial in characterizing these supernova that are invisible through other means. Kool adds, “The supernova rate problem can be resolved using the unique multi-conjugate adaptive optics capability provided by Gemini, which allows us to achieve the highest spatial resolution in order to probe very close to the nuclear regions of galaxies.” This work is published in the Monthly Notices of the Royal Astronomical Society.

    See the full article here .

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    Gemini/North telescope at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

    AURA Icon

    Gemini’s mission is to advance our knowledge of the Universe by providing the international Gemini Community with forefront access to the entire sky.

    The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

    The Gemini Observatory provides the astronomical communities in six partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country’s contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.

     
  • richardmitnick 1:12 pm on January 20, 2018 Permalink | Reply
    Tags: , , , Basic Research, , Galaxies Show Order in Chaotic Young Universe, , ,   

    From Sky & Telescope: “Galaxies Show Order in Chaotic Young Universe” 

    SKY&Telescope bloc

    Sky & Telescope

    January 15, 2018
    Monica Young

    New observations of galaxies in a universe just 800 million years old show that they’ve already settled into rotating disks. They must have evolved quickly to display such surprising maturity.

    1
    Data visualization of the the velocity gradient across the two surprisingly evolved young galaxies.
    Hubble (NASA/ESA), ALMA (ESO/NAOJ/NRAO), P. Oesch (University of Geneva) and R. Smit (University of Cambridge).

    NASA/ESA Hubble Telescope

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

    Our cosmos was a messy youngster. Hotter and denser than the universe we live in now, it was home to turbulent gas flinging about under the influence of gravity. Theorists think the earliest galaxies built up gradually, first clump by clump, then by mergers with other galaxies.

    Astronomers expected that most galaxies living among this early chaos would be turbulent masses themselves. But new observations have revealed two surprisingly mature galaxies when the universe was only 800 million years old. Renske Smit (University of Cambridge, UK) and colleagues report in the January 11th Nature that these two galaxies have already settled into rotating disks, suggesting they evolved rapidly right after they were born.

    Smit and colleagues first found the two galaxies in deep Spitzer Space Telescope images,

    NASA/Spitzer Infrared Telescope

    then followed up using the Atacama Large Millimeter/submillimeter Array (ALMA), a network of radio dishes high in the Atacama Desert in Chile. ALMA’s incredible resolution enabled the astronomers to measure radiation from ionized carbon — an element associated with forming stars — across the face of these diminutive galaxies.

    Consider for a moment: These galaxies are a fifth the size of the Milky Way, and they’re incredibly far away — their light has traveled 13 billion years to Earth. Even in images taken by the eagle-eyed Hubble Space Telescope, such galaxies appear as small red dots.

    3
    Distant Galaxies in the Hubble Ultra Deep Field
    This Hubble Space Telescope image shows 28 of the more than 500 young galaxies that existed when the universe was less than 1 billion years old. The galaxies were uncovered in a study of two of the most distant surveys of the cosmos, the Hubble Ultra Deep Field (HUDF), completed in 2004, and the Great Observatories Origins Deep Survey (GOODS), made in 2003.

    Just a few years ago, astronomers had not spotted any galaxies that existed significantly less than 1 billion years after the Big Bang. The galaxies spied in the HUDF and GOODS surveys are blue galaxies brimming with star birth.

    The large image at left shows the Hubble Ultra Deep Field, taken by the Hubble telescope. The numbers next to the small boxes correspond to close-up views of 28 of the newly found galaxies at right. The galaxies in the postage-stamp size images appear red because of their tremendous distance from Earth. The blue light from their young stars took nearly 13 billion years to arrive at Earth. During the journey, the blue light was shifted to red light due to the expansion of space.

    Yet astronomers are now able to point an array of radio dishes to not only spot the galaxies themselves but also capture features within them down to a couple thousand light-years across.

