Tagged: Dark Energy Spectroscopic Instrument (DESI) Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:25 pm on July 18, 2021 Permalink | Reply
    Tags: "Curiosity and technology drive quest to reveal fundamental secrets of the universe", A very specific particle called a J/psi might provide a clearer picture of what’s going on inside a proton’s gluonic field., , Argonne-driven technology is part of a broad initiative to answer fundamental questions about the birth of matter in the universe and the building blocks that hold it all together., , , , , , Computational Science, , , Dark Energy Spectroscopic Instrument (DESI), , , Developing and fabricating detectors that search for signatures from the early universe or enhance our understanding of the most fundamental of particles., , Electron-Ion Collider (EIC) at DOE's Brookhaven National Laboratory (US) to be built inside the tunnel that currently houses the Relativistic Heavy Ion Collider [RHIC]., Exploring the hearts of protons and neutrons, , , Neutrinoless double beta decay can only happen if the neutrino is its own anti-particle., , , , , , , SLAC National Accelerator Laboratory(US), , ,   

    From DOE’s Argonne National Laboratory (US) : “Curiosity and technology drive quest to reveal fundamental secrets of the universe” 

    Argonne Lab

    From DOE’s Argonne National Laboratory (US)

    July 15, 2021
    John Spizzirri

    Argonne-driven technology is part of a broad initiative to answer fundamental questions about the birth of matter in the universe and the building blocks that hold it all together.

    Imagine the first of our species to lie beneath the glow of an evening sky. An enormous sense of awe, perhaps a little fear, fills them as they wonder at those seemingly infinite points of light and what they might mean. As humans, we evolved the capacity to ask big insightful questions about the world around us and worlds beyond us. We dare, even, to question our own origins.

    “The place of humans in the universe is important to understand,” said physicist and computational scientist Salman Habib. ​“Once you realize that there are billions of galaxies we can detect, each with many billions of stars, you understand the insignificance of being human in some sense. But at the same time, you appreciate being human a lot more.”

    The South Pole Telescope is part of a collaboration between Argonne and a number of national labs and universities to measure the CMB, considered the oldest light in the universe.

    The high altitude and extremely dry conditions of the South Pole keep water vapor from absorbing select light wavelengths.

    With no less a sense of wonder than most of us, Habib and colleagues at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are actively researching these questions through an initiative that investigates the fundamental components of both particle physics and astrophysics.

    The breadth of Argonne’s research in these areas is mind-boggling. It takes us back to the very edge of time itself, to some infinitesimally small portion of a second after the Big Bang when random fluctuations in temperature and density arose, eventually forming the breeding grounds of galaxies and planets.

    It explores the heart of protons and neutrons to understand the most fundamental constructs of the visible universe, particles and energy once free in the early post-Big Bang universe, but later confined forever within a basic atomic structure as that universe began to cool.

    And it addresses slightly newer, more controversial questions about the nature of Dark Matter and Dark Energy, both of which play a dominant role in the makeup and dynamics of the universe but are little understood.
    _____________________________________________________________________________________
    Dark Energy Survey

    Dark Energy Camera [DECam] built at DOE’s Fermi National Accelerator Laboratory(US)

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

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

    Timeline of the Inflationary Universe WMAP

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

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

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

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.
    _____________________________________________________________________________________

    “And this world-class research we’re doing could not happen without advances in technology,” said Argonne Associate Laboratory Director Kawtar Hafidi, who helped define and merge the different aspects of the initiative.

    “We are developing and fabricating detectors that search for signatures from the early universe or enhance our understanding of the most fundamental of particles,” she added. ​“And because all of these detectors create big data that have to be analyzed, we are developing, among other things, artificial intelligence techniques to do that as well.”

    Decoding messages from the universe

    Fleshing out a theory of the universe on cosmic or subatomic scales requires a combination of observations, experiments, theories, simulations and analyses, which in turn requires access to the world’s most sophisticated telescopes, particle colliders, detectors and supercomputers.

    Argonne is uniquely suited to this mission, equipped as it is with many of those tools, the ability to manufacture others and collaborative privileges with other federal laboratories and leading research institutions to access other capabilities and expertise.

    As lead of the initiative’s cosmology component, Habib uses many of these tools in his quest to understand the origins of the universe and what makes it tick.

    And what better way to do that than to observe it, he said.

    “If you look at the universe as a laboratory, then obviously we should study it and try to figure out what it is telling us about foundational science,” noted Habib. ​“So, one part of what we are trying to do is build ever more sensitive probes to decipher what the universe is trying to tell us.”

    To date, Argonne is involved in several significant sky surveys, which use an array of observational platforms, like telescopes and satellites, to map different corners of the universe and collect information that furthers or rejects a specific theory.

    For example, the South Pole Telescope survey, a collaboration between Argonne and a number of national labs and universities, is measuring the cosmic microwave background (CMB) [above], considered the oldest light in the universe. Variations in CMB properties, such as temperature, signal the original fluctuations in density that ultimately led to all the visible structure in the universe.

    Additionally, the Dark Energy Spectroscopic Instrument and the forthcoming Vera C. Rubin Observatory are specially outfitted, ground-based telescopes designed to shed light on dark energy and dark matter, as well as the formation of luminous structure in the universe.

    DOE’s Lawrence Berkeley National Laboratory(US) DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory, in 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).

