Tagged: U Hawaii Manoa Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 1:13 pm on July 14, 2018 Permalink | Reply
    Tags: , , , , U Hawaii Manoa   

    From U Hawaii via Eureka Alert: Late to the Party, but “Hawaii telescopes help unravel long-standing cosmic mystery” 

    U Hawaii

    From University of Hawaii Manoa

    via

    EurekAlert!

    12-Jul-2018

    Astronomers and physicists around the world, including in Hawaii, have begun to unravel a long-standing cosmic mystery. Using a vast array of telescopes in space and on Earth, they have identified a source of cosmic rays.

    Artist’s impression of a blazar emitting neutrinos and gamma rays via IceCube and NASA

    Blazar. NASA Fermi Gamma ray Space Telescope. Credits M. Weiss/ CfA

    NASA/Fermi LAT

    NASA/Fermi Gamma Ray Space Telescope

    Astronomers and physicists around the world, including in Hawaii, have begun to unravel a long-standing cosmic mystery. Using a vast array of telescopes in space and on Earth, they have identified a source of cosmic rays–highly energetic particles that continuously rain down on Earth from space.

    In a paper published this week in the journal Science, scientists have, for the first time, provided evidence for a known blazar, designated TXS 0506+056, as a source of high-energy neutrinos. At 8:54 p.m. on September 22, 2017, the National Science Foundation-supported IceCube neutrino observatory at the South Pole detected a high energy neutrino from a direction near the constellation Orion. Just 44 seconds later an alert went out to the entire astronomical community.

    U Wisconsin ICECUBE neutrino detector at the South Pole

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

    The All Sky Automated Survey for SuperNovae team (ASAS-SN), an international collaboration headquartered at Ohio State University, immediately jumped into action. ASAS-SN uses a network of 20 small, 14-centimeter telescopes in Hawaii, Texas, Chile and South Africa to scan the visible sky every 20 hours looking for very bright supernovae. It is the only all-sky, real-time variability survey in existence.

    ASAS-SN Brutus at lcogt site Hawaii

    LCOGT Las Cumbres Observatory Global Telescope Network, Haleakala Hawaii, USA, Elevation 10,023 ft (3,055 m)

    “When ASAS-SN receives an alert from IceCube, we automatically find the first available ASAS-SN telescope that can see that area of the sky and observe it as quickly as possible,” said Benjamin Shappee, an astronomer at the University of Hawaii’s Institute for Astronomy and an ASAS-SN core member.

    On September 23, only 13 hours after the initial alert, the recently commissioned ASAS-SN unit at McDonald Observatory in Texas [image of exas unit N/A] mapped the sky in the area of the neutrino detection. Those observations and the more than 800 images of the same part of the sky taken since October 2012 by the first ASAS-SN unit, located on Maui’s Haleakala, showed that TXS 0506+056 had entered its highest state since 2012.

    “The IceCube detection and the ASAS-SN detection combined with gamma-ray detections from NASA’s Fermi gamma-ray space telescope and the MAGIC telescopes that show TXS 0506+056 was undergoing the strongest gamma-ray flare in a decade, indicate that this could be the first identified source of high-energy neutrinos, and thus a cosmic-ray source,” said Anna Franckowiak, ASAS-SN and IceCube team member, Helmholtz Young Investigator, and staff scientist at DESY in Germany.

    MAGIC Cherenkov telescope array at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, Spain, sited on a volcanic peak 2,267 metres (7,438 ft) above sea level

    Since they were first detected more than one hundred years ago, cosmic rays have posed an enduring mystery: What creates and launches these particles across such vast distances? Where do they come from?

    One of the best suspects have been quasars, supermassive black holes at the centers of galaxies that are actively consuming gas and dust.

    Quasar. ESO/M. Kornmesser

    Quasars are among the most energetic phenomena in the universe and can form relativistic jets where elementary particles are accelerate and launched at nearly the speed of light. If that jet happens to be pointed toward Earth, the light from the jet outshines all other emission from the host galaxy and the highly accelerated particles are launched toward the Milky Way. This specific type of quasar is called a blazar [above].

    However, because cosmic rays are charged particles, their paths cannot be traced directly back to their places of origin. Due to the powerful magnetic fields that fill space, they don’t travel along a straight path. Luckily, the powerful cosmic accelerators that produce them also emit neutrinos, which are uncharged and unaffected by even the most powerful magnetic fields. Because they rarely interact with matter and have almost no mass, these “ghost particles” travel nearly undisturbed from their cosmic accelerators, giving scientists an almost direct pointer to their source.

    “Crucially, the presence of neutrinos also differentiates between two types of gamma-ray sources: those that accelerate only cosmic-ray electrons, which do not produce neutrinos, and those that accelerate cosmic-ray protons, which do,” said John Beacom, an astrophysicist at the Ohio State University and an ASAS-SN member.

    Detecting the highest energy neutrinos requires a massive particle detector, and the National Science Foundation-supported IceCube observatory [above] is the world’s largest. The detector is composed of more than 5,000 light sensors arranged in a grid, buried in a cubic kilometer of deep, pristine ice a mile beneath the surface at the South Pole. When a neutrino interacts with an atomic nucleus, it creates a secondary charged particle, which, in turn, produces a characteristic cone of blue light that is detected by IceCube’s grid of photomultiplier tubes. Because the charged particle and the light it creates stay essentially true to the neutrino’s original direction, they give scientists a path to follow back to the source.

