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  • richardmitnick 8:43 pm on December 9, 2016 Permalink | Reply
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    From LBNL: “$40M to Establish New Observatory Probing Early Universe” 

    Berkeley Logo

    Berkeley Lab

    May 12, 2016 [OMG, where has this been?]
    No writer credit found

    1
    The Simons Array will be located in Chile’s High Atacama Desert, at an elevation of about 17,000 feet. The site currently hosts the Atacama Cosmology Telescope (bowl-shaped structure at upper right) and the Simons Array (the three telescopes at bottom left, center and right). The Simons Observatory will merge these two experiments, add several new telescopes and set the stage for a next-generation experiment. (Credit: University of Pennsylvania)

    The Simons Foundation has given $38.4 million to establish a new astronomy facility in Chile’s Atacama Desert, adding new telescopes and detectors alongside existing instruments in order to boost ongoing studies of the evolution of the universe, from its earliest moments to today. The Heising-Simons Foundation is providing an additional $1.7 million for the project.

    The Simons Observatory is a collaboration among the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab); UC Berkeley; Princeton University; the University of California at San Diego; and University of Pennsylvania, all of which are also providing financial support.

    The observatory will probe the subtle properties of the universe’s first light, known as cosmic microwave background (CMB) radiation.

    CMB per ESA/Planck
    CMB per ESA/Planck

    ESA/Planck
    ESA/Planck

    The observatory will pay particular attention to the polarization, or directional information, in the CMB light to better understand what took place a fraction of a second after the Big Bang. While these events are hidden from view behind the glare of the microwave radiation, the disturbances they caused in the fabric of space-time affected the microwave’s polarization, and scientists hope to work backwards from these measurements to test theories about how the universe came into existence.

    “The Simons Observatory will allow us to peer behind the dust in our galaxy and search for a true signal from the Big Bang,” said Adrian Lee, a physicist at Berkeley Lab, a UC Berkeley physics professor and one of the lead investigators at the observatory.

    A key goal of the project is to detect gravitational waves generated by cosmic inflation, an extraordinarily rapid expansion of space that, according to the most popular cosmological theory, took place in an instant after the Big Bang. These primordial gravitational waves induced a very small but characteristic polarization pattern, called B-mode polarization, in the microwave background radiation that can be detected by telescopes and cameras like those planned for the Simons Observatory.

    3
    B-mode polarization Image: BICEP2 Collaboration

    4
    The Milky Way’s galactic plane rises above the Atacama Cosmology Telescope. The Simons Observatory is planned at the same site in Chile’s High Atacama Desert and will merge existing experiments and add new telescopes and detectors. (Credit: Jon Ward/University of Pennsylvania)

    “While patterns that we see in the microwave sky are a picture of the structure of the universe 380,000 years after the Big Bang, we believe that some of these patterns were generated much earlier, by gravitational waves produced in the first moments of the universe’s expansion,” said project spokesperson Mark Devlin, a cosmologist at the University of Pennsylvania who leads the university’s team in the collaboration. “By measuring how the gravitational waves affect electrons and matter 380,000 years after the Big Bang we are observing fossils from the very, very early universe.”

    Lee added, “Once we see the signal of inflation, it will be the beginning of a whole new era of cosmology.” We will then be looking at a time when the energy scale in the universe was a trillion times higher than the energy accessible in any particle accelerator on Earth.

    By measuring how radiation from the early universe changed as it traveled through space to Earth, the observatory also will teach us about the nature of dark energy and dark matter, the properties of neutrinos and how large-scale structure formed as the universe expanded and evolved.

    Primordial gravitational waves

    Princeton ACT new ,  on Cerro Toco in the Atacama Desert in the north of Chile, near the Llano de Chajnantor Observatory.
    Princeton ACT, on Cerro Toco in the Atacama Desert in the north of Chile, near the Llano de Chajnantor Observatory, pictured here, will merge with another set of instruments, the Simons Array, and new telescopes and equipment will be added at the site with the launch of the Simons Observatory project. (Credit: Princeton University)

    Two existing instruments at the site—the Atacama Cosmology Telescope and the Simons Array—are currently measuring this polarization. The foundation funds will merge these two experiments, expand the search and develop new technology for a fourth-stage, next-generation project—dubbed CMB-Stage 4 or CMB-S4—that could conceivably mine all the cosmological information in the cosmic microwave background fluctuations possible from a ground-based observatory.

    LBL The Simons Array in the Atacama in Chile, with the  Atacama Cosmology Telescope
    LBL The Simons Array in the Atacama in Chile, with the Atacama Cosmology Telescope, on Cerro Toco in the Atacama Desert in the north of Chile, near the Llano de Chajnantor Observatory.

