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  • richardmitnick 11:03 am on August 18, 2017 Permalink | Reply
    Tags: A Closer Look at an Undersea Source of Alaskan Earthquakes, , , , ,   

    From Eos: “A Closer Look at an Undersea Source of Alaskan Earthquakes” 

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    Eos

    15 August 2017
    Daniel S. Brothers
    Peter Haeussler
    Amy East
    Uri ten Brink
    Brian Andrews
    Peter Dartnell
    Nathan Miller
    Jared Kluesner

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    All is calm in southern Alaska’s Lisianski Inlet in this 2015 view from the deck of the R/V Solstice. A systematic survey of the nearby Queen Charlotte–Fairweather Fault, the source of several major earthquakes, has produced valuable information on the fault’s structure and slip mechanisms. Credit: Daniel S. Brothers

    During the past century, movement along the Queen Charlotte–Fairweather fault, which lies for most of its length beneath the waters off southeastern Alaska and British Columbia, has generated at least seven earthquakes of magnitude 7 or greater. This includes a magnitude 8.1 earthquake in 1949, the largest ever recorded in Canada.

    Other events include a magnitude 7.8 earthquake in 1958 that dislodged a massive landslide above Lituya Bay, Alaska. The earthquake generated a tsunami that sent water 525 meters up the mountainside, a world record run-up [Miller, 1960]. The 2012 magnitude 7.8 Haida Gwaii earthquake, centered on Moresby Island, British Columbia, and the 2013 magnitude 7.5 earthquake near Craig, Alaska [Walton et al., 2015], increased awareness of the potential geologic hazards posed to residents of southeastern Alaska and western British Columbia.

    Together, these events highlight the need for a greater understanding of the Queen Charlotte–Fairweather fault and its history.

    Yet despite the dramatic effects of this fault’s activity, a near absence of high-resolution marine geophysical and geological data limits scientific understanding of its slip rate, earthquake recurrence interval, paleoseismic history, and rupture dynamics.

    The U.S. Geological Survey (USGS) has now completed a systematic examination of the tectonic geomorphology along a 500-kilometer-long undersea section of the Queen Charlotte–Fairweather fault that offers new insights into activity at this strike-slip boundary, where the North American and Pacific plates slide horizontally past each other.

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    Fig. 1. Recent geophysical surveys provided high-resolution seafloor depth data for the northernmost undersea portion of the Queen Charlotte–Fairweather fault (area outlined in red). The colored seafloor relief represents multibeam echo sounder data acquired along the continental shelf and slope in 2015 and 2016; the gray seafloor relief in deeper water west of the fault was acquired by the University of New Hampshire in 2005. Black boxes are locations of depth imagery shown in Figures 2a–2d. Purple lines represent high-resolution seismic reflection profiles that were acquired in 2016 aboard the R/V Norseman. One such profile (green line) is shown in Figure 3. AMT represents the Alaska-Aleutian megathrust, and ME indicates Mount Edgecumbe.

    A Complicated Boundary

    The Queen Charlotte–Fairweather fault system and its better known counterpart, the San Andreas fault (which is highly visible on land in California), form the boundary between the North American and Pacific tectonic plates. The Queen Charlotte–Fairweather fault system defines this plate boundary for a distance of more than 1,200 kilometers, from Yakutat, Alaska, to the Queen Charlotte Triple Junction, a confluence of three faults west of British Columbia (Figure 1). Within this system, the Queen Charlotte fault represents the underwater section and is widely recognized as one of the world’s most seismically active continent-ocean transform faults [Plafker et al., 1978; Bruns and Carlson, 1987; Nishenko and Jacob, 1990; Walton et al., 2015].

    The northern part of the boundary between the North American and Pacific plates is complicated by the collision of the Yakutat terrane, a block of crustal material surrounded by faults, with southern Alaska. In this region, the Pacific Plate begins to subduct, or plunge beneath, the North American Plate along a boundary known as the Alaska-Aleutian megathrust.

