Tagged: NASA Chandra Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 11:56 am on May 11, 2020 Permalink | Reply
    Tags: "Abell 2384: Bending the Bridge Between Two Galaxy Clusters", , , , , NASA Chandra   

    From NASA Chandra: “Abell 2384: Bending the Bridge Between Two Galaxy Clusters” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    May 11, 2020

    1
    Composite

    2
    X-ray

    3
    Optical

    4
    Radio

    A bridge of gas extending over three million light years from two galaxy clusters has been spotted.

    The two clusters collided several hundred million years ago and then passed through each other to arrive in this configuration.

    The collision released a large amount of hot gas that now spans the distance between the two clusters.

    This superheated bridge of gas glows brightly in X-rays, which Chandra and XMM-Newton have detected.

    Several hundred million years ago, two galaxy clusters collided and then passed through each other. This mighty event released a flood of hot gas from each galaxy cluster that formed an unusual bridge between the two objects. This bridge is now being pummeled by particles driven away from a supermassive black hole.

    Galaxy clusters are the largest objects in the universe held together by gravity. They contain hundreds or thousands of galaxies, vast amounts of multi-million-degree gas that glow in X-rays, and enormous reservoirs of unseen dark matter.

    The system known as Abell 2384 shows the giant structures that can result when two galaxy clusters collide. A superheated gas bridge in Abell 2384 is shown in this composite image of X-rays from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton (blue), as well as the Giant Metrewave Radio Telescope in India (red).

    ESA/XMM Newton

    Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India

    This new multi-wavelength view reveals the effects of a jet shooting away from a supermassive black hole in the center of a galaxy in one of the clusters. The jet is so powerful that it is bending the shape of the gas bridge, which extends for over 3 million light years and has the mass of about 6 trillion Suns.

    A labeled version of the image traces the shape of the bridge, marks the position of the supermassive black hole, and shows where the jet is pushing the hot gas in the bridge sideways at the collision site. The lobe of radio emission marking the end of each jet is also shown. At the collision site, astronomers found evidence for a shock front, similar to a sonic boom from a supersonic aircraft, which can keep the gas hot and prevent it from cooling to form new stars.

    The radio emission extends about 1.2 million light years from the black hole to the north and about 1.7 million light years to the south. The northern radio emission is also fainter than the southern emission. These differences might be explained by the radio emission to the north being slowed down by the jet’s impact with the hot gas in the bridge.

    Chandra has often observed cavities in hot gas created by jets in the centers of galaxy clusters, such as the Perseus cluster, MS 0735 and the Ophiuchus Cluster. However, Abell 2384 offers a rare case of such an interaction occurring in the outer region of a cluster. It is also unusual that the supermassive black hole driving the jet is not in the largest galaxy located in the center of the cluster.

    Astronomers consider objects like Abell 2384 to be important for understanding the growth of galaxy clusters. Based on computer simulations, it has been shown that after a collision between two galaxy clusters, they oscillate like a pendulum and pass through each other several times before merging to form a larger cluster. Based on these simulations, astronomers think that the two clusters in Abell 2384 will eventually merge.

    Abell 2384 is located 1.2 billion light years from Earth. Based on previous work, scientists estimate the total mass of Abell 2384 is 260 trillion times the mass of the Sun. This includes the dark matter, hot gas and the individual galaxies.

    A paper describing this work was published in the January 2020 issue of the Monthly Notices of the Royal Astronomical Society, and is available online. The authors are Viral Parekh (South African Radio Astronomy Observatory and Rhodes University, South Africa); Tatiana Lagana (Universidade Cruzeiro do Sul/Universidade Cidade de São Paulo, Brazil); Kshitij Thorat (Rhodes University); Kurt van der Heyden (University of Cape Town, South Africa); Asif Iqbal Ahanger (Raman Research Institute, India); and Florence Durret (Institut d’Astrophysique de Paris and Sorbonne Université, France).