    “We are still in the planning stage for CMB-S4, and this is a wonderful opportunity for the foundations to create a seed for the ultimate experiment,” said Akito Kusaka, a Berkeley Lab physicist and one of the lead investigators. “This gets us off to a quick start.”

    The Simons Observatory is designed to be a first step toward CMB-S4. This next-generation experiment builds on years of support from the National Science Foundation (NSF), and the Department of Energy (DOE) Office of Science has announced its intent to participate in CMB-S4, following the recommendation by its particle physics project prioritization panel. Such a project is envisioned to have telescopes at multiple sites and draw together a broad community of experts from the U.S. and abroad. The Atacama site in Chile has already been identified as an excellent location for CMB-S4, and the Simons Foundation funding will help develop it for that role.

    “We are hopeful that CMB-S4 would shed light not only on inflation, but also on the dark elements of the universe: neutrinos and so-called dark energy and dark matter,” Kusaka said. “The nature of these invisible elements is among the biggest questions in particle physics as well.”

    Beyond POLARBEAR

    Experiments at the Chilean site have already paved the way for CMB-S4. A 2012 UC Berkeley-led experiment with participation by Berkeley Lab researchers, called POLARBEAR, used a 3.5-meter telescope at the Chilean site to measure the gravitational-lensing-generated B-mode polarization of the cosmic microwave background radiation.

    POLARBEAR McGill Telescope located in the Atacama Desert of northern Chile in the Antofagasta Region. The POLARBEAR experiment is mounted on the Huan Tran Telescope (HTT) at the James Ax Observatory in the Chajnantor Science Reserve.
    The POLARBEAR experiment is mounted on the Huan Tran Telescope (HTT) at the James Ax Observatory in the Chajnantor Science Reserve.

    Team scientists confirmed in 2014 that the signal was strong enough to allow them eventually to measure the neutrino mass and the evolution of dark energy.

    The recent addition of two more telescopes upgrades POLARBEAR to the Simons Array, which will speed up the mapping of the CMB and improve sky and frequency coverage. The $40 million in new funding will make possible the successor to the Simons Array and the nearby Atacama Cosmology Telescope.

    Current stage-3 experiments for these short-wavelength microwaves, which must be chilled to three-tenths of a degree Kelvin above absolute zero, have about 10,000 pixels, Lee said.

    “We need to make a leap in our technology to pave the way for the 500,000 detectors required for the ultimate experiment,” he said. “We’ll be generating the blueprint for a much more capable telescope.”

    “The generosity of this award is unprecedented in our field, and will enable a major leap in scientific capability,” said Brian Keating, leader of the UC San Diego contingent and current project director. “People are used to thinking about mega- or gigapixel detectors in optical telescopes, but for signals in the microwave range 10,000 pixels is a lot. What we’re trying to do—the real revolution here—is to pave the way to increase our pixels number by more than an order of magnitude.”

    Berkeley Lab and UC Berkeley will contribute $1.25 million in matching funds to the project over the next five years. The $1.7 million contributed by the Heising-Simons Foundation will be devoted to supporting research at Berkeley to improve the microwave detectors and to develop fabrication methods that are more efficient and cheaper, with the goal of boosting the number of detectors in CMB experiments by more than a factor of a 10.

    The site in Chile is located in the Parque Astronómico, which is administered by the Comisión Nacional de Investigación Científica y Tecnológica (CONICYT). Since 1998, U.S. investigators and the NSF have worked with Chilean scientists, the University of Chile, and CONICYT to locate multiple projects at this high, dry site to study the CMB.

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 11:21 am on May 14, 2015 Permalink | Reply
    Tags: , , , Princeton ACT,   

    From Sky and Telescope: “Mapping Dark Matter” 

    SKY&Telescope bloc

    Sky & Telescope

    May 7, 2015
    Monica Young

    Two projects are mapping the distribution of dark matter in the universe, probing scales both large and small.

    1
    A snapshot from the Bolshoi cosmology simulation shows what the universe’s current dark matter distribution should look like. This box is roughly 800 million light-years across. Anatoly Klypin (NMSU), Joel R. Primack (UCSC), and Stefan Gottloeber (AIP, Germany)

    Observations show the universe to be a cosmic spider web: galaxies and clusters of galaxies are strung along its nodes and filaments like so many caught flies. Yet the thread — dark matter, which makes up 85% of the universe’s mass — is largely invisible, fully visualized only in simulations.

    Scientists are finding ways to map this unseen backbone of the universe, plotting its effect on light coming from distant galaxies and even from the remnant glow of the Big Bang, the cosmic microwave background [CMB].

