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  • richardmitnick 11:37 am on December 10, 2018 Permalink | Reply
    Tags: Advances like those made by Hubble are possible only through sustained publicly-funded research, Arthur “Art” Code, , , , , Lyman Spitzer, , OAO-2, , Space Astronomy Laboratory at UW–Madison, U Wisconsin   

    From Scientific American: “The World’s First Space Telescope” 

    Scientific American

    From Scientific American

    December 7, 2018
    James Lattis

    50 years ago, astronomers launched the Orbiting Astronomical Observatory, whose descendants include the Hubble, Spitzer and James Webb telescopes.

    In July 1958, an astronomer at the University of Wisconsin–Madison named Arthur “Art” Code received a telegram from the fledgling Space Science Board of the National Academy of Sciences. The agency wanted to know what he and his colleagues would do if given the opportunity to launch into Earth’s orbit an instrument weighing up to 100 pounds.

    Code, newly-minted director of the University’s Washburn Observatory, had something in mind. His department was already well known for pioneering a technique for measuring the light emitted by celestial objects, called photoelectric photometry, and Code had joined the university with the intent of adapting it to the burgeoning field of space astronomy.

    He founded the Space Astronomy Laboratory at UW–Madison and, with his colleagues, proposed to launch a small telescope equipped with a photoelectric photometer, designed to measure the ultraviolet (UV) energy output of stars—a task impossible from Earth’s surface. Fifty years ago, on December 7, 1968, that idea culminated in NASA’s launch of the first successful space-based observatory: the Orbiting Astronomical Observatory, or OAO-2.

    NASA U Wisconsin Orbiting Astronomical Observatory OAO-2

    With it was born the era of America’s Great Observatories, bearing the Hubble, Spitzer, Chandra and Compton space telescopes, a time during which our understanding of the universe repeatedly deepened and transformed.

    NASA/ESA Hubble Telescope

    NASA/Spitzer Infrared Telescope

    NASA/Chandra X-ray Telescope

    NASA Compton Gamma Ray Observatory

    Today, dwindling political appetite and lean funding threaten our progress. Contemporary projects like the James Webb Space Telescope flounder, and federal budgets omit promising projects like the Wide Field Infrared Survey Telescope (WFIRST).

    NASA/ESA/CSA Webb Telescope annotated

    NASA WFIRST

    In celebrating the half century since OAO-2’s launch, we are reminded that major scientific achievements like it become part of the public trust, and to make good on the public trust, we must repay our debt to history by investing in our future. Advances like those made by Hubble are possible only through sustained, publicly-funded research.

    These first investments originated in the late 1950s, during the space race between the U.S. the USSR. They led to economic gains in the private sector, technological and scientific innovations, and the birth of new fields of exploration.

    Astronomer Lyman Spitzer, considered the father of the Hubble Space Telescope, first posited the idea of space-based observing seriously in a 1946 RAND Corporation study. By leaving Earth’s atmosphere, he argued, astronomers could point telescopes at and follow nearly anything in the sky, from comets to galaxy clusters, and measure light in a broader range of the electromagnetic spectrum.

    When Code pitched Wisconsin’s idea to the Space Board, the result was NASA funding to create part of the scientific payload for OAO. The agency went to work planning a spacecraft that could support these astronomical instruments. The Cook Electric Company in Chicago and Grumman Aircraft Engineering Corporation in New York won contracts to help pull it off.

    The payload, named the Wisconsin Experiment Package (WEP), bundled five telescopes equipped with photoelectric photometers and two scanning spectrophotometers, all with UV capabilities. The Massachusetts Institute of Technology created a package of X-ray and gamma detectors.

    Scientists and engineers had to make the instruments on OAO both programmable and capable of operating autonomously between ground contacts. Because repairs were impossible once in orbit, they designed redundant systems and operating modes. Scientists also had to innovate systems for handling complex observations, transmitting data to Earth digitally (still a novelty in those days), and for processing data before they landed in the hands of astronomers.

    The first effort, OAO-1, suffered a fatal power failure after launch in 1966, and the scientific instruments were never turned on. But NASA reinvested, and OAO-2 launched with a new WEP from Wisconsin, and this time a complementary instrument from the Smithsonian Astrophysical Observatory, called Celescope, that used television camera technology to produce images of celestial objects emitting UV light. Expected to operate just one year, OAO-2 continued to make observations for four years.

    Numerous “guest” astronomers received access to the instruments during the extended mission. Such collaborations ultimately led to the creation of the Space Telescope Science Institute, which Code helped organize as acting director in 1981.

    And the data yielded many scientific firsts, including a modern understanding of stellar physics, surprise insights into stellar explosions called novae, and exploration of a comet that had far-reaching implications for theories of planet formation and evolution.