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 9:35 am on April 25, 2020 Permalink | Reply
    Tags: "Star Survives Close Call with a Black Hole", , , , , GSN 069 is now caught in an elliptical orbit around the black hole making one trip around about once every nine hours.", It will try hard to get away but there is no escape., NASA Chandra, The black hole located in a galaxy called GSN 069 has a mass about 400000 times that of the Sun- putting it on the small end of the scale for supermassive black holes.,   

    From NASA Chandra: “Star Survives Close Call with a Black Hole” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    April 23, 2020

    Media contacts:
    Molly Porter
    NASA Marshall Space Flight Center, Huntsville, Ala.
    256-424-5158
    molly.a.porter@nasa.gov

    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    1
    X-ray: NASA/CXO/CSIC-INTA/G.Miniutti et al.; Illustration: NASA/CXC/M. Weiss;

    Astronomers may have discovered a new kind of survival story: a star that had a brush with a giant black hole and lived to tell the tale through exclamations of X-rays.

    Data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton uncovered the account that began with a red giant star wandering too close to a supermassive black hole in a galaxy about 250 million light years from Earth.

    ESA/XMM Newton

    The black hole, located in a galaxy called GSN 069, has a mass about 400,000 times that of the Sun, putting it on the small end of the scale for supermassive black holes.

    Once the red giant was captured by the black hole’s gravity, the outer layers of the star containing hydrogen were stripped off and careened toward the black hole, leaving the core of the star — known as a white dwarf — behind.

    “In my interpretation of the X-ray data the white dwarf survived, but it did not escape,” said Andrew King of the University of Leicester in the UK, who performed this study. “It is now caught in an elliptical orbit around the black hole, making one trip around about once every nine hours.”

    As the white dwarf makes its nearly thrice-daily orbit, the black hole pulls material off at its closest approach (no more than 15 times the radius of the event horizon — the point of no return — away from the black hole). The stellar detritus enters into a disk surrounding the black hole and releases a burst of X-rays that Chandra and XMM-Newton can detect. In addition, King predicts gravitational waves will be emitted by the black hole and white dwarf pair, especially at their nearest point.

    What would be the future of the star and its orbit? The combined effect of gravitational waves and a change in the star’s size as it loses mass should cause the orbit to become more circular and grow in size. The rate of mass loss steadily slows down, as does the increase in the white dwarf’s distance from the black hole.

    “It will try hard to get away, but there is no escape. The black hole will eat it more and more slowly, but never stop,” said King. “In principle, this loss of mass would continue until and even after the white dwarf dwindled down to the mass of Jupiter, in about a trillion years. This would be a remarkably slow and convoluted way for the universe to make a planet!”

    Astronomers have found many stars that have been completely torn apart by encounters with black holes (so-called tidal disruption events), but there are very few reported cases of near misses, where the star likely survived.

    Grazing encounters like this should be more common than direct collisions given the statistics of cosmic traffic patterns, but they could easily be missed for a couple of reasons. First, it can take a more massive, surviving star too long to complete an orbit around a black hole for astronomers to see repeated bursts. Another issue is that supermassive black holes that are much more massive than the one in GSN 069 may directly swallow a star rather than the star falling into orbits where they periodically lose mass. In these cases, astronomers wouldn’t observe anything.

    “In astronomical terms, this event is only visible to our current telescopes for a short time — about 2,000 years,” said King. “So unless we were extraordinarily lucky to have caught this one, there may be many more that we are missing. Such encounters could be one of the main ways for black holes the size of the one in GSN 069 to grow.”

    King predicts that the white dwarf has a mass of only two tenths the mass of the Sun. If the white dwarf was the core of the red giant that was completely stripped of its hydrogen, then it should be rich in helium. The helium would have been created by the fusion of hydrogen atoms during the evolution of the red giant.

    “It’s remarkable to think that the orbit, mass and composition of a tiny star 250 million light years away could be inferred,” said King.

    King made a prediction based on his scenario. Because the white dwarf is so close to the black hole, effects from the Theory of General Relativity mean that the direction of the orbit’s axis should wobble, or “precess.” This wobble should repeat every two days and may be detectable with sufficiently long observations.

    A paper describing these results appears in the March 2020 issue of the Monthly Notices of the Royal Astronomical Society, and is available online.

    Other materials about the findings are available at:
    http://chandra.si.edu

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 2:29 pm on March 31, 2020 Permalink | Reply
    Tags: "Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole", (IMBH)-intermediate-mass black hole, , , , , , NASA Chandra, , The X-ray source named 3XMM J215022.4−055108   

    From NASA/ESA Hubble Telescope: “Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole” 

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    March 31, 2020

    Leah Ramsay
    Space Telescope Science Institute, Baltimore, Maryland
    667-218-6439
    lramsay@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Dacheng Lin
    University of New Hampshire, Durham, New Hampshire
    dacheng.lin@unh.edu

    High-resolution imaging reveals black hole’s hideout in extra-galactic star cluster.