    National Optical Astronomy Observatory (US) Mayall 4 m telescope at NSF NOIRLab NOAO Kitt Peak National Observatory (US) in 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).

    National Science Foundation(US) NSF (US) NOIRLab NOAO Kitt Peak National Observatory on 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).

    National Science Foundation(US) NOIRLab (US) NOAO Kitt Peak National Observatory (US) on Kitt Peak 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). annotated.

    NSF (US) NOIRLab (US) NOAO (US) Vera C. Rubin Observatory [LSST] Telescope 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 NSF (US) NOIRLab (US) NOAO (US) Gemini South Telescope and NSF (US) NOIRLab (US) NOAO (US) Southern Astrophysical Research Telescope.

    Darker matters

    All the data sets derived from these observations are connected to the second component of Argonne’s cosmology push, which revolves around theory and modeling. Cosmologists combine observations, measurements and the prevailing laws of physics to form theories that resolve some of the mysteries of the universe.

    But the universe is complex, and it has an annoying tendency to throw a curve ball just when we thought we had a theory cinched. Discoveries within the past 100 years have revealed that the universe is both expanding and accelerating its expansion — realizations that came as separate but equal surprises.

    Saul Perlmutter (center) [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt (right) and Adam Riess (left) [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    “To say that we understand the universe would be incorrect. To say that we sort of understand it is fine,” exclaimed Habib. ​“We have a theory that describes what the universe is doing, but each time the universe surprises us, we have to add a new ingredient to that theory.”

    Modeling helps scientists get a clearer picture of whether and how those new ingredients will fit a theory. They make predictions for observations that have not yet been made, telling observers what new measurements to take.

    Habib’s group is applying this same sort of process to gain an ever-so-tentative grasp on the nature of dark energy and dark matter. While scientists can tell us that both exist, that they comprise about 68 and 26% of the universe, respectively, beyond that not much else is known.

    ______________________________________________________________________________________________________________

    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, some 30 years later, 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

    Dark Matter Research

    Inside the Axion Dark Matter eXperiment U Washington (US) Credit : Mark Stone U. of Washington. Axion Dark Matter Experiment.
    _____________________________________________________________________________________

    Observations of cosmological structure — the distribution of galaxies and even of their shapes — provide clues about the nature of dark matter, which in turn feeds simple dark matter models and subsequent predictions. If observations, models and predictions aren’t in agreement, that tells scientists that there may be some missing ingredient in their description of dark matter.

    But there are also experiments that are looking for direct evidence of dark matter particles, which require highly sensitive detectors [above]. Argonne has initiated development of specialized superconducting detector technology for the detection of low-mass dark matter particles.

    This technology requires the ability to control properties of layered materials and adjust the temperature where the material transitions from finite to zero resistance, when it becomes a superconductor. And unlike other applications where scientists would like this temperature to be as high as possible — room temperature, for example — here, the transition needs to be very close to absolute zero.

    Habib refers to these dark matter detectors as traps, like those used for hunting — which, in essence, is what cosmologists are doing. Because it’s possible that dark matter doesn’t come in just one species, they need different types of traps.

    “It’s almost like you’re in a jungle in search of a certain animal, but you don’t quite know what it is — it could be a bird, a snake, a tiger — so you build different kinds of traps,” he said.

    Lab researchers are working on technologies to capture these elusive species through new classes of dark matter searches. Collaborating with other institutions, they are now designing and building a first set of pilot projects aimed at looking for dark matter candidates with low mass.

    Tuning in to the early universe

    Amy Bender is working on a different kind of detector — well, a lot of detectors — which are at the heart of a survey of the cosmic microwave background (CMB).

    “The CMB is radiation that has been around the universe for 13 billion years, and we’re directly measuring that,” said Bender, an assistant physicist at Argonne.

    The Argonne-developed detectors — all 16,000 of them — capture photons, or light particles, from that primordial sky through the aforementioned South Pole Telescope, to help answer questions about the early universe, fundamental physics and the formation of cosmic structures.

    Now, the CMB experimental effort is moving into a new phase, CMB-Stage 4 (CMB-S4).

    CMB-S4 is the next-generation ground-based cosmic microwave background experiment.With 21 telescopes at the South Pole and in the Chilean Atacama desert surveying the sky with 550,000 cryogenically-cooled superconducting detectors for 7 years, CMB-S4 will deliver transformative discoveries in fundamental physics, cosmology, astrophysics, and astronomy. CMB-S4 is supported by the Department of Energy Office of Science and the National Science Foundation.

    This larger project tackles even more complex topics like Inflationary Theory, which suggests that the universe expanded faster than the speed of light for a fraction of a second, shortly after the Big Bang.
    _____________________________________________________________________________________
    Inflation

    4
    Alan Guth, from Highland Park High School and M.I.T., who first proposed cosmic inflation
    [caption id="attachment_55311" align="alignnone" width="632"] HPHS Owls

    Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes
    Alex Mittelmann, Coldcreation


    Alan Guth’s notes:

    Alan Guth’s original notes on inflation


    _____________________________________________________________________________________

    3
    A section of a detector array with architecture suitable for future CMB experiments, such as the upcoming CMB-S4 project. Fabricated at Argonne’s Center for Nanoscale Materials, 16,000 of these detectors currently drive measurements collected from the South Pole Telescope. (Image by Argonne National Laboratory.)