    To be responsible beneficiaries of such insights, we must remember that just as we are yesterday’s future, the firsts of tomorrow depend on today. We honor that public trust only by continuing to fund James Webb, WFIRST, and other projects not yet conceived.

    In the forward of a 1971 volume publishing OAO-2’s scientific results, NASA’s Chief of Astronomy Nancy G. Roman wrote: “The performance of this satellite has completely vindicated the early planners and has rewarded … the entire astronomical community with many exciting new discoveries and much important data to aid in the unravelling of the secrets of the stars.”

    Let’s keep unraveling these stellar secrets.

    See the full article here .


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    Please help promote STEM in your local schools.

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    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 2:38 pm on April 14, 2017 Permalink | Reply
    Tags: , , , Ionized hydrogen gas in the Milky Way, U Wisconsin, Wisconsin H-Alpha Mapper (WHAM)   

    From U Wisconsin: “UW project brings Milky Way’s ionized hydrogen into focus” 

    U Wisconsin

    University of Wisconsin

    April 11, 2017
    Terry Devitt
    trdevitt@wisc.edu

    1
    A survey image of ionized hydrogen gas in the Milky Way. The gas, shown in red, is recognized as a distinct feature of the galaxy — the Reynolds Layer — named after former UW–Madison astrophysicist Ron Reynolds, who discovered it. WHAM Collaboration, UW–Madison, Space Science Institute & National Science Foundation.

    Like a lot of pioneering science, the Wisconsin H-Alpha Mapper (WHAM) got its start as the shoestring project of a curious young researcher.

    2
    Wisconsin H-Alpha Mapper (WHAM) at the Cerro Tololo Inter-American Observatory in Chile. WHAM has been an astronomical workhorse, mapping a key ingredient of the Milky Way’s interstellar soup of dust and gas for two decades — first atop Kitt Peak, Arizona, and for about the last decade in the Andes mountains. Photo: L.M. Haffner

    Building on those first efforts to tease out a new and mostly hidden feature of our galaxy, Reynolds and his colleagues, including Matt Haffner, a senior scientist in UW–Madison’s astronomy department, developed WHAM, a spectrometer capable of detecting the faint, diffuse light emanating from the space between the stars. The instrument, supported by the National Science Foundation and operated by the Space Science Institute in Boulder, Colorado, has been in almost continuous operation for the past 20 years. It was first atop Kitt Peak in Arizona and then relocated to Cerro Tololo in Chile, where it has been observing the Southern Hemisphere sky for about the past decade.

    NOAO Kitt Peak National Observatory on the Tohono O’odham reservation outside Tucson, AZ, USA

    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

    This past month, Haffner, who assumed direction of WHAM upon Reynolds’ retirement in 2005, and his colleagues released the deepest, most comprehensive survey to date of the ionized hydrogen that permeates the Milky Way. Now known to astrophysicists as the “Reynolds Layer” after the UW–Madison scientist who discovered it, the feature mapped by WHAM shows a massive amount of ionized hydrogen — a structure 75,000 light years in diameter and 6,000 light years thick — that both envelops the plane of the galaxy and rotates in step with it.

    “It’s kind of like a galactic atmosphere,” says Haffner. “We’re tracing the same kind of emission in the visible part of the spectrum that gives rise to bright nebulae. But over much of the galaxy, it’s just very, very faint.”

    Ionized hydrogen is one ingredient in the soup of elements that make up what astronomers call the interstellar medium, the patchy mix of dust and gas that exists between the stars. The materials found there are part of the big story of galactic life and death, says Haffner, explaining that the clouds of materials found in interstellar space come from dead and dying stars and ultimately will be recycled into new stars and planets.

    The composition and dynamics of the interstellar medium, he says, can reveal how a galaxy evolves over time.

    “Our galaxy is middle-aged,” Haffner says. Middle age for a galaxy means it is not going through the dramatic changes typically experienced by older or younger galaxies. “In that kind of steady state, how does everything work?”

    A critical insight derived from WHAM is that some stars may be bigger actors than previously believed, exerting their influence at greater distances. Ionizing hydrogen or any other element requires energy, and stars are known to ionize atoms in their immediate neighborhoods.

    3
    Infrared image from NASA’s Spitzer Space Telescope shows hundreds of thousands of stars crowded into the swirling core of the Milky Way. NASA photo

    NASA/Spitzer Telescope

    One reason WHAM observes so much ionized hydrogen in the plane of the galaxy is that lots of hot stars reside there. What puzzled astrophysicists, Haffner says, is how clouds of ionized hydrogen can occur light years above the plane.

    “For us to see this emission everywhere, the gas has to be actively ionized,” he says. “What are the sources of energy that keep it going?”

    What Haffner and other scientists think is happening is that what are known as O-type stars — very large, bright and relatively short-lived stars ranging in size from 15 to 90 times the mass of the sun and born deep in the plane of the galaxy — are somehow able to ionize gas across the galaxy, far from the stellar nurseries in its plane. Evidence for this idea was supplied by WHAM data, which in 2003 toppled the notion that ionized hydrogen in the galaxy occurred only in what are known as Strömgren Spheres, nebulae in the immediate vicinity of O-type stars.

    WHAM may one day provide enough data to unravel the mystery of how hydrogen in interstellar deserts can be ionized, far from the stars astronomers think are responsible. It continues its survey of the galaxy on every clear, moonless night, stepping and gathering data in 30-second exposures across wide quadrants of sky.

    More recently, Haffner and his colleagues have been gathering data from the Magellanic Clouds, two smaller neighboring galaxies visible from the Southern Hemisphere.

    4
    Seen from the southern skies, the Large and Small Magellanic Clouds (the LMC and SMC, respectively) are bright patches in the sky. These two irregular dwarf galaxies, together with our Milky Way Galaxy, belong to the so-called Local Group of galaxies.

    Local Group. Andrew Z. Colvin 3 March 2011

    Astronomers once thought that the two Magellanic Clouds orbited the Milky Way, but recent research suggests this is not the case, and that they are in fact on their first pass by the Milky Way. The LMC, lying at a distance of 160 000 light-years, and its neighbour the SMC, some 200 000 light-years away, are among the largest distant objects we can observe with the unaided eye. Both galaxies have notable bar features across their central discs, although the very strong tidal forces exerted by the Milky Way have distorted the galaxies considerably. The mutual gravitational pull of the three interacting galaxies has drawn out long streams of neutral hydrogen that interlink the three galaxies.

    Having data from galaxies beyond the Milky Way, he says, may well provide insight into the puzzles of our own galaxy.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 8:36 pm on March 25, 2015 Permalink | Reply
    Tags: , , , , U Wisconsin   

    From U Wisconsin: “Automation offers big solution to big data in astronomy” 

    U Wisconsin

    University of Wisconsin

    March 24, 2015
    David Tenenbaum

    SKA Map

    It’s almost a rite of passage in physics and astronomy. Scientists spend years scrounging up money to build a fantastic new instrument. Then, when the long-awaited device finally approaches completion, the panic begins: How will they handle the torrent of data?

    That’s the situation now, at least, with the Square Kilometer Array (SKA), a radio telescope planned for Africa and Australia that will have an unprecedented ability to deliver data — lots of data points, with lots of details — on the location and properties of stars, galaxies and giant clouds of hydrogen gas.

    SKA Square Kilometer Array

    In a study published in The Astronomical Journal, a team of scientists at the University of Wisconsin-Madison has developed a new, faster approach to analyzing all that data.

    Hydrogen clouds may seem less flashy than other radio telescope targets, like exploding galaxies. But hydrogen is fundamental to understanding the cosmos, as it is the most common substance in existence and also the “stuff” of stars and galaxies.

    2
    Hubble telescope image of stars forming inside a cloud of cold hydrogen gas and dust in the Carina Nebula, 7,500 light-years away.
    Credit: Space Telescope Science Institute

    As astronomers get ready for SKA, which is expected to be fully operational in the mid-2020s, “there are all these discussions about what we are going to do with the data,” says Robert Lindner, who performed the research as a postdoctoral fellow in astronomy and now works as a data scientist in the private sector. “We don’t have enough servers to store the data. We don’t even have enough electricity to power the servers. And nobody has a clear idea how to process this tidal wave of data so we can make sense out of it.”

    Lindner worked in the lab of Associate Professor Snežana Stanimirović, who studies how hydrogen clouds form and morph into stars, in turn shaping the evolution of galaxies like our own Milky Way.

    In many respects, the hydrogen data from SKA will resemble the vastly slower stream coming from existing radio telescopes. The smallest unit, or pixel, will store every bit of information about all hydrogen directly behind a tiny square in the sky. At first, it is not clear if that pixel registers one cloud of hydrogen or many — but answering that question is the basis for knowing the actual location of all that hydrogen.

    1
    Robert Lindner

    People are visually oriented and talented in making this interpretation, but interpreting each pixel requires 20 to 30 minutes of concentration using the best existing models and software. So, Lindner asks, how will astronomers interpret hydrogen data from the millions of pixels that SKA will spew? “SKA is so much more sensitive than today’s radio telescopes, and so we are making it impossible to do what we have done in the past.”

    In the new study, Lindner and colleagues present a computational approach that solves the hydrogen location problem with just a second of computer time.

