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  • richardmitnick 12:55 pm on July 3, 2019 Permalink | Reply
    Tags: , , , , , , Quasars   

    From NASA Chandra: “X-rays Spot Spinning Black Holes Across Cosmic Sea” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    2019-07-03

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    Quasars. Credit: NASA/CXC/Univ. of Oklahoma/X. Dai et al.

    Like whirlpools in the ocean, spinning black holes in space create a swirling torrent around them. However, black holes do not create eddies of wind or water. Rather, they generate disks of gas and dust heated to hundreds of millions of degrees that glow in X-ray light.

    Using data from NASA’s Chandra X-ray Observatory and chance alignments across billions of light years, astronomers have deployed a new technique to measure the spin of five supermassive black holes. The matter in one of these cosmic vortices is swirling around its black hole at greater than about 70% of the speed of light.

    The astronomers took advantage of a natural phenomenon called a gravitational lens.

    Gravitational Lensing NASA/ESA

    With just the right alignment, the bending of space-time by a massive object, such as a large galaxy, can magnify and produce multiple images of a distant object, as predicted by Einstein.

    In this latest research, astronomers used Chandra and gravitational lensing to study five quasars, each consisting of a supermassive black hole rapidly consuming matter from a surrounding accretion disk. Gravitational lensing of the light from each of these quasars by an intervening galaxy has created multiple images of each quasar, as shown by these Chandra images of four of the targets. The sharp imaging ability of Chandra is needed to separate the multiple, lensed images of each quasar.

    The key advance made by researchers in this study was that they took advantage of “microlensing,” where individual stars in the intervening, lensing galaxy provided additional magnification of the light from the quasar.

    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    A higher magnification means a smaller region is producing the X-ray emission.

    The researchers then used the property that a spinning black hole is dragging space around with it and allows matter to orbit closer to the black hole than is possible for a non-spinning black hole. Therefore, a smaller emitting region corresponding to a tight orbit generally implies a more rapidly spinning black hole. The authors concluded from their microlensing analysis that the X-rays come from such a small region that the black holes must be spinning rapidly.

    The results showed that one of the black holes, in the lensed quasar called the “Einstein Cross,” (labeled Q2237 in the image above) is spinning at, or almost at, the maximum rate possible. This corresponds to the event horizon, the black hole’s point of no return, spinning at the speed of light, which is about 670 million miles per hour. Four other black holes in the sample are spinning, on average, at about half this maximum rate.

    For the Einstein Cross the X-ray emission is from a part of the disk that is less than about 2.5 times the size of the event horizon, and for the other 4 quasars the X-rays come from a region four to five times the size of the event horizon.

    How can these black holes spin so quickly? The researchers think that these supermassive black holes likely grew by accumulating most of their material over billions of years from an accretion disk spinning with a similar orientation and direction of spin, rather than from random directions. Like a merry-go-round that keeps getting pushed in the same direction, the black holes kept picking up speed.

    The X-rays detected by Chandra are produced when the accretion disk surrounding the black hole creates a multimillion-degree cloud, or corona above the disk near the black hole. X-rays from this corona reflect off the inner edge of the accretion disk, and the strong gravitational forces near the black hole distort the reflected X-ray spectrum, that is, the amount of X-rays seen at different energies. The large distortions seen in the X-ray spectra of the quasars studied here imply that the inner edge of the disk must be close to the black holes, giving further evidence that they must be spinning rapidly.

    The quasars are located at distances ranging from 9.8 billion to 10.9 billion light years from Earth, and the black holes have masses between 160 and 500 million times that of the sun. These observations were the longest ever made with Chandra of gravitationally lensed quasars, with total exposure times ranging between 1.7 and 5.4 days.

    A paper describing these results is published in the July 2nd issue of The Astrophysical Journal. The authors are Xinyu Dai, Shaun Steele and Eduardo Guerras from the University of Oklahoma in Norman, Oklahoma, Christopher Morgan from the United States Naval Academy in Annapolis, Maryland, and Bin Chen from Florida State University in Tallahassee, Florida.

    See the full article here .


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    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

     
  • richardmitnick 10:45 am on June 17, 2019 Permalink | Reply
    Tags: , , “There is a quasar in the Milky Way’s future”, , , , Feeding black holes produce large amounts of X-rays, Giant black holes form when two galaxies each with black holes at its own heart collide, Nobody before had ever caught one in the act of making the transition from red to blue, Quasars, Red quasars are common as are blue ones   

    From COSMOS Magazine: “New class of quasars offers clue to fate of our galaxy” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    17 June 2019
    Richard A Lovett

    Astronomers looking for the blue ones make an important discovery.

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    The Milky Way, as seen from Lake Tekapo, New Zealand. There is a quasar in its future, astronomers now believe. ARUTTHAPHON POOLSAWASD / Getty Images

    Astronomers peering back in time by studying galaxies so far away that their light has been travelling for more than half the age of the universe have discovered a new class of quasar – and a clue to the ultimate fate of our own galaxy.

    Quasars are the most luminous objects in the universe, emitting as much energy as 10 trillion suns, says Allison Kirkpatrick, an astronomer at the University of Kansas, Lawrence, US, and are associated with gigantic black holes at the heart of the largest galaxies.

    “I am a black-hole hunter, and quasars are the most massive of these,” she said at a meeting of the American Astronomical Society in St. Louis, Missouri.

    Such giant black holes form when two galaxies, each with black holes at its own heart, collide.

    At that point, several things happen.

    First, the collision stirs up the gas and dust in these galaxies, pushing it toward their centres. Then, the gas and dust start to fall into the black holes, now in the process of merging.

    “They begin to feed rapidly on the gas around them,” Kirkpatrick says. “This is the quasar stage. They are almost universally produced by major mergers.”

    Feeding black holes produce large amounts of X-rays, but initially, these X-rays are blocked by the gas and dust clouds that have been drawn into the merging galaxies’ centre.

    “It obscures the X-rays,” says Kirkpatrick says – but the heated gas and dust isn’t invisible. Instead of X-rays, it emits vast amounts of infrared light that can be detected by earthly astronomers.

    “We have a dust-reddened quasar,” she says, “[with] very massive black-hole activity going on, but hidden from view.”

    Then, things shift. The powerful radiation being emitted by the quasar overcomes the gravity drawing dust and gas inward toward it, and rapidly blows dust and gas entirely out of the galaxy. “Now we see a luminous blue quasar,” she says.

    But nobody before had ever caught one in the act of making the transition, where the gas and dust have been blown out of the inner part of the galaxy, but not yet out of its outer reaches.

    To find one, Kirkpatrick’s team examined the 1600 most active known quasars, looking for ones that were blue – indicating that their cores had been swept sufficiently free of gas and dust for us to see the quasar itself – but which also emitted a lot of infrared light, indicating that their outer reaches still contained rings of hot gas and dust.

    And, while such objects were rare, Kirkpatrick’s team found 22 of them, all six to 12 billion light years away, including a galaxy that had both a blue quasar and 100 times more dust than our own Milky Way.

    That said, it’s a transition phase. “This new population of quasars are rare and short-lived, she says.

    They also mark the beginning of these galaxies’ deaths, because without their gas and dust, they can no longer form new stars. “We believe that it is the massive black hole that kills them,” Kirkpatrick says.