    About 20 observatories on Earth and in space have also participated in this discovery. This includes the 8.4-meter Subaru Telescope on Maunakea, which was used to observe the host galaxy of TXS 0506+056 in an attempt to measure its distance, and thus determine the intrinsic luminosity, or energy output, of the blazar.


    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    These observations are difficult, because the blazar jet is much brighter than the host galaxy. Disentangling the jet and the host requires the largest telescopes in the world, like those on Maunakea.

    “This discovery demonstrates how the many different telescopes and detectors around and above the world can come together to tell us something amazing about our Universe. This also emphasizes the critical role that telescopes in Hawaii play in that community,” said Shappee.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 9:36 am on March 12, 2018 Permalink | Reply
    Tags: , , , , , Carbon-based molecules are a by-product of red giants, Circumstellar envelopes, , , , , U Hawaii Manoa   

    From University of Hawaii Manoa via COSMOS: “Complex organic compounds from dying stars could be life precursors” 

    U Hawaii

    University of Hawaii Manoa

    COSMOS

    12 March 2018
    Richard A. Lovett

    Lab experiments reveal carbon-based molecules are a by-product of red giants.

    1
    A red giant star – the font, perhaps, of life… QAI Publishing/UIG via Getty Images

    Laboratory experiments designed to recreate conditions around carbon-rich red giant stars have revealed that startlingly complex organic compounds can form in the “circumstellar envelopes” created by stellar winds blowing off from them.

    The carbon is present because nuclear reactions in these dying stars have progressed to the point that much of their initial complement of hydrogen and helium has been converted into heavier elements such as carbon.

    “There is a lot of carbon in these circumstellar envelopes,” says Ralf Kaiser, a physical chemist at the University of Hawaii at Manoa, US.

    In research published in the journal Nature Astronomy, a team led by Kaiser used a high-temperature chemical reactor to simulate conditions inside these circumstellar envelopes.

    The goal, he says, is to demonstrate how complex compounds can be assembled a couple of carbon atoms at a time at temperatures of up to about 1200 degrees Celsius. Previous research found that a host of organic chemicals can indeed be formed, but the new study pushed the process farther, demonstrating that it is possible to create chemicals at least as complex as pyrene, a 16-carbon compound with a structure like four fused benzene rings.

    So far, pyrene is the most complex molecule constructed in this manner, but Kaiser thinks that it might be just the beginning. “We hope when we do further experiments that this can be extended,” he says.

    What this means, he explains, is that circumstellar envelopes might be able to create molecules with 60 or 70 carbons, or even nanoparticle-sized sheets of graphene, a material composed of a larger array of fused rings.

    Such materials, he says, can act as building blocks on which other molecules, such as water, methane, methanol, carbon monoxide, and ammonia can condense as they move away from the star and cool to temperatures as low as minu-263 degrees Celsius. When the resulting chemical stew is exposed to ionising radiation either from nearby sources or galactic cosmic rays, Kaiser says, they can form sugars, amino acids, and dipeptides.

    “These are molecules relevant to the origins of life,” he adds.

    Billions of years ago, such organic-rich particles may have found their way into asteroids that then rained down onto the primordial Earth, endowing us with the precursors for life.

    Pyrene is a member of a family of compounds called polycyclic aromatic hydrocarbons (PAHs), the simplest of which is naphthalene, the primary ingredient of mothballs. Simple PAHs have already been detected in space, but the holy grail, Kaiser says, will be if more complex ones, such as pyrene, are found by NASA’s OSIRIS-REx mission, now en route to asteroid 101955 Bennu, from which it is expected to send back a sample in 2023.

    NASA OSIRIS-REx Spacecraft

    “We do not know what this mission will find,” Kaiser says. But, “if they find carbonaceous materials such as PAHs, then our experiments say how this organic matter can be formed.”

    Humberto Campins, a planetary scientist from Central Florida University, Orlando, Florida, and member of the OSIRIS REx science team, agrees. Studying the chemical makeup of asteroids, he says, doesn’t just tell us about the composition of our own early solar system, but can also reveal information about “pre-solar” compounds.

    “One of the beauties of sample return missions is that the latest analytical techniques for chemical, mineralogical, and isotopic composition can be applied to very small components of the sample, such as pre-solar grains or molecules,” he says.

    “We know that the dust from these kinds of stars gets incorporated into meteorites, so they are absolutely contributing to the compounds that would be present within Bennu,” adds Chris Bennett, also of the University of Central Florida (and a former student of Kaiser’s, although he was not part of the present study team).

    Chris McKay, an astrobiologist at NASA Ames Research Centre in Moffett Field, California, adds that the paper supports the notion that that the universe contains a large amount of carbon in the form of organic molecules. “[That’s] not a new result,” he says, “but [it is] further support for this key idea in astrobiology.”

    Kaiser adds that the finding demonstrates the value of interdisciplinary studies.

    “Most of the scientists dealing with PAHs [in space] are astronomers,” he says. “They are excellent spectroscopists, but by nature, astronomy sometimes lacks fundamental knowledge about chemistry.”

    Laboratory studies are necessary to turn theories for how complex chemicals can form in space from “hand-waving” into something more definitive, he says.

    But the interdisciplinary impact goes beyond astronomy. Pyrene and other PAHs are common pollutants that can be incorporated into dangerous soot particles created by internal combustion engines and other industrial processes.

    Lessons from astrochemistry about how they can be formed, he says, says Kaiser, can therefore have the very practical side effect of helping us develop less-polluting automobile engines.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: