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  • richardmitnick 10:42 am on August 31, 2015 Permalink | Reply
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    From SLAC: “World’s Most Powerful Digital Camera Sees Construction Green Light” 


    SLAC Lab

    August 31, 2015

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    The LSST’s camera will include a filter-changing mechanism and shutter. This animation shows that mechanism at work, which allows the camera to view different wavelengths; the camera is capable of viewing light from near-ultraviolet to near-infrared (0.3-1 μm) wavelengths. (SLAC National Accelerator Laboratory)

    The Department of Energy has approved the start of construction for a 3.2-gigapixel digital camera – the world’s largest – at the heart of the Large Synoptic Survey Telescope (LSST). Assembled at the DOE’s SLAC National Accelerator Laboratory, the camera will be the eye of LSST, revealing unprecedented details of the universe and helping unravel some of its greatest mysteries.

    The construction milestone, known as Critical Decision 3, is the last major approval decision before the acceptance of the finished camera, said LSST Director Steven Kahn: “Now we can go ahead and procure components and start building it.”

    Starting in 2022, LSST will take digital images of the entire visible southern sky every few nights from atop a mountain called Cerro Pachón in Chile. It will produce a wide, deep and fast survey of the night sky, cataloguing by far the largest number of stars and galaxies ever observed. During a 10-year time frame, LSST will detect tens of billions of objects—the first time a telescope will observe more galaxies than there are people on Earth – and will create movies of the sky with unprecedented details. Funding for the camera comes from the DOE, while financial support for the telescope and site facilities, the data management system, and the education and public outreach infrastructure of LSST comes primarily from the National Science Foundation (NSF).

    The telescope’s camera – the size of a small car and weighing more than three tons – will capture full-sky images at such high resolution that it would take 1,500 high-definition television screens to display just one of them.

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    Rendering of the LSST camera. SLAC is leading the construction of the 3.2-gigapixel camera, which will be the size of a small car and weigh more than 3 tons. The digital camera will be the largest ever built, allowing LSST to create an unprecedented archive of astronomical data that will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand mysterious dark matter and dark energy, which make up 95 percent of the universe. (SLAC National Accelerator Laboratory)

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    In one shot, the Large Synoptic Survey Telescope’s 3.2-gigapixel camera will capture an area of the sky 40 times the size of the full moon (or almost 10 square degrees of sky). LSST’s large mirror and large field of view work together to deliver more light from faint astronomical objects than any optical telescope in the world. (SLAC National Accelerator Laboratory)

    This has already been a busy year for the LSST Project. Its dual-surface primary/tertiary mirror – the first of its kind for a major telescope – was completed; a traditional stone-laying ceremony in northern Chile marked the beginning of on-site construction of the facility; and a nearly 2,000-square-foot, 2-story-tall clean room was completed at SLAC to accommodate fabrication of the camera.

    “We are very gratified to see everyone’s hard work appreciated and acknowledged by this DOE approval,” said SLAC Director Chi-Chang Kao. “SLAC is honored to be partnering with the National Science Foundation and other DOE labs on this groundbreaking endeavor. We’re also excited about the wide range of scientific opportunities offered by LSST, in particular increasing our understanding of dark energy.”

    Components of the camera are being built by an international collaboration of universities and labs, including DOE’s Brookhaven National Laboratory, Lawrence Livermore National Laboratory and SLAC. SLAC is responsible for overall project management and systems engineering, camera body design and fabrication, data acquisition and camera control software, cryostat design and fabrication, and integration and testing of the entire camera. Building and testing the camera will take approximately five years.

    SLAC is also designing and constructing the NSF-funded database for the telescope’s data management system. LSST will generate a vast public archive of data—approximately 6 million gigabytes per year, or the equivalent of shooting roughly 800,000 images with a regular 8-megapixel digital camera every night, albeit of much higher quality and scientific value. This data will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand dark matter and dark energy, which together make up 95 percent of the universe but whose natures remain unknown.

    “We have a busy agenda for the rest of 2015 and 2016,” said Kahn. “Construction of the telescope on the mountain is well underway. The contracts for fabrication of the telescope mount and the dome enclosure have been awarded and the vendors are at full steam.”

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    This exploded view of the LSST’s digital camera highlights its various components, including lenses, shutter and filters. (SLAC National Accelerator Laboratory)

    Nadine Kurita, camera project manager at SLAC, said fabrication of the state-of-the-art sensors for the camera has already begun, and contracts are being awarded for optical elements and other major components. “After several years of focusing on designs and prototypes, we are excited to start construction of key parts of the camera. The coming year will be crucial as we assemble and test the sensors for the focal plane.”

    The National Research Council’s Astronomy and Astrophysics decadal survey, Astro2010, ranked the LSST as the top ground-based priority for the field for the current decade. The recent report of the Particle Physics Project Prioritization Panel of the federal High Energy Physics Advisory Panel, setting forth the strategic plan for U.S. particle physics, also recommended completion of the LSST.

    “We’ve been working hard for years to get to this point,” said Kurita. “Everyone is very excited to start building the camera and take a big step toward conducting a deep survey of the Southern night sky.”

    LSST Exterior
    LSST Interior
    Housing the LSST in Chile at Cerro Pachón

    See the full article here.

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    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 9:27 am on May 18, 2015 Permalink | Reply
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    From BNL: “Galaxy-Gazing Telescope Sensors Pass Important Vision Tests” 

    Brookhaven Lab

    April 28, 2015
    Karen McNulty Walsh

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    Brookhaven physicist Morgan May and Yuki Okura, a postdoctoral fellow from Japan’s RIKEN laboratory stationed at the RIKEN-Brookhaven Research Center, holding Large Synoptic Survey Telescope (LSST) sensor components. Screens show an image of the sensors’ “tree ring” defects and a rendering of the telescope design.

    When you’re building a massive telescope designed to detect subtle shapes in the light emitted by distant galaxies, you’d like to know that the shapes you are seeing are accurate and not the result of defects in your telescope’s sensors. Fortunately sensors for the camera of the Large Synoptic Survey Telescope (LSST), expected to see “first light” from atop a mountain in Chile in 2020, just received very promising “vision” test results from physicists at the U.S. Department of Energy’s Brookhaven National Laboratory.

    LSST Camera
    LSST Interior
    LSST Exterior
    Top, LSST Camera, Balance LSST building and interior

    That’s exciting, said Brookhaven physicist Morgan May, who led the tests, because the galaxy shapes the LSST seeks to see will offer insight into the most mysterious components of our universe: invisible dark matter, which makes up a quarter of the cosmos, and the dark energy scientists suspect has driven the accelerating expansion of the universe and affected the clumpiness of its structure as we see it today.

    “We’ll be looking at 10 billion galaxies to create an unparalleled wide-field astronomical survey of our universe—wider and deeper than all previous telescopes combined. So we’ll have tremendous statistical power to explore the distribution of dark matter and the nature of dark energy, two of the greatest puzzles in physics. We don’t want to be limited by systematic errors in our detectors,” he said.

    Brookhaven scientists are in a unique position to do the testing because, in addition to collaborating on the cosmological mission of the LSST, the Lab is leading the design and fabrication of the sensors for the telescope’s 3.2-gigapixel camera. “We have access to the detectors and can measure their properties; we can simulate the evolution of the universe as a function of the properties of dark energy; and we can determine how the properties of the detector will affect our determination of the properties of dark energy,” May said.

    Working with May, Yuki Okura, a postdoctoral fellow from Japan’s RIKEN laboratory stationed at the RIKEN-Brookhaven Research Center, performed precision studies of micron-sized defects and pixel-by-pixel variations in the silicon sensors, and then modeled their potential impact on the telescope’s ability to detect the effects of dark matter. Their results will be described in a series of publications, including one soon to appear in the Journal of Instrumentation, with former Brookhaven postdoc Andrés Plazas (now at the Jet Propulsion Laboratory) and Toru Tamagawa, head of RIKEN Astrophysics in Japan, as co-authors.

    “What we found is that, although there are still subtle defects and minor variations in the sensors, they are far, far better than those on previous sky survey telescopes, and better even than early prototypes that were built for the LSST,” said May. “Based on these tests, we now know that the primary measurements of the LSST will not be affected by these structural defects.”

    Setting the stage

    The LSST, originally known as the Dark Matter Telescope, will detect the distribution of dark matter throughout the cosmos. The telescope won’t see dark matter directly, but will detect its gravitational interaction with visible forms of matter, namely galaxies.

    “The gravity of dark matter can bend light,” explained May. “So concentrations of dark matter in the universe act as ‘gravitational lenses’ that can change the brightness and shape of background objects, altering their appearance in a way that creates arcs around central mass distributions.”

    The LSST will look at billions of background galaxies and use gravitational lensing to map where the dark matter concentrations are and how much dark matter there is. By looking at galaxies at varying distances from Earth, the LSST collaboration will be able to explore how the distribution of dark matter (and the sprinkling of visible matter) has changed over time.

    “The light is coming to us from very far away, say a billion light years*. That means we are seeing those objects as they were a billion years ago; we are looking at the distant past. When we look at the distribution of dark matter and how it has changed over billions of years, we get insight into the force that shaped the expansion and uneven distribution of matter in the universe today,” said May.