    The Fairweather fault is the only stretch of the fault system accessible by land. To the south of Icy Point, the Fairweather fault runs offshore, becoming the Queen Charlotte fault, which extends about 900 kilometers southward along the continental slope.

    Earlier studies estimated a slip rate of 41 to 58 millimeters per year on the Fairweather fault [Plafker et al., 1978; Bruns and Carlson, 1987; Elliot et al., 2010], but few direct observations of horizontal seafloor displacement existed [Bruns and Carlson, 1987] because of the absence of high-resolution seabed data.

    Geophysical Surveys

    In 2015, our team conducted two marine geophysical surveys, one aboard the research vessel R/V Solstice and a second on R/V Alaskan Gyre. We collected high-resolution seafloor depth data using multibeam sonar along the northernmost section of the fault. We also used a chirp subbottom profiler, which returns detailed images down to 50 meters beneath the seafloor.

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    The Queen Charlotte–Fairweather fault lies off the coast of southeastern Alaska. New imagery of a 400-kilometer-long undersea section of this transform fault provides a striking view of its structure and offers insights into activity at the boundary between the North American and Pacific tectonic plates. This perspective view of depth data acquired during recent surveys of the area shows the fault as it emerges from the Alaskan coast and stretches as a distinct line across the ocean floor. The color spectrum from red to purple represents increasing water depth.

    In 2016, two additional cruises (aboard R/V Medeia and R/V Norseman) extended data coverage of the Queen Charlotte–Fairweather fault an additional 325 kilometers southward. We again used multibeam sonar to map the ocean floor and multichannel seismic reflection to image deeper layers of sediment. Most recently, seismic reflection and chirp surveys were completed in July 2017 aboard the R/V Ocean Starr.

    In total, during 95 days of seagoing operations, we collected more than 5,000 square kilometers of high-resolution depth data, 9,400 kilometers of high-resolution multichannel seismic reflection profiles, and 500 kilometers of subbottom chirp data.

    A Clearer View of the Fault System

    Imagery from the surveys shows the fault in pristine detail, cutting straight across the seafloor, with offsetting seabed channels and submerged glacial valleys (Figure 2). The continuous knife-edge character of the fault is evident over the entire 500-kilometer-long survey area. At the same time, we can see several previously unknown features, including a series of subtle bends and steps in the fault that appear to form basins within the fault zone.

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    Fig. 2. High-resolution depth images at four locations along the Queen Charlotte fault show the morphological features of the fault and the continental slope. Red arrows indicate the relative sense of motion (see Figure 1 for locations).

    Because the surveys spanned four sections of the fault that ruptured in significant historical earthquakes, the results provide a unique catalog of geomorphic features commonly associated with active strike-slip faults.

    The Fairweather fault bends 20° as it extends southward across the shoreline near Icy Point (Figures 1 and 2a) and then continues southward at a 340° strike along the shelf edge as a single fault trace for another 150 kilometers.

    Numerous submarine canyons, gullies, and ridges have been displaced or warped along the fault. Fault valleys parallel to the margin locally separate geomorphically distinct upper and lower sections of the continental slope (Figures 2b and 3). A Pleistocene basaltic-andesitic volcanic edifice exposed at the seabed extends from Mount Edgecumbe to the shelf edge (Figure 2b).

    West of southern Baranof Island, the fault takes a series of subtle 3° to 5° right steps and bends that form en echelon pull-apart basins along the shelf edge (Figure 2c). The fault continues southward as a single lineament but exhibits a subtle warp and series of westward steps displacing submarine canyon valleys (Figure 2d) before crossing Noyes Canyon and extending southward into Canadian waters [see, e.g., Barrie et al., 2013].

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    Fig. 3. A seismic reflection profile acquired in August 2016 highlights the structure and stratigraphy of the continental slope.

    Fault Slip Rates

    The offset features along the seabed provide important information for reconstructing past fault motion. From the ages of these features we can calculate the average rate of motion along the fault, then estimate the typical recurrence interval for large earthquakes.

