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  • richardmitnick 12:32 pm on August 19, 2017 Permalink | Reply
    Tags: , , Basic Research, , Cosmic Magnifying Lens Reveals Inner Jets of Black Holes, , Gravitational lensing system discovered by OVRO, Much more distant galaxy containing a jet-spewing supermassive black hole, OVRO-Caltech's Owens Valley Radio Observatory   

    From Caltech: “Cosmic Magnifying Lens Reveals Inner Jets of Black Holes” 

    Caltech Logo

    Caltech

    08/15/2017

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Illustration shows the likely configuration of a gravitational lensing system discovered by OVRO. The “milli-lens” is located in or near the intervening spiral galaxy. The lens is magnifying blobs of jet material within the active galaxy PKS1413+135, but the blobs are too small to be seen in the radio image (top left), taken by MOJAVE. Only when the blobs move far away from the yellow core do they expand and are visible as the pink blobs in the image.
    Credit: Anthony Readhead/Caltech/MOJAVE

    Caltech Owens Valley Radio Observatory, Owens Valley, California

    1
    Image of the 40-meter telescope of the Owens Valley Radio Observatory (OVRO), located near Bishop, California.
    Credit: Anthony Readhead/Caltech

    Astronomers using Caltech’s Owens Valley Radio Observatory (OVRO) have found evidence for a bizarre lensing system in space, in which a large assemblage of stars is magnifying a much more distant galaxy containing a jet-spewing supermassive black hole. The discovery provides the best view yet of blobs of hot gas that shoot out from supermassive black holes.

    “We have known about the existence of these clumps of material streaming along black hole jets, and that they move close to the speed of light, but not much is known about their internal structure or how they are launched,” says Harish Vedantham, a Caltech Millikan Postdoctoral Scholar. “With lensing systems like this one, we can see the clumps closer to the central engine of the black hole and in much more detail than before.” Vedantham is lead author of two new studies describing the results in the Aug. 15 issue of The Astrophysical Journal. The international project is led by Anthony Readhead, the Robinson Professor of Astronomy, Emeritus, and director of the OVRO.

    Many supermassive black holes at the centers of galaxies blast out jets of gas traveling near the speed of light. The gravity of black holes pulls material toward them, but some of that material ends up ejected away from the black hole in jets. The jets are active for one to 10 million years—every few years, they spit out additional clumps of hot material. With the new gravitational lensing system, these clumps can be seen at scales about 100 times smaller than before.

    “The clumps we’re seeing are very close to the central black hole and are tiny—only a few light-days across. We think these tiny components moving at close to the speed of light are being magnified by a gravitational lens in the foreground spiral galaxy,” says Readhead. “This provides exquisite resolution of a millionth of a second of arc, which is equivalent to viewing a grain of salt on the moon from Earth.”

    A critical element of this lensing system is the lens itself. The scientists think that this could be the first lens of intermediate mass—which means that it is bigger than previously observed “micro” lenses consisting of single stars and smaller than the well-studied massive lenses as big as galaxies. The lens described in the new paper, dubbed a “milli-lens,” is thought to be about 10,000 solar masses, and most likely consists of a cluster of stars. An advantage of a milli-sized lens is that it is small enough not to block the entire source, which allows the jet clumps to be magnified and viewed as they travel, one by one, behind the lens. What’s more, the researchers say the lens itself is of scientific interest because not much is known about objects of this intermediate-mass range.

    “This system could provide a superb cosmic laboratory for both the study of gravitational milli-lensing and the inner workings of the nuclear jet in an active galaxy,” says Readhead.

    The new findings are part of an OVRO program to obtain twice-weekly observations of 1,800 active supermassive black holes and their host galaxies, using OVRO’s 40-meter telescope, which detects radio emissions from celestial objects. The program has been running since 2008 in support of NASA’s Fermi mission, which observes the same galaxies in higher-energy gamma rays.

    In 2010, the OVRO researchers noticed something unusual happening with the galaxy in the study, an active galaxy called PKS 1413+ 135. Its radio emission had brightened, faded, and then brightened again in a very symmetrical fashion over the course of a year. The same type of event happened again in 2015. After a careful analysis that ruled out other scenarios, the researchers concluded that the overall brightening of the galaxy is most likely due to two successive high-speed clumps ejected by the galaxy’s black hole a few years apart. The clumps traveled along the jet and became magnified when they passed behind the milli-lens.

    “It has taken observations of a huge number of galaxies to find this one object with the symmetrical dips in brightness that point to the presence of a gravitational lens,” says coauthor Timothy Pearson, a senior research scientist at Caltech who helped discover in 1981 that the jet clumps travel at close to the speed of light. “We are now looking hard at all our other data to try to find similar objects that can give a magnified view of galactic nuclei.”

    The next step to confirm the PKS 1413+ 135 results is to observe the galaxy with a technique called very-long-baseline interferometry (VLBI), in which radio telescopes across the globe work together to image cosmic objects in detail. The researchers plan to use this technique beginning this fall to look at the galaxy and its supermassive black hole, which is expected to shoot out another clump of jet material in the next few years. With the VLBI technique, they should be able to see the clump smeared out into an arc across the sky via the light-bending effects of the milli-lens. Identifying an arc would confirm that indeed a milli-lens is magnifying the ultra-fast jet clumps spewing from a supermassive black hole.

    “We couldn’t do studies like these without a university observatory like the Owens Valley Radio Observatory, where we have the time to dedicate a large telescope exclusively to a single program,” said Readhead.

    Additional authors of The Astrophysical Journal studies are: Vikram Ravi of Caltech; Walter Max-Moerbeck (MS ’08, PhD ’13) and Anton Zensus of the Max Planck Institute for Radio Astronomy; Talvikki Hovatta of University of Turku and the Aalto University Metsähovi Radio Observatory; Anne Lähteenmäki and Merja Tornikoski of the Aalto University Metsähovi Radio Observatory; Mark Gurwell (MS ’92, PhD ’96) of the Smithsonian Astrophysical Observatory; Roger Blandford of Stanford University; Rodrigo Reeves of the University of Concepción; and Vasiliki Pavlidou of the University of Crete.

