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  • richardmitnick 10:19 am on May 27, 2020 Permalink | Reply
    Tags: "New infrared telescope to spot cosmic hidden treasures", , , , , , DREAMS - the Dynamic REd All-Sky Monitoring Survey, DREAMS consists of a fully automated 0.5m telescope and infrared camera., DREAMS will enable multi-messenger astronomy, DREAMS will help detect the source of gravitational waves and the collision of neutron stars and black holes., The DREAMS telescope will be located at the historic Siding Spring Observatory in northern New South Wales.   

    From Australian National University: “New infrared telescope to spot cosmic hidden treasures” 

    ANU Australian National University Bloc

    From Australian National University

    26 May 2020
    James Giggacher
    +61 2 6125 7979
    media@anu.edu.au

    1
    The DREAMS telescope will help find colliding neutron stars. Image: NASA

    A new infrared telescope, to be designed and built by astronomers at The Australian National University (ANU), will monitor the entire southern sky in search of new cosmic events as they take place.

    DREAMS – the Dynamic REd All-Sky Monitoring Survey – will be located at the historic Siding Spring Observatory in northern New South Wales.

    Siding Spring Mountain with Anglo-Australian Telescope dome visible near centre of image at an altitude of 1,165 m (3,822 ft)

    The telescope will be used by researchers all over the globe and propel Australia to the forefront of the emerging field of transient astronomy – the study of cosmic events almost in ‘real time’.

    Lead researcher Professor Anna Moore, Director of the ANU Institute for Space (InSpace), said a transient survey of the southern sky in the infrared had never been done and would help find many hidden treasures in the Universe.

    “DREAMS will allow us to ‘see’ the Universe in an entirely new way,” Professor Moore said.

    “Infrared telescopes can study dusty and distant regions of space that are impenetrable to optical telescopes, unveiling new stars, nebulae, mergers, galaxies, supernovae, quasars and other sources of radiation new to science.

    “By monitoring the sky continuously and rapidly, we will be able to search for varying and explosive phenomena. This ‘real-time’ astronomy, which allows us to study events taking place over months, weeks or days instead of millions of years, is a window into the great unknown.

    “DREAMS will give us a fresh take on many aspects of the Universe.”

    DREAMS consists of a fully automated 0.5m telescope and infrared camera. In each snapshot, DREAMS “sees” 3.75 square degrees (20 times the Moon’s size) and will be able to map the entire southern sky in three clear nights. The telescope is 10 times more powerful than its nearest competitors.

    The data captured by DREAMS will help detect the source of gravitational waves, and the collision of neutron stars and black holes.

    “DREAMS will enable multi-messenger astronomy – the discovery of new events by observing the sky using different wavelengths of light,” lead research partner Assistant Mansi Kasliwal, from the California Institute of Technology (Caltech), said.

    “By doing so it aspires to pinpoint elusive gravitational wave events.

    “Neutron star black hole mergers are especially exciting as they create heavy elements that shine in the infrared.”

    According to Dr Tony Travoillan, a co-investigator and lead technical manager on the project, DREAMS is innovative and economical.

    “Surveying the sky in the infrared has always been limited by the cost of the cameras and not the telescope,” Dr Travouillon, who is based at the ANU Research School of Astrophysics and Astronomy, said.

    “The development of infrared cameras using Indium Gallium Arsenide technology, with the help of our collaborators at MIT, has given astronomers an economical alternative that we are the first to implement on a wide field survey.

    “We are using six of these cameras on our telescope. It gives us a scalable design that minimises instrument complexity and cost.”

    The telescope will be completed in early 2021, with operations beginning soon after. Co-investigator Professor Orsola DeMarco, from Macquarie University, will use simulations to explain coalescing, or merging, stars captured by DREAM.

    “I hope the telescope will see merging stars so dusty that they shine brightly in the infrared,” she said.

    DREAMS is funded through an Australian Research Council Linkage Infrastructure, Equipment and Facilities award of $632,000 and a cash contribution of $750,000 from ANU and partners the Australian Astronomical Optics, Caltech, the Chinese Academy of Sciences, Curtin University, Swinburne University, Macquarie University, Monash University, MIT, the University of New South Wales, the University of Sydney, and the University of Western Australia.

    See the full article here .

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    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.

     
  • richardmitnick 9:40 am on May 27, 2020 Permalink | Reply
    Tags: "The 'Where’s Waldo?' of Astrochemistry", , , , The Missing Molecule-Propadienone (CH2CCO)   

    From astrobites: “The ‘Where’s Waldo?’ of Astrochemistry” 

    26 May 2020

    1
    Searching for molecules in space can sometimes feel like a Where’s Waldo hunt — but finding the missing pieces helps us better understand our universe. [NASA/Jenny Mottar]

    Title: The Case of H2C3O Isomers, Revisited: Solving the Mystery of the Missing Propadienone
    Authors: Christopher N. Shingledecker et al.
    First Author’s Institution: Center for Astrophysics Studies Max Plank Institute for Extraterrestrial Physics & Institute for Theoretical Chemistry at the University of Stuttgart

    MPG Institute for Astrophysics


    Status: Published in ApJ

    Finding and Making Molecules

    Looking for different chemicals in space is a lot like searching for Waldo in the infamous search and find series “Where’s Wally?” Only imagine that the search and find page is light years away from you and all you have is a flashlight.

    3

    As our knowledge and understanding of chemical evolution in space grows, astronomers are seeking the detection of more and more complex organic molecules (COMs). Molecules that could lead to the production of life (like prebiotic molecules that may eventually form DNA) and other larger COMs are rather difficult to detect, so we often use theoretical calculations to predict the evolution and abundance of these larger molecules.

    Chemical models commonly use kinetics, how energy changes over as a reaction progresses, to determine the rate at which chemical reactions occur, and thus the rate at which more complex molecules form and how abundances vary over time. Kinetics tells us that chemical reactions typically have an energy barrier to get from reactants to products. However, space is so cold that there isn’t enough energy available to overcome energy barriers (imagine pushing a 500 pound boulder over the top of Mount Everest). So, we assume that only barrier-less reactions can occur in space. There is a noteworthy exception of ultra hot regions like HII regions, supernovae, and such, where temperatures are high enough to overcome reaction barriers.

    4
    Most chemical reactions must overcome a reaction barrier to get from reactants to products, but most astronomical settings aren’t warm enough to provide the energy necessary to overcome these barriers. [Libretexts]

    One of the most important aspects of theoretical research is matching observational data. If theoretical models using activation barriers and chemical kinetics are not able to match observations, then that usually indicates that there is a physical or chemical process that we don’t know about.