    And while her study was peering six billion to 12 billion years back in time, it also predicts the future our own Milky Way. “There is a quasar in the Milky Way’s future,” she says.

    That’s because our galaxy will eventually collide with the Andromeda galaxy, a galaxy about the size of our own, currently about 2.5 million light years away.

    Both galaxies have giant black holes at their centres. Neither black hole is currently doing anything dangerous, but when they collide, Kirkpatrick says, both will light up dramatically.

    “That will dominate our night sky,” she says. “They will be incredibly bright. The nice plane of the Milky Way will be dominated by this bright halo [marking the location of the merging black holes].”

    Then, all the gas and dust will be blown out of the merged galaxies and star and planet formation will be shut off. Existing planets will probably survive, Kirkpatrick says, “but you won’t get anything new. They’ll just be going around red dwarfs until eventually [their stars] burn out”.

    Not that this is anything of immediate concern to humans. The merger won’t occur for another three to four billion years, Kirkpatrick says. “That will be about the same time the sun has turned into a red giant, so we will have other problems to occupy us at the time.”

    See the full article here .


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  • richardmitnick 2:24 pm on March 28, 2019 Permalink | Reply
    Tags: , LOFAR is the first radio facility operating at long radio wavelengths which produces sharp images with a resolution similar to that of the Hubble Space Telescope, Low Frequency Array (LOFAR) telescope, Quasar 4C+19.44, Quasars,   

    Netherlands Institute for Radio Astronomy (ASTRON): “Energy loss gives unexpected insights in evolution of quasar jets” 

    ASTRON bloc

    Netherlands Institute for Radio Astronomy (ASTRON)

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    The radio jet of the quasar 4C+19.44, powered by a supermassive black hole lying in the center of its host galaxy and shining at long radio wavelengths as seen by the LOFAR radio telescope (magenta). The background image shows neighboring galaxies in the visible light highlighted thanks to the Hubble Space Telescope (cyan and orange) having the radio jet passing into the dark voids of intergalactic space (Harris et al. 2019). Image Credit: NASA/HST/LOFAR; Courtesy of J. DePasquale

    An international team of astrophysicists observed for the first time that the jet of a quasar is less powerful on long radio wavelengths than earlier predicted. This discovery gives new insights in the evolution of quasar jets. They made this observation using the international Low Frequency Array (LOFAR) telescope [below], that produced high resolution radio images of quasar 4C+19.44 located over 5 billion light-years from Earth.

    Supermassive black holes, many millions of times more massive than our Sun reside in the central regions of galaxies. They grow even larger by attracting and consuming nearby gas and dust. If they consume material rapidly, the infalling matter shines brightly and the source is known as a quasar. Some of this infalling matter is not digested, but instead is ejected in the form of so-called jets that punch through the surrounding galaxy and into intergalactic space for millions of light years. These jets, shining brightly at radio wavelengths, are composed of particles accelerated up to nearly the speed of light, but exactly how these particles achieve energies not attainable on the Earth is yet to be completely solved.

    The discovery on quasar 4C+19.44 gives new insights to the balance between the energy in the field surrounding the quasar and that residing in the quasar jet. This finding indicates to an intrinsic property of the source rather than due to absorption effects. It implies that the energy budget available to accelerate particles and the balance between energy stored in particles and in the magnetic field, is less than expected.

    “This is an important discovery that will be used for the years to come to improve simulations of jets. We observed for the first time a new signature of particle acceleration in the power emitted of quasar jets at long radio wavelengths. An unexpected behaviour that changes our interpretation on their evolution.” Said Prof. Francesco Massaro from University of Turin. “We knew that this was already discovered in other cosmic sources but it was never before observed in quasars.”

    The international team of astrophysicists had observed the jet of the quasar 4C+19.44 at short radio wavelengths, in visible light, and X-ray wavelengths. The addition of the LOFAR images allowed astrophysicists to make this discovery. LOFAR is the first radio facility operating at long radio wavelengths, which produces sharp images with a resolution similar to that of the Hubble Space Telescope.

    “We have been able to perform this experiment thanks to the highest resolution ever achieved at these long radio wavelengths, made possible by LOFAR.” Said Dr Adam Deller, an astrophysicist of the Swinburne University of Technology who contributed to the LOFAR data analysis and imaging of 4C +19.44 while at ASTRON in the Netherlands, heart of the LOFAR collaboration.

    Dr Raymond Oonk, an astronomer at ASTRON and Leiden University and Dr Javier Moldon, astronomer at the University of Manchester, explained that “We have developed new calibration techniques for LOFAR and this has allowed us to separate compact radio structures in the quasar jet known as radio knots, and measure their emitted light. This result was unexpected and demands to future deeper investigations. New insights and clues on particle acceleration will come soon thanks to the international stations of LOFAR.”

    The observation performed on the radio jet of 4C+19.44 was designed by Dr D. E. Harris, supervisor of Prof. Francesco Massaro, while working at the Harvard-Smithsonian Center for Astrophysics, several years ago. He performed the observation in collaboration with Dr Raffaella Morganti and his friends and colleagues at ASTRON. He only got the opportunity to see preliminary results as he passed away on 2015 December 6th. This publication, published in the first March issue of The Astrophysical Journal, is in memory of a career spanned much of the history of radio astronomy.

    See the full article here .

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    LOFAR is a radio telescope composed of an international network of antenna stations and is designed to observe the universe at frequencies between 10 and 250 MHz. Operated by ASTRON, the network includes stations in the Netherlands, Germany, Sweden, the U.K., France, Poland and Ireland.

    ASTRON LOFAR Radio Antenna Bank, Netherlands

    ASTRON-Westerbork Synthesis Radio Telescope
    Westerbork Synthesis Radio Telescope (WSRT)

    ASTRON was founded in 1949, as the Foundation for Radio radiation from the Sun and Milky Way (SRZM). Its original charge was to develop and operate radio telescopes, the first being systems using surplus wartime radar dishes. The organisation has grown from twenty employees in the early 1960’s to about 180 staff members today.

     
  • richardmitnick 10:03 am on January 25, 2019 Permalink | Reply
    Tags: , , , , , , Quasars   

    From ALMA via NRAO: “Tale As Old As Time” 

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

    From ALMA

    via

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    January 7, 2019

    Hot spots in the cosmic microwave background tell us about the history and evolution of distant quasars.

    1
    Credit: NRAO/AUI/NSF

    2
    Image author of a quasar. Credit: NRAO / AUI / NSF.

    Synopsis: Using data from ALMA, a team of astronomers studied the growth and evolution of bubbles of hot plasma produced by active quasar HE 0515-4414. The bubble was analyzed by observing its effect on light from the cosmic microwave background. It is the first time this method has been used to directly study outflows from quasars.

    Cosmic microwave background radiation is the first light in the cosmos.

    Cosmic microwave background radiation. Stephen Hawking Center for Theoretical Cosmology U Cambridge

    The light we see began its journey when the universe was just 380,000 years old, when the temperature of the universe had finally dropped to the point where the primordial plasma of electrons and protons cooled enough to form transparent hydrogen gas. At first, the cosmic background was a nearly perfect blackbody spectrum. A blackbody spectrum is the spectrum of light caused by the temperature of an object. Sunlight, for example, is also a blackbody spectrum. Shortly after it first appeared, the cosmic blackbody was an orange glow, but during its 13.7 billion year journey the expansion of the universe shifted it to infrared and then microwave radiation. We now see this background as a faint glow of microwave light coming from all directions.