    For example, the southern margin of the Yakobi Sea Valley has been sliced and translated about 925 meters by the linear, knife-edge fault trace (Figure 2a). Ice likely retreated from the valley about 17,000 years ago. Thus, the slip rate of the Queen Charlotte–Fairweather fault across the Yakobi Sea Valley exceeds 50 millimeters per year: one of the fastest-slipping continent-ocean transform faults in the world [Brothers et al., 2015].

    Furthermore, we observe coincidence between the pull-apart basins shown in Figure 2c and the northernmost extent of the 2013 Craig earthquake, implying that changes in fault geometry likely influenced the length of rupture propagation [e.g., Walton et al., 2015].

    Future Plans

    The USGS, the Geological Survey of Canada, the Sitka Sound Science Center, and the University of Calgary will jointly lead a research cruise in September 2017 to collect sediment cores along the Queen Charlotte–Fairweather fault in Canadian and U.S. territories to constrain the sedimentation history along the margin and date features offset by fault motion.

    Overall, this project has shown that the Queen Charlotte–Fairweather fault is an ideal laboratory to examine the tectonic geomorphology of a major strike-slip fault and the associated processes responsible for generating offshore hazards.

    Acknowledgments

    We thank J. Currie, G. Hatcher, R. Wyland, A. Balster-Gee, P. Hart, J. Conrad, T. O’Brien, A. Nichols, M. Walton, R. Marcuson, and E. Moore of the U.S. Geological Survey (USGS); K. Green of the Alaska Department of Fish and Game; G. Greene of Moss Landing Marine Laboratories; V. Barrie and K. Conway of the Geological Survey of Canada; and the crews of the R/V Solstice, R/V Medeia, R/V Norseman, R/V Ocean Starr, and R/V Alaskan Gyre. We also thank J. Warrick, R. von Huene, J. Watt, and an anonymous reader for helpful reviews. The USGS Coastal and Marine Geology Program funded this study. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. government.

    References

    Barrie, J. V., K. W. Conway, and P. T. Harris (2013), The Queen Charlotte fault, British Columbia: Seafloor anatomy of a transform fault and its influence on sediment processes, Geo Mar. Lett., 33, 311–318, https://doi.org/10.1007/s00367-013-0333-3.

    Brothers, D. S., et al. (2015), High-resolution geophysical constraints on late Pleistocene–Present deformation history, seabed morphology, and slip-rate along the Queen Charlotte-Fairweather fault, offshore southeastern Alaska, Abstract NH23B-1882 presented at 2015 Fall Meeting, AGU, San Francisco, Calif.

    Bruns, T. R., and P. R. Carlson (1987), Geology and petroleum potential of the southeast Alaska continental margin, in Geology and Petroleum Potential of the Continental Margin of Western North America and Adjacent Ocean Basins, Beaufort Sea to Baja California, Earth Sci. Ser., vol. 9, edited by D. W. Scholl, A. Grantz, and J. G. Vedder, pp. 269–282, Circum-Pac. Counc. for Energy and Miner. Resour., Houston, Texas.

    Elliot, J. L., et al. (2010), Tectonic block motion and glacial isostatic adjustment in southeast Alaska and adjacent Canada constrained by GPS measurements, J. Geophys. Res., 115, B09407, https://doi.org/10.1029/2009JB007139.

    Miller, D. J. (1960), Giant waves in Lituya Bay, Alaska, U.S. Geol. Surv. Prof. Pap., 354-C, 51–86, scale 1:50,000.

    Nishenko, S. P., and K. H. Jacob (1990), Seismic potential of the Queen Charlotte-Alaska-Aleutian seismic zone, J. Geophys. Res., 95(B3), 2511–2532, https://doi.org/10.1029/JB095iB03p02511.

    Plafker, G., et al. (1978), Late Quaternary offsets along the Fairweather fault and crustal plate interactions in southern Alaska, Can. J. Earth Sci., 15(5), 805–816, https://doi.org/10.1139/e78-085.