    That “force,” given the name dark energy, makes up 70 percent of the cosmos. By measuring both the growth of structure and the expansion rate of the universe over time, the LSST will help scientists put the idea of dark energy to the test, and uncover its mysterious properties.

    *i light year = about 6 trillion miles

    Testing detectors

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    “Spurious shear” is the calculated distortion that would be caused by “tree ring” defects in an LSST sensor. Images of galaxies falling on the bright arcs would be elongated in the direction tangential to the arcs; those falling on the dark arcs would be elongated perpendicular to the arcs (in the radial direction). The grey scale at right gives the fractional elongation, which is much smaller than in previous sensors, and much smaller than the elongation caused by dark matter’s gravitational lensing—the effect the LSST scientists seek to measure. The sensor contains 4000 x 4000 pixels.

    Detecting the light-bending effects of dark matter requires extreme precision and a high degree of uniformity in the 200 individual silicon sensors that make up the “film” of the LSST’s 3.2-gigapixel digital camera. But growing solid-state silicon sensors from a molten mass is an imperfect process. Even with the best quality control, variation creeps in.

    “The crystals of silicon grow cylindrically from the center outward,” explained May. “If there are tiny variations of impurities in the silicon or the temperature, you can get radial variations in the properties of the silicon that look like concentric tree rings. Those ‘tree rings’ make electric fields that distort the image. The concern is whether this distortion of the image will be confused with the distortion caused by the effects of dark matter.”

    To find out, Okura and May used high-resolution images of the sensor surfaces produced with a uniform light source in Brookhaven Lab’s Instrumentation Division, and image correction software to reveal the barely perceptible presence of tree rings. Then they calculated the electric fields those tree rings would produce and the effect those fields would have on their astronomical images.

    To see whether those effects would distort the LSST’s key measurements, they turned to a two-way process using cosmological simulations.

    “First we program in certain values for the properties of dark energy and run the simulation to see how those properties drive the structure and rate of expansion of the universe,” said Okura. “Then we model how the resulting distribution of dark matter would bend the light picked up in the LSST detectors. Finally, we add the distortion that would be caused by the defects we measured in the sensors, and run the simulation backward to calculate the dark energy properties. If we get essentially the same values we started with, then we know that the distortion caused by the crystal defects is small enough that we don’t have to worry about it.”

    Repeating this process with many different starting values and always coming back to essentially the same starting values, even with the subtle distortion of the detectors added in, has given the team confidence that the tree rings won’t cloud their LSST results.

    “The LSST is going to be able to distinguish very fine differences in dark energy properties,” May said.

    Pixel by pixel

    Working with Columbia University graduate student Andrea Petri, May and Okura conducted another LSST sensor test, this one looking for size variation pixel-by-pixel.

    “The LSST camera is a giant digital camera with over 3 billion pixels. If the pixels are not all the same size, that will also produce something that looks like the lensing effect at a very low level,” May explained.

    So Okura and May undertook a painstaking study to measure pixel size variation. They measured how much light each pixel picks up when light shines on the detector. “Bigger pixels get more light, and smaller ones pick up less,” Okura said, “so you can use the light absorbed as a stand in for pixel size.” The variation they measured is extremely small, but is it small enough to be negligible to the LSST’s measurements?

    Again the team turned to the cosmological simulations. They used calculations to convert the pixel size variation into a virtual lensing effect. Then they added that effect to the gravitational lensing measurements LSST would make when observing simulated universes created from different dark energy starting properties. Again, the calculations worked equally well in reverse, even with the virtual lensing effect added in. These results will soon be submitted for publication in a journal devoted to astrophysics research.

    “We can conclude that the pixel size variation in the LSST sensors we have studied will not confuse our measurement of dark energy properties,” said May.

    With LSST taking pictures of the universe using “film” of unparalleled quality—and capturing images over the widest and deepest expanse of space with enough frequency to create a 3-D map and even a 3-D movie—researchers and the public can look forward to amazing discoveries and surprises.

    Brookhaven’s work on the LSST is funded by the DOE Office of Science.

    See the full article here.

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 3:35 pm on April 14, 2015 Permalink | Reply
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    From Symmetry: “LSST construction begins” 

    Symmetry

    April 14, 2015
    No Writer Credit

    1
    LSST Interior
    LSST Camera
    LSST, exterior, interior, and camera

    The Large Synoptic Survey Telescope will take the most thorough survey ever of the Southern sky

    Today a group will gather in northern Chile to participate in a traditional stone-laying ceremony. The ceremony marks the beginning of construction for a telescope that will use the world’s largest digital camera to take the most thorough survey ever of the Southern sky.

    The 8-meter Large Synoptic Survey Telescope will image the entire visible sky a few times each week for 10 years. It is expected to see first light in 2019 and begin full operation in 2022.