    1
    About This Image. Illustration of Mid-Sized Black Hole Eating a Star
    This artist’s concept depicts a cosmic homicide in action. A wayward star is being shredded by the intense gravitational pull of a black hole that contains tens of thousands of solar masses. The stellar remains are forming an accretion disk around the black hole. Flares of X-ray light from the super-heated gas disk alerted astronomers to the black hole’s location; otherwise it lurked unknown in the dark. The elusive object is classified as an intermediate-mass black hole (IMBH), as it is much less massive than the monster black holes that dwell in the centers of galaxies. Therefore, IMBHs are mostly quiescent because they do not pull in as much material, and are hard to find. Hubble observations provide evidence that the IMBH dwells inside a dense star cluster. The cluster itself may be the stripped-down core of a dwarf galaxy. Credits: NASA/ESA and D. Player (STScI)

    Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as “intermediate-mass,” which betrayed its existence by tearing apart a wayward star that passed too close.

    Weighing in at about 50,000 times the mass of our Sun, the black hole is smaller than the supermassive black holes (at millions or billions of solar masses) that lie at the cores of large galaxies, but larger than stellar-mass black holes formed by the collapse of a massive star.

    These so-called intermediate-mass black holes (IMBHs) are a long-sought “missing link” in black hole evolution. Though there have been a few other IMBH candidates, researchers consider these new observations the strongest evidence yet for mid-sized black holes in the universe.

    It took the combined power of two X-ray observatories and the keen vision of NASA’s Hubble Space Telescope to nail down the cosmic beast.

    “Intermediate-mass black holes are very elusive objects, and so it is critical to carefully consider and rule out alternative explanations for each candidate. That is what Hubble has allowed us to do for our candidate,” said Dacheng Lin of the University of New Hampshire, principal investigator of the study. The results are published on March 31, 2020 in The Astrophysical Journal Letters.

    The story of the discovery reads like a Sherlock Holmes story, involving the meticulous step-by-step case-building necessary to catch the culprit.

    Lin and his team used Hubble to follow up on leads from NASA’s Chandra X-ray Observatory and the European Space Agency’s X-ray Multi-Mirror Mission (XMM-Newton).

    NASA/Chandra X-ray Telescope

    ESA/XMM Newton

    In 2006 these high-energy satellites detected a powerful flare of X-rays, but were not sure if they originated from inside or outside of our galaxy. Researchers attributed it to a star being torn apart after coming too close to a gravitationally powerful compact object, like a black hole.

    Surprisingly, the X-ray source, named 3XMM J215022.4−055108, was not located in a galaxy’s center, where massive black holes normally would reside. This raised hopes that an IMBH was the culprit, but first another possible source of the X-ray flare had to be ruled out: a neutron star in our own Milky Way galaxy, cooling off after being heated to a very high temperature. Neutron stars are the crushed remnants of an exploded star.

    Hubble was pointed at the X-ray source to resolve its precise location. Deep, high-resolution imaging provides strong evidence that the X-rays emanated not from an isolated source in our galaxy, but instead in a distant, dense star cluster on the outskirts of another galaxy — just the type of place astronomers expected to find an IMBH. Previous Hubble research has shown that the mass of a black hole in the center of a galaxy is proportional to that host galaxy’s central bulge. In other words, the more massive the galaxy, the more massive its black hole. Therefore, the star cluster that is home to 3XMM J215022.4−055108 may be the stripped down core of a lower-mass dwarf galaxy that has been gravitationally and tidally disrupted by its close interactions with its current larger galaxy host.

    IMBHs have been particularly difficult to find because they are smaller and less active than supermassive black holes; they do not have readily available sources of fuel, nor as strong a gravitational pull to draw stars and other cosmic material which would produce telltale X-ray glows. Astronomers essentially have to catch an IMBH red-handed in the act of gobbling up a star. Lin and his colleagues combed through the XMM-Newton data archive, searching hundreds of thousands of observations to find one IMBH candidate.