    The Missing Molecule

    In the last decade, one important molecule that has alluded astronomers is CH2CCO, or propadienone. CH2CCO is actually one of three different molecules that can be made from two hydrogen atoms, three carbon atoms, and one oxygen atom (H2C3O). These are known as structural isomers, meaning they’re made up of all the same atoms, but the atoms can be arranged differently to make different molecules.

    5
    The three molecules we can make from H2C3O. Each isomer is made up of the same components, just as the three “Waldo” cartoons above them. However, each H2C3O isomer is put together in a different order, similar to the “Waldo isomers.” Each Waldo is made up of the same colors, but the colors are arranged in different orders.
    [H2C3O isomer structures: Hudson & Gerakines 2019; “Waldo”: Waldo Wiki]

    Propadienone (CH2CCO) is the most stable isomer of H2C3O, meaning CH2CCO has the lowest ground state energy and the H2C3O atoms are “happiest” in the CH2CCO configuration. According the the minimum energy principle, which uses thermodynamics rather than kinetics to predict chemical evolution, CH2CCO should be the most abundant of the three isomers, since it is the most stable of the three. Despite observational efforts and archival data searches, no one has been able to detect CH2CCO in space even though the other two H2C3O isomers have been detected. As the minimum energy principle states that CH2CCO should be detectable as well, this disagreement between observations and theory challenged the minimum energy principle and questioned the validity of relying on kinetics for chemical models.

    Where’s CH2CCO?

    So, where is CH2CCO? As it turns out, we still haven’t detected it in space. However, today’s paper uses theoretical calculations to find “where” CH2CCO is hiding. The authors map reactions associated with the H2C3O isomers using density functional theory (DFT). DFT uses quantum mechanics and kinetics to determine the most stable structures of molecules and their associated energies. CH2CCO can react with two hydrogen atoms to form propenal (CH2CHCHO). The process of adding a single H atom, or a proton, is a common reaction known as hydrogen addition. CH2CCO undergoes two hydrogen additions to form CH2CHCHO, both of which were found to be barrier-less reactions.

    6
    Left: Reaction diagram from today’s paper showing that adding a hydrogen to CH2CCO is a barrier-less reaction, and thus able to occur in space. Right: Hydrogen additions to CH2CCO to form CH2CHCHO. Each reaction adds a single H atom to the carbon chain. Note the black dots are single, unpaired electrons (radicals). [Shingledecker et al. 2019]

    Interestingly enough, hydrogen addition to the second most stable H2C3O isomer, propynal (HCCCHO), is found to have a reaction barrier. Thus propynal is able to persist in molecular clouds, while CH2CCO is converted to CH2CHCHO. These findings are consistent with both previous experimentation and observations of the Sagittarius B2 molecular cloud, where the two less stable H2C3O isomers and CH2CHCHO were detected, but CH2CCO was not.

    Today’s paper shows that the “missing” molecule propadienone (CH2CCO) was never actually missing; it was just masquerading as CH2CHCHO. This discovery is important, since it shows us that kinetic theory and observations of CH2CCO are actually in agreement, rather than disagreement. Additionally, today’s paper confirms the validity of using chemical kinetics and reaction barriers (or lack of barriers) to predict chemical evolution in astronomical settings.

    Sometimes search and finds, like finding molecules in astronomical settings, can be difficult — but ultimately, finding the missing pieces helps us better understand our universe.

    Now that we’ve found CH2CCO, did you find Waldo in the first figure?

    See the full article here .


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    What do we do?

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

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 8:51 am on May 27, 2020 Permalink | Reply
    Tags: "Tiny crown at heart of miniature space thruster", , Indium FEEP Multiemitter (IFM) Nano Thruster   

    From European Space Agency – United Space in Europe: “Tiny crown at heart of miniature space thruster” 

    ESA Space For Europe Banner

    From European Space Agency – United Space in Europe

    5.26.20

    1
    This spiked tungsten crown measuring just 1 cm in diameter – half the size of a ten cent euro coin – is at the heart of Europe’s smallest, most precise thruster.

    The Indium FEEP Multiemitter (IFM) Nano Thruster is able to push back against scanty atmospheric drag or the faint but steady push of sunlight itself if needed, to hold its host satellite steady in space.

    Alternatively, a single thruster or cluster of thrusters can be fitted onto a CubeSat or other small spacecraft, targeting the operating requirements of satellite constellations in particular. The compact thruster might also be used as an efficient means of deorbiting small satellites, fulfilling space debris regulations.

    The IFM Nano Thruster is a miniaturised ion thruster – with an electric field applied to accelerate electrically-charged atoms (known as ions) to produce thrust – that uses liquid indium as its propellant.

    The liquid metal flows by capillary action inside the porous tungsten crown’s 28 needles, resting at tiny holes in their razor-sharp tips. It is held in place there by surface tension, until an electric field is generated. This causes tiny cones to form in the liquid metal, which have positive ions shooting from their tips to create thrust.

    While the thrust of other ion engines is measured in millinewtons, the IFM Nano Thruster’s performance is assessed in terms of micronewtons – a unit one thousand times smaller. Its thrust range goes from 10 to 400 micronewtons, with a possible peak thrust up to 1 000 micronewtons (1 millinewton).

    2
    IFM Nano Thruster

    The result of 15 years of work by ESA with FOTEC in Austria, the IFM Nano Thruster has been flight-proven in space and is now commercially available, marketed by FOTEC’s spin-off company ENPULSION.

    The thruster has no moving parts and its indium propellant is solid at room temperature, requiring heat to begin operating. The long, delicate needles presented a potential weak spot, but a recent ESA Technology Development Element project performed thousands of hours of testing to demonstrate their reliability.

    3
    Thruster cluster

    “The IMF Nano Thruster was initially developed for ESA’s proposed Next Generation Gravity Mission, requiring compensation for air drag at the top of the atmosphere for high-fidelity gravitational measurements,” explains Jose Gonzalez Del Amo, head of ESA’s Electric Propulsion section.

    “It is gratifying to see this product find a commercial niche, especially as it is based on an underlying technology – Field Emission Electric Propulsion, or FEEP for short – that was first invented here at ESTEC, ESA’s technical centre in the Netherlands.”

    The IFM Nano Thrusters have been flown aboard the commercial ICEYE radar satellite constellation, and are under consideration for future ESA missions.