    Collaborators from the US National Science Foundation, the US Department of Energy, Chile’s Ministry of Foreign Affairs and Comisión Nacional de Investigación Científica y Technológica, along with several other international public-private partners will participate in the ceremony.

    “Today, we embark on an exciting moment in astronomical history,” says NSF Director France A. Córdova, an astrophysicist, in a press release. “NSF is thrilled to lead the way in funding a unique facility that has the potential to transform our knowledge of the universe.”

    Equipped with a 3-billion-pixel digital camera, LSST will observe objects as they change or move, providing insight into short-lived transient events such as astronomical explosions and the orbital paths of potentially hazardous asteroids. LSST will take more than 800 panoramic images of the sky each night, allowing for detailed maps of the Milky Way and of our own solar system and charting billions of remote galaxies. Its observations will also probe the imprints of dark matter and dark energy on the evolution of the universe.

    “We are very excited to see the start of the summit construction of the LSST facility,” says James Siegrist, DOE associate director of science for high-energy physics. “By collecting a unique dataset of billions of galaxies, LSST will provide multiple probes of dark energy, helping to tackle one of science’s greatest mysteries.”

    NSF and DOE will share responsibilities over the lifetime of the project. The NSF, through its partnership with the Association of Universities for Research in Astronomy, will develop the site and telescope, along with the extensive data management system. It will also coordinate education and outreach efforts. DOE, through a collaboration led by its SLAC National Accelerator Laboratory, will develop the large-format camera.

    In addition, the Republic of Chile will serve as project host, providing (and protecting) access to some of the darkest and clearest skies in the world over the LSST site on Cerro Pachón, a mountain peak in northern Chile. The site was chosen through an international competition due to the pristine skies, low levels of light pollution, dry climate and the robust and reliable infrastructure available in Chile.

    “Chile has extraordinary natural conditions for astronomical observation, and this is once again demonstrated by the decision to build this unique telescope in Cerro Pachón,” says CONICYT President Francisco Brieva. “We are convinced that the LSST will bring important benefits for science in Chile and worldwide by opening up a new window of observation that will lead to new discoveries.”

    By 2020, 70 percent of the world’s astronomical infrastructure is expected to be concentrated in Chile.

    See the full article here.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 10:55 am on February 3, 2015 Permalink | Reply
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    From NPR: “Hunting For Big Planets Far Beyond Pluto May Soon Be Easier” 

    NPR

    National Public Radio (NPR)

    February 02, 2015
    Nell Greenfieldboyce

    temp
    Stars over the Cerro Tololo Inter-American Observatory in Chile. Sheppard and Trujillo used the new Dark Energy Camera (DECam) on a telescope there to find the distant dwarf planet 2012 VP 113.

    On a mountaintop in Chile, excavators have just started work on a construction site. It will soon be home to a powerful new telescope that will have a good shot at finding the mysterious Planet X, if it exists.

    “Planet X is kind of a catchall name given to any speculation about an unseen companion orbiting the sun,” says Kevin Luhman, an astronomer at Penn State University.

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    The discovery images of 2012 VP113, which has the most distant orbit known in our Solar System. The dwarf planet’s movement suggests its orbit. 2012 VP-113 Source: Carnegie Institution of Science
    Credit: Scott Sheppard

    For more than a century, scientists have observed various things that they thought could be explained by the presence of an unknown planet lurking at the edge of our solar system.

    “There’s a huge volume of space in the outer solar system,” says Luhman. “We know almost nothing about what might be out there.”

    Some conspiracy-minded folks even think that Planet X has already been discovered. “There are a lot of these people on the Internet,” says Luhman, “who think that, for instance, NASA knows about an unseen planet, but it’s on a collision course with Earth and it’s going to destroy us, but they don’t tell us about it.”

    Finding a major new planet would be big news. While dwarf planets like “Sedna” haven’t exactly become household names, a planet the size of Earth or Mars might get added to the list of planets students have to memorize.

    “If you put an object twice as far away, it becomes 16 times fainter. So things get very faint, very fast.”
    Scott Sheppard, astronomer, Carnegie Institution for Science

    Luhman recently went hunting for planet X using WISE, a NASA space telescope that detects infrared light.

    NASA Wise Telescope
    NASA/WISE

    It would have found anything the size of Jupiter or Saturn, because gas giants like these are big enough and warm enough that they produce a lot of infrared light. But last year, Luhman reported that they didn’t see any planet like that.

    3
    Scott Sheppard of the Carnegie Institution of Science. Courtesy of Scott Sheppard/Carnegie Institution of Science

    Still, there may be smaller, cooler planets out there — until recently, scientists had no way to look for them. “Up until a year or two ago, we just didn’t have the technology to do this, because we didn’t have large cameras on large telescopes,” explains Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C.