    CMB per ESA/Planck


    ESA/Planck 2009 to 2013

    The cosmic background is still a blackbody, but not a perfect one. There are small fluctuations in the background. Regions that are a bit warmer than average, and regions that are slightly cooler. Most of these fluctuations are due to variations in the early universe. Slightly warmer regions expanded to fill the vast voids between galaxies, while slightly cooler regions condensed into galaxies and clusters of galaxies.

    But some of these fluctuations are due to the tremendously long journey the light took to reach us. While traveling for billions of years, the light of the cosmic background passed through all the gas, dust and plasma between us and its source. Some of the light was absorbed. Some lost energy by scattering and now appears cooler than it would otherwise. But some of it gained energy, making the cosmic background appear warmer than it should.

    This warming process is known as the Sunyaev–Zel’dovich effect (or SZ effect). When low energy photons from the cosmic microwave background pass through a region of hot plasma, they can collide with fast-moving electrons. The photons are then scattered with a great deal of energy. So the cosmic light leaves the region warmer and brighter – leaving a “hole” in the background at low frequencies, corresponding to lower photon energies. By looking for temperature fluctuations in the cosmic background, astronomers can study regions of hot plasma.

    In a recent paper published in the Monthly Notices of the Royal Astronomical Society, a team of researchers used the SZ effect to study bubbles of hot plasma near distant quasars. Quasars are bright radio beacons in the sky. They are powered by supermassive black holes in the hearts of galaxies. As the black holes consume matter near them, they radiate tremendous energy. They are often more than 100 times brighter than the galaxy in which they live. This can create a quasar wind of ionized gas that streams away from the galaxy, similar to the way our Sun creates a solar wind. When the quasar wind collides with the diffuse and cool gas of intergalactic space, it can create bubbles of hot plasma.

    Quasars aren’t as distant as the cosmic microwave background, but they are still billions of light-years away. That means any light given off by the plasma bubbles is much too faint to be observed directly. But they can be studied through the SZ effect. In order to do that, however, you need to capture high-resolution images of the microwave background. This is where the Atacama Large Millimeter/submillimeter Array (ALMA) comes in. Located high in the Andes of northern Chile, ALMA can capture microwave images at a resolution similar to visible light images captured by the Hubble space telescope. Just as the Hubble can show us beautiful images of distant nebulae, ALMA can capture images of hot plasma bubbles.

    Using data from ALMA, the astronomers detected a bubble near the quasar HE 0515-4414. This is a hyperluminous quasar, meaning that it is extremely bright and active. But surprisingly when they used their data to measure the quasar wind, they found it was smaller than anticipated. The quasar wind is only 0.01% of the total luminosity of the quasar. Theoretical models predicted that the quasar wind should be much stronger. It seems that while quasars can create hot bubbles of plasma around a galaxy, the process isn’t particularly efficient.

    The scale of the bubble also told them it formed over a period of about 100 million years, and it will take about 600 million years to cool down. Those time scales are long enough that hot plasma bubbles could interact with cooler material in the galaxy to influence star production and the evolution of the galaxy.

    Of course this is just the first hot plasma bubble to be observed, and it’s impossible to know if HE 0515-4414 is typical or a rare exception. So the search is on to find more bubble-blowing quasars.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 10:32 am on January 11, 2019 Permalink | Reply
    Tags: , , , Cosmic Telescope Zooms in on the Beginning of Time, , , Quasar known as J0439+1634, Quasars   

    From Gemini Observatory: “Cosmic Telescope Zooms in on the Beginning of Time” 

    NOAO

    Gemini Observatory
    From Gemini Observatory

    January 9, 2019

    Media Contact:

    Peter Michaud
    Public Information and Outreach manager
    Gemini Observatory
    Email: pmichaud@gemini.edu
    Desk: 808-974-2510
    Cell: 808-936-6643

    Science Contacts:

    Xiaohui Fan
    Regents’ Professor of Astronomy
    Steward Observatory
    University of Arizona
    Email: fan@as.arizona.edu
    Desk: 520-360-0956

    John Blakeslee
    Head Scientist
    Gemini Observatory, La Serena, Chile
    Email: jblakeslee@gemini.edu
    Desk: 56-51-2205-628

    The scientific result described in this release is based on a presentation at the 233rd meeting of the American Astronomical Society in Seattle, Washington and published in The Astrophysical Journal Letters. The research was sponsored by grants from the U.S. National Science Foundation (NSF) Division of Astronomical Sciences and NASA. The National Science Foundation also supports the Gemini Observatory.

    Observations from Gemini Observatory identify a key fingerprint of an extremely distant quasar, allowing astronomers to sample light emitted from the dawn of time. Astronomers happened upon this deep glimpse into space and time thanks to an unremarkable foreground galaxy acting as a gravitational lens, which magnified the quasar’s ancient light.

    Gravitational Lensing NASA/ESA

    The Gemini observations provide critical pieces of the puzzle in confirming this object as the brightest appearing quasar so early in the history of the Universe, raising hopes that more sources like this will be found.

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    A number of large telescopes were used to observe quasar J0439+1634 in the optical and infrared light. The 6.5m MMT Telescope was used to discovery this distant quasar.

    CfA U Arizona Fred Lawrence Whipple Observatory Steward Observatory MMT Telescope at the summit of Mount Hopkins near Tucson, Arizona, USA, Altitude 2,616 m (8,583 ft)

    It and the 10m Keck-I Telescope obtained a sensitive spectrum of the quasar in optical light.

    Keck 1 Telescope, Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level,

    The 8.1m Gemini Telescope obtained an infrared spectrum that accurately determined the quasar distance and the mass of its powerful black hole.

    The 2×8.4m Large Binocular Telescope captured an adaptive optics corrected image that suggests the quasar is lensed, later confirmed by the sharper Hubble image. Credit: Feige Wang (UCSB), Xiaohui Fan (University of Arizona)

    U Arizona Large Binocular Telescope, Large Binocular Telescope Interferometer, or LBTI, is a ground-based instrument connecting two 8-meter class telescopes on Mount Graham, Arizona, USA, Altitude 3,221 m (10,568 ft.) to form the largest single-mount telescope in the world. The interferometer is designed to detect and study stars and planets outside our solar system. Image credit: NASA/JPL-Caltech.

    Before the cosmos reached its billionth birthday, some of the very first cosmic light began a long journey through the expanding Universe. One particular beam of light, from an energetic source called a quasar, serendipitously passed near an intervening galaxy, whose gravity bent and magnified the quasar’s light and refocused it in our direction, allowing telescopes like Gemini North to probe the quasar in great detail.

    “If it weren’t for this makeshift cosmic telescope, the quasar’s light would appear about 50 times dimmer,” said Xiaohui Fan of the University of Arizona who led the study. “This discovery demonstrates that strongly gravitationally lensed quasars do exist despite the fact that we’ve been looking for over 20 years and not found any others this far back in time.”

    The Gemini observations provided key pieces of the puzzle by filling a critical hole in the data. The Gemini North telescope on Maunakea, Hawai‘i, utilized the Gemini Near-InfraRed Spectrograph (GNIRS) to dissect a significant swath of the infrared part of the light’s spectrum.