    While the science is amazing, the technology to get us there is just as fascinating.

    Technically called transition edge sensing (TES) bolometers, the detectors on the telescope are made from superconducting materials fabricated at Argonne’s Center for Nanoscale Materials, a DOE Office of Science User Facility.

    Each of the 16,000 detectors acts as a combination of very sensitive thermometer and camera. As incoming radiation is absorbed on the surface of each detector, measurements are made by supercooling them to a fraction of a degree above absolute zero. (That’s over three times as cold as Antarctica’s lowest recorded temperature.)

    Changes in heat are measured and recorded as changes in electrical resistance and will help inform a map of the CMB’s intensity across the sky.

    CMB-S4 will focus on newer technology that will allow researchers to distinguish very specific patterns in light, or polarized light. In this case, they are looking for what Bender calls the Holy Grail of polarization, a pattern called B-modes.

    Capturing this signal from the early universe — one far fainter than the intensity signal — will help to either confirm or disprove a generic prediction of inflation.

    It will also require the addition of 500,000 detectors distributed among 21 telescopes in two distinct regions of the world, the South Pole and the Chilean desert. There, the high altitude and extremely dry conditions keep water vapor in the atmosphere from absorbing millimeter wavelength light, like that of the CMB.

    While previous experiments have touched on this polarization, the large number of new detectors will improve sensitivity to that polarization and grow our ability to capture it.

    “Literally, we have built these cameras completely from the ground up,” said Bender. ​“Our innovation is in how to make these stacks of superconducting materials work together within this detector, where you have to couple many complex factors and then actually read out the results with the TES. And that is where Argonne has contributed, hugely.”

    Down to the basics

    Argonne’s capabilities in detector technology don’t just stop at the edge of time, nor do the initiative’s investigations just look at the big picture.

    Most of the visible universe, including galaxies, stars, planets and people, are made up of protons and neutrons. Understanding the most fundamental components of those building blocks and how they interact to make atoms and molecules and just about everything else is the realm of physicists like Zein-Eddine Meziani.

    “From the perspective of the future of my field, this initiative is extremely important,” said Meziani, who leads Argonne’s Medium Energy Physics group. ​“It has given us the ability to actually explore new concepts, develop better understanding of the science and a pathway to enter into bigger collaborations and take some leadership.”

    Taking the lead of the initiative’s nuclear physics component, Meziani is steering Argonne toward a significant role in the development of the Electron-Ion Collider, a new U.S. Nuclear Physics Program facility slated for construction at DOE’s Brookhaven National Laboratory (US).

    Argonne’s primary interest in the collider is to elucidate the role that quarks, anti-quarks and gluons play in giving mass and a quantum angular momentum, called spin, to protons and neutrons — nucleons — the particles that comprise the nucleus of an atom.


    EIC Electron Animation, Inner Proton Motion.
    Electrons colliding with ions will exchange virtual photons with the nuclear particles to help scientists ​“see” inside the nuclear particles; the collisions will produce precision 3D snapshots of the internal arrangement of quarks and gluons within ordinary nuclear matter; like a combination CT/MRI scanner for atoms. (Image by Brookhaven National Laboratory.)

    While we once thought nucleons were the finite fundamental particles of an atom, the emergence of powerful particle colliders, like the Stanford Linear Accelerator Center at Stanford University and the former Tevatron at DOE’s Fermilab, proved otherwise.

    It turns out that quarks and gluons were independent of nucleons in the extreme energy densities of the early universe; as the universe expanded and cooled, they transformed into ordinary matter.

    “There was a time when quarks and gluons were free in a big soup, if you will, but we have never seen them free,” explained Meziani. ​“So, we are trying to understand how the universe captured all of this energy that was there and put it into confined systems, like these droplets we call protons and neutrons.”

    Some of that energy is tied up in gluons, which, despite the fact that they have no mass, confer the majority of mass to a proton. So, Meziani is hoping that the Electron-Ion Collider will allow science to explore — among other properties — the origins of mass in the universe through a detailed exploration of gluons.

    And just as Amy Bender is looking for the B-modes polarization in the CMB, Meziani and other researchers are hoping to use a very specific particle called a J/psi to provide a clearer picture of what’s going on inside a proton’s gluonic field.

    But producing and detecting the J/psi particle within the collider — while ensuring that the proton target doesn’t break apart — is a tricky enterprise, which requires new technologies. Again, Argonne is positioning itself at the forefront of this endeavor.

    “We are working on the conceptual designs of technologies that will be extremely important for the detection of these types of particles, as well as for testing concepts for other science that will be conducted at the Electron-Ion Collider,” said Meziani.

    Argonne also is producing detector and related technologies in its quest for a phenomenon called neutrinoless double beta decay. A neutrino is one of the particles emitted during the process of neutron radioactive beta decay and serves as a small but mighty connection between particle physics and astrophysics.

    “Neutrinoless double beta decay can only happen if the neutrino is its own anti-particle,” said Hafidi. ​“If the existence of these very rare decays is confirmed, it would have important consequences in understanding why there is more matter than antimatter in the universe.”

    Argonne scientists from different areas of the lab are working on the Neutrino Experiment with Xenon Time Projection Chamber (NEXT) collaboration to design and prototype key systems for the collaborative’s next big experiment. This includes developing a one-of-a-kind test facility and an R&D program for new, specialized detector systems.