    For the study, UW-Madison postdoctoral fellow Carlos Vera-Ciro helped write software that could be trained to interpret the “how many clouds behind the pixel?” problem. The software ran on a high-capacity computer network at UW-Madison called HTCondor. And “graduate student Claire Murray was our ‘human,’” Lindner says. “She provided the hand-analysis for comparison.”

    Those comparisons showed that as the new system swallows SKA’s data deluge, it will be accurate enough to replace manual processing.

    Ultimately, the goal is to explore the formation of stars and galaxies, Lindner says. “We’re trying to understand the initial conditions of star formation — how, where, when do they start? How do you know a star is going to form here and not there?”

    To calculate the overall evolution of the universe, cosmologists rely on crude estimates of initial conditions, Lindner says. By correlating data on hydrogen clouds in the Milky Way with ongoing star formation, data from the new radio telescopes will support real numbers that can be entered into the cosmological models.

    “We are looking at the Milky Way, because that’s what we can study in the greatest detail,” Lindner says, “but when astronomers study extremely distant parts of the universe, they need to assume certain things about gas and star formation, and the Milky Way is the only place we can get good numbers on that.”

    With automated data processing, “suddenly we are not time-limited,” Lindner says. “Let’s take the whole survey from SKA. Even if each pixel is not quite as precise, maybe, as a human calculation, we can do a thousand or a million times more pixels, and so that averages out in our favor.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 4:13 pm on January 14, 2015 Permalink | Reply
    Tags: , , , U Wisconsin   

    From U Wisconsin: “Chemical dial controls attraction between water-repelling molecules” 

    U Wisconsin

    University of Wisconsin

    Jan. 14, 2015
    Chris Barncard

    Fear of water may seem like an irrational hindrance to humans, but on a molecular level, it lends order to the world.

    Some substances — lots of greasy, oily ones in particular — are hydrophobic. They have no attraction to water, and essentially appear repelled by the stuff.

    s
    Sam Gellman

    Combine hydrophobic pieces in a molecule with parts that are instead attracted to water, and sides are taken. Structure appears, as in the membranes that encircle living cells.

    “Those membranes are formed by molecules that are mostly greasy, and that pack together to avoid interacting with water,” says Sam Gellman, a University of Wisconsin–Madison chemistry professor. “The hydrophilic parts point in one direction — toward water — and the hydrophobic parts in the other, and the result is molecular organization that forms a wall.”

    And with it, all the things of life that require the wall’s protection.

    “It’s arguably one of the most important interactions between molecules, because it occurs in water where biology and so much technology happens,” says Nicholas Abbott, a UW–Madison chemical and biological engineering professor.

    Abbott, Gellman and a group of University of Wisconsin–Madison researchers have provided new insights on hydrophobic interactions within complex systems. In a study published today in the journal Nature, the researchers show how the nearby presence of polar (water-attracted, or hydrophilic) substances can change the way the nonpolar hydrophobic groups want to stick to each other.

    The team built simple molecules with stable structures that incorporated hydrophobic and hydrophilic groups in precisely determined patterns. Then they used an atomic force microscope, a tool that allowed them to probe the surface of the molecules by tugging hydrophobic units apart and measuring the stickiness between them.

    n
    Nicholas Abbott

    “We show that if you have two nonpolar groups, and they are going to interact through water, the way they interact depends on their neighbors,” Abbott says. “It’s just like a pair of friends having a conversation. The way in which they interact will depend on who is standing close enough to hear.”

    It’s been theorized that the bonds between hydrophobic particles would indeed change in the presence of charged, water-loving molecules. The researchers’ experiments demonstrated those effects, and noticed also that as the chemical structure of charged hydrophilic groups change, so does the magnitude of their impact on the stickiness between hydrophobic groups.

    “That sticky interaction is defined by the hydrophobic effect,” Gellman says. “And our measurements show that it’s possible to place polar groups in a way that can dial up or dial down the adhesion between two hydrophobic surfaces in water.”

    This level of control could offer a new way to design all sorts of molecules that perform useful functions in water, such as ointments based on emulsions, food products, detergents and more.

    “You can imagine new designs of switchable materials, smart materials, and maybe drug delivery systems that can release an active agent in a controlled manner by manipulating this interaction,” Abbott says.

    The collaborators’ work, which was supported by the National Science Foundation and sparked by a partnership made possible through UW–Madison’s Nanoscale Science and Engineering Center, may also sharpen the way biologists view changes in proteins.

    Proteins that catalyze reactions and pass information at the molecular level in living cells are often very complex combinations of hydrophobic and hydrophilic groups. The qualities of their component parts that attract or repel water play a role in the way proteins fold up, which then determines whether and how they perform their intended tasks.

    After proteins are synthesized and fold up in their proper shapes, biological processes begin to modify their structure — adding here or replacing there.

    “Another implication of our research,” Gellman says, “is that those changes can have profound effects that have not previously been understood.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
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