    Gemini/North telescope at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level


    Gemini Near-Infrared Spectrograph on Gemini North, Mauna Kea, Hawaii USA

    The Gemini data contained the tell-tale signature of magnesium which is critical for determining how far back in time we are looking. The Gemini observations also led to a determination of the mass of the black hole powering the quasar. “When we combined the Gemini data with observations from multiple observatories on Maunakea, the Hubble Space Telescope, and other observatories around the world, we were able to paint a complete picture of the quasar and the intervening galaxy,” said Feige Wang of the University of California, Santa Barbara, who is a member of the discovery team.

    That picture reveals that the quasar is located extremely far back in time and space – shortly after what is known as the Epoch of Reionization — when the very first light emerged from the Big Bang.

    Reionization era and first stars, Caltech

    “This is one of the first sources to shine as the Universe emerged from the cosmic dark ages,” said Jinyi Yang of the University of Arizona, another member of the discovery team. “Prior to this, no stars, quasars, or galaxies had been formed, until objects like this appeared like candles in the dark.”

    The foreground galaxy that enhances our view of the quasar is especially dim, which is extremely fortuitous. “If this galaxy were much brighter, we wouldn’t have been able to differentiate it from the quasar,” explained Fan, adding that this finding will change the way astronomers look for lensed quasars in the future and could significantly increase the number of lensed quasar discoveries. However, as Fan suggested, “We don’t expect to find many quasars brighter than this one in the whole observable Universe.”

    The intense brilliance of the quasar, known as J0439+1634 (J0439+1634 for short), also suggests that it is fueled by a supermassive black hole at the heart of a young forming galaxy. The broad appearance of the magnesium fingerprint captured by Gemini also allowed astronomers to measure the mass of the quasar’s supermassive black hole at 700 million times that of the Sun. The supermassive black hole is most likely surrounded by a sizable flattened disk of dust and gas. This torus of matter — known as an accretion disk — most likely continually spirals inward to feed the black hole powerhouse. Observations at submillimeter wavelengths with the James Clerk Maxwell Telescope on Maunakea suggest that the black hole is not only accreting gas but may be triggering star birth at a prodigious rate — which appears to be up to 10,000 stars per year; by comparison, our Milky Way Galaxy makes one star per year. However, because of the boosting effect of gravitational lensing, the actual rate of star formation could be much lower.

    Quasars are extremely energetic sources powered by huge black holes thought to have resided in the very first galaxies to form in the Universe. Because of their brightness and distance, quasars provide a unique glimpse into the conditions in the early Universe. This quasar has a redshift of 6.51, which translates to a distance of 12.8 billion light years, and appears to shine with a combined light of about 600 trillion Suns, boosted by the gravitational lensing magnification. The foreground galaxy which bent the quasar’s light is about half that distance away, at a mere 6 billion light years from us.

    Fan’s team selected J0439+1634 as a very distant quasar candidate based on optical data from several sources: the Panoramic Survey Telescope and Rapid Response System1 (Pan-STARRS1; operated by the University of Hawai‘i’s Institute for Astronomy), the United Kingdom Infra-Red Telescope Hemisphere Survey (conducted on Maunakea, Hawai‘i), and NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope archive.

    Pann-STARSR1 Telescope, U Hawaii, Mauna Kea, Hawaii, USA, Altitude 3,052 m (10,013 ft)


    UKIRT, located on Mauna Kea, Hawai’i, USA as part of Mauna Kea Observatory,4,207 m (13,802 ft) above sea level

    NASA Wise Telescope

    The first follow-up spectroscopic observations, conducted at the Multi-Mirror Telescope in Arizona, confirmed the object as a high-redshift quasar. Subsequent observations with the Gemini North and Keck I telescopes in Hawai‘i confirmed the MMT’s finding, and led to Gemini’s detection of the crucial magnesium fingerprint — the key to nailing down the quasar’s fantastic distance. However, the foreground lensing galaxy and the quasar appear so close that it is impossible to separate them with images taken from the ground due to blurring of the Earth’s atmosphere. It took the exquisitely sharp images by the Hubble Space Telescope to reveal that the quasar image is split into three components by a faint lensing galaxy.r.

    The quasar is ripe for future scrutiny. Astronomers also plan to use the Atacama Large Millimeter/submillimeter Array, and eventually NASA’s James Webb Space Telescope, to look within 150 light-years of the black hole and directly detect the influence of the gravity from black hole on gas motion and star formation in its vicinity.

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

    NASA/ESA/CSA Webb Telescope annotated

    Any future discoveries of very distant quasars like J0439+1634 will continue to teach astronomers about the chemical environment and the growth of massive black holes in our early Universe.

    See the full article here .


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    Gemini/North telescope at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

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

    AURA Icon

    Gemini’s mission is to advance our knowledge of the Universe by providing the international Gemini Community with forefront access to the entire sky.

    The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

    The Gemini Observatory provides the astronomical communities in six partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country’s contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.

     
  • richardmitnick 9:55 am on July 9, 2018 Permalink | Reply
    Tags: , , , , , PSO J352.4034-15.3373 (P352-15 for short), Quasars,   

    From National Radio Astronomy Observatory via Science Alert: “BREAKING: We Just Found The Brightest Object in The Early Universe – 13 Billion Light-Years Away” 

    NRAO Icon
    From National Radio Astronomy Observatory

    NRAO Banner

    via

    Science Alert

    9 JUL 2018
    MICHELLE STARR

    1
    (NASA Goddard)

    Astronomers have found the brightest object ever discovered in the early Universe, 13 billion light-years away – a quasar from a time when our Universe was just seven percent of its current age.

    A quasar is a galaxy that orbits a supermassive black hole actively feeding on material. The light and radio emissions we see are caused by material around the black hole, called an accretion disk.

    This disk contains dust and gas swirling at tremendous speeds like water going down a drain, generating immense friction as it’s pulled by the massive gravitational force of the black hole in the centre.

    As they consume matter, these quasar black holes expel powerful jets of plasma at near light-speed from the coronae – regions of hot, swirling gas above and below the accretion disk.

    These jets are extremely bright in the radio frequency spectrum. It was this signal emanating from the newly discovered quasar, named PSO J352.4034-15.3373 (P352-15 for short), that was picked up by the Very Long Baseline Array radio telescope.

    NRAO/VLBA

    “There is a dearth of known strong radio emitters from the Universe’s youth and this is the brightest radio quasar at that epoch by a factor of 10,” said astrophysicist Eduardo Bañados of the Carnegie Institution for Science in Pasadena, California.

    2
    (Momjian, et al.; B. Saxton (NRAO/AUI/NSF))

    The VLBA’s observations showed the quasar split into three distinct components, for which there are two possible interpretations.

    The first is that the black hole is at one end, and the two other components are parts of a single jet. The second is that the black hole is in the middle, with a jet on either side.

    According to optical telescopes, which show the quasar in visible light, the position of the black hole aligns with one of the end components – making the first interpretation the most likely.

    This means that, by studying and analysing the two parts of the jet, astrophysicists may be able to measure how fast it is expanding.

    “This quasar may be the most distant object in which we could measure the speed of such a jet,” said NRAO astronomer Emmanuel Momjian.