    4
    ICEYE satellite

    See the full article here .


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    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.

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  • richardmitnick 11:35 am on May 26, 2020 Permalink | Reply
    Tags: "The ‘Cow’ Mystery Strikes Back: Two More Rare Explosive Events Captured", , , , , , The ‘Koala’ and a similar mysterious bright object called CSS161010.   

    From Keck Observatory: “The ‘Cow’ Mystery Strikes Back: Two More Rare, Explosive Events Captured” 

    Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, 4,207 m (13,802 ft)

    From Keck Observatory

    May 26, 2020

    Mari-Ela Chock
    Communications Officer
    W. M. Keck Observatory
    (808) 554-0567 mobile
    mchock@keck.hawaii.edu

    Discoveries Reveal New Class of Fast Blue Optical Transient Events.

    1
    An artist’s illustration of a fast blue optical transient, or FBOT. Credit: Bill Saxton,NRAO/AUI/NSF

    The ‘Cow’ is not alone; with the help of W. M. Keck Observatory on Maunakea in Hawaii, astronomers have discovered two more like it – the ‘Koala’ and a similar mysterious bright object called CSS161010. This trio of fast blue optical transients (FBOTs) appear to be relatives, all belonging to a highly-luminous family that has a track record for surprising astronomers with their fast, powerful bursts of energy.

    The ‘Koala,’ which is a nickname derived from the tail end of its official name ZTF18abvkwla, suddenly appeared as a bright new source in the optical sky before disappearing within just a few nights. A team of astronomers at Caltech realized this behavior was similar to the ‘Cow’ and requested radio observations to see if the two were connected.

    “When I reduced the data, I thought I made a mistake,” said Anna Ho, graduate student of astronomy at Caltech and lead author of the study. “The ‘Koala’ resembled the ‘Cow’ but the radio emission was ten times brighter – as bright as a gamma-ray burst!”

    Ho and her research team’s paper is published in today’s issue of The Astrophysical Journal.

    Another cosmic explosion of this type, CSS161010, fascinated a team of astronomers led by Northwestern University. Based on radio observations, they calculated this transient launched material into space faster than 0.55 times the speed of light.

    “This was unexpected,” said Deanne Coppejans, postdoctoral associate at Northwestern University and lead author of the study on CSS161010. “We know of energetic stellar explosions that can eject material at almost the speed of light, specifically gamma-ray bursts, but they only launch a small amount of mass – about 1 millionth the mass of the Sun. CSS161010 launched 1 to 10 percent the mass of the Sun to relativistic speeds – evidence that this is a new class of transient!”

    Coppejans and her team’s paper is published in today’s issue of The Astrophysical Journal Letters.

    These three strange events make up a new subtype of FBOTs, which first dazzled the world in the summer of 2018 when the ‘Cow,’ short for AT2018cow, exploded in the sky.

    Three months later, Ho’s team captured the ‘Koala.’ Though the ‘Cow’ was the first to make world headlines, CSS161010 was actually the first FBOT discovered with luminous radio and X-ray emission, but astronomers did not know how to interpret these findings yet.

    “At that time, there was really no theoretical model that predicted bright radio emission from bright FBOTs,” said Coppejans. “It wasn’t until we conducted follow-up radio and X-ray observations that the true nature of CSS161010 revealed itself. Seeing it at these wavelengths is important because the data showed we were looking at something new and highly energetic.”

    What makes these luminous FBOTs strange is they look like supernova explosions, but flare up and vanish much faster. They’re also extremely hot, making them appear bluer in color than your standard supernovae.

    2
    Artist’s illustration comparing FBOTs to normal supernovae and gamma-ray bursts. Credit: Bill Saxton, NRAO/AUI/NSF

    Also, while these new FBOTs explosions are just as violent as long gamma-ray bursts (GRBs) and can also launch outflows at relativistic velocities, their observational signatures are different in that they are surrounded by a lot of circumstellar matter. And unlike GRBs, the ‘Cow’ and CSS161010 contain hydrogen.

    “We don’t see these two elements in GRB-supernova spectra because we think GRBs come from dying stars that were ‘stripped’ of their hydrogen and helium envelopes prior to collapsing into a new black hole,” said Ho.

    ORIGIN OF LUMINOUS FBOTS

    The two teams used Keck Observatory’s Low Resolution Imaging Spectrometer (LRIS) and DEep Imaging and Multi-Object Spectrograph (DEIMOS) to characterize the host galaxies of the ‘Koala’ and CSS161010; they found both FBOTs come from low-mass dwarf galaxies, just like the ‘Cow.’

    UCO Keck LRIS

    Keck/DEIMOS on Keck 2

    “The host galaxy of CSS161010 is so small that only a 10-meter class telescope like Keck can collect enough light to allow us to physically model the emission,” said co-author Giacomo Terreran, postdoctoral associate at Northwestern University’s CIERA (Center for Interdisciplinary Exploration and Research for Astrophysics). “Remarkably, the Keck data showed the host galaxies of CSS161010, the ‘Koala’, and the ‘Cow,’ while tiny, are actively forming stars, indicating their home base has a very small stellar mass typical of dwarf galaxies.”

    4
    A direct image of CSS161010’s host galaxy taken with W. M. Keck Observatory’s DEIMOS instrument, shown in the bottom square and magnified in the larger top square. Observations show it is a dwarf galaxy located 500,000,000 light years away in the direction of the constellation Eridanus. Image credit: G. Terreran, Northwestern University.

    “This likely indicates the dwarf galaxy properties, such as the metallicity or formation history, might allow some very rare evolutionary paths of stars that lead to the most violent explosions,” said Coppejans.

    While both teams attribute the explosions of massive stars as the most likely cause of these new FBOTs, another possibility still under consideration is they originate from stars being devoured by black holes. If so, this new class of FBOTs could be key in the hunt for medium-sized black holes, which have yet to be detected. In general, the more massive a galaxy is, the heavier its central black hole; following this trend, it is expected that dwarf galaxies are candidates for hosting intermediate mass black holes.

    “One idea is that FBOTs could be the flare of a star being ripped apart by an intermediate mass black hole. If this is the case, then they could potentially be beacons to help find these elusive black holes,” said CSS161010 co-author Rafaella Margutti, assistant professor of physics and astronomy at Northwestern University and faculty member of Northwestern’s CIERA.

    While the origin of this type of FBOT is still hotly debated, the new data provide fresh insight on how they may have formed.