    “We are really working on dramatic new ideas,” said Meziani. ​“We are investing in certain technologies to produce some proof of principle that they will be the ones to pursue later, that the technology breakthroughs that will take us to the highest sensitivity detection of this process will be driven by Argonne.”

    The tools of detection

    Ultimately, fundamental science is science derived from human curiosity. And while we may not always see the reason for pursuing it, more often than not, fundamental science produces results that benefit all of us. Sometimes it’s a gratifying answer to an age-old question, other times it’s a technological breakthrough intended for one science that proves useful in a host of other applications.

    Through their various efforts, Argonne scientists are aiming for both outcomes. But it will take more than curiosity and brain power to solve the questions they are asking. It will take our skills at toolmaking, like the telescopes that peer deep into the heavens and the detectors that capture hints of the earliest light or the most elusive of particles.

    We will need to employ the ultrafast computing power of new supercomputers. Argonne’s forthcoming Aurora exascale machine will analyze mountains of data for help in creating massive models that simulate the dynamics of the universe or subatomic world, which, in turn, might guide new experiments — or introduce new questions.

    Depiction of ANL ALCF Cray Intel SC18 Shasta Aurora exascale supercomputer, to be built at DOE’s Argonne National Laboratory.

    And we will apply artificial intelligence to recognize patterns in complex observations — on the subatomic and cosmic scales — far more quickly than the human eye can, or use it to optimize machinery and experiments for greater efficiency and faster results.

    “I think we have been given the flexibility to explore new technologies that will allow us to answer the big questions,” said Bender. ​“What we’re developing is so cutting edge, you never know where it will show up in everyday life.”

    Funding for research mentioned in this article was provided by Argonne Laboratory Directed Research and Development; Argonne program development; DOE Office of High Energy Physics: Cosmic Frontier, South Pole Telescope-3G project, Detector R&D; and DOE Office of Nuclear Physics.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    DOE’s Argonne National Laboratory (US) seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their is a science and engineering research national laboratory operated by UChicago Argonne LLC for the United States Department of Energy. The facility is located in Lemont, Illinois, outside of Chicago, and is the largest national laboratory by size and scope in the Midwest.

    Argonne had its beginnings in the Metallurgical Laboratory of the University of Chicago, formed in part to carry out Enrico Fermi’s work on nuclear reactors for the Manhattan Project during World War II. After the war, it was designated as the first national laboratory in the United States on July 1, 1946. In the post-war era the lab focused primarily on non-weapon related nuclear physics, designing and building the first power-producing nuclear reactors, helping design the reactors used by the United States’ nuclear navy, and a wide variety of similar projects. In 1994, the lab’s nuclear mission ended, and today it maintains a broad portfolio in basic science research, energy storage and renewable energy, environmental sustainability, supercomputing, and national security.

    UChicago Argonne, LLC, the operator of the laboratory, “brings together the expertise of the University of Chicago (the sole member of the LLC) with Jacobs Engineering Group Inc.” Argonne is a part of the expanding Illinois Technology and Research Corridor. Argonne formerly ran a smaller facility called Argonne National Laboratory-West (or simply Argonne-West) in Idaho next to the Idaho National Engineering and Environmental Laboratory. In 2005, the two Idaho-based laboratories merged to become the DOE’s Idaho National Laboratory.
    What would become Argonne began in 1942 as the Metallurgical Laboratory at the University of Chicago, which had become part of the Manhattan Project. The Met Lab built Chicago Pile-1, the world’s first nuclear reactor, under the stands of the University of Chicago sports stadium. Considered unsafe, in 1943, CP-1 was reconstructed as CP-2, in what is today known as Red Gate Woods but was then the Argonne Forest of the Cook County Forest Preserve District near Palos Hills. The lab was named after the surrounding forest, which in turn was named after the Forest of Argonne in France where U.S. troops fought in World War I. Fermi’s pile was originally going to be constructed in the Argonne forest, and construction plans were set in motion, but a labor dispute brought the project to a halt. Since speed was paramount, the project was moved to the squash court under Stagg Field, the football stadium on the campus of the University of Chicago. Fermi told them that he was sure of his calculations, which said that it would not lead to a runaway reaction, which would have contaminated the city.

    Other activities were added to Argonne over the next five years. On July 1, 1946, the “Metallurgical Laboratory” was formally re-chartered as Argonne National Laboratory for “cooperative research in nucleonics.” At the request of the U.S. Atomic Energy Commission, it began developing nuclear reactors for the nation’s peaceful nuclear energy program. In the late 1940s and early 1950s, the laboratory moved to a larger location in unincorporated DuPage County, Illinois and established a remote location in Idaho, called “Argonne-West,” to conduct further nuclear research.

    In quick succession, the laboratory designed and built Chicago Pile 3 (1944), the world’s first heavy-water moderated reactor, and the Experimental Breeder Reactor I (Chicago Pile 4), built-in Idaho, which lit a string of four light bulbs with the world’s first nuclear-generated electricity in 1951. A complete list of the reactors designed and, in most cases, built and operated by Argonne can be viewed in the, Reactors Designed by Argonne page. The knowledge gained from the Argonne experiments conducted with these reactors 1) formed the foundation for the designs of most of the commercial reactors currently used throughout the world for electric power generation and 2) inform the current evolving designs of liquid-metal reactors for future commercial power stations.