    On the other hand, if the black hole turns out to be in the centre, it means the jets are much smaller – which would mean a much younger object, or one that is embedded in dense material that’s slowing down the jets.

    Further research will need to be done to determine which of the two scenarios is true. In the meantime, P352-15 is still a highly valuable object for study.

    It’s not as old as J1342+0928, a quasar also discovered by a team led by Bañados, from when the Universe was only five percent of its current age.

    4
    J1342+0928

    But the light of quasars can be used to study the intergalactic medium. This is because the hydrogen it travels through on its long journey to Earth changes the light’s spectrum – recently, a quasar was used in just this way to find the Universe’s missing baryonic matter in the space between galaxies.

    P352-15 has great potential as a tool of this nature.

    “We are seeing P352-15 as it was when the Universe was less than a billion years old,” said astrophysicist Chris Carilli of NRAO.

    “This is near the end of a period when the first stars and galaxies were re-ionising the neutral hydrogen atoms that pervaded intergalactic space. Further observations may allow us to use this quasar as a background ‘lamp’ to measure the amount of neutral hydrogen remaining at that time.

    “This quasar’s brightness and its great distance make it a unique tool to study the conditions and processes that prevailed in the first galaxies in the Universe.”

    The research has been published in The Astrophysical Journal Resolving the Powerful Radio-loud Quasar at z ~ 6, and A Powerful Radio-loud Quasar at the End of Cosmic Reionization.

    See the full article here .


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    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), and the Very Long Baseline Array (VLBA)*.

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

    Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).

    NRAO VLBA

    NRAO VLBA

    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

    And the future Expanded Very Large Array (EVLA).

     
  • richardmitnick 12:32 pm on March 13, 2018 Permalink | Reply
    Tags: , , , , Double or Nothing: Astronomers Rethink Quasar Environment, , Quasars, ,   

    From NAOJ: “Double or Nothing: Astronomers Rethink Quasar Environment” 

    NAOJ

    NAOJ

    March 12, 2018
    No writer credit

    Using Hyper Suprime-Cam (HSC) mounted on the Subaru Telescope, astronomers have identified nearly 200 “protoclusters,” the progenitors of galaxy clusters, in the early Universe, about 12 billion years ago, about ten times more than previously known.

    NAOJ Subaru Hyper Suprime-Cam

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

    They also found that quasars don’t tend to reside in protoclusters; but if there is one quasar in a protocluster, there is likely a second nearby. This result raises doubts about the relation between protoclusters and quasars.

    In the Universe, galaxies are not distributed uniformly. There are some places, known as clusters, where dozens or hundreds of galaxies are found close together. Other galaxies are isolated. To determine how and why clusters formed, it is critical to investigate not only mature galaxy clusters as seen in the present Universe but also observe protoclusters, galaxy clusters in the process of forming.

    Because the speed of light is finite, observing distant objects allows us to look back in time. For example, the light from an object 1 billion light-years away was actually emitted 1 billion years ago and has spent the time since then traveling through space to reach us. By observing this light, astronomers can see an image of how the Universe looked when that light was emitted.

    Even when observing the distant (early) Universe, protoclusters are rare and difficult to discover. Only about 20 were previously known. Because distant protoclusters are difficult to observe directly, quasars are sometimes used as a proxy. When a large volume of gas falls towards the super massive black hole in the center of a galaxy, it collides with other gas and is heated to extreme temperatures. This hot gas shines brightly and is known as a quasar. The thought was that when many galaxies are close together, a merger, two galaxies colliding and melding together, would create instabilities and cause gas to fall into the super massive black hole in one of the galaxies, creating a quasar. However, this relationship was not confirmed observationally due to the rarity of both quasars and protoclusters.

    In order to understand protoclusters in the distant Universe a larger observational sample was needed. A team including astronomers from the National Astronomical Observatory of Japan, the University of Tokyo, the Graduate University for Advanced Studies, and other institutes is now conducting an unprecedented wide-field systematic survey of protoclusters using the Subaru Telescope’s very wide-field camera, Hyper Suprime-Cam (HSC). By analyzing the data from this survey, the team has already identified nearly 200 regions where galaxies are gathering together to form protoclusters in the early Universe 12 billion years ago.

    1
    Figure 1: Galaxy distribution and close-ups of some protoclusters revealed by HSC. Higher- and lower-density regions are represented by redder and bluer colors, respectively. In the close-ups, white circles indicate the positions of distant galaxies. The red regions are expected to evolve into galaxy clusters. From the close-ups, we can see various morphologies of the overdense regions: some have another neighboring overdense region, or are elongated like a filament, while there are also isolated overdense regions. (Credit: NAOJ)

    The team also addressed the relationship between protoclusters and quasars. The team sampled 151 luminous quasars at the same epoch as the HSC protoclusters and to their surprise found that most of those quasars are not close to the overdense regions of galaxies. In fact, their most luminous quasars even avoid the densest regions of galaxies. These results suggest that quasars are not a good proxy for protoclusters and more importantly, mechanisms other than galactic mergers may be needed to explain quasar activity. Furthermore, since they did not find many galaxies near the brightest quasars, that could mean that hard radiation from a quasar suppresses galaxy formation in its vicinity.

    On the other hand, the team found two “pairs” of quasars residing in protoclusters. Quasars are rare and pairs of them are even rarer. The fact that both pairs were associated with protoclusters suggests that quasar activity is perhaps synchronous in protocluster environments. “We have succeeded in discovering a number of protoclusters in the distant Universe for the first time and have witnessed the diversity of the quasar environments thanks to our wide-and-deep observations with HSC,” says the team’s leader Nobunari Kashikawa (NAOJ).

    2
    Figure 2: The two quasar pairs and surrounding galaxies. Stars indicate quasars and bright (faint) galaxies at the same epoch are shown as circles (dots). The galaxy overdensity with respect to the average density is shown by the contour. The pair members are associated with high density regions of galaxies. (Credit: NAOJ)

    “HSC observations have enabled us to systematically study protoclusters for the first time.” says Jun Toshikawa, lead author of the a paper reporting the discovery of the HSC protoclusters, “The HSC protoclusters will steadily increase as the survey proceeds. Thousands of protoclusters located 12 billion light-years away will be found by the time the observations finish. With those new observations we will clarify the growth history of protoclusters.”

    These results were published on January 1, 2018 in the HSC special issue of the Publications of the Astronomical Society of Japan (Toshikawa et al. 2018, GOLDRUSH. III. A Systematic Search of Protoclusters at z~4 Based on the >100 deg2 Area, PASJ, 70, S12; Uchiyama et al. 2018, Luminous Quasars Do Not Live in the Most Overdense Regions of Galaxies at z~4, PASJ, 70, S32; Onoue et al. 2018, Enhancement of Galaxy Overdensity around Quasar Pairs at z<3.6 based on the Hyper Suprime-Cam Subaru Strategic Program Survey, PASJ, 70, S31). These projects are supported by Grants-In-Aid JP15H03645, JP15K17617, and JP15J02115.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

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


    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array
    sft
    Solar Flare Telescope

    Nobeyama Radio Telescope - Copy
    Nobeyama Radio Observatory

    Nobeyama Solar Radio Telescope Array
    Nobeyama Radio Observatory: Solar

    Misuzawa Station Japan
    Mizusawa VERA Observatory

    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

     
  • richardmitnick 7:59 am on January 17, 2018 Permalink | Reply
    Tags: , , , , , Quasars, Steward Observatory,   

    From U Arizona: “Students Help Little Telescope Do Big Things” 

    U Arizona bloc

    University of Arizona

    Jan. 11, 2018
    Daniel Stolte

    A four-year effort involving UA students helped a team of astronomers measure the masses of a large sample of supermassive black holes in the farthest reaches of the universe. As part of a robotic telescope network in southern Arizona, instruments such as the Bok Telescope could play a crucial role in future “grand challenge” science endeavors.