    “The observations prove the most luminous FBOTs have a ‘central engine’ – a source like a neutron star or black hole that powers the transient,” said Margutti. “It’s not yet clear if these bright FBOTs are rare supernovae, stars being shredded by black holes, or other energetic phenomena. Multi-wavelength observations of more FBOTs and their environment will answer this question.”

    METHODOLOGY AND NEXT STEPS

    Due to their extremely rapid rise to maximum light, these rare FBOTs are difficult to detect. But recent developments in high-cadence optical surveys scanning huge swaths of the sky every night make the hunt for rare, short-duration transients more feasible. The key to determining their true nature is to conduct follow-up multi-wavelength observations.

    The ‘Koala’ was first detected using the Zwicky Transient Facility at Palomar Observatory. Ho’s team then used the Hale Telescope to obtain spectra, followed by the Very Large Array (VLA) and the Giant Metrewave Radio Telescope (GMRT) to conduct radio observations.

    Zwicky Transient Facility (ZTF) instrument installed on the 1.2m diameter Samuel Oschin Telescope at Palomar Observatory in California. Courtesy Caltech Optical Observatories

    Caltech Palomar 200 inch Hale Telescope, Altitude 1,713 m (5,620 ft), located in San Diego County, California, United States

    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)

    Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India

    CSS161010 was first captured by the Catalina Real-time Transient Survey and independently discovered by the All-Sky Automated Survey for Supernovae. Coppejans and her team then conducted follow-up radio observations with the VLA and GMRT, and X-ray observations with NASA’s Chandra X-ray Observatory.

    NASA/Chandra X-ray Telescope

    4
    Artist’s illustration detailing the structure of FBOTs. Image credit: Bill Saxton, NRAO/AUI/NSF

    The radio emission is produced by the shock wave of the material slamming into the surrounding medium at more than 0.55 times the speed of light, but the X-ray emission cannot be explained this way. The team speculates they might be directly seeing the central engine in X-rays, like in the ‘Cow.’

    “One lesson learned is while FBOTs have proven rarer and harder to find than some of us were hoping, in the radio band they’re also much more luminous than we’d guessed, allowing us to provide quite comprehensive data even on events that are far away,” said Daniel Perley, senior lecturer at Liverpool John Moores University’s Astrophysics Research Institute and co-author of the ‘Koala’ study.

    “These observations of the ‘Koala’ and CSS161010 show how much we can learn from radio and X-ray observations of FBOTs,” said Ho. “The challenge going forward is to delineate different FBOT subtypes and to develop more precise vocabulary. It’s exciting to help investigate a new and unexpected phenomenon. In science, you sometimes don’t find what you were expecting to find, but along the way you uncover new directions.”

    The CSS161010 study was supported by grants from the Heising-Simons Foundation, NASA, and the National Science Foundation.

    See the full article here .


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    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.


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  • richardmitnick 11:06 am on May 26, 2020 Permalink | Reply
    Tags: , , , , ,   

    From Carnegie Institution for Science: “‘Elegant’ solution reveals how the universe got its structure” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    April 27, 2020

    The universe is full of billions of galaxies—but their distribution across space is far from uniform. Why do we see so much structure in the universe today and how did it all form and grow?

    A 10-year survey of tens of thousands of galaxies made using the Magellan Baade Telescope at Carnegie’s Las Campanas Observatory in Chile [below] provided a new approach to answering this fundamental mystery. The results, led by Carnegie’s Daniel Kelson, are published in Monthly Notices of the Royal Astronomical Society.

    1
    Why is the distribution of structure in the cosmos not uniform? The universe’s first structure originated when some of the material flung outward by the Big Bang overcame its trajectory and collapsed on itself, forming clumps. A team of Carnegie researchers showed that denser clumps of matter grew faster, and less-dense clumps grew more slowly. The group’s data revealed the distribution of density in the universe over the last 9 billion years. (On the illustration, violet represents low-density regions and red represents high-density regions.) Working backward in time, their findings reveal the density fluctuations (far right, in purple and blue) that created the universe’s earliest structure. This aligns with what we know about the ancient universe from the afterglow of the Big Bang, called the Cosmic Microwave Background (far right in yellow and green). The researchers achieved their results by surveying the distances and masses of nearly 100,000 galaxies, going back to a time when the universe was only 4.5 billion years old. About 35,000 of the galaxies studied by the Carnegie-Spitzer-IMACS Redshift Survey are represented here as small spheres. The illustration is courtesy of Daniel Kelson. CMB data is based on observations obtained with Planck, an ESA science mission with instruments and contributions directly funded by ESA Member States, NASA, and Canada.

    “How do you describe the indescribable?” asks Kelson. “By taking an entirely new approach to the problem.”

    “Our tactic provides new—and intuitive—insights into how gravity drove the growth of structure from the universe’s earliest times,” said co-author Andrew Benson. “This is a direct, observation-based test of one of the pillars of cosmology.”

    The Carnegie-Spitzer-IMACS Redshift Survey was designed to study the relationship between galaxy growth and the surrounding environment over the last 9 billion years, when modern galaxies’ appearances were defined.

    The first galaxies were formed a few hundred million years after the Big Bang, which started the universe as a hot, murky soup of extremely energetic particles. As this material expanded outward from the initial explosion, it cooled, and the particles coalesced into neutral hydrogen gas. Some patches were denser than others and, eventually, their gravity overcame the universe’s outward trajectory and the material collapsed inward, forming the first clumps of structure in the cosmos.

    The density differences that allowed for structures both large and small to form in some places and not in others have been a longstanding topic of fascination. But until now, astronomers’ abilities to model how structure grew in the universe over the last 13 billion years faced mathematical limitations.

    “The gravitational interactions occurring between all the particles in the universe are too complex to explain with simple mathematics,” Benson said.

    So, astronomers either used mathematical approximations—which compromised the accuracy of their models—or large computer simulations that numerically model all the interactions between galaxies, but not all the interactions occurring between all of the particles, which was considered too complicated.

    “A key goal of our survey was to count up the mass present in stars found in an enormous selection of distant galaxies and then use this information to formulate a new approach to understanding how structure formed in the universe,” Kelson explained.

    The research team—which also included Carnegie’s Louis Abramson, Shannon Patel, Stephen Shectman, Alan Dressler, Patrick McCarthy, and John S. Mulchaey, as well as Rik Williams , now of Uber Technologies—demonstrated for the first time that the growth of individual proto-structures can be calculated and then averaged over all of space.