    Walton, M. A. L., et al. (2015), Basement and regional structure along strike of the Queen Charlotte fault in the context of modern and historical earthquake ruptures, Bull. Seismol. Soc. Am., 105, 1090–1105, https://doi.org/10.1785/0120140174.

    Author Information

    Daniel S. Brothers (email: dbrothers@usgs.gov; @DBrothersSC), Pacific Coastal and Marine Science Center, U.S. Geological Survey (USGS), Santa Cruz, Calif.; Peter Haeussler, Alaska Science Center, USGS, Anchorage; Amy East, Pacific Coastal and Marine Science Center, USGS, Santa Cruz, Calif.; Uri ten Brink and Brian Andrews, Woods Hole Science Center, USGS, Mass.; Peter Dartnell, Pacific Coastal and Marine Science Center, USGS, Santa Cruz, Calif.; Nathan Miller, Woods Hole Science Center, USGS, Mass.; and Jared Kluesner, Pacific Coastal and Marine Science Center, USGS, Santa Cruz, Calif.
    Citation: Brothers, D. S., P. Haeussler, A. East, U. ten Brink, B. Andrews, P. Dartnell, N. Miller, and J. Kluesner (2017), A closer look at an undersea source of Alaskan earthquakes, Eos, 98, https://doi.org/10.1029/2017EO079019. Published on 15 August 2017.

    © 2017. The authors. CC BY-NC-ND 3.0

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    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

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

    From UCSB: “A Fleeting Blue Glow” 

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    UC Santa Barbara

    August 14, 2017
    Julie Cohen

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

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    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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    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 10:13 am on August 18, 2017 Permalink | Reply
    Tags: NASA’s Tracking Data Relay Satellite-M Vital for Science Relay Poised for Liftoff Aug. 18,   

    From Universe Today: “NASA’s Tracking Data Relay Satellite-M Vital for Science Relay Poised for Liftoff Aug. 18 – Watch Live” 

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    Universe Today

    17 Aug , 2017
    Ken Kremer

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    Up close clean room visit with NASA’s newest science data relay comsat – Tracking and Data Relay Satellite-M (TDRS-M) inside the Astrotech payload processing facility high bay in Titusville, FL. Two gigantic fold out antennae’s, plus space to ground antenna dish visible inside the ‘cicada like cocoon’ with solar arrays below. Launch on ULA Atlas V slated for August 2017 from Cape Canaveral Air Force Station, Fl. Credit: Ken Kremer/kenkremer.com

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    The United Launch Alliance Atlas V rocket carrying NASA’s Tracking and Data Relay Satellite-M (TDRS-M) stands on the launch pad at Space Launch Complex 41 on Cape Canaveral Air Force Station poised for liftoff on Aug. 18, 2017. The rocket rolled out to the pad two days earlier on Aug. 16. Credit: Ken Kremer/kenkremer.com

    KENNEDY SPACE CENTER, FL – The last of NASA’s next generation Tracking and Data Relay Satellites (TRDS) that looks like a giant alien fish or cocooned creature but actually plays an absolutely vital role in relaying critical science measurements, research data and tracking observations gathered by the International Space Station (ISS), Hubble and a plethora of Earth science missions is poised for blastoff Friday, Aug. 18, morning from the Florida Space Coast.

    Liftoff atop a United Launch Alliance Atlas V rocket Liftoff of NASA’s $408 million eerily insectoid-looking TDRS-M science relay comsat atop a United Launch Alliance (ULA) Atlas V rocket is scheduled to take place from Space Launch Complex 41 at Cape Canaveral Air Force Station at 8:03 a.m. EDT (2:03 GMT) Aug. 18.

    You can witness the launch with you own eyes from many puiblic beaches, parks and spots ringing the Kennedy Space Center.

    If you can’t personally be here to witness the launch in Florida, you can always watch NASA’s live coverage on NASA Television and the agency’s website.