    Conducting classified research, the laboratory was heavily secured; all employees and visitors needed badges to pass a checkpoint, many of the buildings were classified, and the laboratory itself was fenced and guarded. Such alluring secrecy drew visitors both authorized—including King Leopold III of Belgium and Queen Frederica of Greece—and unauthorized. Shortly past 1 a.m. on February 6, 1951, Argonne guards discovered reporter Paul Harvey near the 10-foot (3.0 m) perimeter fence, his coat tangled in the barbed wire. Searching his car, guards found a previously prepared four-page broadcast detailing the saga of his unauthorized entrance into a classified “hot zone”. He was brought before a federal grand jury on charges of conspiracy to obtain information on national security and transmit it to the public, but was not indicted.

    Not all nuclear technology went into developing reactors, however. While designing a scanner for reactor fuel elements in 1957, Argonne physicist William Nelson Beck put his own arm inside the scanner and obtained one of the first ultrasound images of the human body. Remote manipulators designed to handle radioactive materials laid the groundwork for more complex machines used to clean up contaminated areas, sealed laboratories or caves. In 1964, the “Janus” reactor opened to study the effects of neutron radiation on biological life, providing research for guidelines on safe exposure levels for workers at power plants, laboratories and hospitals. Scientists at Argonne pioneered a technique to analyze the moon’s surface using alpha radiation, which launched aboard the Surveyor 5 in 1967 and later analyzed lunar samples from the Apollo 11 mission.

    In addition to nuclear work, the laboratory maintained a strong presence in the basic research of physics and chemistry. In 1955, Argonne chemists co-discovered the elements einsteinium and fermium, elements 99 and 100 in the periodic table. In 1962, laboratory chemists produced the first compound of the inert noble gas xenon, opening up a new field of chemical bonding research. In 1963, they discovered the hydrated electron.

    High-energy physics made a leap forward when Argonne was chosen as the site of the 12.5 GeV Zero Gradient Synchrotron, a proton accelerator that opened in 1963. A bubble chamber allowed scientists to track the motions of subatomic particles as they zipped through the chamber; in 1970, they observed the neutrino in a hydrogen bubble chamber for the first time.

    Meanwhile, the laboratory was also helping to design the reactor for the world’s first nuclear-powered submarine, the U.S.S. Nautilus, which steamed for more than 513,550 nautical miles (951,090 km). The next nuclear reactor model was Experimental Boiling Water Reactor, the forerunner of many modern nuclear plants, and Experimental Breeder Reactor II (EBR-II), which was sodium-cooled, and included a fuel recycling facility. EBR-II was later modified to test other reactor designs, including a fast-neutron reactor and, in 1982, the Integral Fast Reactor concept—a revolutionary design that reprocessed its own fuel, reduced its atomic waste and withstood safety tests of the same failures that triggered the Chernobyl and Three Mile Island disasters. In 1994, however, the U.S. Congress terminated funding for the bulk of Argonne’s nuclear programs.

    Argonne moved to specialize in other areas, while capitalizing on its experience in physics, chemical sciences and metallurgy. In 1987, the laboratory was the first to successfully demonstrate a pioneering technique called plasma wakefield acceleration, which accelerates particles in much shorter distances than conventional accelerators. It also cultivated a strong battery research program.

    Following a major push by then-director Alan Schriesheim, the laboratory was chosen as the site of the Advanced Photon Source, a major X-ray facility which was completed in 1995 and produced the brightest X-rays in the world at the time of its construction.

    On 19 March 2019, it was reported in the Chicago Tribune that the laboratory was constructing the world’s most powerful supercomputer. Costing $500 million it will have the processing power of 1 quintillion flops. Applications will include the analysis of stars and improvements in the power grid.

    With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science. For more visit http://www.anl.gov.

    About the Advanced Photon Source

    The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

    With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science. For more visit http://www.anl.gov.

    About the Advanced Photon Source

    The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

    Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

    Argonne Lab Campus

     
  • richardmitnick 10:29 pm on January 13, 2021 Permalink | Reply
    Tags: "Giant Map of the Sky Sets Stage for Ambitious DESI Survey", , , , , , Dark Energy Spectroscopic Instrument (DESI), , , The DESI collaboration will select 35 million galaxies and 2.4 million quasars in the map — some as far away as 12 billion light-years — as targets for the DESI survey.   

    From NOIRLab: “Giant Map of the Sky Sets Stage for Ambitious DESI Survey” 

    NOIRLab composite

    From NOIRLab

    13 January 2021

    David Schlegel
    Lawrence Berkeley National Laboratory (LBNL)
    Cell: +1 510 965 3287
    Email: djschlegel@lbl.gov

    Arjun Dey
    NSF’s NOIRLab
    Cell: +1 520 981 9024
    Email: dey@noao.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    1
    A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo.
    Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies.

    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), annotated.

    NOIRLab 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.

    The ninth and final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. The map was released today at the January 2021 meeting of the American Astronomical Society.

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory started in 2018.

    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    For millennia humans have used maps to understand and navigate our world and put ourselves in context: we rely on maps to show us where we are, where we came from, and where we’re going. Astronomical maps continue this tradition on a vast scale. They locate us within the cosmos and tell the story of the history and fate of the Universe: it will expand forever, the expansion currently accelerating because of an unknown quantity called dark energy. Astronomical maps may help explain what this dark energy is and why it exists.