    The two studies, titled, Symmetric Achromatic Variability in Active Galaxies: A Powerful New Gravitational Lensing Probe? and The Peculiar Light Curve of J1415+1320: A Case Study in Extreme Scattering Events, are funded by NASA, the National Science Foundation, the Smithsonian Institution, the Academia Sinica, the Academy of Finland, and the Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA).

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

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  • richardmitnick 3:49 pm on August 18, 2017 Permalink | Reply
    Tags: , , Basic Research, , , The Origin of Binary Stars   

    From CfA: “The Origin of Binary Stars” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

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    An image taken at submillimeter wavelengths of a star-forming core, showing that it contains two young stellar embryos. Astronomers have concluded from a systematic study of very young cores that most embryonic stars form in multiple systems, and later some of them separate.
    Sadavoy and Stahler

    The origin of binary stars has long been one of the central problems of astronomy. One of the main questions is how stellar mass affects the tendency to be multiple. There have been numerous studies of young stars in molecular clouds to look for variations in binary frequency with stellar mass, but so many other effects can influence the result that the results have been inconclusive. These complicating factors include dynamical interactions between stars that can eject one member of a multiple system, or on the other hand might capture a passing star under the right circumstances. Some studies, for example, found that younger stars are more likely to be found in binary pairs. One issue with much of the previous observational work, however, has been the small sample sizes.

    CfA astronomer Sarah Sadavoy and her colleague used combined observations from a large radio wavelength survey of young stars in the Perseus cloud with submillimeter observations of the natal dense core material around these stars to identify twenty-four multiple systems. The scientists then used a submillimeter study to identify and characterize the dust cores in which the stars are buried. They found that most of the embedded binaries are located near the centers of their dust cores, indicative of their still being young enough to have not drifted away. About half of the binaries are in elongated core structures, and they conclude that the initial cores were also elongated structures. After modeling their findings, they argue that the most likely scenarios are the ones predicting that all stars, both single and binaries, form in widely separated binary pair systems, but that most of these break apart either due to ejection or to the core itself breaking apart. A few systems become more tightly bound. Although other studies have suggested this idea as well, this is the first study to do so based on observations of very young, still embedded stars. One of their most significant major conclusions is that each dusty core of material is likely to be the birthplace of two stars, not the single star usually modeled. This means that there are probably twice as many stars being formed per core than is generally believed.

    Reference(s):

    Embedded Binaries and Their Dense Cores, Sarah I. Sadavoy and Steven W. Stahler, MNRAS

    See the full article here .

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    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 3:30 pm on August 18, 2017 Permalink | Reply
    Tags: , , Basic Research, , , Gliese 832b and Gliese 832c were discovered by the radial velocity technique, Star system Gliese 832,   

    From U Texas Arlington: “UTA astrophysicists predict Earth-like planet may exist in star system only 16 light years away” 

    U Texas Arlington

    University of Texas at Arlington

    August 17, 2017
    Louisa Kellie
    Office: 817‑272‑0864
    Cell: 817-524-8926
    louisa.kellie@uta.edu

    1
    Astrophysicists at the University of Texas at Arlington have predicted that an Earth-like planet may be lurking in a star system just 16 light years away.

    The team investigated the star system Gliese 832 for additional exoplanets residing between the two currently known alien worlds in this system. Their computations revealed that an additional Earth-like planet with a dynamically stable configuration may be residing at a distance ranging from 0.25 to 2.0 astronomical unit (AU) from the star.

    “According to our calculations, this hypothetical alien world would probably have a mass between 1 to 15 Earth’s masses,” said the lead author Suman Satyal, UTA physics researcher, lecturer and laboratory supervisor. The paper is co-authored by John Griffith, UTA undergraduate student and long-time UTA physics professor Zdzislaw Musielak.

    The astrophysicists published their findings this week as Dynamics of a probable Earth-Like Planet in the GJ 832 System in The Astrophysical Journal.

    UTA Physics Chair Alexander Weiss congratulated the researchers on their work, which underscores the University’s commitment to data-driven discovery within its Strategic Plan 2020: Bold Solutions | Global Impact.

    “This is an important breakthrough demonstrating the possible existence of a potential new planet orbiting a star close to our own,” Weiss said. “The fact that Dr. Satyal was able to demonstrate that the planet could maintain a stable orbit in the habitable zone of a red dwarf for more than 1 billion years is extremely impressive and demonstrates the world class capabilities of our department’s astrophysics group.”

    Gliese 832 is a red dwarf and has just under half the mass and radius of our sun. The star is orbited by a giant Jupiter-like exoplanet designated Gliese 832b and by a super-Earth planet Gliese 832c. The gas giant with 0.64 Jupiter masses is orbiting the star at a distance of 3.53 AU, while the other planet is potentially a rocky world, around five times more massive than the Earth, residing very close its host star—about 0.16 AU

    For this research, the team analyzed the simulated data with an injected Earth-mass planet on this nearby planetary system hoping to find a stable orbital configuration for the planet that may be located in a vast space between the two known planets.

    Gliese 832b and Gliese 832c were discovered by the radial velocity technique, which detects variations in the velocity of the central star, due to the changing direction of the gravitational pull from an unseen exoplanet as it orbits the star. By regularly looking at the spectrum of a star – and so, measuring its velocity – one can see if it moves periodically due to the influence of a companion.

    “We also used the integrated data from the time evolution of orbital parameters to generate the synthetic radial velocity curves of the known and the Earth-like planets in the system,” said Satyal, who earned his Ph.D. in Astrophysics from UTA in 2014. “We obtained several radial velocity curves for varying masses and distances indicating a possible new middle planet,” the astrophysicist noted.

    For instance, if the new planet is located around 1 AU from the star, it has an upper mass limit of 10 Earth masses and a generated radial velocity signal of 1.4 meters per second. A planet with about the mass of the Earth at the same location would have radial velocity signal of only 0.14 m/s, thus much smaller and hard to detect with the current technology.

    “The existence of this possible planet is supported by long-term orbital stability of the system, orbital dynamics and the synthetic radial velocity signal analysis”, Satyal said. “At the same time, a significantly large number of radial velocity observations, transit method studies, as well as direct imaging are still needed to confirm the presence of possible new planets in the Gliese 832 system.”