    The NASA/ULA/TDRS-M launch coverage will be broadcast on NASA TV beginning at 7:30 a.m. as the countdown milestones occur on Aug. 18 with additional commentary on the NASA launch blog:

    https://blogs.nasa.gov/tdrs/

    You can watch the launch live at NASA TV at – http://www.nasa.gov/nasatv

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

    From CSIRO: “Back to school for Science Week” 

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    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.

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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.

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    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.

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  • richardmitnick 9:45 am on August 18, 2017 Permalink | Reply
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    From ESO: “Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations” 

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    At the Very Large Telescope Interferometer under the VLT platform at ESO’s Paranal Observatory, engineers and astronomers are working against the clock. They are building new tunnels and rooms to house one of the most eagerly anticipated instruments in the astronomical world: ESPRESSO, or the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations.

    ESPRESSO will be the successor to HARPS, one of most productive and precise planet hunters. With 71 papers in 2014 alone, HARPS has been much in demand by astronomers around the world, and has been the most productive instrument at the La Silla Observatory for several years. This is one of the reasons why astronomers are greatly looking forward to the arrival of ESPRESSO on a much bigger telescope.

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    The ESPRESSO spectrograph concept.

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    This picture shows an engineering sample of one of the CCD detectors to be used in the cameras of the ESPRESSO instrument. These very large CCD samples were provided by the company e2v and have more than 80 million pixels over an area 92 x 92 millimetres. Credit: ESO/ESPRESSO Consortium/e2v

    ESPRESSO will take the search for exoplanets to the next level. It will be fed by the four Unit Telescopes (UTs) of the VLT and its primary goal will be to make very high precision radial velocity measurements of solar-type stars to search for rocky planets.

    Stars and their exoplanets are bound together by gravity: an exoplanet orbits its distant parent star just as the planets of the Solar System orbit the Sun. But a planet in orbit around a star exerts its own gentle gravitational pull, so that the centre of gravity of the entire system (the barycentre) is a little away from the centre of the star and the star itself orbits about this point. This regular movement of the star along our line of sight creates a tiny shift in the spectrum of the star, through the Doppler effect. This minute effect can be detected by very sensitive instruments and is the evidence for the presence of a planet that can then be further studied. This tug of war between stars and their exoplanets can be seen (or rather, measured) by ESPRESSO.

    ESPRESSO will combine unprecedented radial velocity measurement accuracy with the large collecting area of the UTs. This means that we will be able to gather light simultaneously from the 4 UTs and measure fainter objects in the sky with greater accuracy. HARPS has the precision to detect stellar motions moving at the speed of a gentle walking pace — 3.5 km/h! ESPRESSO is projected to be able to detect stellar motions at almost a snail’s pace — only 0.35 km/h — corresponding to an Earth-mass planet in the habitable zone of a low-mass star. It is expected that a vast number of planets with masses smaller than Neptune will be discovered.

    Astronomers are keenly looking forward to this new instrument!

    See the full article here .

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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

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

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    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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

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    ALMA on the Chajnantor plateau at 5,000 metres.

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    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

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    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

     
  • richardmitnick 3:07 pm on August 17, 2017 Permalink | Reply
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    From JPL: “Scientists Improve Brown Dwarf Weather Forecasts” 

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    JPL-Caltech

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

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    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: , , , , , ,   

    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 2:25 pm on August 17, 2017 Permalink | Reply
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    From CfA: “Properties of a Massive Galaxy 800 Million Years after the Big Bang” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    August 11, 2017 [Not brought to social media. Why?]
    No writer credit

    1
    A Hubble image of the galaxy cluster Abell 1689, which acts as a lens to focus the light from much more distant galaxies, including some very dusty star-forming galaxies in the early universe (seen as the nearly point-like blue smudges in this image). A submillimeter study of a different massive dusty galaxy in the early universe uses carbon monoxide gas to characterize the interstellar medium and determine the mass and star-formation rate. NASA/ESA Hubble

    Searches for the most distant galaxies have now probed earlier than the first billion years in the history of the universe, early enough to start seeing the primary effects of the first stars: the reionization of neutral atoms.