    2.3-metre Bok Telescope at the Steward Observatory at Kitt Peak in Arizona, USA, altitude 2,096 m (6,877 ft)


    U Arizona Steward Observatory at Kitt Peak, AZ, USA, altitude 2,096 m (6,877 ft)

    The Bok Telescope on Kitt Peak is the largest telescope operated solely by the UA’s Steward Observatory. Named in honor of Bart Bok, who was Steward’s director from 1966-1969, the telescope operates every night of the year except Christmas Eve and a maintenance period scheduled during the summer rainy season.

    By today’s standards, the University of Arizona’s Bok Telescope, perched on Kitt Peak southwest of Tucson, is a small telescope: Its primary mirror stands a mere five inches taller than Dušan Ristić, the 7-foot center of the UA men’s basketball team.

    Yet, despite its modest size and advanced age of almost 50 years, the instrument keeps churning out big science, helping us unravel some of the biggest questions about the cosmos. Using observations made with the Bok Telescope, a team of astronomers managed to directly measure the masses of an unprecedented number of the universe’s most distant supermassive black holes, also called quasars. Lurking in the centers of nearly every large galaxy, these Leviathans range from 5 million to 1.7 billion times the mass of the sun.

    “This is the first time that we have directly measured masses for so many supermassive black holes so far away,” said Catherine Grier, a postdoctoral fellow at the Penn State University, who led the research. “These new measurements, and future measurements like them, will provide vital information for people studying how galaxies grow and evolve throughout cosmic time.”

    The results, presented at the American Astronomical Society meeting in National Harbor, Maryland, are published in The Astrophysical Journal and represent a major step forward in our ability to measure supermassive black hole masses in large numbers of distant quasars and galaxies. In addition to the Bok Telescope, the project used the Sloan Digital Sky Survey, or SDSS, and the Canada-France-Hawaii Telescope, or CFHT, atop Hawaii’s Mauna Kea volcano.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)


    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft)


    CFHT Telescope, Maunakea, Hawaii, USA, at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    3
    An artist’s rendering of the inner regions of a quasar, with a supermassive black hole at the center surrounded by a disk of hot material falling in. The two light curves at the bottom illustrates how astronomers use reverberation to map black holes. (Image: Nahks Tr’Ehnl and Catherine Grier/Penn State, SDSS)

    “The Bok Telescope provided key data that allow measurement of how the quasars vary over time, which tells us about the size of the light-emitting region around the black hole,” said Xiaohui Fan, a Regents’ Professor of Astronomy at the UA’s Steward Observatory and a member of the Sloan Digital Sky Survey. “The data is then used to determine the mass of the black hole.”

    Producing ‘World-Class Results’

    The Bok Telescope’s large field of view, combined with the sensitive detectors, means that astronomers can monitor many quasars at the same time, a feat that is crucial to establish the large sample used in the study.

    “This result shows that the Bok can still produce world-class results,” said Ian McGreer, an assistant astronomer at Steward and one of the study’s authors, who managed the observations with the Bok Telescope. “We got involved because the SDSS did a survey of facilities that could support this program, and the Bok came out as one of the few with the required capabilities.”

    The Bok investment was quite substantial, McGreer explained, with more than 100 nights spread over four years so far.

    “The data in this paper are based on the first year, 2014, when the monitoring was the most intense,” he said. “Sixty nights that year were covered by a rotating cast of observers, many of whom were UA undergrads, grads and visiting students.

    “The Bok does not have a nighttime operator, which means the students received valuable training not only in collecting the data and operating the instrument, but in learning how to operate a telescope at night. This is a fairly rare opportunity these days.”

    As they suck in nearby dust and gas, supermassive black holes heat the material to such high temperatures that it glows brightly enough to be seen all the way across the universe. These bright disks of hot gas are known as quasars, and they are clear indicators of the presence of supermassive black holes. By studying these quasars, we learn not only about supermassive black holes, or SMBHs, but also about the distant galaxies they live in. But to do all of this requires measurements of the properties of the SMBHs, most importantly their masses.

    Measuring the masses of extragalactic SMBHs — in this study, up to 8 billion light-years away — is a daunting task and requires a technique called reverberation mapping. Reverberation mapping works by comparing the brightness of light coming from gas very close in to the black hole (referred to as the “continuum” light) to the brightness of light coming from fast-moving gas farther out. Changes occurring in the continuum region impact the outer region, but light takes time to travel outward, or “reverberate.” By measuring this time delay, astronomers can determine how far out the gas is from the black hole. Knowing that distance allows them to measure the mass of the supermassive black hole — even though they can’t see the details of the black hole itself.

    In this new work, the team used an industrial-scale application of the reverberation mapping technique, with the goal of measuring black hole masses in tens to hundreds of quasars. These new SDSS measurements increase the total number of active galaxies with SMBH mass measurements by about two-thirds, and push the measurements farther back in time to when the universe was only half of its current age.

    Faint Quasars Pose a Challenge

    The key to the success of the SDSS reverberation mapping project lies in the SDSS’ ability to study many quasars at once — the program is currently observing 850 quasars simultaneously. But even with the SDSS’ powerful telescope, this is a challenging task because these distant quasars are incredibly faint.

    “You have to calibrate these measurements very carefully to make sure you really understand what the quasar system is doing,” said Jon Trump, an assistant professor at the University of Connecticut and a member of the research team.

    Observing the quasars over the same season with the Bok Telescope and the CFHT improved these calibrations, allowing the team to find reverberation time delays for 44 quasars and use the time delay measurements to calculate black hole masses that range from about 5 million to 1.7 billion times the mass of our sun.

    In the words of McGreer, the future is bright for this kind of work, with plans to develop a robotic telescope network in southern Arizona using telescopes such as the Bok, which could help guide efforts to combine such a network with “grand challenge” science projects like the Large Synoptic Survey Telescope, or LSST.

    Slated to begin operations in 2023, the LSST will conduct an unprecedented 10-year survey, repeatedly imaging every part of the visible sky every few nights. The heart of the instrument, a 8.4-meter primary mirror, was cast and polished at the UA’s Richard F. Caris Mirror Lab.

    “The lessons learned from this reverberation mapping project serve as a pathfinder, or proof of concept, for something that could be done on a much larger scale when LSST arrives,” McGreer said.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    See the full article here .