    In 2014, Noyola, Satyal and Musielak published findings related to radio emissions indicating that an exomoon could be orbiting an exoplanet in The Astrophysical Journal, where they suggested that interactions between Jupiter’s magnetic field and its moon Io may be used to detect exomoons at distant exoplanetary systems.

    Zdzislaw Musielak joined the UTA physics faculty in 1998 following his doctoral program at the University of Gdansk in Poland and appointments at the University of Heidelberg in Germany; Massachusetts Institute of Technology, NASA Marshall Space Flight Center and the University of Alabama in Huntsville.

    Suman Satyal is a research assistant, laboratory supervisor and physics lecturer at UTA and his research area includes the detection of exoplanets and exomoons, and orbital stability analysis of Exoplanets in single and binary star systems. He previously worked in the National Synchrotron Light Source located at the Brookhaven National Laboratory in New York, where he measured the background in auger-photoemission coincidence spectra associated with multi-electron valence band photoemission processes.

    See the full article here .

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    U Texas Arlington Campus

    The University of Texas at Arlington is a growing research powerhouse committed to life-enhancing discovery, innovative instruction, and caring community engagement. An educational leader in the heart of the thriving North Texas region, UT Arlington nurtures minds within an environment that values excellence, ingenuity, and diversity.

    Guided by world-class faculty members, the University’s more than 48,000 students in Texas and around the world represent 120 countries and pursue more than 180 bachelor’s, master’s, and doctoral degrees in a broad range of disciplines. UT Arlington is dedicated to producing the lifelong learners and critical thinkers our region and nation demand. More than 60 percent of the University’s 190,000 alumni live in North Texas and contribute to our annual economic impact of $12.8 billion in the region.

    With a growing number of campus residents, UT Arlington has become a first-choice university for students seeking a vibrant college experience. In addition to receiving a first-rate education, our students participate in a robust slate of co-curricular activities that prepare them to become the next generation of leaders.

     
  • richardmitnick 2:19 pm on August 18, 2017 Permalink | Reply
    Tags: , , Basic Research, Brown dwarf binaries, , , Goal was to measure the masses of the objects in these binaries, ,   

    From CFHT: “Astronomers prove what separates true stars from wannabes” 

    CFHT icon
    Canada France Hawaii Telescope

    June 5, 2017 [Just presented in social media.]

    Dr. Roy Gal
    University of Hawaii at Manoa
    +1 301-728-8637
    rgal@ifa.hawaii.edu

    Dr. Trent Dupuy
    The University of Texas at Austin
    +1 318-344-0975
    tdupuy@astro.as.utexas.edu

    Dr. Michael Liu
    University of Hawaii at Manoa
    +1 808-956-6666
    mliu@ifa.hawaii.edu

    “When we look up and see the stars shining at night, we are seeing only part of the story,” said Trent Dupuy of the University of Texas at Austin and a graduate of the Institute for Astronomy at the University of Hawaii at Manoa. “Not everything that could be a star ‘makes it,’ and figuring out why this process sometimes fails is just as important as understanding when it succeeds.”

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    Professor Michael Liu stands in front of WIRCam, CFHT’s infrared camera that was used for this decade long study.

    Dupuy is the lead author of the study and will present his research today in a news conference at the semi-annual meeting of the American Astronomical Society in Austin.

    Stars form when a cloud of gas and dust collapses due to gravity, and the resulting ball of matter becomes hot enough and dense enough to sustain nuclear fusion at its core. Fusion produces huge amounts of energy — it’s what makes stars shine. In the Sun’s case, it’s what makes most life on Earth possible.

    But not all collapsing gas clouds are created equal. Sometimes, the collapsing cloud makes a ball that isn’t dense enough to ignite fusion. These ‘failed stars’ are known as brown dwarfs.

    This simple division between stars and brown dwarfs has been used for a long time. In fact, astronomers have had theories about how massive the collapsing ball has to be in order to form a star (or not) for over 50 years. However, the dividing line in mass has never been confirmed by experiment.

    Now, astronomers Dupuy and Michael Liu of the University of Hawaii, who is a co-author of the study, have done just that. They found that an object must weigh at least 70 Jupiters in order to start hydrogen fusion. If it weighs less, the star does not ignite and becomes a brown dwarf instead.

    How did they reach that conclusion? For a decade, the two studied 31 faint brown dwarf binaries (pairs of these objects that orbit each other) using two powerful telescopes in Hawaii — the W. M. Keck Observatory and Canada-France-Hawaii telescopes — as well as data from the Hubble Space Telescope.


    Keck Observatory, Maunakea, Hawaii, USA

    NASA/ESA Hubble Telescope

    Their goal was to measure the masses of the objects in these binaries, since mass defines the boundary between stars and brown dwarfs. Astronomers have been using binaries to measure masses of stars for more than a century. To determine the masses of a binary, one measures the size and speed of the stars’ orbits around an invisible point between them where the pull of gravity is equal (known as the “center of mass”). However, binary brown dwarfs orbit much more slowly than binary stars, due to their lower masses. And because brown dwarfs are dimmer than stars, they can only be well studied with the world’s most powerful telescopes.

    To measure masses, Dupuy and Liu collected images of the brown-dwarf binaries over several years, tracking their orbital motions using high-precision observations. They used the 10-meter Keck Observatory telescope, along with its laser guide star adaptive optics system, and the Hubble Space Telescope, to obtain the extremely sharp images needed to distinguish the light from each object in the pair.

    However, the price of such zoomed-in, high-resolution images is that there is no reference frame to identify the center of mass. Wide-field images from the Canada-France-Hawaii Telescope containing hundreds of stars provided the reference grid needed to measure the center of mass for every binary. The precise positions needed to make these measurements are one of the specialties of WIRCam, the wide field infrared camera at CFHT. “Working with Trent Dupuy and Mike Liu over the last decade has not only benefited their work but our understanding of what is possible with WIRCam as well” says Daniel Devost, director of science operations at CFHT. “This is one of the first programs I worked on when I started at CFHT so this makes this discovery even more exciting.”