    The X-ray glow from the shredded star allowed astronomers to estimate the black hole’s mass of 50,000 solar masses. The mass of the IMBH was estimated based on both X-ray luminosity and the spectral shape. “This is much more reliable than using X-ray luminosity alone as typically done before for previous IMBH candidates,” said Lin. “The reason why we can use the spectral fits to estimate the IMBH mass for our object is that its spectral evolution showed that it has been in the thermal spectral state, a state commonly seen and well understood in accreting stellar-mass black holes.”

    This object isn’t the first to be considered a likely candidate for an intermediate-mass black hole. In 2009 Hubble teamed up with NASA’s Swift observatory and the XMM-Newton X-ray space telescope to identify what is interpreted as an IMBH, called HLX-1, located towards the edge of the galaxy ESO 243-49.

    NASA Neil Gehrels Swift Observatory

    It too is in the center of a young, massive cluster of blue stars, that may be a stripped down dwarf galaxy core. The X-rays come from a hot accretion disk around the black hole. “The main difference is that our object is tearing a star apart, providing strong evidence that it is a massive black hole, instead of a stellar-mass black hole as people often worry about for previous candidates including HLX-1,” Lin said.

    Finding this IMBH opens the door to the possibility of many more lurking undetected in the dark, waiting to be given away by a star passing too close. Lin plans to continue his meticulous detective work, using the methods his team has proved successful. Many questions remain to be answered. Does a supermassive black hole grow from an IMBH? How do IMBHs themselves form? Are dense star clusters their favored home?

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

    ESA50 Logo large

     
  • richardmitnick 4:20 pm on March 19, 2020 Permalink | Reply
    Tags: "Chandra Data Tests 'Theory of Everything'", but did not find signals of any axion-like particles., NASA Chandra, The researchers were looking for a type of particle known as an "axion" and other similar particles., The team looked at the Perseus galaxy cluster for over 5 days with Chandra   

    From NASA Chandra: “Chandra Data Tests ‘Theory of Everything'” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    4
    X-ray full field; X-ray close up

    Astronomers used Chandra to perform a test of string theory, a possible “theory of everything” that would tie all of known physics together.

    The researchers were looking for a type of particle known as an “axion” and other similar particles.

    Galaxy clusters with their strong magnetic fields and X-ray emission can be excellent places to search for evidence for axions.

    The team looked at the Perseus galaxy cluster for over 5 days with Chandra, but did not find signals of any axion-like particles.

    Astronomers using NASA’s Chandra X-ray Observatory have made one of the first experimental tests of string theory, a set of models intended to tie together all known forces, particles, and interactions. As described in our latest press release, researchers used Chandra to look for signs of an as-yet undetected particle predicted by string theory. The lack of a detection in these Chandra observations helps rule out some versions of string theory.

    The team looked for extraordinarily low-mass “axion-like” particles in the Perseus galaxy cluster, shown in a Chandra image in the main panel of this graphic (red, green and blue colors are low, medium and high X-ray energies respectively). Galaxy clusters, the largest structures in the Universe held together by gravity, offer an excellent opportunity to search for these particles. In a galaxy cluster, X-ray photons from an embedded or a background source can travel through a large amount of hot gas permeated with magnetic field lines. Some of the X-ray photons may undergo conversion into axion-like particles, or the other way around, along this journey. A simplified illustration shows this process, with shorter wavelength X-ray photons (in blue) converting into axion-like particles (yellow) and back to photons, as they travel across magnetic field lines (grey) in the cluster. Longer wavelength X-ray photons (red) are converting into axion-like particles, but not back into photons. Such conversions would cause a distortion in the X-ray spectrum (the amount of X-rays at different energies) of a bright or embedded source of X-rays.

    2
    Illustration Credit: Amanda Smith/Institute of Astronomy/University of Cambridge

    Astronomers obtained a long Chandra observation, lasting over five days, of the central supermassive black hole in the center of the Perseus galaxy cluster (shown in the inset.) The spectrum of the region around the black hole showed no distortions, allowing the team to rule out the presence of most types of axion-like particles in the relatively low mass range their search was sensitive to.

    Here the Chandra spectrum (red) of Perseus’ central black hole shows the intensity of X-rays as a function of X-ray energy, along with an example (black) of a model X-ray spectrum predicted if axion-like particles were actually being converted from and into photons. To highlight the distortions that could have been detected, the data divided by the example model are also shown.