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 5:09 pm on December 26, 2017 Permalink | Reply
    Tags: 'Direct Collapse' Black Holes May Explain Our Universe's Mysterious Quasars, , , , , , , , , Quasars, , Star formation is a violent process, ,   

    From Ethan Siegel: “‘Direct Collapse’ Black Holes May Explain Our Universe’s Mysterious Quasars” 

    From Ethan Siegel
    Dec 26, 2017

    1
    The most distant X-ray jet in the Universe, from quasar GB 1428, is approximately the same distance and age, as viewed from Earth, as quasar S5 0014+81; both are over 12 billion light years away. X-ray: NASA/CXC/NRC/C.Cheung et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA

    NASA/Chandra Telescope


    NASA/ESA Hubble Telescope


    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    There’s a big problem when we look at the brightest, most energetic objects we can see in the early stages of the Universe. Shortly after the first stars and galaxies form, we find the first quasars: extremely luminous sources of radiation that span the electromagnetic spectrum, from radio up through the X-ray. Only a supermassive black hole could possibly serve as the engine for one of these cosmic behemoths, and the study of active objects like quasars, blazars, and AGNs all support this idea. But there’s a problem: it may not be possible to make a black hole so large, so quickly, to explain these young quasars that we see. Unless, that is, there’s a new way to make black holes beyond what we previously thought. This year, we found the first evidence for a direct collapse black hole, and it may lead to the solution we’ve sought for so long.

    2
    While distant host galaxies for quasars and active galactic nuclei can often be imaged in visible/infrared light, the jets themselves and the surrounding emission is best viewed in both the X-ray and the radio, as illustrated here for the galaxy Hercules A. It takes a black hole to power an engine such as this. NASA, ESA, S. Baum and C. O’Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA).

    Generically known as ‘active galaxies,’ almost all galaxies posses supermassive black holes at their center, but only a few emit the intense radiation associated with quasars or AGNs. The leading idea is that supermassive black holes will feed on matter, accelerating and heating it, which causes it to ionize and give off light. Based on the light we observe, we can successfully infer the mass of the central black hole, which often reaches billions of times the mass of our Sun. Even for the earliest quasars, such as J1342+0928, we can get up to a mass of 800 million solar masses just 690 million years after the Big Bang: when the Universe was just 5% of its current age.

    3
    This artist’s concept shows the most distant supermassive black hole ever discovered. It is part of a quasar from just 690 million years after the Big Bang. Robin Dienel/Carnegie Institution for Science.

    If you try to build a black hole in the conventional way, by having massive stars go supernova, form small black holes, and have them merge together, you run into problems. Star formation is a violent process, as when nuclear fusion ignites, the intense radiation burns off the remaining gas that would otherwise go into forming progressively more and more massive stars. From nearby star-forming regions to the most distant ones we’ve ever observed, this same process seems to be in place, preventing stars (and, hence, black holes) beyond a certain mass from ever forming.

    4
    An artist’s conception of what the Universe might look like as it forms stars for the first time. While stars might reach many hundreds or even a thousand solar masses, it’s very difficult to see how you could get a black hole of the mass the earliest quasars are known to possess. NASA/JPL-Caltech/R. Hurt (SSC).

    We have a standard scenario that’s very powerful and compelling: of supernova explosions, gravitational interactions, and then growth by mergers and accretion. But the early quasars we see are too massive too quickly to be explained by this. Our other known pathway to create black holes, from merging neutron stars, provides no further help. Instead, a third scenario of direct collapse may be responsible. This idea has been helped along by three pieces of evidence in the past year:

    1.The discovery of ultra-young quasars like J1342+0928, in possession of black holes many hundred of millions of solar masses.
    2.Theoretical advances that show how, if the direct collapse scenario is true, we could form early “seed” black holes a thousand times as massive as the ones formed by supernova.
    3.And the discovery of the first stars that become black holes via direct collapse, validating the process.

    5
    In addition to formation by supernovae and neutron star mergers, it should be possible for black holes to form via direct collapse. Simulations such as the one shown here demonstrate that, under the right condition, seed black holes of 100,000 to 1,000,000 solar masses could form in the very early stages of the Universe. Aaron Smith/TACC/UT-Austin.

    Normally, it’s the hottest, youngest, most massive, and newest stars in the Universe that will lead to a black hole. There are plenty of galaxies like this in the early stages of the Universe, but there are also plenty of proto-galaxies that are all gas, dust, and dark matter, with no stars in them yet. Out in the great cosmic abyss, we’ve even found an example of a pair of galaxies just like this: where one has furiously formed stars and the other one may not have formed any yet. The ultra-distant galaxy, known as CR7, has a massive population of young stars, and a nearby patch of light-emitting gas that may not have yet formed a single star in it.

    6
    Illustration of the distant galaxy CR7, which last year was discovered to house a pristine population of stars formed from the material direct from the Big Bang. One of these galaxies definitely houses stars; the other may not have formed any yet. M. Kornmesser / ESO.

    In a theoretical study published in March [Nature Astronomy] of this year, a fascinating mechanism for producing direct collapse black holes from a mechanism like this was introduced. A young, luminous galaxy could irradiate a nearby partner, which prevents the gas within it from fragmenting to form tiny clumps. Normally, it’s the tiny clumps that collapse into individual stars, but if you fail to form those clumps, you instead can just get a monolithic collapse of a huge amount of gas into a single bound structure. Gravitation then does its thing, and your net result could be a black hole over 100,000 times as massive as our Sun, perhaps even all the way up to 1,000,000 solar masses.

    6
    Distant, massive quasars show ultramassive black holes in their cores. It’s very difficult to form them without a large seed, but a direct collapse black hole could solve that puzzle quite elegantly. J. Wise/Georgia Institute of Technology and J. Regan/Dublin City University.

    There are many theoretical mechanisms that turn out to be intriguing, however, that aren’t borne out when it comes to real, physical environments. Is direct collapse possible? We can now definitively answer that question with a “yes,” as the first star that was massive enough to go supernova was seen to simply wink out of existence. No fireworks; no explosion; no increase in luminosity. Just a star that was there one moment, and replaces with a black hole the next. As spotted before-and-after with Hubble, there is no doubt that the direct collapse of matter to a black hole occurs in our Universe.

    7
    The visible/near-IR photos from Hubble show a massive star, about 25 times the mass of the Sun, that has winked out of existence, with no supernova or other explanation. Direct collapse is the only reasonable candidate explanation. NASA/ESA/C. Kochanek (OSU).

    Put all three of these pieces of information together, and you arrive at the following picture for how these supermassive black holes form so early.

    A region of space collapses to form stars, while a nearby region of space has also undergone gravitational collapse but hasn’t formed stars yet.
    The region with stars emits an intense amount of radiation, where the photon pressure keeps the gas in the other cloud from fragmenting into potential stars.
    The cloud itself continues to collapse, doing so in a monolithic fashion. It expels energy (radiation) as it does so, but without any stars inside.
    When a critical threshold is crossed, that huge amount of mass, perhaps hundreds of thousands or even millions of times the mass of our Sun, directly collapses to form a black hole.
    From this massive, early seed, it’s easy to get supermassive black holes simply by the physics of gravitation, merger, accretion, and time.

    It might not only be possible, but with the new array of radio telescopes coming online, as well as the James Webb Space Telescope, we may be able to witness the process in action.

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

    SKA Square Kilometer Array


    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia


    SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    The galaxy CR7 is likely one example of many similar objects likely to be out there. As Volker Bromm, the theorist behind the direct collapse mechanism first said [RAS], a nearby, luminous galaxy could cause a nearby cloud of gas to directly collapse. All you need to do is begin with a

    “primordial cloud of hydrogen and helium, suffused in a sea of ultraviolet radiation. You crunch this cloud in the gravitational field of a dark-matter halo. Normally, the cloud would be able to cool, and fragment to form stars. However, the ultraviolet photons keep the gas hot, thus suppressing any star formation. These are the desired, near-miraculous conditions: collapse without fragmentation! As the gas gets more and more compact, eventually you have the conditions for a massive black hole.”