    The result of the decade-long observing program is the first large sample of brown dwarf masses. The information they have assembled has allowed them to draw a number of conclusions about what distinguishes stars from brown dwarfs.

    Objects heavier than 70 Jupiter masses are not cold enough to be brown dwarfs, implying that they are all stars powered by nuclear fusion. Therefore 70 Jupiters is the critical mass below which objects are fated to be brown dwarfs. This minimum mass is somewhat lower than theories had predicted but still consistent with the latest models of brown dwarf evolution.

    In addition to the mass cutoff, they discovered a surface temperature cutoff. Any object cooler than 1,600 Kelvin (about 2,400 degrees Fahrenheit) is not a star, but a brown dwarf.

    This new work will help astronomers understand the conditions under which stars form and evolve — or sometimes fail. In turn, the success or failure of star formation has an impact on how, where, and why solar systems form.

    “As they say, good things come to those who wait. While we’ve had many interesting brown dwarf results over the past 10 years, this large sample of masses is the big payoff. These measurements will be fundamental to understanding both brown dwarfs and stars for a very long time,” concludes Liu.

    This research will be published in The Astrophysical Journal Supplement.

    See the full article here .
    See the U Hawaii press release here .

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    The CFH observatory hosts a world-class, 3.6 meter optical/infrared telescope. The observatory is located atop the summit of Mauna Kea, a 4200 meter, dormant volcano located on the island of Hawaii. The CFH Telescope became operational in 1979. The mission of CFHT is to provide for its user community a versatile and state-of-the-art astronomical observing facility which is well matched to the scientific goals of that community and which fully exploits the potential of the Mauna Kea site.

    CFHT Telescope
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  • richardmitnick 10:34 am on August 18, 2017 Permalink | Reply
    Tags: A Fleeting Blue Glow, , , Basic Research, , LCO-Las Cumbres Observatory, Supernova,   

    From UCSB: “A Fleeting Blue Glow” 

    UC Santa Barbara Name bloc
    UC Santa Barbara

    August 14, 2017
    Julie Cohen

    Observations of a supernova colliding with a nearby companion star take UCSB astrophysicists by surprise.

    1
    Only 55 million lightyears away, this is one of the closest supernovae discovered in recent years.

    In the 2009 film “Star Trek,” a supernova hurtles through space and obliterates a planet unfortunate enough to be in its path. Fiction, of course, but it turns out the notion is not so farfetched.

    Using the nearby Las Cumbres Observatory (LCO), astrophysicists from UC Santa Barbara have observed something similar: an exploding star slamming into a nearby companion star.

    LCOGT Las Cumbres Observatory Global Telescope Network, Haleakala Hawaii, USA

    What’s more, they detected the fleeting blue glow from the interaction at an unprecedented level of detail. Their observations revealed surprising information about the mysterious companion star, a feat made possible by recent advances in linking telescopes into a robotic network. The team’s findings appear in the journal Astrophyiscal Journal Letters.

    The identity of this particular companion has been hotly debated for more than 50 years. Prevailing theory over the last few years has held that the supernovae happen when two white dwarfs spiral together and merge. This new study demonstrates that the supernova collided with the companion star that was not a white dwarf. White dwarf stars are the dead cores of what used to be normal stars like the sun.

    “We’ve been looking for this effect — a supernova crashing into its companion star — since it was predicted in 2010,” said lead author Griffin Hosseinzadeh, a UCSB graduate student. “Hints have been seen before, but this time the evidence is overwhelming.”

    The supernova in question is SN 2017cbv, a thermonuclear Type Ia, which astronomers use to measure the acceleration of the expansion of the universe. This kind of supernova is known to be the explosion of a white dwarf star, though it requires additional mass from a companion star to explode.

    The UCSB-led research implies that the white dwarf was stealing matter from a much larger companion star — approximately 20 times the radius of the sun — which caused the white dwarf to explode. The collision of the supernova and the companion star shocked the supernova material, heating it to a blue glow heavy in ultraviolet light. Such a shock could not have been produced if the companion were another white dwarf star.

    “The universe is crazier than science fiction authors have dared to imagine,” said Andy Howell, a staff scientist at LCO and Hosseinzadeh’s Ph.D. adviser. “Supernovae can wreck nearby stars, too, releasing unbelievable amounts of energy in the process.”

    Co-author David Sand, an associate professor at the University of Arizona, discovered the supernova on March 10, 2017, in the galaxy NGC 5643. Only 55 million lightyears away, SN 2017cbv was one of the closest supernovae discovered in recent years, found by the DLT40 survey using the Panchromatic Robotic Optical Monitoring and Polarimetry Telescope (PROMPT) in Chile, which monitors galaxies nightly at distances less than 40 megaparsecs (120 million light-years). This was one of the earliest catches ever — within a day, perhaps even hours, of its explosion. The DLT40 survey was created by Sand and study co-author Stefano Valenti, an assistant professor at UC Davis; both were previously postdoctoral researchers at LCO.

    Within minutes of discovery, Sand activated observations with LCO’s global network of 18 robotic telescopes, spaced around the Earth so that one is always on the night side. This allowed the team to take immediate and near-continuous observations.

    “With LCO’s ability to monitor the supernova every few hours, we were able to see the full extent of the rise and fall of the blue glow for the first time,” Hosseinzadeh said. “Conventional telescopes would have had only a data point or two and missed it.”

    Howell likened the event to gaining astronomical superpowers that give astronomers the ability to see the universe in new ways. “These capabilities were just a dream a few years ago,” he said. “But now we’re living the dream and unlocking the origins of supernovae in the process.”

    See the full article here .

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    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 9:58 am on August 18, 2017 Permalink | Reply
    Tags: , Back to school for Science Week, Basic Research, ,   

    From CSIRO: “Back to school for Science Week” 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    18 Aug 2017
    Ashleigh Fortington
    +61 2 4960 6142
    Ashleigh.Fortington@csiro.au

    More than 350 Australian schools are today welcoming Science, Technology, Engineering and Maths (STEM) professionals into their classrooms – virtually and physically – to promote the importance of STEM to Australia’s future.