    3
    Credit: NASA/CXC/Cambridge Univ./C.S. Reynolds

    One possible interpretation of this work is that axion-like particles do not exist. Another possible interpretation is that the particles undergo conversion from and into photons less easily than some particle physicists have expected. They also could have higher masses than probed with the Chandra data.

    There has been a surge of interest in studies of these particles in recent years for three reasons: First, despite a lot of work, there continues to be no detection of Weakly Interacting Massive Particles (WIMPs), either with gamma-ray observations, or earth-based experiments that could explain the nature of dark matter. These particles are predicted to interact with normal matter only via the weak force, and have been considered to be one of the strongest candidates for dark matter. Secondly, scientists have realized that axions and axion-like particles are predicted by string theory. Finally, there are a large number of experiments or observations that can be done to search for these particles.

    A paper describing these results appeared in the February 10th, 2020 issue of The Astrophysical Journal. The authors are Christopher Reynolds (University of Cambridge, UK), David Marsh (Stockholm University, Sweden), Helen Russell (University of Nottingham, UK), Andrew C. Fabian (University of Cambridge), Robyn Smith (University of Maryland in College Park, Francesco Tombesi (University of Rome, Italy), and Sylvain Veilleux (University of Maryland).

    March 19, 2020
    Media contacts:
    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 4:29 pm on February 27, 2020 Permalink | Reply
    Tags: , , , Biggest explosion in the history of the Universe, Caltech 2MASS Telescopes a joint project of UMass/Caltech at the Whipple Observatory Mt. Hopkins near Tucson AZ USA Altitude 8550 ft and at the Cerro Tololo Inter-American Observatory altitude 2200 m., , , , , , NASA Chandra   

    From International Centre for Radio Astronomy Research: “Astronomers detect biggest explosion in the history of the Universe” 

    ICRAR Logo
    From International Centre for Radio Astronomy Research

    February 28, 2020
    Professor Melanie Johnson-Hollitt — ICRAR / Curtin University
    Ph: +61 400 951 815
    E: Melanie.Johnston-Hollitt@curtin.edu.au

    Pete Wheeler — Media Contact, ICRAR
    Ph: +61 423 982 018
    E: Pete.Wheeler@icrar.org

    April Kleer — Media Contact, Curtin University
    Ph: +61 9266 3353
    E: April.Kleer@curtin.edu.au

    Scientists studying a distant galaxy cluster have discovered the biggest explosion seen in the Universe since the Big Bang.

    2
    This extremely powerful eruption occurred in the Ophiuchus galaxy cluster, which is located about 390 million light-years from Earth. Galaxy clusters are the largest structures in the Universe held together by gravity, containing thousands of individual galaxies, dark matter, and hot gas. Credits: X-ray: NASA/CXC/Naval Research Lab/Giacintucci, S.; XMM:ESA/XMM; Radio: NCRA/TIFR/GMRTN; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF

    NASA/Chandra X-ray Telescope

    ESA/XMM Newton

    Giant Metrewave Radio Telescope, located near Pune (Narayangaon) in India, operated by the National Centre for Radio Astrophysics, a part of the Tata Institute of Fundamental Research, Mumbai


    Caltech 2MASS Telescopes, a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center (IPAC) at Caltech, at the Whipple Observatory on Mt. Hopkins south of Tucson, AZ, USA Altitude 2,606 m (8,550 ft) and at the Cerro Tololo Inter-American Observatory at an altitude of 2200 meters near La Serena, Chile.

    The blast came from a supermassive black hole at the centre of a galaxy hundreds of millions of light-years away.

    It released five times more energy than the previous record holder.

    Professor Melanie Johnston-Hollitt, from the Curtin University node of the International Centre for Radio Astronomy Research, said the event was extraordinarily energetic.

    “We’ve seen outbursts in the centres of galaxies before but this one is really, really massive,” she said.

    “And we don’t know why it’s so big.

    “But it happened very slowly—like an explosion in slow motion that took place over hundreds of millions of years.”

    The explosion occurred in the Ophiuchus galaxy cluster, about 390 million light-years from Earth.

    It was so powerful it punched a cavity in the cluster plasma—the super-hot gas surrounding the black hole.

    Lead author of the study Dr Simona Giacintucci, from the Naval Research Laboratory in the United States, said the blast was similar to the 1980 eruption of Mount St. Helens, which ripped the top off the mountain.