    8
    The directly collapsing star we observed exhibited a brief brightening before having its luminosity drop to zero, an example of a failed supernova. For a large cloud of gas, the luminous emission of light is expected, but no stars are necessary to form a black hole this way.
    NASA/ESA/P. Jeffries (STScI)

    With a little luck, by time 2020 rolls around, this is one longstanding mystery that might finally be solved.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 8:40 pm on December 17, 2017 Permalink | Reply
    Tags: , , Atacama Desert of Chile so important for Optical Astonomy, , Carnegie Institution for Science Las Campanas Observatory, , , Earliest Black Hole Gives Rare Glimpse of Ancient Universe, , Quasars, ,   

    From Quanta: “Earliest Black Hole Gives Rare Glimpse of Ancient Universe” 

    Quanta Magazine
    Quanta Magazine

    December 6, 2017 [Today in social media]
    Joshua Sokol

    1
    Olena Shmahalo/Quanta Magazine

    2
    The two Carnegie Magellan telescopes: Baade (left) and Clay (right)

    Astronomers have at least two gnawing questions about the first billion years of the universe, an era steeped in literal fog and figurative mystery. They want to know what burned the fog away: stars, supermassive black holes, or both in tandem? And how did those behemoth black holes grow so big in so little time?

    Now the discovery of a supermassive black hole smack in the middle of this period is helping astronomers resolve both questions. “It’s a dream come true that all of these data are coming along,” said Avi Loeb, the chair of the astronomy department at Harvard University.

    The black hole, announced today in the journal Nature, is the most distant ever found. It dates back to 690 million years after the Big Bang. Analysis of this object reveals that reionization, the process that defogged the universe like a hair dryer on a steamy bathroom mirror, was about half complete at that time.

    First Stars and Reionization Era, Caltech

    The researchers also show that the black hole already weighed a hard-to-explain 780 million times the mass of the sun.

    A team led by Eduardo Bañados, an astronomer at the Carnegie Institution for Science in Pasadena, found the new black hole by searching through old data for objects with the right color to be ultradistant quasars — the visible signatures of supermassive black holes swallowing gas. The team went through a preliminary list of candidates, observing each in turn with a powerful telescope at Las Campanas Observatory in Chile.

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    Carnegie Institution for Science Las Campanas Observatory telescopes in the southern Atacama Desert of Chile approximately 100 kilometres (62 mi) northeast of the city of La Serena,near the southern end and over 2,500 m (8,200 ft) high.

    On March 9, Bañados observed a faint dot in the southern sky for just 10 minutes. A glance at the raw, unprocessed data confirmed it was a quasar — not a nearer object masquerading as one — and that it was perhaps the oldest ever found. “That night I couldn’t even sleep,” he said.

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    Eduardo Bañados at the Las Campanas Observatory in Chile, where the new quasar was discovered. Courtesy of Eduardo Bañados. Baade and Clay in the background.

    The new black hole’s mass, calculated after more observations, adds to an existing problem. Black holes grow when cosmic matter falls into them. But this process generates light and heat. At some point, the radiation released by material as it falls into the black hole carries out so much momentum that it blocks new gas from falling in and disrupts the flow. This tug-of-war creates an effective speed limit for black hole growth called the Eddington rate. If this black hole began as a star-size object and grew as fast as theoretically possible, it couldn’t have reached its estimated mass in time.

    Other quasars share this kind of precocious heaviness, too. The second-farthest one known, reported on in 2011, tipped the scales at an estimated 2 billion solar masses after 770 million years of cosmic time.

    These objects are too young to be so massive. “They’re rare, but they’re very much there, and we need to figure out how they form,” said Priyamvada Natarajan, an astrophysicist at Yale University who was not part of the research team. Theorists have spent years learning how to bulk up a black hole in computer models, she said. Recent work suggests that these black holes could have gone through episodic growth spurts during which they devoured gas well over the Eddington rate.

    Bañados and colleagues explored another possibility: If you start at the new black hole’s current mass and rewind the tape, sucking away matter at the Eddington rate until you approach the Big Bang, you see it must have initially formed as an object heavier than 1,000 times the mass of the sun. In this approach, collapsing clouds in the early universe gave birth to overgrown baby black holes that weighed thousands or tens of thousands of solar masses. Yet this scenario requires exceptional conditions that would have allowed gas clouds to condense all together into a single object instead of splintering into many stars, as is typically the case.

    Cosmic Dark Ages

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    Cosmic Dark Ages. ESO.

    Even earlier in the early universe, before any stars or black holes existed, the chaotic scramble of naked protons and electrons came together to make hydrogen atoms. These neutral atoms then absorbed the bright ultraviolet light coming from the first stars. After hundreds of millions of years, young stars or quasars emitted enough light to strip the electrons back off these atoms, dissipating the cosmic fog like mist at dawn.

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    Lucy Reading-Ikkanda/Quanta Magazine

    Astronomers have known that reionization was largely complete by around a billion years after the Big Bang.

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex Mittelmann Cold creation

    At that time, only traces of neutral hydrogen remained. But the gas around the newly discovered quasar is about half neutral, half ionized, which indicates that, at least in this part of the universe, reionization was only half finished. “This is super interesting, to really map the epoch of reionization,” said Volker Bromm, an astrophysicist at the University of Texas.

    When the light sources that powered reionization first switched on, they must have carved out the opaque cosmos like Swiss cheese.

    Inflationary Universe. NASA/WMAP

    But what these sources were, when it happened, and how patchy or homogeneous the process was are all debated. The new quasar shows that reionization took place relatively late. That scenario squares with what the known population of early galaxies and their stars could have done, without requiring astronomers to hunt for even earlier sources to accomplish it quicker, said study coauthor Bram Venemans of the Max Planck Institute for Astronomy in Heidelberg.

    More data points may be on the way. For radio astronomers, who are gearing up to search for emissions from the neutral hydrogen itself, this discovery shows that they are looking in the right time period. “The good news is that there will be neutral hydrogen for them to see,” said Loeb. “We were not sure about that.”

    The team also hopes to identify more quasars that date back to the same time period but in different parts of the early universe. Bañados believes that there are between 20 and 100 such very distant, very bright objects across the entire sky. The current discovery comes from his team’s searches in the southern sky; next year, they plan to begin searching in the northern sky as well.

    “Let’s hope that pans out,” said Bromm. For years, he said, the baton has been handed off between different classes of objects that seem to give the best glimpses at early cosmic time, with recent attention often going to faraway galaxies or fleeting gamma-ray bursts. “People had almost given up on quasars,” he said.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Formerly known as Simons Science News, Quanta Magazine is an editorially independent online publication launched by the Simons Foundation to enhance public understanding of science. Why Quanta? Albert Einstein called photons “quanta of light.” Our goal is to “illuminate science.” At Quanta Magazine, scientific accuracy is every bit as important as telling a good story. All of our articles are meticulously researched, reported, edited, copy-edited and fact-checked.

     
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