    1

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    Minister for Industry, Innovation and Science, Senator the Hon Arthur Sinodinos AO talks to Gundaroo primary students about all things science during our STEM in Schools event.

    3
    Minister for Education and Training, Senator the Hon Simon Birmingham working with East Adelaide Primary School students as part of STEM in Schools.

    The STEM in Schools event, run by CSIRO, Australia’s national science agency, forms part of National Science Week and will see classrooms across the country come alive with science as students participate in a virtual classroom discussion with STEM professionals working in the international space industry.

    Many also have the opportunity to take part in hands-on science activities with CSIRO scientists.

    More than 30 Federal MPs will also head back to school for the day and join students in the activities, underlining the national importance of STEM for Australia’s future.

    With research indicating that 75 per cent of the fastest growing occupations now require STEM skills and knowledge, it is now more important than ever to engage students in science, technology, engineering and maths.

    CSIRO Chief Executive Dr Larry Marshall said the event was about inspiring a curiosity and passion in science that will encourage more students to pursue STEM as a foundation of their future.

    “For Australia to prosper, we need to empower our students to calmly and confidently stare into the face of Australia’s challenges, knowing that science has the power to solve the impossible and turn challenge into opportunity,” Dr Marshall said.

    “STEM in Schools teaches our children how they can reshape the future, inspiring them with the possibilities of science. These students will go on to become our scientists, engineers, business leaders and entrepreneurs of tomorrow.”

    STEM in Schools events are taking place in over 350 schools around Australia, with over 70 CSIRO staff and 30 members of parliament visiting schools across the country to conduct activities and share their passion for STEM.

    Follow the conversation and see all the action from the events across the country with #STEMinSchools on Twitter, Facebook and Instagram.

    See the full article here .

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    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 3:07 pm on August 17, 2017 Permalink | Reply
    Tags: , , Basic Research, , ,   

    From JPL: “Scientists Improve Brown Dwarf Weather Forecasts” 

    NASA JPL Banner

    JPL-Caltech

    August 17, 2017
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    1
    This artist’s concept shows a brown dwarf with bands of clouds, thought to resemble those seen at Neptune and the other outer planets. Credit: NASA/JPL-Caltech

    Dim objects called brown dwarfs, less massive than the Sun but more massive than Jupiter, have powerful winds and clouds — specifically, hot patchy clouds made of iron droplets and silicate dust. Scientists recently realized these giant clouds can move and thicken or thin surprisingly rapidly, in less than an Earth day, but did not understand why.

    Now, researchers have a new model for explaining how clouds move and change shape in brown dwarfs, using insights from NASA’s Spitzer Space Telescope. Giant waves cause large-scale movement of particles in brown dwarfs’ atmospheres, changing the thickness of the silicate clouds, researchers report in the journal Science. The study also suggests these clouds are organized in bands confined to different latitudes, traveling with different speeds in different bands.

    “This is the first time we have seen atmospheric bands and waves in brown dwarfs,” said lead author Daniel Apai, associate professor of astronomy and planetary sciences at the University of Arizona in Tucson.

    Just as in Earth’s ocean, different types of waves can form in planetary atmospheres. For example, in Earth’s atmosphere, very long waves mix cold air from the polar regions to mid-latitudes, which often lead clouds to form or dissipate.

    The distribution and motions of the clouds on brown dwarfs in this study are more similar to those seen on Jupiter, Saturn, Uranus and Neptune. Neptune has cloud structures that follow banded paths too, but its clouds are made of ice. Observations of Neptune from NASA’s Kepler spacecraft, operating in its K2 mission, were important in this comparison between the planet and brown dwarfs.

    “The atmospheric winds of brown dwarfs seem to be more like Jupiter’s familiar regular pattern of belts and zones than the chaotic atmospheric boiling seen on the Sun and many other stars,” said study co-author Mark Marley at NASA’s Ames Research Center in California’s Silicon Valley.

    Brown dwarfs can be thought of as failed stars because they are too small to fuse chemical elements in their cores. They can also be thought of as “super planets” because they are more massive than Jupiter, yet have roughly the same diameter. Like gas giant planets, brown dwarfs are mostly made of hydrogen and helium, but they are often found apart from any planetary systems. In a 2014 study using Spitzer, scientists found that brown dwarfs commonly have atmospheric storms.

    Due to their similarity to giant exoplanets, brown dwarfs are windows into planetary systems beyond our own. It is easier to study brown dwarfs than planets because they often do not have a bright host star that obscures them.

    “It is likely the banded structure and large atmospheric waves we found in brown dwarfs will also be common in giant exoplanets,” Apai said.

    Using Spitzer, scientists monitored brightness changes in six brown dwarfs over more than a year, observing each of them rotate 32 times. As a brown dwarf rotates, its clouds move in and out of the hemisphere seen by the telescope, causing changes in the brightness of the brown dwarf. Scientists then analyzed these brightness variations to explore how silicate clouds are distributed in the brown dwarfs.

    Researchers had been expecting these brown dwarfs to have elliptical storms resembling Jupiter’s Great Red Spot, caused by high-pressure zones. The Great Red Spot has been present in Jupiter for hundreds of years and changes very slowly: Such “spots” could not explain the rapid changes in brightness that scientists saw while observing these brown dwarfs. The brightness levels of the brown dwarfs varied markedly just over the course of an Earth day.

    To make sense of the ups and downs of brightness, scientists had to rethink their assumptions about what was going on in the brown dwarf atmospheres. The best model to explain the variations involves large waves, propagating through the atmosphere with different periods. These waves would make the cloud structures rotate with different speeds in different bands.

    University of Arizona researcher Theodora Karalidi used a supercomputer and a new computer algorithm to create maps of how clouds travel on these brown dwarfs.

    “When the peaks of the two waves are offset, over the course of the day there are two points of maximum brightness,” Karalidi said. “When the waves are in sync, you get one large peak, making the brown dwarf twice as bright as with a single wave.”

    The results explain the puzzling behavior and brightness changes that researchers previously saw. The next step is to try to better understand what causes the waves that drive cloud behavior.

    See the full article here .