    Reionization era and first stars, Caltech

    Astronomers want to understand how galaxies formed and evolved in this period, the timescale over which this reionization took place, the nature of the objects that provided the ionizing photons, and the scenarios in which galaxies and their interstellar medium (ISM) become enriched with atoms made in stellar furnaces. Although galaxies from this era are currently being discovered in deep optical and near-infrared surveys, most of them are low-mass galaxies, very faint, and the enrichment process is difficult to study. More luminous, massive star-forming galaxies are thought to be present and to play a major role in reionization, but because these large objects are difficult to assemble so early in cosmic time there are not many of them.

    Massive star-forming galaxies that contain dust emit strongly radiation at submillimeter wavelengths and these objects can be find using telescopes.

    CfA Submillimeter Array Mauna Kea, Hawaii, USA

    They therefore offer the opportunity to study extreme cases of metal/dust enrichment of the ISM early in the era of reionization. CfA astronomers Matt Ashby and Chris Hayward were members of a large team using the South Pole Telescope to detect a set of these dusty galaxies.

    South Pole Telescope SPTPOL

    They determined their distances using the ALMA telescopes by looking at the redshifted wavelength of carbon monoxide molecule in their ISM.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    The farthest known dusty galaxy was detected in this way, and subsequent observations of it with other facilities confirmed its cosmological distance. The scientists constrained the properties of the object by modeling the observed continuum and spectral lines, and found that the object has a mass in gas of about 330 billion solar-masses; for comparison, the estimated gas mass of the Milky Way is about five billion solar-masses (most of its mass is in stars). The dusty galaxy is forming new stars at an estimated rate of several thousand per year – although with the assumption that the process is similar to what is seen in nearby galaxies. This rare and distant object offers one of the best probes so far into the activity in galaxies when the universe was very young.

    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 1:56 pm on August 17, 2017 Permalink | Reply
    Tags: , , , , 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 1:24 pm on August 17, 2017 Permalink | Reply
    Tags: , Large Pixel Detector,   

    From STFC: “UK provides first advanced detector for world’s largest X-ray laser” 


    STFC

    17 August 2017

    Becky Parker-Ellis
    becky.parker-ellis@stfc.ac.uk
    STFC Media office
    01793 444564

    1
    The Large Pixel Detector. (Credit: European XFEL)

    One of the world’s fastest detectors, capable of capturing images in billionths of a second, has been developed by the UK for use at the world’s largest X-ray laser, the European XFEL.

    XFEL


    XFEL map

    The Large Pixel Detector (LPD) is the first advanced detector to be installed at the European XFEL in Hamburg, Germany. The LPD is a cutting-edge X-ray camera developed at the Science and Technology Facilities Council’s (STFC) Rutherford Appleton Laboratory near Oxford.

    Dr Brian Bowsher, Chief Executive of STFC, said: “This is a significant milestone for the European XFEL and we are delighted to make such an important contribution to the project.

    “International collaborations are key to developing these state-of-the-art facilities and this work reinforces the international role STFC and the UK has in science.

    “It’s an extremely exciting time for the XFEL facility, and I am looking forward to seeing the first experiments taking place.”

    The LPD is the first fully functional X-ray light detector to record at a rate of 4.5 MHz—4.5 million pictures per second, fast enough to keep up with the European XFEL’s high repetition rate of 27,000 pulses per second, which are arranged into short bursts. The LPD will allow users to take clear snapshots of ultrafast processes such as chemical reactions as they take place.

    STFC’s Matthew Hart, the lead engineer who has worked on the LPD since 2007, said: “It’s such a great feeling to see the detector installed ready for experiments. It’s taken 10 years of development to meet some really challenging requirements and finally the day has arrived to see it working for real.

    “It was made possible thanks to the world class engineering team we have at STFC’s Rutherford lab in the UK, huge credit goes to them for their hard work and commitment over such a long and difficult project.