    Capitalizing on that possibility requires an unprecedented map — one that charts faint galaxies more uniformly and over a larger area of sky than ever before. To meet that challenge, astronomers have now created a new two-dimensional map of the sky that is the largest ever made in terms of sky coverage, sensitivity, and the total number of galaxies mapped.

    From among the more than 1 billion galaxies in the map, astronomers will select tens of millions of galaxies for further study with the Dark Energy Spectroscopic Instrument (DESI), in order to construct the largest 3D map ever attempted. The results from the DESI survey, which will be carried out at Kitt Peak National Observatory (KPNO), a Program of National Science Foundation’s NOIRLab, will ultimately provide new insights into the nature of dark energy.

    The new map is the result of the DESI Legacy Imaging Surveys, an ambitious 6-year effort involving 1405 observing nights at three telescopes, years of data from a space telescope, 150 observers and 50 other researchers from around the world, 1 petabyte of data (1000 trillion bytes), and 100 million CPU hours on one of the world’s most powerful computers. The images were taken at KPNO and Cerro Tololo Inter-American Observatory (CTIO), also a Program of NOIRLab, and supplemented by images from NASA’s Wide-field Infrared Survey Explorer (WISE) mission.

    NASA/WISE NEOWISE Telescope.

    The data were reduced at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC).

    National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory

    NERSC Cray Cori II supercomputer, named after Gerty Cori, the first American woman to win a Nobel Prize in science.

    NERSC Hopper Cray XE6 supercomputer, named after Grace Hopper, One of the first programmers of the Harvard Mark I computer.

    NERSC Cray XC30 Edison supercomputer.

    NERSC GPFS for Life Sciences.


    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

    NERSC PDSF computer cluster in 2003.

    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    Future:

    Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supeercomputer

    NERSC is a DOE Office of Science User Facility.

    Arjun Dey, the DESI Project Scientist for NOIRLab, co-led two of the three imaging surveys, serving as the lead scientist for the Mayall z-band Legacy Survey (MzLS) observed by the Mosaic3 camera on the Nicholas U. Mayall 4-meter Telescope at KPNO, and as co-lead scientist with Schlegel for the Dark Energy Camera Legacy Survey (DECaLS) on DECam on the Víctor M. Blanco 4-meter Telescope at CTIO in Chile.

    Dark Energy Camera [DECam], built at FNAL.

    The third survey is the Beijing-Arizona Sky Survey (BASS) observed by the 90Prime camera on the Bok 2.3-meter Telescope, which is owned and operated by the University of Arizona and located at KPNO.

    2.3-metre Bok Telescope at the Steward Observatory at Kitt Peak in the the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, USA, Altitude 2,096 m (6,877 ft).

    The collective effort of the three surveys, Dey said, “was one of the most uniform, deep surveys of the sky that has ever been undertaken. It was really exciting to participate.”

    The DESI collaboration will select 35 million galaxies and 2.4 million quasars in the map — some as far away as 12 billion light-years — as targets for the DESI survey. Over five years of operations, DESI will create a giant 3D map of the Universe by measuring the galaxies’ distances and the rate at which they are moving away from us. To make these measurements, DESI will take the fingerprint of a galaxy by measuring its spectrum: the light from individual galaxies will be dispersed into fine bands of color.

    Capturing the spectra of so many galaxies so quickly requires a high degree of automation. DESI — equipped with an array of 5000 swiveling, automated robots, each toting a thin fiber-optic cable that can point at individual galaxies — is designed to measure the spectra of 5000 galaxies at a time. The results will ultimately provide new insights into the mysterious dark energy that is driving the Universe’s accelerating expansion.

    The quest to understand the nature of dark energy has led to major opportunities for discovery in other areas of astronomy. Adam Bolton, Director of NOIRLab’s Community Science and Data Center, explained: “To solve some of the biggest mysteries in fundamental physics today, we are driven to create huge digital databases of stars and galaxies, which in turn enable a new data-mining approach to making additional astronomical discoveries.”

    With the completion of the DESI Legacy Imaging Surveys, all data have been released to the scientific community and the public. This final data release, known as Data Release 9, has been preceded by eight other intermediate data releases.

    NOIRLab will host these data products in the Astro Data Archive, from the original images taken at the telescopes to the catalogs that report the positions and other properties of stars and galaxies. Astro Data Lab also serves the catalogs as databases, which astronomers can easily analyze using the Astro Data Lab tools and services, and cross-match them with other datasets, giving more opportunities for discovery. In addition, Astro Data Lab provides astronomers with example scientific applications and tutorials to assist with their research. The DESI Legacy Imaging Surveys data have already been used for many other research projects [1] [2], including citizen science efforts that utilize the wisdom of crowds [3].

    Notes

    [1] One study uses a machine-learning algorithm to automatically identify light-bending phenomena known as gravitational lenses in the DESI surveys data.

    [2] Another study employs spectroscopy from the Sloan Digital Sky Survey together with the Legacy Surveys imaging to reveal the presence of active black holes in galaxies, and giving us a preview of a large population of active galaxies to be discovered with the DESI spectroscopic survey. This work is being led by NOIRLab astronomer Stephanie Juneau.