    Cosmic Microwave Background  Planck
    CMB per ESA/Planck

    ESA Planck
    ESA/Planck

    Two projects making the invisible visible are the Dark Energy Survey, led by Josh Frieman (Fermilab) and conducted at the Cerro Tololo Inter-American Observatory in the Chilean Andes, and the Atacama Cosmology Telescope [ACT] polarization survey, also in Chile and high in the Atacama Desert. These complementary surveys are taking on the universe on scales big and small.

    Dark Energy Camera
    DECam, built at FNAL
    CTIO Victor M Blanco 4m Telescope
    CTIO Victor M Blanco 4m Telescope interior
    CTIO Victor M Blanco telescope, which houses the DECam

    Princeton ACT Telescope
    ACT

    Mapping Superclusters and Supervoids

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    By measuring dark matter’s smearing effect on galaxy shapes, the Dark Energy Survey mapped out the mysterious stuff’s density over a 139-square-degree swath of sky. The color scale reflects dark matter density; grey circles mark galaxy clusters – bigger circles represent larger clusters.
    Dark Energy Survey

    Frieman’s team is tackling the large-scale universe using the Dark Energy Camera, a 570-megapixel CCD camera that’s in the process of surveying a huge, 5,000-square-degree swath of Southern Hemisphere sky. (Compare that to the cutting-edge yet still-measly 16-megapixel camera in a Samsung Galaxy S6 smartphone!)

    Using preliminary data that covers just 3% of the full survey, a team led by Vinu Vikram (Argonne National Laboratory) examined the shapes of more than 1 million faraway galaxies, whose light has traveled between 5.8 billion and 8.5 billion years to reach us. The team was looking for the smearing effect of intervening dark matter.

    Dark matter’s gravity acts like a lens to magnify and distort the galaxies’ light, but its effect is weak — individual galaxies vary enough in shape that the gravitational lensing isn’t noticeable. The key is quantity: measure enough galaxies and the smearing becomes plain.

    Vikram and colleagues measured the smearing to construct a two-dimensional dark matter map, plotting out how much dark matter lies along lines of sight within a 139-square-degree area.

    Since the map traces normal, luminous matter (galaxies and galaxy clusters) as well as the now-visible dark matter web, astronomers can use it to study the connection between the two. Galaxies and clusters don’t exactly trace the underlying dark matter distribution, since normal and dark matter follow different physical laws, so knowing how the two differ is essential for puzzling out longstanding mysteries.

    Mapping Galaxies’ Dark Matter Halos

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    This stacked image of ACT polarization data shows what a single, average dark matter halo looks like. As blobby as it is, its measurements match predictions from dark matter simulations. M. Madhavacheril & others

    After viewing the grand, 500-million-light-year scales of the Dark Energy Survey results, which still only hint at the mammoth survey to come, zooming into recent observations from the Atacama Cosmology Telescope (ACT) is like taking a sip of the shrinking potion in Alice in Wonderland.

    The ACT dark matter maps focus on a scale of a mere 3 million light-years, roughly the size of a dark matter halo around an individual galaxy. Graduate student Mathew Madhavacheril and his advisor Neelima Sehgal (both Stony Brook University) led a team in measuring dark matter’s smearing effect, not on the light from faraway galaxies, but on the most well-traveled light in the universe: the cosmic microwave background (CMB).

    ACT’s polarimeter spent 3 months surveying the glow from photons freed 380,000 years after the Big Bang at a frequency of 146 GHz (corresponding to a wavelength of 2 millimeters). Even though this glow is “bumpy,” varying in brightness from one spot to the next, it’s actually pretty smooth on the arcminute scales probed by ACT. But a million-light-year-wide hunk of intervening dark matter will distort the light and create sharp changes in brightness on these small scales.

    The team looked for such brightness changes and found about 12,000 that matched up with galaxies listed in a Sloan Digital Sky Survey catalog. Each of these galaxies has a massive halo roughly 10 times that of the Milky Way. Stacking all the ACT images together, the team created an image of an average dark matter halo.

    Simply measuring the signal from galaxies’ dark matter halos is an accomplishment — little has been done on these small scales before. The average dark halo’s mass and concentration, as measured from this blobby image, so far match what’s expected from dark matter simulations. The same technique will be applied to the Advanced ACT polarization survey taking place between 2016 and 2018, which will cover ten times the sky area. Eventually, Madhavacheril hopes to trace the growth of dark matter halos over cosmic time.

    Preliminary as they are, these maps pave the way for understanding dark matter’s role in the universe, including its structure, its connection to ordinary matter, and its role in the evolution and fate of the universe.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

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

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

     
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