    Any planet that far away would be very faint, because light would have to travel billions of miles from the sun to the planet, bounce off, and then travel all the way back to our telescopes. “And because of that, if you put an object twice as far away, it becomes 16 times fainter,” Sheppard says. “So, things get very faint, very fast.”

    Sheppard and his colleagues have been searching for very faint objects using a massive camera on a powerful telescope in Chile. Last year, he and Chad Trujillo, of the Gemini Observatory, announced that they’d found a dwarf planet that they nicknamed “Biden,” since its temporary name is 2012 VP113. It’s a little pink ball of ice that’s far beyond Pluto.

    There’s a framed photo of the dwarf planet hanging on the wall of Sheppard’s office; if he has his way, there soon will be more photos up there.

    “Part of this search for these planets in the outer part of the solar system is trying to find out about the neighborhood. I think to find out more about our neighborhood is just really a cool thing.”
    Scott Kenyon, astrophysicist, Smithsonian Astrophysical Observatory

    “We believe there are probably a lot of objects bigger than Pluto still out there,” Sheppard says, “and there could easily be objects as big as Mars or even Earth, out beyond in the very far distant solar system.”

    He’s already found hints of something big: When he looks at the orbits of his dwarf planet and some other small icy bodies, he sees a pattern. “And you wouldn’t expect that,” Sheppard says. “You’d expect the orbits to be completely random.”

    One possible explanation is that the array of objects are all being influenced by the force of a large, unknown planet. “I think, like all new discoveries, this is just the tip of the iceberg,” Trujillo told NPR via email. “And it will probably be quite a while until someone can explain things and most people accept their explanation.”

    In Trujillo’s view, if a large planet is out there, astronomers are unlikely to find it until the Large Synoptic Survey Telescope comes online.

    LSST Exterior
    LSST Interior
    LSST Camera
    LSST

    The device is designed to scan huge swaths of sky for faint objects; the building site for it is already being prepared on top of a mountain in Chile, and construction will begin in earnest this year. The telescope is expected to start operations in the early 2020s.

    “But, we could get lucky,” Trujillo notes — somebody might find the distant planet sooner than that.

    Others agree that the chances of finding something sizable are good.

    “With the next generation of telescopes, or if we’re lucky with the current generation of telescope, it will be possible to detect the light from this planet,” says Scott Kenyon, an astrophysicist at the Smithsonian Astrophysical Observatory in Cambridge, Mass. “If we can see it and pinpoint its position, then everybody will get excited.”

    Finding a big new planet would be like meeting a new neighbor, says Kenyon.

    “You like to know people on your street, or in your apartment building,” he says. “I think that part of this search for these planets in the outer part of the solar system is trying to find out about the neighborhood. I think to find out more about our neighborhood is just really a cool thing.”

    See the full article here.

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  • richardmitnick 1:26 pm on January 22, 2015 Permalink | Reply
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    From FNAL: “Fermilab leads in developing software for LSST Dark Energy Science Collaboration” 

    FNAL Home


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    1
    From left: Fermilab’s Jim Kowalkowski, Marc Paterno, Saba Sehrish, Steve Kent, all of the Scientific Computing Division, and Scott Dodelson, Particle Physics Division, contributed to DESC as part of its Software Working Group, which Dodelson leads. Photo: Rich Blaustein

    Thursday, Jan. 22, 2015
    Rich Blaustein

    At the supercomputing conference SC14, held in November, Fermilab astrophysics and computing experts achieved a milestone with a demonstration run of the analysis framework software they are developing for the Dark Energy Science Collaboration (DESC) of the Large Synoptic Survey Telescope.

    LSST Exterior
    LSST Telescope
    LSST

    LSST Camera
    LSST Camera, being built at SLAC

    The LSST, whose construction is led by SLAC National Accelerator Laboratory, is currently in the advanced design phase and will be placed in Cerro Pachon, Chile. It will be the tool for the world’s largest imaging survey, taking repeated images of the southern sky beginning in 2020.

    The software and data processing demands for the DESC are challenging, to say the least.

    “LSST will truly be a next-generation survey: It will surpass preceding surveys in terms of data size in its first few months of operation,” said University of Pennsylvania astrophysicist Bhuvnesh Jain, spokesperson for the Dark Energy Science Collaboration.

    More than 200 scientists from five countries are currently involved with DESC, and Jain expects the number of scientists involved in DESC to double in the next decade.

    Fermilab astrophysicist Scott Dodelson, convener of the DESC Software Working Group, says the group is designing a framework for all DESC scientists that will facilitate their collaboration and use of tools built by the LSST project team. Steve Kent, Jim Kowalkowski, Marc Paterno and Saba Sehrish, all in Fermilab’s Scientific Computing Division, worked to develop the DESC framework. Sehrish ran the November demonstration.