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

    NASA image

     
  • richardmitnick 2:46 pm on August 17, 2017 Permalink | Reply
    Tags: , , Basic Research, , , ,   

    From Many Worlds: “Of White Dwarfs, “Zombie” Stars and Supernovae Explosions” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-08-17
    Marc Kaufman

    1
    Artistic view of the aftermath of a supernova explosion, with an unexpected white dwarf remnant. These super-dense but no longer active stars are thought to play a key role in many supernovae explosion. (Copyright Russell Kightley)

    White dwarf stars, the remnant cores of low-mass stars that have exhausted all their nuclear fuel, are among the most dense objects in the sky.

    Their mass is comparable to that of the sun, while their volume is comparable to that of Earth. Very roughly, this means the average density of matter in a white dwarf would be on the order of 1,000,000 times greater than the average density of the sun.

    Thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star — a category that includes the sun and over 97% of the other stars in the Milky Way — they are dim objects first identified a century ago but only in the last decade the subject of broad study.

    In recent years the white dwarfs have become more and more closely associated with supernovae explosions, though the processes involved remained hotly debated. A team using the Hubble Space Telescope even captured before and after images of what is hypothesized to be an incomplete white dwarf supernova. What was left behind has been described by some as a “zombie star.”

    Now a team of astronomers led by Stephane Vennes of the Czech Academy of Sciences has detected another zombie white dwarf, LP-40-365 , that they put forward as a far-flung remnant of a long-ago supernova explosion. This is considered important and unusual because it would represent a first detection of such a remnant long after the supernova conflagration.

    This dynamic is well captured in an animation accompanying the Science paper that describes the possible remnant.

    A supernova — among the most powerful forces in the universe — occurs when there is a change in the core of a star. A change can occur in two different ways, with both resulting in a thermonuclear explosion.

    Type Ia supernova occurs at the end of a single star’s lifetime. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova. The sun is a single star, but it does not have enough mass to become a supernova.

    The second type takes place only in binary star systems. Binary stars are two stars that orbit the same point. One of the stars, a carbon-oxygen white dwarf, steals matter from its companion star. Eventually, the white dwarf accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova.

    Type Ia supernovae, which are the result of the complete destruction of the star in a thermonuclear explosion, have a fairly uniform brightness that makes them useful for cosmology. The light emitted by the supernova explosion can be, for a short while at least, as bright as the whole of the Milky Way.

    Recently, astronomers have discovered a related form of supernova, called Type Iax, which look like Type Ia, but are much fainter. Type Iax supernovae may be caused by the partial destruction of a white dwarf star in such an explosion. If that interpretation is correct, part of the white dwarf should survive as a leftover object.

    And that leftover object is precisely what Vennes et al claim to have found.

    They have identified LP 40-365 as an unusual white dwarf with a low mass, high velocity and strange composition of oxygen, sodium and magnesium – exactly as might be expected for the leftover star from a Type Iax event. Vennes describes the white dwarf remnant his team has detected as a “compact star,” and perhaps the first of its kind in terms of the elements it contains.

    The team calculate that the explosion must have occurred between five and 50 million years ago.

    2
    The two inset images show before-and-after images captured by NASA’s Hubble Space Telescope of Supernova 2012Z in the spiral galaxy NGC 1309, what some call a “zombie star.”. The white X at the top of the main image marks the location of the supernova in the galaxy. A supernova typically obliterates the exploding white dwarf, or dying star. In 2014, scientists found that this faint supernova may have left behind a surviving portion of the white dwarf star.(NASA,ESA)

    In an email exchange, Vennes told me that he has been studying the local white dwarf population for thirty years.

    “These compact, dead stars tell us a lot about the “old” Milky Way, how stars were born and how they died,” he wrote.

    “Tens of thousands of these white dwarfs have been catalogued over this past century, most of them in the last decade, but we keep an eye on outliers, objects that are out of the norm. We look for exceedingly large velocity, peculiar chemical composition or abnormal mass or radii.

    “The strange case of LP40-365 came unexpectedly, but this was a classic case of serendipity in astronomy. Out of hundreds of targets we observed at the telescope, this one was uniquely peculiar. Fortunately, theorists are very imaginative and the model we adopted to interpret the observed properties of this object were only recently published. Our research on this object was certainly inspired and directed by their theory.”

    Vennes says the team was surprised to learn that the white dwarf LP40-365 is relatively bright among its peers and that similar objects did not show up in large-scale surveys such as the Sloan Digital Sky Survey.

    “This fact has convinced us that many more similarly peculiar white dwarfs await discovery. We should search among fainter, more distant samples of white dwarfs,” he wrote.

    And that search can be done by the European Space Agency’s Gaia astrometric space telescope, with follow-up observations at large telescopes such as the European Southern Observatory’s Very Large Telescope and the Gemini observatory in Chile.

    ESA/GAIA satellite

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level


    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

    “It is also likely that our adopted model involving a subluminous {faint} Type Ia supernova will be modified or even superseded by teams of theorists coming up with new ideas. But we remain confident that these new ideas would still involve a cataclysmic event on the scale of a supernova.”

    A supernova burns for only a short period of time, but it can tell scientists a lot about the universe.

    One kind of supernova has shown scientists that we live in an expanding universe, one that is growing at an ever increasing rate.

    Scientists also have determined that supernovas play a key role in distributing elements throughout the universe. When the star explodes, it shoots elements and debris into space. Many of the elements we find here on Earth are made in the core of stars.

    These elements travel on to form new stars, planets and everything else in the universe — making white dwarfs and supernovae essential to the process that ultimately led to life.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 1:56 pm on August 17, 2017 Permalink | Reply
    Tags: Basic Research, , , , MPG Institute for Nuclear Physics, ,   

    From MPG Institute for Nuclear Physics: “Sharp x-ray pulses from the atomic nucleus” 

    Max Planck Gesellschaft Institute for Nuclear Physics

    August 17, 2017
    PD Dr. Jörg Evers
    Research Group Leader
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-177
    joerg.evers@mpi-hd.mpg.de

    Prof. Dr. Thomas Pfeifer
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-380Fax:+49 6221 516-802
    Thomas.Pfeifer@mpi-hd.mpg.de

    Honorary Professor Dr. Christoph H. Keitel
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-150Fax:+49 6221 516-152
    keitel@mpi-hd.mpg

    Using a mechanical trick, scientists have succeeded in narrowing the spectrum of the pulses emitted by x-ray lasers.