    They Grow Up So Fast

    The ALMA observations revealed that these two galaxies aren’t the turbulent free-for-all that astronomers expect for most galaxies in this early time period. Their rotating disks aren’t quite like the Milky Way’s, as spiral arms take time to form. Instead, they look more like the fluffy disk galaxies typically seen at so-called cosmic noon, the universe’s adolescent period of star formation and galaxy growth. That implies rapid evolution, as cosmic noon occurred more than 2 billion years after these two galaxies existed.

    Simulations had predicted that it’s possible for some galaxies to evolve more quickly than their peers, notes Nicolas LaPorte (University College London), but it had never been observed before. “This paper represents a great leap forward in the study of the first galaxies,” he says.

    Smit says that these two galaxies seem to stand out from their cohort, which makes sense given their quick growth: Among other things, they’re forming tens of Suns’ worth of stars every year, more than is typical for their time period. Smit is already planning additional observations to see just how different these galaxies are from their peers.

    See the full article here .

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    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 12:41 pm on January 20, 2018 Permalink | Reply
    Tags: , , Basic Research, , , , Meteoritic stardust unlocks timing of supernova dust formation, Type II supernovae   

    From Carnegie Institution for Science: “Meteoritic stardust unlocks timing of supernova dust formation” 

    Carnegie Institution for Science
    Carnegie Institution for Science

    January 18, 2018
    Conel Alexander
    Larry Nittler

    Dust is everywhere—not just in your attic or under your bed, but also in outer space. To astronomers, dust can be a nuisance by blocking the light of distant stars, or it can be a tool to study the history of our universe, galaxy, and Solar System.

    For example, astronomers have been trying to explain why some recently discovered distant, but young, galaxies contain massive amounts of dust. These observations indicate that type II supernovae—explosions of stars more than ten times as massive as the Sun—produce copious amounts of dust, but how and when they do so is not well understood.

    1
    An electron microscope image of a micron-sized supernova silicon carbide, SiC, stardust grain (lower right) extracted from a primitive meteorite. Such grains originated more than 4.6 billion years ago in the ashes of Type II supernovae, typified here by a Hubble Space Telescope image of the Crab Nebula, the remnant of a supernova explosion in 1054. Laboratory analysis of such tiny dust grains provides unique information on these massive stellar explosions. (1 μm is one millionth of a meter.) Image credits: NASA and Larry Nittler.

    New work from a team of Carnegie cosmochemists published by Science Advances reports analyses of carbon-rich dust grains extracted from meteorites that show that these grains formed in the outflows from one or more type II supernovae more than two years after the progenitor stars exploded. This dust was then blown into space to be eventually incorporated into new stellar systems, including in this case, our own.

    The researchers—led by former-postdoctoral fellow Nan Liu, along with Larry Nittler, Conel Alexander, and Jianhua Wang of Carnegie’s Department of Terrestrial Magnetism—came to their conclusion not by studying supernovae with telescopes. Rather, they analyzed microscopic silicon carbide, SiC, dust grains that formed in supernovae more than 4.6 billion years ago and were trapped in meteorites as our Solar System formed from the ashes of the galaxy’s previous generations of stars.

    Some meteorites have been known for decades to contain a record of the original building blocks of the Solar System, including stardust grains that formed in prior generations of stars.

    “Because these presolar grains are literally stardust that can be studied in detail in the laboratory,” explained Nittler, “they are excellent probes of a range of astrophysical processes.”

    For this study, the team set out to investigate the timing of supernova dust formation by measuring isotopes—versions of elements with the same number of protons but different numbers of neutrons—in rare presolar silicon carbide grains with compositions indicating that they formed in type II supernovae.

    Certain isotopes enable scientists to establish a time frame for cosmic events because they are radioactive. In these instances, the number of neutrons present in the isotope make it unstable. To gain stability, it releases energetic particles in a way that alters the number of protons and neutrons, transmuting it into a different element.