    Doing this revealed that denser clumps grew faster, and less-dense clumps grew more slowly.

    They were then able to work backward and determine the original distributions and growth rates of the fluctuations in density, which would eventually become the large-scale structures that determined the distributions of galaxies we see today.

    In essence, their work provided a simple, yet accurate, description of why and how density fluctuations grow the way they do in the real universe, as well as in the computational-based work that underpins our understanding of the universe’s infancy.

    “And it’s just so simple, with a real elegance to it,” added Kelson.

    The findings would not have been possible without the allocation of an extraordinary number of observing nights at Las Campanas.

    “Many institutions wouldn’t have had the capacity to take on a project of this scope on their own,” said Observatories Director John Mulchaey. “But thanks to our Magellan Telescopes, we were able to execute this survey and create this novel approach to answering a classic question.”

    “While there’s no doubt that this project required the resources of an institution like Carnegie, our work also could not have happened without the tremendous number of additional infrared images that we were able to obtain at Kitt Peak and Cerro Tololo, which are both part of the NSF’s National Optical-Infrared Astronomy Research Laboratory,” Kelson added.

    Kitt Peak National Observatory of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft)

    CTIO Cerro Tololo Inter-American Observatory, CTIO Cerro Tololo Inter-American Observatory,approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters

    See the full article here .


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    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    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.

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high


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


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

     
  • richardmitnick 10:06 am on May 26, 2020 Permalink | Reply
    Tags: "A star shredded by a black hole may have spit out an extremely energetic neutrino", , , , ,   

    From Science News: “A star shredded by a black hole may have spit out an extremely energetic neutrino” 

    From Science News

    If true, this would be only the second time such a neutrino has been traced back to its source.

    1
    A high-energy neutrino may have been born when a star was ripped apart by a black hole (illustrated), scientists report. Gas (red) stripped from the star spirals toward the black hole. Some stellar material is swallowed up while some is flung outward (blue). Credit: M.Weiss/CXC/NASA

    5.26.20
    Emily Conover

    A neutrino that plowed into the Antarctic ice offers up a cautionary message: Don’t stray too close to the edge of an abyss.

    The subatomic particle may have been blasted outward when a star was ripped to pieces during a close encounter with a black hole, physicists report May 11 at arXiv.org. If it holds up, the result would be the first direct evidence that such star-shredding events can accelerate subatomic particles to extreme energies. And it would mark only the second time that a high-energy neutrino has been traced back to its cosmic origins.

    With no electric charge and very little mass, neutrinos are known to blast across the cosmos at high energies. But scientists have yet to fully track down how the particles get so juiced up.

    One potential source of energetic neutrinos is what’s called a tidal disruption event. When a star gets too close to a supermassive black hole, gravitational forces pull the star apart (SN: 10/11/19). Some of the star’s guts spiral toward the black hole, forming a hot pancake of gas called an accretion disk before the black hole gobbles the gas up. Other bits of the doomed star are spewed outward. Scientists had predicted that such violent events might beget energetic neutrinos like the one detected.

    Spotted on October 1, 2019, the little neutrino packed a punch: an energy of 200 trillion electron volts. That’s about 30 times the energy of the protons in the most powerful human-made particle accelerator, the Large Hadron Collider. The neutrino’s signature was picked up by IceCube, a detector frozen deep in the Antarctic ice. That detector senses light produced when neutrinos interact with the ice.

    When IceCube finds a high-energy neutrino, astronomers scour the sky for anything unusual in the direction from which the particle came, such as a short-lived flash of light, or transient, in the sky. This time, astronomers with the Zwicky Transient Facility came up with a possible match: a tidal disruption event called AT2019dsg.

    First observed in April 2019, that event had been spied emitting light of various wavelengths: visible, ultraviolet, radio and X-rays. And the maelstrom was still raging when IceCube detected the neutrino, according to a team of physicists including Marek Kowalski of the Deutsches Elektronen-Synchrotron, or DESY, in Zeuthen, Germany.

    While intriguing, the association between the neutrino and the shredded star is not certain, says IceCube physicist Francis Halzen of the University of Wisconsin–Madison, who was not involved with the new study. “I don’t know if I have to bet my wallet, but I probably would,” Halzen says. “But it doesn’t have much money in it.”

    The probability that a neutrino and a similar tidal disruption event would overlap by chance is only 0.2 percent, the researchers report. But that doesn’t meet physicists’ stringent burden of proof. “Just one event is difficult to convince [us] this source is really a neutrino emitter,” says astrophysicist Kohta Murase of Penn State University. “I am waiting for more data.”

    Kowalski declined to comment for this article, as the paper has not yet been accepted for publication in a scientific journal.

    To have birthed such an energetic neutrino, the star-shredding event must have first accelerated protons to high energies. Those protons must then have crashed into other protons or photons (particles of light). That process produces other particles, called pions, that emit neutrinos as they decay.

    Now, scientists are aiming to pin down exactly how that acceleration happened. The protons might have been launched within a wind of debris that flowed outward in all directions. Or they could have been accelerated in a powerful, geyserlike jet of matter and radiation.

    AT2019dsg shows some unusual features that any explanation should be able to account for. X-rays produced in the event, for example, appeared to drop off rapidly. So physicists WalterWinter of DESY and Cecilia Lunardini of Arizona State University in Tempe suggest May 13 at arXiv.org that the event did produce a jet, but that a cocoon of material gradually shrouded the region, hiding the X-rays from view while still allowing the neutrino to escape. Lunardini declined to comment because the paper is not yet published in a journal.

    But Murase argues that for the jet to be hidden, that means it can’t be that powerful of an outflow, making it hard to explain the energetic neutrino this way. “If it injects a lot of energy, this energy gets out,” he says. In a third study posted May 18 at arXiv.org, Murase and colleagues favor the idea that the protons get accelerated in an outward flowing wind or in a corona, a superhot region near the black hole’s accretion disk.

    Determining where these particles come from can help scientists better understand some of the most extreme environments in the cosmos. Previously, astronomers had matched up a different energetic neutrino with a blazar experiencing a flare-up (SN:7/12/18). A blazar is a bright source of light powered by a supermassive black hole at the center of a galaxy. Both a blazar flare and a tidal disruption event “are very special activities, which is when a lot of energy is released in a small amount of time,” says astrophysicist Ke Fang of Stanford University, who was not involved with the study.