    [3] The citizen science project Backyard Worlds: Planet 9 enlists the general public’s help in finding a possible ninth planet in our Solar System, by searching for moving objects in the data. Participants have already discovered new cool worlds in the vicinity of the Sun — objects more massive than planets but lighter than stars, known as brown dwarfs. Several of these are among the very coolest brown dwarfs known, with a few approaching the temperature of Earth and cool enough to harbor water clouds. Recently the largest map of brown dwarfs in our neighborhood was published. Backyard Worlds is co-led by Aaron Meisner, a NOIRLab astronomer and DESI participant.

    DESI is supported by the US Department of Energy’s Office of High Energy Physics; the US National Science Foundation, Division of Astronomical Sciences under contract to the NSF’s NOIRLab; the Science and Technologies Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising-Simons Foundation; the French Alternative Energies and Atomic Energy Commission (CEA); the National Council of Science and Technology of Mexico; the Ministry of Economy of Spain; and DESI member institutions. The DESI scientists are honored to be permitted to conduct astronomical research on Iolkam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.

    Current DESI Member Institutions include: Aix-Marseille University; Argonne National Laboratory; Barcelona-Madrid Regional Participation Group; Brookhaven National Laboratory; Boston University; Brazil Regional Participation Group; Carnegie Mellon University; CEA-IRFU, Saclay (FR); China Participation Group (CN); Cornell University; Durham University (UK); École Polytechnique Fédérale de Lausanne (CH); Eidgenössische Technische Hochschule, Zürich; Fermi National Accelerator Laboratory; Granada-Madrid-Tenerife Regional Participation Group (ES); Harvard University; Kansas State University; Korea Astronomy and Space Science Institute (KR); Korea Institute for Advanced Study; Lawrence Berkeley National Laboratory; Laboratoire de Physique Nucléaire et de Hautes Énergies (FR); Max Planck Institute (DE); Mexico Regional Participation Group (MX); New York University; NSF’s NOIRLab; Ohio University; Perimeter Institute (CA); Shanghai Jiao Tong University (CN); Siena College; SLAC National Accelerator Laboratory; Southern Methodist University; Swinburne University (UK); The Ohio State University; Universidad de los Andes (CO); University of Arizona; University of Barcelona (ES); University of California, Berkeley; University of California, Irvine; University of California, Santa Cruz; University College London (UK); University of Florida; University of Michigan at Ann Arbor; University of Pennsylvania; University of Pittsburgh; University of Portsmouth (UK); University of Queensland (AU); University of Rochester; University of Toronto (CA); University of Utah; University of Waterloo (CA); University of Wyoming; University of Zurich (CH); UK Regional Participation Group; Yale University.

    For more information, visit desi.lbl.gov.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

     
  • richardmitnick 5:21 pm on March 22, 2017 Permalink | Reply
    Tags: , , , , , , , Dark Energy Spectroscopic Instrument (DESI), , , New Study Maps Space Dust in 3-D, ,   

    From LBNL: “New Study Maps Space Dust in 3-D” 

    Berkeley Logo

    Berkeley Lab

    March 22, 2017
    Glenn Roberts Jr
    geroberts@lbl.gov
    510-486-5582


    Access mp4 video here .
    This animation shows a 3-D rendering of space dust, as viewed in a several-kiloparsec (thousands of light years) loop through and out of the Milky Way’s galactic plane. The animation uses data for hundreds of millions of stars from Pan-STARRS1 and 2MASS surveys, and is made available through a Creative Commons License. (Credit: Gregory M. Green/SLAC, KIPAC)

    Consider that the Earth is just a giant cosmic dust bunny—a big bundle of debris amassed from exploded stars. We Earthlings are essentially just little clumps of stardust, too, albeit with very complex chemistry.

    And because outer space is a very dusty place, that makes things very difficult for astronomers and astrophysicists who are trying to peer farther across the universe or deep into the center of our own galaxy to learn more about their structure, formation and evolution.

    Building a better dust map

    Now, a new study led by Edward F. Schlafly, a Hubble Fellow in the Physics Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), is providing a detailed, 3-D look at dust on a scale spanning thousands of light-years in our Milky Way galaxy. The study was published today in The Astrophysical Journal.

    This dust map is of critical importance for the Dark Energy Spectroscopic Instrument (DESI), a Berkeley Lab-led project that will measure the universe’s accelerating expansion rate when it starts up in 2019. DESI will build a map of more than 30 million distant galaxies, but that map will be distorted if this dust is ignored.

    “The light from those distant galaxies travels for billions of years before we see it,” according to Schlafly, “but in the last thousand years of its journey toward us a few percent of that light is absorbed and scattered by dust in our own galaxy. We need to correct for that.”

    Just as airborne dust in Earth’s sky contributes to the atmospheric haze that gives us brilliant oranges and reds in sunrises and sunsets, dust can also make distant galaxies and other space objects appear redder in the sky, distorting their distance and in some cases concealing them from view.

    Scientists are constantly developing better ways to map out this interstellar dust and understand its concentration, composition, and common particle sizes and shapes.

    1
    The dark regions show very dense dust clouds. The red stars tend to be reddened by dust, while the blue stars are in front of the dust clouds. These images are part of a survey of the southern galactic plane. (Credit: Legacy Survey/NOAO, AURA, NSF)

    Once we can solve the dust problem by creating better dust maps and learning new details about the properties of this space dust, this can give us a much more precise gauge of distances to faraway stars in the Milky Way, like a galactic GPS. Dust maps can also help to better gauge the distance to supernovae events by taking into account the effects of dust in reddening their light.