    The framework links some programs specifically produced for LSST with others written externally or by the scientists themselves. It runs them on supercomputers, networks such as FermiGrid and local resources.

    “The scientists running the DESC workflows will not have to worry about details such as file transport or access to supercomputers to do their dark energy science,” Paterno said. “We demonstrated how this could be done.”

    Dodelson and Kent say that the demonstration was very successful and bodes well for the DESC.

    “The demo was an end-to-end simulation of LSST data and science analyses — that was the really important thing,” Kent said. “It was a walking-through of all the steps and with an eye on eventually expanding to the LSST scale.”

    The group ran simulated images through the interlinked software until at the end it was run through CosmoSIS, a cosmological parameter estimation program to which Dodelson, Kowalkowski, Paterno and Sehrish have contributed.

    The DESC Software Working Group is currently developing another version of the demonstrated framework for the DESC scientists to consider at their February gathering at SLAC.

    Jain said that innovative DESC software will enable explorations of the many astronomical mysteries that LSST will open up.

    “The work of the Fermilab group is really going to pave the way for a new mode of doing software analyses and how people collaborate,” Jain said. “I think it will have far-reaching implications for how we do cosmology.”

    See the full article here.

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    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.

     
  • richardmitnick 7:08 pm on January 12, 2015 Permalink | Reply
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    From Symmetry: “Mirror, mirror” 

    Symmetry

    January 12, 2015
    Kathryn Jepsen

    After more than six years of grinding and polishing, the first-ever dual-surface mirror for a major telescope is complete.

    In March 2008, a group of people gathered around a giant, red oven in a six-story workshop space beneath the bleachers of the University of Arizona football stadium.

    The oven was about 10 meters wide and 2 meters tall, big enough to live in, really. But that day it was rendered less than hospitable by its extreme internal temperature—2200 degrees Fahrenheit—and its persistent spinning at 35 miles per hour. Also, it was full of 22 tons of molten glass.

    This was the “high-fire event,” the day the glass reached its melting point, freeing it to flow into a honeycomb-patterned mold on its way to becoming one of the largest telescope mirrors in the world.

    Now, after months of cooling and more than six years of grinding and polishing, the mirror is complete.

    On Saturday, a new group gathered in the Steward Observatory Mirror Labhttp://mirrorlab.as.arizona.edu/
    —still located under the bleachers—to admire the finished product.

    2
    s
    Steward Observatory Mirror Lab

    It is the first completed piece of the Large Synoptic Survey Telescope, which will eventually be located on Cerro Pachón, a mountain in Chile. In 2022, the massive mirror will enable LSST scientists to begin the most thorough survey ever of the Southern sky.
    Making a movie of the universe

    The mirror goes by the name M1M3, and it’s actually two mirrors in one. The outer ring serves as the first mirror, M1, and another, more steeply curved mirror, M3, has been carved out of the center.

    LSST will capture and focus images of the night sky by bouncing them through a series of three mirrors. Light will shine onto M1, which will reflect it up to another mirror, the 3.4-meter M2, which will reflect it down to M3, which will reflect it up into the lens of a 3.2-gigapixel camera.

    The three-mirror optical system, unique among large telescopes, will allow LSST to take in nearly 10 square degrees of sky with each image—a field of view large enough to fit 40 full moons.

    The combined dual-surface mirror, also unique among large telescopes, will allow scientists to align LSST just as quickly as they could a two-mirror telescope. This will help make LSST nimble enough to scan across the entire Southern sky once every three nights.

    LSST’s frequent sweeps across the same areas of sky will allow scientists to monitor changes to our galaxy and others in a way that has never before been possible.

    They will create time-lapse videos of asteroids, supernovae, variable stars, the effects of dark matter and dark energy—as LSST Director Steve Kahn puts it, “anything that can go bump in the night.” In the end, they hope the survey will lead to a new understanding of our universe.

    The multi-year mirror

    The LSST project has already met a major milestone with the completion of M1M3, although it only recently received federal funding for its construction start.

    In August 2014 the National Science Foundation authorized $473 million for the project. And just this month the US Department of Energy approved $165 million for construction of the LSST camera.

    LSST Camera
    LSST Camera

    The early development of LSST was supported by the LSST Corporation, a non-profit consortium of 40 universities and other research institutions. Building M1M3 and getting started on M2 have been supported by private funding: $20 million from the Charles and Lisa Simonyi Fund for Arts and Sciences; $10 million from Microsoft founder Bill Gates; and more contributions from Interface Inc. founder and chair Richard Caris; the WM Keck Foundation; Wayne Rosing and Dorothy Largay; Eric and Wendy Schmidt; and Edgar Smith.