    Making more observations of high-energy neutrinos is crucial, Fang says. “This is the only way we can clearly understand how the universe is operating at this extreme energy.”

    See the full article here .


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  • richardmitnick 9:18 am on May 26, 2020 Permalink | Reply
    Tags: , , , black holes feast", , ,   

    From Yale University: “Under pressure, black holes feast” 

    From Yale University

    May 22, 2020
    Jim Shelton

    1
    Side-by-side images of “jellyfish” galaxies. On the left is galaxy ESO 137-001 from a combination of images from NASA Hubble Space Telescope and Chandra X-ray Observatory. On the right is a galaxy falling into the RomulusC galaxy cluster simulation.

    A new, Yale-led study shows that some supermassive black holes actually thrive under pressure.

    It has been known for some time that when distant galaxies — and the supermassive black holes within their cores — aggregate into clusters, these clusters create a volatile, highly pressurized environment. Individual galaxies falling into clusters are often deformed during the process and begin to resemble cosmic jellyfish.

    Curiously, the intense pressure squelches the creation of new stars in these galaxies and eventually shuts off normal black hole feeding on nearby interstellar gas. But not before allowing the black holes one final feast of gas clouds and the occasional star.

    The researchers also suggested this rapid feeding might be responsible for the eventual lack of new stars in those environments. The research team said “outflows” of gas, driven by the black holes, might be shutting off star formation.

    “We know that the feeding habits of central supermassive black holes and the formation of stars in the host galaxy are intricately related. Understanding precisely how they operate in different larger-scale environments has been a challenge. Our study has revealed this complex interplay,” said astrophysicist Priyamvada Natarajan, whose team initiated the research. Natarajan is a professor of astronomy and physics in Yale’s Faculty of Arts and Sciences.

    The study is published in The Astrophysical Journal Letters. The first author is Angelo Ricarte, a former member of Natarajan’s lab now at Harvard, who started this work as a Yale doctoral student. Co-authors are Yale Center for Astronomy and Astrophysics Prize postdoctoral associate Michael Tremmel and Thomas Quinn of the University of Washington.

    The new study adds to a significant body of work from Natarajan’s research group regarding how supermassive black holes form, grow, and interact with their host galaxies in various cosmic environments.

    The researchers conducted sophisticated simulations of black holes within galaxy clusters using RomulusC, a cosmological simulation that Tremmel, Quinn and others developed.

    Ricarte developed new tools for extracting information from RomulusC. While analyzing black hole activity in the cluster simulation, he said, he noticed “something weird happening once their host galaxies stopped forming stars. Surprisingly, I often spotted a peak in black hole activity at the same time that the galaxy died.”

    That “peak” would be the black hole’s big, final feast, under pressure.

    Tremmel said that “RomulusC is unique because of its exquisite resolution and the detailed way in which it treats supermassive black holes and their environments, allowing us to track their growth.”

    Support for the research came from a number of sources, including NASA and the National Science Foundation. The research is part of the Blue Waters computing project supported by the National Science Foundation and the University of Illinois at Urbana-Champaign.


    Black Holes Under Pressure

    See the full article here .

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    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 8:53 am on May 26, 2020 Permalink | Reply
    Tags: , , , ,   

    From Sanford Underground Research Facility: ‘Why DUNE? [Part III] Shedding light on the unification of nature’s forces” 

    SURF logo

    From Sanford Underground Research Facility


    Homestake Mining Company

    May 22, 2020
    Erin Broberg

    Part III in our series exploring the science goals of the international Deep Underground Neutrino Experiment [image below].

    1
    The Deep Underground Neutrino Experiment (DUNE) could help us learn more about physics beyond the Standard Model. Courtesy Fermilab

    Master theoretical physicists laid the foundations of the Standard Model throughout the second half of the twentieth century. With outstanding success, it explained how particles like protons, neutrons and electrons interact on a subatomic level. It also made Nobel Prize-winning predictions about new particles, such as the Higgs Boson, that were later observed in experiments. For decades, the Standard Model has been the scaffolding on which physicists drape quantum concepts from magnetism to nuclear fusion.

    Despite its remarkable dexterity and longevity, however, some physicists have described the Standard Model as “incomplete,” “ugly” and, in some instances, even “grotesque.”

    “The Standard Model is an effective theory, but we are not satisfied,” said Chang Kee Jung, a professor of physics at Stony Brook University. “Physicists, in some sense, are perfectionists. We always want to know exactly why things work a certain way.” While the Standard Model is incredibly useful, it is far from perfect.

    2
    A portion of the Lagrangian standard model transcribed by T.D. Gutierrez. Courtesy Symmetry Magazine.

    Standard Model of Particle Physics, Quantum Diaries

    In a bewildering example, the Standard Model predicted that neutrinos, the universe’s most abundant particle, would be massless. In 1998, the Super-Kamiokande experiment in Japan caught the Standard Model in a lie.

    Super-Kamiokande experiment. located under Mount Ikeno near the city of Hida, Gifu Prefecture, Japan

    Neutrinos do indeed have mass, albeit very little. Further complicating matters, the Standard Model doesn’t explain dark matter or dark energy; combined, these account for 95 percent of the universe. In other cases, the Standard Model requires physicists to begrudgingly plug in arbitrary parameters to reflect experimental data.

    Unwilling to ignore these flaws, physicists are looking for a new, more perfect model of the subatomic universe. And many are hoping that the Deep Underground Neutrino Experiment, hosted by the Department of Energy’s Fermi National Accelerator Laboratory, can put their theories to the test.

    Grander theories of the quantum world

    Leading alternatives to the Standard Model attempt to unify the three quantum forces: strong, weak and electromagnetic. Physicists have demonstrated that, at extremely high energies, the weak and electromagnetic force become indistinguishable. Many believe that the strong force can be unified in the same way.

    “Grand unification is the beautiful idea that there was a single force at the beginning of the universe, and what we see now is three manifestations of that original force,” said Jonathan Lee Feng, particle and cosmology theorist at the University of California, Irvine. This class of “Grand Unified Theories” is charmingly abbreviated as “GUTs.”

    In their search for a GUT, theorists have been a bit too successful. They haven’t created just one alternative to the Standard Model—they’ve created hundreds. These models unify quantum forces, explain the mass of a neutrino and eliminate many arbitrary parameters. Some are practical and bare-boned, others far-fetched and elaborate, but nearly all are mathematically solid.

    Even so, they can’t all be “right.”