    “The overarching aim of this project is to map dust in three dimensions—to find out how much dust is in any 3-D region in the sky and in the Milky Way galaxy,” Schlafly said.

    Combined data from sky surveys shed new light on dust

    Taking data from separate sky surveys conducted with telescopes on Maui and in New Mexico, Schlafly’s research team composed maps that compare dust within one kiloparsec, or 3,262 light-years, in the outer Milky Way—including collections of gas and dust known as molecular clouds that can contain dense star- and planet-forming regions known as nebulae—with more distant dust in the galaxy.

    2
    Pan-STARRS2 and PanSTARS1 telescopes atop Haleakalā on the island of Maui, Hawaii. (Credit: Pan-STARRS)

    The resolution of these 3-D dust maps is many times better than anything that previously existed,” said Schlafly.

    This undertaking was made possible by the combination of a very detailed multiyear survey known as Pan-STARRS that is powered by a 1.4-gigapixel digital camera and covers three-fourths of the visible sky, and a separate survey called APOGEE that used a technique known as infrared spectroscopy.

    3
    A compressed view of the entire sky visible from Hawaii by the Pan-STARRS1 Observatory. The image is a compilation of half a million exposures, each about 45 seconds in length, taken over a period of four years. The disk of the Milky Way looks like a yellow arc, and the dust lanes show up as reddish-brown filaments. The background is made up of billions of faint stars and galaxies. (Credit: D. Farrow/Pan-STARRS1 Science Consortium, and Max Planck Institute for Extraterrestrial Physics)

    Infrared measurements can effectively cut through the dust that obscures many other types of observations and provides a more precise measurement of stars’ natural color. The APOGEE experiment focused on the light from about 100,000 red giant stars across the Milky Way, including those in its central halo.


    SDSS Telescope at Apache Point Observatory, NM, USA

    What they found is a more complex picture of dust than earlier research and models had suggested. The dust properties within 1 kiloparsec of the sun, which scientists measure with a light-obscuring property known as its “extinction curve,” is different than that of the dust properties in the more remote galactic plane and outer galaxy.

    New questions emerge on the makeup of space dust

    The results, researchers found, appear to be in conflict with models that expect dust to be more predictably distributed, and to simply exhibit larger grain sizes in areas where more dust resides. But the observations find that the dust properties vary little with the amount of dust, so the models may need to be adjusted to account for a different chemical makeup, for example.

    “In denser regions, it was thought that dust grains will conglomerate, so you have more big grains and fewer small grains,” Schlafly said. But the observations show that dense dust clouds look much the same as less concentrated dust clouds, so that variations in dust properties are not just a product of dust density: “whatever is driving this is not just conglomeration in these regions.”

    He added, “The message to me that we don’t yet know what’s going on. I don’t think the existing (models) are correct, or they are only right at the very highest densities.”

    Accurate measures of the chemical makeup of space dust are important, Schlafly said. “A large amount of chemistry takes place on dust grains, and you can only form molecular hydrogen on the surface of dust grains,” he said—this molecular hydrogen is essential in the formation of stars and planets.


    Access mp4 video here .
    This animation shows a 3-D rendering of dust, as viewed from a 50-parsec (163-light-year) loop around the sun. The animation uses data for hundreds of millions of stars from Pan-STARRS1 and 2MASS surveys, and is made available through a Creative Commons License: https://creativecommons.org/licenses/by-sa/4.0/. (Credit: Gregory M. Green/SLAC, KIPAC)

    Even with a growing collection of dust data, we still have an incomplete dust map of our galaxy. “There is about one-third of the galaxy that’s missing,” Schlafly said, “and we’re working right now on imaging this ‘missing third’ of the galaxy.” A sky survey that will complete the imaging of the southern galactic plane and provide this missing data should wrap up in May, he said.

    APOGEE-2, a follow-up survey to APOGEE, for example, will provide more complete maps of the dust in the local galaxy, and other instruments are expected to provide better dust maps for nearby galaxies, too.

    While the density of dust shrouds our view of the center of the Milky Way, Schlafly said there will be progress, too, in seeing deeper and collecting better dust measurements there as well.

    Researchers at the Harvard-Smithsonian Center for Astrophysics and Harvard University also participated in this work.

    4
    The planned APOGEE-2 survey area overlain on an image of the Milky Way. Each dot shows a position where APOGEE-2 will obtain stellar spectra. (Credit: APOGEE-2)

    APOGEE is a part of the Sloan Digital Sky Survey III (SDSS-III), with participating institutions including Berkeley Lab, the Alfred P. Sloan Foundation, and the National Science Foundation. PanSTARRS1 surveys are supported by the University of Hawaii Institute for Astronomy; the Pan-STARRS Project Office; the Max-Planck Society and its participating institutes in Germany; the Johns Hopkins University; the University of Durham, the University of Edinburgh, and the Queen’s University Belfast in the U.K.; the Harvard-Smithsonian Center for Astrophysics; the Las Cumbres Observatory Global Telescope Network Inc.; and the National Central University of Taiwan. Pan-STARRS is supported by the U.S. Air Force.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    A U.S. Department of Energy National Laboratory Operated by the University of California

    University of California Seal

    DOE Seal

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