    X-rays make the invisible visible: they permit the way materials are structured to be determined all the way down to the level of individual atoms. In the 1950s it was x-rays which revealed the double-helix structure of DNA. With new x-ray sources, such as the XFEL free-electron laser in Hamburg, it is even possible to “film” chemical reactions.

    XFEL


    XFEL map

    The results obtained from studies using these new x-ray sources may be about to become even more precise. A team around Kilian Heeg from the Max Planck Institute for Nuclear Physics in Heidelberg has now found a way to make the spectrum of the x-ray pulses emitted by these sources even narrower. In contrast to standard lasers, which generate light of a single colour and wavelength, x-ray sources generally produce pulses with a broad spectrum of different wavelengths. Sharper pulses could soon drive applications that were previously not feasible. This includes testing physical constants and measuring lengths and times even more precisely than can be achieved at present.

    1
    Upgrading x-ray lasers – a mechanical trick can be used to narrow the spectrum of the pulses emitted by x-ray lasers such as the XFEL free electron laser shown here. This would enable x-ray lasers to be used for experiments which would otherwise not be possible, for example testing whether physical constants are really constant. © DESY, Hamburg

    Researchers use light and other electromagnetic radiation for developing new materials at work in electronics, automobiles, aircraft or power plants, as well as for studies on biomolecules such as protein function. Electromagnetic radiation is also the tool of choice for observing chemical reactions and physical processes in the micro and nano ranges. Different types of spectroscopy use different individual wavelengths to stimulate characteristic oscillations in specific components of a structure. Which wavelengths interact with the structure – physicists use the term resonance – tells us something about their composition and how they are constructed; for example, how atoms within a molecule are arranged in space.

    In contrast to visible light, which has a much lower energy, x-rays can trigger resonance not just in the electron shell of an atom, but also deep in the atomic core, its nucleus. X-ray spectroscopy therefore provides unique knowledge about materials. In addition, the resonances of some atomic nuclei are very sharp, in principle allowing extremely precise measurements.

    X-ray sources generate ultra-short flashes with a broad spectrum

    Modern x-ray sources such as the XFEL free electron laser in Hamburg and the PETRA III (Hamburg), and ESRF (Grenoble) synchrotron sources are prime candidates for carrying out such studies.

    DESI Petra III

    ESRF. Grenoble, France

    Free- electron lasers in particular are optimized for generating very short x-ray flashes, which are primarily used to study very fast processes in the microscopic world of atoms and molecules. Ultra short light pulses, however, in turn have a broad spectrum of wavelengths. Consequently, only a small fraction of the light is at the right wavelength to cause resonance in the sample. The rest passes straight through the sample, making spectroscopy of sharp resonances rather inefficient.

    It is possible to generate a very sharp x-ray spectrum – i.e. x-rays of a single wavelength – using filters; however, since this involves removing unused wavelengths, the resulting resonance signal is still weak.

    The new method developed by the researchers in Heidelberg delivers a three to four-fold increase in the intensity of the resonance signal. Together with scientists from DESY in Hamburg and ESRF in Grenoble, Kilian Heeg and Jörg Evers from Christoph Keitel’s Division and a team around Thomas Pfeifer at the Max Planck Institute for Nuclear Physics in Heidelberg have succeeded in making some of the x-ray radiation that would not normally interact with the sample contribute to the resonance signal. They have successfully tested their method on iron nuclei both at the ESRF in Grenoble and at the PETRA III synchrotron of DESY in Hamburg.

    A tiny jolt amplifies the radiation

    The researchers’ approach to amplifying the x-rays is based on the fact that, when x-rays interact with iron nuclei (or any other nuclei) to produce resonance, they are re-emitted after a short delay. These re-emitted x-rays then lag exactly half a wavelength behind that part of the radiation which has passed straight through. This means that the peaks of one wave coincide exactly with the troughs of the other wave, with the result that they cancel each other out. This destructive interference attenuates the X-ray pulses at the resonant wavelength, which is also the fundamental origin of absorption of light.

    “We utilize the time window of about 100 nanoseconds before the iron nuclei re-emit the x-rays,” explains project leader Jörg Evers. During this time window, the researchers move the iron foil by about 40 billionths of a millimetre (0.4 angstroms). This tiny jolt has the effect of producing constructive interference between the emitted and transmitted light waves. “It’s as if two rivers, the waves on one of which are offset by half a wavelength from the waves on the other, meet,” says Evers, “and you shift one of the rivers by exactly this distance.” This has the effect that, after the rivers meet, the waves on the two rivers move in time with each other. Wave peaks coincide with wave peaks and the waves amplify, rather than attenuating, each other. This trick, however, does not just work on light at the resonance wavelengths, but also has the reverse effect (i.e. attenuation) on a broader range of wavelengths around the resonance wavelength. Kilian Heeg puts it like this. “We squeeze otherwise unused x-ray radiation into the resonance.”

    To enable the physicists to move the iron foil fast enough and precisely enough, it is mounted on a piezoelectric crystal. This crystal expands or contracts in response to an applied electrical voltage. Using a specially developed computer program, the Heidelberg-based researchers were able to adjust the electrical signal that controls the piezoelectric crystal to maximize the amplification of the resonance signal.

    Applications in length measurement and atomic clocks

    The researchers see a wide range of potential applications for their new technique. According to Thomas Pfeifer, the procedure will expand the utility of new high-power x-ray sources for high-resolution x-ray spectroscopy. This will enable more accurate modelling of what happens in atoms and molecules. Pfeifer also stresses the utility of the technique in metrology, in particular for high-precision measurements of lengths and the quantum-mechanical definition of time. “With x-rays, it is possible to measure lengths 10,000 times more accurately than with visible light,” explains Pfeifer. This can be used to study and optimize nanostructures such as computer chips and newly developed batteries. Pfeifer also envisages x-ray atomic clocks which are far more precise than even the most advanced optical atomic clocks nowadays based on visible light.