    “The difference is that you could fit 15 Milky Way galaxies in a row into the crater this eruption punched into the cluster’s hot gas,” she said.

    Professor Johnston-Hollitt said the cavity in the cluster plasma had been seen previously with X-ray telescopes.

    But scientists initially dismissed the idea that it could have been caused by an energetic outburst, because it would have been too big.

    “People were sceptical because the size of outburst,” she said. “But it really is that. The Universe is a weird place.”

    The researchers only realised what they had discovered when they looked at the Ophiuchus galaxy cluster with radio telescopes.

    “The radio data fit inside the X-rays like a hand in a glove,” said co-author Dr Maxim Markevitch, from NASA’s Goddard Space Flight Center.

    “This is the clincher that tells us an eruption of unprecedented size occurred here.”

    The discovery was made using four telescopes; NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton, the Murchison Widefield Array (MWA) in Western Australia and the Giant Metrewave Radio Telescope (GMRT) in India.

    5
    The Murchison Widefield Array (MWA) is a low frequency radio telescope and is the first of four Square Kilometre Array (SKA) precursors to be completed, at the Boolardy station in outback Western Australia. at the Murchison Radio-astronomy Observatory (MRO)

    6
    Tile 107, or “the Outlier” as it is known, is one of 256 tiles of this SKA precursor instruments located 1.5km from the core of the telescope. Lighting the tile and the ancient landscape is the Moon. Photographed by Pete Wheeler, ICRAR.

    Professor Johnston-Hollitt, who is the director of the MWA and an expert in galaxy clusters, likened the finding to discovering the first dinosaur bones.

    “It’s a bit like archaeology,” she said.

    “We’ve been given the tools to dig deeper with low frequency radio telescopes so we should be able to find more outbursts like this now.”

    The finding underscores the importance of studying the Universe at different wavelengths, Professor Johnston-Hollitt said.

    “Going back and doing a multi-wavelength study has really made the difference here,” she said.

    Professor Johnston-Hollitt said the finding is likely to be the first of many.

    “We made this discovery with Phase 1 of the MWA, when the telescope had 2048 antennas pointed towards the sky,” she said.

    “We’re soon going to be gathering observations with 4096 antennas, which should be ten times more sensitive.”

    “I think that’s pretty exciting.”

    The Murchison Widefield Array

    The Murchison Widefield Array (MWA) is a low-frequency radio telescope and is the first of four Square Kilometre Array (SKA) precursors to be completed.


    SKA Square Kilometer Array


    SKA South Africa

    A consortium of partner institutions from seven countries (Australia, USA, India, New Zealand, Canada, Japan, and China) financed the development, construction, commissioning, and operations of the facility. The MWA consortium is led by Curtin University.

    Publication:

    ‘‘Discovery of a giant radio fossil in the Ophiuchus Galaxy Cluster’, published in The Astrophysical Journal on February 28th, 2020.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

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

    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 12:51 pm on February 22, 2020 Permalink | Reply
    Tags: "A Cosmic Jekyll and Hyde", , , , , NASA Chandra, The binary Terzan 5 CX1   

    From NASA Chandra: “A Cosmic Jekyll and Hyde” Terzan 5 CX1 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    February 20, 2020

    1
    Credit. X-ray: NASA/CXC/Univ. of Amsterdam/N.Degenaar, et al.; Optical: NASA, ESA

    A binary, or double, star system is acting in a very unusual way, according to Chandra data obtained over nearly a decade and a half.

    Terzan 5 CX1 is located in a globular cluster about 19,000 light years from Earth and has shown behavior traits of two different types of objects.

    Chandra data from 2003 show this system acted as a low-mass X-ray binary, with a neutron star pulling material from a star like the Sun.

    Chandra and VLA data between 2009 and 2014 show the system changed into behaving like a millisecond pulsar, then in 2016 went back to acting like a low-mass X-ray binary.

    A double star system has been flipping between two alter egos, according to observations with NASA’s Chandra X-ray Observatory and the National Science Foundation’s Karl F. Jansky Very Large Array (VLA).

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

    Using nearly a decade and a half worth of Chandra data, researchers noticed that a stellar duo behaved like one type of object before switching its identity, and then returning to its original state after a few years. This is a rare example of a star system changing its behavior in this way.