    “You can write a logically and mathematically consistent theory, but that doesn’t mean it matches the real mechanisms of the universe,” Jung said. “Nature chooses its own way.”

    Testing physics beyond the Standard Model

    GUTs are a major branch of theory. But others also attempt to reshape our understanding of the universe. Surrounded by more models than could possibly be correct, theorists around the world are asking the universe for a nudge in the right direction.

    Just as the Standard Model predicted novel particles in the twentieth century that were later discovered through experimentation, new theories also predict never-before-seen phenomena. Some models predict the decay of a particle once thought immortal. Others hint at a fourth generation of neutrino. Still others foretell of particles that communicate between our realm and the realm of dark matter.

    “We can continue to speculate and refine these models, but if we actually witnessed one of these predictions, we’d have much more precise hints about where to go,” Feng said.

    Enter DUNE. The main goal of the international Deep Underground Neutrino Experiment is to keep a watchful eye on a beam of neutrinos traveling from Fermilab to detectors deep under the earth at Sanford Underground Research Facility. However, the experiment is also designed to be sensitive to a slew of interactions predicted by avant-garde theories. The observation of even one of these predictions would rule out dozens of theories and guide the next generation of quantum theory.

    Tuned to witness quantum strangeness

    Proton decay

    The Standard Model dictates that protons—basic building blocks of matter best known for how they clump with neutrons in the center of an atom—are stable particles, destined to live forever.

    However, many Grand Unified Theories have predicted that, eventually, protons will decay. While different models disagree on the specific mechanisms that cause this decay, the general consensus is that proton decay is a good place to start investigating physics beyond the Standard Model.

    To validate these theories, physicists just have to glimpse the death of a proton.

    In the early 1950s, Maurice Goldhaber, an esteemed physicist who later directed Brookhaven National Laboratory, postulated that protons live at least 10^16 years. If their lifespan were any shorter, the radiation from frequent decays would destroy the human body. Thus, Goldhaber said, you could “feel it in your bones” that the proton was long-lived. Over time, experiments determined that protons lifetime was even longer—at least 10^34 years.

    According to current estimates, you would have to watch one proton for a minimum of 100,000,000,000,000,000,000,000,000,000,000,000 years—without blinking—in order to see it decay. Sensible physicists aren’t quite that patient.

    By watching a multitude of protons at once, researchers can greatly increase their chances of seeing a decay within their own lifetime (and still be alive to receive the Nobel Prize for their discovery). DUNE detectors will monitor 40,000 tons of liquid argon.

    FNAL DUNE Argon tank at SURF

    Each atom of argon contains 18 protons. If one out of this incredible number of protons decays during DUNE’s lifetime, it will show up in DUNE’s data.

    “If a proton decay is discovered, it is a revolutionary discovery—a once-in-a-generation discovery,” said Jung, who has played various leadership roles in DUNE.

    An invisible neutrino

    Neutrinos are subatomic particles; waiflike, abundant and neutral, they hardly interact with normal matter at all. DUNE is designed to monitor how neutrinos oscillate, or change between three different types of neutrino, as they stream through the Earth. But DUNE could also see something extra hidden in its data.

    “In the Standard Model, there are three types of neutrino: the electron neutrino, the muon neutrino and the tau neutrino. But why is there not a fourth generation? Why not five? What stops it at three? That is not known,” Jung said.

    There are subatomic hints of another type of neutrino, called a sterile neutrino, that interacts even less than the other known types. If it exists, the only way it could be measured is the way in which it joins the oscillation pattern of neutrinos, disrupting the pattern physicists expect to see.

    4
    There are subatomic hints of another type of neutrino, called a sterile neutrino, that interacts even less than the other known types. Courtesy Fermilab.

    “If what we see doesn’t match our three-flavor oscillation pattern, it will tell us a lot about what is incomplete about our understanding of the universe,” said Elizabeth Worcester, DUNE physics co-coordinator and physicist at Brookhaven National Laboratory. “It could point to the existence of sterile neutrinos, a new interaction or even some other crazy thing we haven’t thought of yet. It would take some untangling to understand what the data is really telling us.”

    Investigating dark matter

    Dark matter is a mysterious, invisible source of matter responsible for holding vast galaxies together. Although not directly tied to theories of unification, the long-standing mystery of dark matter transcends the Standard Model. And depending on its true characteristics, DUNE could be the first to detect it.

    “Dark matter is an enormous question in our field,” said Feng, who has worked on a specific dark matter theory, called WIMP theory, for 22 years. “There is a lot of interesting creative work being done in theory, but hints from experiments like DUNE would be really helpful.”

    According to WIMP theory, dark matter is composed of weakly interacting, massive particles (WIMPs). If these particles exist, some of them are expected to pass through the Sun. There, they would interact with other particles, losing energy and sinking into the Sun’s core. Over time, enough WIMPs would gravitate toward the Sun’s core that they would annihilate with each other and release high-energy neutrinos in all directions. As you might guess, DUNE would be ready to detect these neutrinos. Researchers could reconstruct their trajectory, tracing them back to the Sun and, indirectly, to the WIMPs that produced them.
    ________________________________________________
    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


    ________________________________________________

    While Feng hasn’t given up on WIMPs, he has recently started working on another dark matter theory that involves light dark matter particles. This theory predicts that, in addition to looking for dark matter directly, we could also learn more about dark matter through so-called “mediator particles.”

    “If you imagine we could talk to dark matter on the phone, mediator particles would be the wire that connects us to it,” Feng said. If this theory is accurate, mediator particles could potentially be created as by-products in Fermilab’s particle accelerator and show themselves in one of DUNE’s detectors.

    Whatever its true characteristics, dark matter might reveal itself in DUNE, offering clues to yet another universe-sized mystery.

    Looking where the light is

    “There are other interactions beyond the Standard Model that DUNE could be sensitive to,” Worcester said. “Spontaneous neutron-antineutron oscillation, nonstandard interactions, exotic things like Lorentz violation, which would mean that almost all theory is broken.” The list goes on. “If it feels like a grab bag, that’s because it is.”

    Worcester likens DUNE’s multifaceted approach to the streetlamp effect. If you drop your keys on a dark street, you look under the streetlamp to find them. They may not be within the beam of light created by the streetlamp, but you have no hope of finding the keys in the darkness. So, you look where the light is.

    When researchers are attempting to look beyond what is known, advanced experiments like DUNE become their streetlamps, casting puddles of light onto unfamiliar physics.