    Not least, better X-ray spectroscopy could enable us to answer one of physics’ great unanswered questions – whether physical constants really are constant or whether they change slowly with time. If the latter were true, resonance lines would drift slowly over time. Extremely sharp x-ray spectra would make it possible to determine whether this is the case over a relatively short period.

    Evers reckons that, once mature, the technique would be relatively easy to integrate into experiments at DESY and ESRF. “It should be possible to make a shoe-box sized device that could be rapidly installed and, according to our calculations, could enable an approximately 10-fold amplification,” he adds.

    Science paper:
    Spectral narrowing of x-ray pulses for precision spectroscopy with nuclear resonances
    http://science.sciencemag.org/content/357/6349/375

    See the full article here .

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    The Max-Planck-Institut für Kernphysik (“MPI for Nuclear Physics” or MPIK for short) is a research institute in Heidelberg, Germany.

    The institute is one of the 80 institutes of the Max-Planck-Gesellschaft (Max Planck Society), an independent, non-profit research organization. The Max Planck Institute for Nuclear Physics was founded in 1958 under the leadership of Wolfgang Gentner. Its precursor was the Institute for Physics at the MPI for Medical Research.

    The Max Planck Society is Germany’s most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field.

    What is the basis of this success? The scientific attractiveness of the Max Planck Society is based on its understanding of research: Max Planck Institutes are built up solely around the world’s leading researchers. They themselves define their research subjects and are given the best working conditions, as well as free reign in selecting their staff. This is the core of the Harnack principle, which dates back to Adolph von Harnack, the first president of the Kaiser Wilhelm Society, which was established in 1911. This principle has been successfully applied for nearly one hundred years. The Max Planck Society continues the tradition of its predecessor institution with this structural principle of the person-centered research organization.

    The currently 83 Max Planck Institutes and facilities conduct basic research in the service of the general public in the natural sciences, life sciences, social sciences, and the humanities. Max Planck Institutes focus on research fields that are particularly innovative, or that are especially demanding in terms of funding or time requirements. And their research spectrum is continually evolving: new institutes are established to find answers to seminal, forward-looking scientific questions, while others are closed when, for example, their research field has been widely established at universities. This continuous renewal preserves the scope the Max Planck Society needs to react quickly to pioneering scientific developments.

     
  • richardmitnick 1:10 pm on August 17, 2017 Permalink | Reply
    Tags: , Basic Research, , New diffractometer,   

    From BNL: “NSLS-II Welcomes New Tool for Studying the Physics of Materials” 

    Brookhaven Lab

    August 17, 2017
    Kelsey Harper
    kharper@bnl.gov

    Versatile instrument for precisely studying materials’ structural, electronic, magnetic characteristics arrives at Brookhaven Lab.

    1
    Beamline lead scientist Christie Nelson works with a diffractometer located at beamline 4-ID.

    A new instrument for studying the physics of materials using high intensity x-ray beams has arrived at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. This new diffractometer, installed at beamline 4-ID at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility that produces extremely bright beams of x-rays, will offer researchers greater precision when studying materials with unique structural, electronic, and magnetic characteristics. Understanding these materials’ properties could lead to better electronics, solar cells, or superconductors (materials that carry electricity with almost no energy loss).

    A diffractometer allows researchers to “see” the structure of a material by shooting highly focused x-rays at it and measuring how they diffract, or bounce off. According to Brookhaven physicist Christie Nelson, who worked with Huber X-Ray Diffraction Equipment to design the diffractometer, the new instrument has big advantages compared to one that operated at Brookhaven’s original light source, NSLS. Most significantly, it gives researchers additional ways to control where the beam hits the sample and how the x-rays are detected.

    In all diffractometers, both the sample and x-ray detector can rotate in certain directions to let researchers control where the beam hits the sample and where they measure the x-rays that bounce off. This diffractometer, however, has a uniquely large range of motion. The sample can rotate in four directions with extremely high precision, and in two of those directions it rotates much farther than in most other instruments. With this amount of control, researchers can target the precision of the x-ray beam to within 60 millionths of a meter.

    The instrument also has two detectors. While one allows users to quickly survey the overall structure of a sample, the other gives a zoomed-in view of the material’s subtler details. Since this diffractometer can have both detectors attached at the same time, researchers can quickly switch between these two views.

    “It’s a huge upgrade. There’s only one other like it in the world,” said Nelson, referring to a similar instrument at PETRA-III, an x-ray light source in Germany.

    DESY Petra III interior

    This diffractometer can also hold a cold chamber for looking at samples over a wide range of temperatures, all the way down to two Kelvin, or -271 degrees Celsius.

    “That’s crazy cold,” said Nelson—it’s just two degrees above “absolute zero,” the coldest anything can be.

    This cold chamber lets researchers study materials whose properties change with temperature. A research group from the University of California, Berkeley, has already used it to study superconductors, which need intense cold to function. The diffractometer allowed them to see fundamental changes in the material’s electronic structure as the temperature decreased.

    In the future, Nelson expects scientists will use the tool to examine materials at very high temperatures, under an electric or magnetic field, or in an environment with a custom atmosphere.

    “It’s a very versatile instrument,” said Nelson.

    2
    The newly acquired diffractometer before its installation at NSLS-II.

    The diffractometer additionally allows researchers to study magnetism. Similar to the way polarized sunglasses only let in light oriented in a certain direction, NSLS-II produces ‘polarized’ beams of x-rays that are all lined up the same way. When these x-rays interact with magnetic areas of a sample, their orientation shifts. The diffractometer can detect these subtle changes, allowing researchers to study a material’s different magnetic characteristics.

    A group from the University of Toronto used this feature to study the magnetic properties of “double perovskites.” Although these materials are structurally similar to those used in prototype solar cells, the Toronto group is most interested in their unique magnetic properties and potential applications in quantum computing and information storage.

    Nelson looks forward to welcoming future research teams to use the new instrument at NSLS-II. “It’s yet another tool that enables the cutting-edge discoveries that happen here,” she said.

    NSLS-II 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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