    “Now the detector is in the hands of the scientists at XFEL I’m really looking forward to hearing about their research and discoveries they will make.”

    The LPD operates far beyond the scope of any commercial detector or camera. Its design enables the detector to capture an image every 222 nanoseconds (billionths of a second)—an unprecedented rate that allows it to capture individual ultrashort X-ray laser flashes from the European XFEL. Additionally, the detector has a very high so-called dynamic range, meaning it can pick up signals as weak as a single particle of light, also known as a photon, and as strong as a flash of several tens of thousands of photons in two neighbouring pixels.

    In a typical experiment at the European XFEL, users will place samples in the path of incoming X-ray laser pulses in order to study their structure at the atomic level. Detectors will pick up the X-ray laser light scattering off of the sample, which often consists of individual molecules. The LPD’s high dynamic range allows for very high resolutions showing the finest details from samples.

    European XFEL Detector Development group leader Markus Kuster said: “The years of intensive collaboration with STFC’s Rutherford Appleton Laboratory on the LPD have paid off, and resulted in a unique detector that can record data on the timescale of a billionth of a second.”

    See the full article here .

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    STFC Hartree Centre

    Helping build a globally competitive, knowledge-based UK economy

    We are a world-leading multi-disciplinary science organisation, and our goal is to deliver economic, societal, scientific and international benefits to the UK and its people – and more broadly to the world. Our strength comes from our distinct but interrelated functions:

    Universities: we support university-based research, innovation and skills development in astronomy, particle physics, nuclear physics, and space science
    Scientific Facilities: we provide access to world-leading, large-scale facilities across a range of physical and life sciences, enabling research, innovation and skills training in these areas
    National Campuses: we work with partners to build National Science and Innovation Campuses based around our National Laboratories to promote academic and industrial collaboration and translation of our research to market through direct interaction with industry
    Inspiring and Involving: we help ensure a future pipeline of skilled and enthusiastic young people by using the excitement of our sciences to encourage wider take-up of STEM subjects in school and future life (science, technology, engineering and mathematics)

    We support an academic community of around 1,700 in particle physics, nuclear physics, and astronomy including space science, who work at more than 50 universities and research institutes in the UK, Europe, Japan and the United States, including a rolling cohort of more than 900 PhD students.

    STFC-funded universities produce physics postgraduates with outstanding high-end scientific, analytic and technical skills who on graduation enjoy almost full employment. Roughly half of our PhD students continue in research, sustaining national capability and creating the bedrock of the UK’s scientific excellence. The remainder – much valued for their numerical, problem solving and project management skills – choose equally important industrial, commercial or government careers.

    Our large-scale scientific facilities in the UK and Europe are used by more than 3,500 users each year, carrying out more than 2,000 experiments and generating around 900 publications. The facilities provide a range of research techniques using neutrons, muons, lasers and x-rays, and high performance computing and complex analysis of large data sets.

    They are used by scientists across a huge variety of science disciplines ranging from the physical and heritage sciences to medicine, biosciences, the environment, energy, and more. These facilities provide a massive productivity boost for UK science, as well as unique capabilities for UK industry.

    Our two Campuses are based around our Rutherford Appleton Laboratory at Harwell in Oxfordshire, and our Daresbury Laboratory in Cheshire – each of which offers a different cluster of technological expertise that underpins and ties together diverse research fields.

    The combination of access to world-class research facilities and scientists, office and laboratory space, business support, and an environment which encourages innovation has proven a compelling combination, attracting start-ups, SMEs and large blue chips such as IBM and Unilever.

    We think our science is awesome – and we know students, teachers and parents think so too. That’s why we run an extensive Public Engagement and science communication programme, ranging from loans to schools of Moon Rocks, funding support for academics to inspire more young people, embedding public engagement in our funded grant programme, and running a series of lectures, travelling exhibitions and visits to our sites across the year.

    Ninety per cent of physics undergraduates say that they were attracted to the course by our sciences, and applications for physics courses are up – despite an overall decline in university enrolment.

     
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