    “It could be that some answers are still in the dark, but if we keep creating sophisticated experiments, we’ll find them,” Worcester said.

    So, why DUNE? Amidst its search for the origin of matter and supernovas on the galactic horizon, DUNE will also shine a bright light on physics beyond the Standard Model.

    See the full article here .


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    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.

    LBNL LZ project at SURF, Lead, SD, USA, will replace LUX at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

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


    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 8:23 am on May 26, 2020 Permalink | Reply
    Tags: "Cosmic rays may have left indelible imprint on early life Stanford physicist says", , , ,   

    From Stanford University: “Cosmic rays may have left indelible imprint on early life, Stanford physicist says” 

    Stanford University Name
    From Stanford University

    May 20, 2020
    Taylor Kubota
    Stanford News Service
    (650) 724-7707
    tkubota@stanford.edu

    Physicists propose that the influence of cosmic rays on early life may explain nature’s preference for a uniform “handedness” among biology’s critical molecules.

    Before there were animals, bacteria or even DNA on Earth, self-replicating molecules were slowly evolving their way from simple matter to life beneath a constant shower of energetic particles from space.

    Cosmic rays produced by high-energy astrophysics sources (ASPERA collaboration – AStroParticle ERAnet)

    1
    Magnetically polarized radiation preferentially ionized one type of “handedness” leading to a slightly different mutation rate between the two mirror proto-lifeforms. Over time, right-handed molecules out-evolved their left-handed counterparts. (Image credit: Simons Foundation)

    In a new paper, [Astrophysical Journal Letters], a Stanford professor and a former postdoctoral scholar speculate that this interaction between ancient proto-organisms and cosmic rays may be responsible for a crucial structural preference, called chirality, in biological molecules. If their idea is correct, it suggests that all life throughout the universe could share the same chiral preference.

    Chirality, also known as handedness, is the existence of mirror-image versions of molecules. Like the left and right hand, two chiral forms of a single molecule reflect each other in shape but don’t line up if stacked. In every major biomolecule – amino acids, DNA, RNA – life only uses one form of molecular handedness. If the mirror version of a molecule is substituted for the regular version within a biological system, the system will often malfunction or stop functioning entirely. In the case of DNA, a single wrong handed sugar would disrupt the stable helical structure of the molecule.

    Louis Pasteur first discovered this biological homochirality in 1848. Since then, scientists have debated whether the handedness of life was driven by random chance or some unknown deterministic influence. Pasteur hypothesized that, if life is asymmetric, then it may be due to an asymmetry in the fundamental interactions of physics that exist throughout the cosmos.

    “We propose that the biological handedness we witness now on Earth is due to evolution amidst magnetically polarized radiation, where a tiny difference in the mutation rate may have promoted the evolution of DNA-based life, rather than its mirror image,” said Noémie Globus, lead author of the paper and a former Koret Fellow at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC).

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Stanford University campus. No image credit

    Stanford University

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

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  • richardmitnick 7:49 am on May 26, 2020 Permalink | Reply
    Tags: "Sandia to receive Fujitsu ‘green’ processor", , Fujitsu PRIMEHPC FX700, ,   

    From Sandia Lab: “Sandia to receive Fujitsu ‘green’ processor” 

    From Sandia Lab

    5.26.20
    Neal Singer
    nsinger@sandia.gov
    505-845-7078

    New system to help break down memory-speed bottleneck.

    This spring, Sandia National Laboratories anticipates being one of the first Department of Energy laboratories to receive the newest A64FX Fujitsu processor, a Japanese Arm-based processor optimized for high-performance computing.

    1
    Fujitsu PRIMEHPC FX700

    Arm-based processors are used widely in small electronic devices like cell phones. More recently, Arm-based processors were installed in Sandia’s Astra supercomputer, where they are the frontline in a DOE effort to keep competitive the market of supercomputer chip providers.

    HPE Vanguard Astra supercomputer with ARM technology at Sandia Labs

    “Being early adopters of this technology benefits all parties involved,” said Scott Collis, director of Sandia’s Center for Computing Research.

    Penguin Computer Inc. will deliver the new system — the first Fujitsu PRIMEHPC FX700 with A64FX processors.

    “This Fujitsu-Penguin computer offers the potential to improve algorithms that may not perform well on GPU (graphics processing unit) accelerators,” Collis said. “In these cases, code performance is often limited by memory speed, not the speed of computation. This system is the first that closely couples efficient and powerful Arm processors to really fast memory to help breakdown this memory-speed bottleneck.”

    Said Ken Gudenrath, Penguin’s director of interactions with DOE, “Our goal is to provide early access to upcoming technologies.”

    Sandia will evaluate Fujitsu’s new processor and compiler using DOE mini- and proxy-applications and share the results with Fujitsu and Penguin. Mini- and proxy-apps are small, manageable versions of applications used for initial testing and collaborations. They are also open source, which means they can be freely modified to fit particular problems.

    Said James Laros, program lead of Sandia’s advanced-architectures technology-prototype program called Vanguard, tasked to explore emerging techniques in supercomputing, “This acquisition furthers the lab’s research and development in Arm-based computing technologies and builds upon the highly successful Astra platform, the world’s first petascale Arm-based supercomputer.”

    Processor maximizes green computational power.

    The 48-core A64FX processor was designed for Japan’s soon-to-be-deployed Fugaku supercomputer, which incorporates high-bandwidth memory. It also is the first to fully utilize wide vector lanes that were designed around Arm’s Scalable Vector Extensions. These wide vector lanes make possible a type of data level parallelism where a single instruction operates on multiple data elements arranged in parallel.

    “The new processor’s efficiency and increased performance per watt provides researchers with significantly greater fractions of usable peak performance,” said Sandia manager Robert Hoekstra. “The Japanese supercomputing team at the RIKEN Center for Computational Science has partnered with Fujitsu and focused on increasing vectorization and memory bandwidth to maximize the computational power of the system. The result is that an early A64FX-based system sits atop the Green500 list of most efficient supercomputers.”

    In addition to expanding Sandia’s efforts to develop new suppliers by advancing Arm-based technologies for high-performance computing, this acquisition also supports DOE’s collaboration with the Japanese supercomputing community. Cooperation with the RIKEN center is part of a memorandum of understanding signed in 2014 between DOE and the Japanese Ministry of Education, Culture, Sports, Science and Technology. Both organizations have agreed to work together to improve high performance computing, including collaborative development of computing architectures.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sandia National Laboratory

    Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.



     
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