    For its part, the Tucson-based Research Corporation for Science Advancement contributed $400,000 toward the purchase of the glass.

    This was no ordinary glass; it was high-quality glass made by a specialty company in Japan. It came in chunks weighing a couple of pounds each—light enough for technicians kneeling on a ramp suspended over the mold to pick them up and gently nestle them into place.

    4
    Courtesy of: LSST

    Once the mold was filled, technicians heated it in the oven, which rotated to encourage the glass to travel up the sides and form a shallow bowl shape. The honeycomb design in the mold formed 1600 air pockets in the back of the mirror to reduce its mass and increase temperature-regulating airflow.

    To avoid cracking the mirror, technicians cooled it down slowly over 90 days.

    Scientist Chuck Claver, who has been a part of LSST since it was no more than an interesting idea, was one of the few people in the room when the oven was finally opened.

    “It’s like a cake cover,” he says. “They lift it off with a crane and then there it is… You walk up to this thing and your jaw just drops.”

    Claver keeps a picture of himself and a few other scientists standing in the center of the freshly baked M1M3. “Glass is actually pretty strong stuff. You can take your shoes off and walk on it in socks,” he says.

    “I hate it when they do that,” says LSST Project Manager Victor Krabbendam.

    Once the baking was done, the grinding and polishing began. A special machine shaved and sanded away layers of glass—including several tons from the center to form M2—in a process that removed millimeters and then nanometers at a time.

    “The shape of this mirror has to be good to small fractions of the diameter of a human hair across the whole surface,” Krabbendam says.

    Soon the mirror began to take on a dull shine, like an ice-skating rink after a Zamboni polish. Today, it’s crystal clear.

    After enduring a series of tests, M1M3 will go into storage in a hangar at Tucson International Airport. In a couple of years, scientists will apply a reflective surface and load it on a truck to start its journey to its mountaintop home in Chile.

    5
    Courtesy of: LSST

    See the full article here.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:51 pm on January 9, 2015 Permalink | Reply
    Tags: , , LSST,   

    From SLAC: “World’s Most Powerful Camera Receives Funding Approval” 


    SLAC Lab

    January 9, 2015
    Press Office Contact:
    Andrew Gordon, SLAC National Accelerator Laboratory:
    agordon@slac.stanford.edu, (650) 926-2282

    Scientist Contacts:
    Steven Kahn, SLAC National Accelerator Laboratory/LSST:
    skahn@slac.stanford.edu

    Large Synoptic Survey Telescope Passes Major Milestone

    LSST Exterior
    LSST Interior
    LSST

    Plans for the construction of the world’s largest digital camera at the Department of Energy’s SLAC National Accelerator Laboratory have reached a major milestone. The 3,200-megapixel centerpiece of the Large Synoptic Survey Telescope (LSST), which will provide unprecedented details of the universe and help address some of its biggest mysteries, has received key “Critical Decision 2” approval from the DOE.

    “This important decision endorses the camera fabrication budget that we proposed,” said LSST Director Steven Kahn. “Together with the construction funding we received from the National Science Foundation in August, it is now clear that LSST will have the support it needs to be completed on schedule.”

    Science operations are scheduled to begin in 2022 with LSST taking digital images of the entire visible southern sky every few nights from atop a mountain called Cerro Pachón in Chile. It will produce the widest, deepest and fastest views of the night sky ever observed. Over a 10-year time frame, the observatory will detect tens of billions of objects—the first time a telescope will catalog more objects in the universe than there are people on Earth—and will create movies of the sky with details that have never been seen before.

    LSST will generate a vast public archive of data—approximately 6 million gigabytes per year—that will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand dark matter and dark energy, which make up 95 percent of the universe but whose nature remains unknown.

    “The telescope is a key part of the long-term strategy to study dark energy and other scientific topics in the United States and elsewhere,” said David MacFarlane, SLAC’s director of particle physics and astrophysics. “SLAC places high priority on the successful development and construction of the LSST camera, and is very pleased that the project has achieved this major approval milestone.”

    The LSST team can now move forward with the development of the camera and prepare for the “Critical Decision 3” review process next summer, the last requirement before actual fabrication of the camera can begin. Components of the camera, which will be the size of a small car and weigh more than 3 tons, will be built by an international collaboration of labs and universities, including DOE’s Brookhaven National Laboratory, Lawrence Livermore National Laboratory and SLAC, where the camera will be assembled and tested.

    “Many excellent, hard-working people have been developing LSST for a long time and it is gratifying to see the quality of their efforts being recognized by the DOE approval,” said Steve Ritz of the University of California, Santa Cruz, the lead scientist of the camera project. “We are all excited about the amount of great science that LSST will enable.”