    The Carnegie team focused on a rare isotope of titanium, titanium-49, because this isotope is the product of radioactive decay of vanadium-49 which is produced during supernova explosions and transmutes into titanium-49 with a half-life of 330 days. How much titanium-49 gets incorporated into a supernova dust grain thus depends on when the grain forms after the explosion.

    Using a state-of-the-art mass spectrometer to measure the titanium isotopes in supernova SiC grains with much better precision than could be accomplished by previous studies, the team found that the grains must have formed at least two years after their massive parent stars exploded.

    Because presolar supernova graphite grains are isotopically similar in many ways to the SiC grains, the team also argues that the delayed formation timing applies generally to carbon-rich supernova dust, in line with some recent theoretical calculations.

    “This dust-formation process can occur continuously for years, with the dust slowly building up over time, which aligns with astronomer’s observations of varying amounts of dust surrounding the sites of stellar explosions,” added lead author Liu. “As we learn more about the sources for dust, we can gain additional knowledge about the history of the universe and how various stellar objects within it evolve.”

    See the full article here .

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    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
  • richardmitnick 8:57 am on January 20, 2018 Permalink | Reply
    Tags: A Black Hole is Pushing the Stars Around in this Globular Cluster, , , Basic Research, ,   

    From Universe Today: “A Black Hole is Pushing the Stars Around in this Globular Cluster” 

    universe-today

    Universe Today

    19 Jan , 2018
    Matt Williams

    1
    Artist’s impression of the star cluster NGC 3201 orbiting an black hole with about four times the mass of the Sun. Credit: ESO/L. Calçada

    Astronomers have been fascinated with globular clusters ever since they were first observed in 17th century. These spherical collections of stars are among the oldest known stellar systems in the Universe, dating back to the early Universe when galaxies were just beginning to grow and evolve. Such clusters orbit the centers of most galaxies, with over 150 known to belong to the Milky Way alone.

    One of these clusters is known as NGC 3201, a cluster located about 16,300 light years away in the southern constellation of Vela. Using the ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile, a team of astronomers recently studied this cluster and noticed something very interesting. According to the study they released, this cluster appears to have a black hole embedded in it.

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)

    The study appeared in the Monthly Notices of the Royal Astronomical Society under the title A detached stellar-mass black hole candidate in the globular cluster NGC 3201. The study was led by Benjamin Giesers of the Georg-August-University of Göttingen and included members from Liverpool John Moores University, Queen Mary University of London, the Leiden Observatory, the Institute of Astrophysics and Space Sciences, ETH Zurich, and the Leibniz Institute for Astrophysics Potsdam (AIP).

    See the full article here .

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  • richardmitnick 8:43 am on January 20, 2018 Permalink | Reply
    Tags: , , Basic Research, , Researchers Develop a New Low Cost/Low Weight Method of Searching for Life on Mars,   

    From Universe Today: “Researchers Develop a New Low Cost/Low Weight Method of Searching for Life on Mars” 

    universe-today

    Universe Today

    19 Jan , 2018
    Evan Gough

    1
    Study co-author I. Altshuler sampling permafrost terrain near the McGill Arctic research station, Canadian high Arctic. Image: Dr. Jacqueline Goordial

    Researchers at Canada’s McGill University have shown for the first time how existing technology could be used to directly detect life on Mars and other planets. The team conducted tests in Canada’s high arctic, which is a close analog to Martian conditions. They showed how low-weight, low-cost, low-energy instruments could detect and sequence alien micro-organisms. They presented their results in the journal Frontiers in Microbiology.

    Getting samples back to a lab to test is a time consuming process here on Earth. Add in the difficulty of returning samples from Mars, or from Ganymede or other worlds in our Solar System, and the search for life looks like a daunting task. But the search for life elsewhere in our Solar System is a major goal of today’s space science. The team at McGill wanted to show that, conceptually at least, samples could be tested, sequenced, and grown in-situ at Mars or other locations. And it looks like they’ve succeeded.

    See the full article here .

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