    See the full article here.

    Please help promote STEM in your local schools.

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    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 5:28 pm on August 12, 2014 Permalink | Reply
    Tags: , , , , LSST   

    From LSST E-News: “LSST’s Calypso telescope moved from Kitt Peak to Tucson” 

    LSST E-News

    LSST E-News

    Early in the morning on May 28th, 2014, LSST’s 1.2-meter Calypso telescope took the first step of a long voyage from Kitt Peak National Observatory to Chile’s Cerro Pachón mountain, where it will accompany LSST as an essential calibration instrument. Through the efforts of a skilled team and thorough preparation, the move was successful, and by late-afternoon on the same day, Calypso had been delivered to the NOAO loading bay in Tucson.

    calypso
    Calypso leaving Kitt Peak. Image credit: LSST / Gary Poczulp

    As part of LSST’s calibration work package, Calypso is slated for transport to Chile in 2017. Until then, it will reside at NOAO, where it is being upgraded with a new control system, new drives, and a recoated mirror.

    Once the only privately-owned telescope among the state-of-the-art suite of astronomical facilities on Kitt Peak, Calypso was generously donated to LSST in 2008 by its proprietor, astrophysicist and entrepreneur Dr. Edgar Smith.

    Smith named Calypso after the sharp-sighted Greek goddess who captured Odysseus for seven years – “about the time it took to build [the telescope],” he recalls in Timothy Ferris’s book Seeing in the Dark.

    Now, more than a decade after its initial installation, LSST engineers were faced with the colossal task of dismantling Calypso and removing it from its site before the onset of the summer monsoon season.

    Perched 35 feet off the ground on a 14,000-pound mount, Calypso’s uninstallation was a dedicated operation, requiring over one month of planning, a $25,000 investment in transportation costs, 6 NOAO staff members for truss and optics removal and 8 individuals involved in lifting the telescope from its mount, and a 175-ton crane to complete the job.

    Even so, “Calypso was built to be relocated,” says LSST Telescope and Site subsystem manager Bill Gressler.

    Gressler’s team crafted a custom-made stand in-house for test and transport of the telescope. All optics were carefully removed and placed in special containers to protect them from shock during transportation. The container carrying the mirror – insured at $2.5 million – was carried on a truck with air-ride suspension.

    But the biggest challenge was navigating a 5-axle crane down the narrow road to the Calypso site, a meticulous ¼-mile journey that took 30 minutes.

    Refurbished Calypso “will be a cool robotic machine with a slick, jazzy instrument,” promises Gressler.

    Once installed on Cerro Pachón, Calypso will be used for atmospheric monitoring, measuring water vapor and overall assisting with post-processing of astronomical data produced by LSST. Adjacent to the main telescope on a mound casually known as “Calibration Hill,” Calypso will withstand the same environmental conditions as its much larger companion, surviving 120 mile-per-hour winds while functioning autonomously to provide precise calibration data.

    In the meantime, Calypso’s vacant site at Kitt Peak is up for sale – great views!

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  • richardmitnick 4:37 pm on August 12, 2014 Permalink | Reply
    Tags: , , , LSST,   

    From SLAC Lab: “Construction of Large Synoptic Survey Telescope to Begin” 


    SLAC Lab

    August 4, 2014

    LSST Will Capture Unprecedented View of Night Sky

    LSST Telescope

    On August 1, 2014, the National Science Foundation (NSF) announced an award to the Association of Universities for Research in Astronomy (AURA) to manage construction of the Large Synoptic Survey Telescope (LSST); with this announcement, construction of the LSST observatory can begin.

    When the LSST observatory starts surveying the entire visible southern sky from a Chilean mountaintop in October 2022, it will produce a unique view of the universe—the widest and fastest views of the night sky ever observed. LSST’s vast public archive of data will dramatically advance knowledge of the dark energy and dark matter that make up much of the universe, as well as galaxy formation and potentially hazardous asteroids. The LSST is expected to see “engineering first light” by 2020.

    LSST Camera
    SLAC is leading the construction of the 3,200-megapixel LSST camera, which will be the size of a small car and will weigh more than 3 tons. The digital camera will be the largest ever built for astronomy, allowing LSST to create an unprecedented public archive of data – about 6 million gigabytes per year, the equivalent of shooting roughly 800,000 images with a regular eight-megapixel digital camera every night. (SLAC National Accelerator Laboratory)

    LSST is an NSF and DOE partnership. NSF is responsible for the telescope and site, education and outreach, and the data management system, and DOE is providing the camera and related instrumentation. The National Research Council’s Astronomy and Astrophysics decadal survey ranked the LSST as the top new ground-based priority for the field in its 2010 report “New Worlds, New Horizons.”

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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