    Astronomers found this volatile double, or binary, system in a dense collection of stars, the globular cluster Terzan 5, which is located about 19,000 light years from Earth in the Milky Way galaxy. This stellar duo, known as Terzan 5 CX1, has a neutron star (the extremely dense remnant left behind by a supernova explosion) in close orbit around a star similar to the Sun, but with less mass.

    In this new image of Terzan 5 (right), low, medium and high-energy X-rays detected by Chandra are colored red, green and blue respectively. On the left, an image from the Hubble Space Telescope shows the same field of view in optical light. Terzan 5 CX1 is labeled as CX1 in the Chandra image.

    NASA/ESA Hubble Telescope

    In binary systems like Terzan 5 CX1, the heavier neutron star pulls material from the lower-mass companion into a surrounding disk. Astronomers can detect these so-called accretion disks by their bright X-ray light, and refer to these objects as “low-mass X-ray binaries.”

    Spinning material in the disk falls onto the surface of the neutron star, increasing its rotation rate. The neutron star can spin faster and faster until the roughly 10-mile-wide sphere, packed with more mass than the Sun, is rotating hundreds of times per second. Eventually, the transfer of matter slows down and the remaining material is swept away by the whirling magnetic field of the neutron star, which becomes a millisecond pulsar. Astronomers detect pulses of radio waves from these millisecond pulsars as the neutron star’s beam of radio emission sweeps over the Earth during each rotation.

    While scientists expect the complete evolution of a low-mass X-ray binary into a millisecond pulsar should happen over several billion years, there is a period of time when the system can switch rapidly between these two states. Chandra observations of Terzan 5 CX1 show that it was acting like a low-mass X-ray binary in 2003, because it was brighter in X-rays than any of the dozens of other sources in the globular cluster. This was a sign that the neutron star was likely accumulating matter.

    3
    Terzan 5, Labeled (Credit: NASA/CXC/Univ. of Amsterdam/N.Degenaar, et al.)

    In Chandra data taken from 2009 to 2014, Terzan 5 CX1 had become about ten times fainter in X-rays. Astronomers also detected it as a radio source with the VLA in 2012 and 2014. The amount of radio and X-ray emission and the corresponding spectra (the amount of emission at different wavelengths) agree with expectations for a millisecond pulsar. Although the radio data used did not allow a search for millisecond pulses, these results imply that Terzan 5 CX1 underwent a transformation into behaving like a millisecond pulsar and was blowing material outwards. By the time Chandra had observed Terzan 5 CX1 again in 2016, it had become brighter in X-rays and changed back to acting like a low-mass X-ray binary again.

    To confirm this pattern of “Jekyll and Hyde” behavior, astronomers need to detect radio pulses while Terzan 5 CX1 is faint in X-rays. More radio and X-ray observations are planned to search for this behavior, along with sensitive searches for pulses in existing data. Only three confirmed examples of these identity-changing systems are known, with the first discovered in 2013 using Chandra and several other X-ray and radio telescopes.

    The study of this binary was led by Arash Bahramian of the International Centre for Radio Astronomy Research (ICRAR), Australia and was published in the September 1st, 2018 issue of The Astrophysical Journal.

    Two other recent studies have used Chandra observations of Terzan 5 to study how neutron stars in two different low-mass X-ray binaries recover after having had large amounts of material dumped on their surface by a companion star. Such studies are important for understanding the structure of a neutron star’s outer layer, known as its crust.

    In one of these studies, of the low-mass X-ray binary Swift J174805.3–244637 (T5 X-3 for short), material dumped onto the neutron star during an X-ray outburst detected by Chandra in 2012 heated up the star’s crust. The crust of the neutron star then cooled down, taking about a hundred days to fall back to the temperature seen before the outburst. The rate of cooling agrees with a computer model for such a process.

    In a separate Chandra study of a different low-mass X-ray binary in Terzan 5, IGR J17480–2446 (T5 X-2 for short) the neutron star was still cooling when its temperature was taken five and a half years after it was known to have an outburst. These results show this neutron star’s crust ability to transfer, or conduct, heat may be lower than what astronomers have found in other cooling neutron stars in low-mass X-ray binaries. This difference in the ability to conduct heat may be related to T5 X-2 having a higher magnetic field compared to other cooling neutron stars, or being much younger than T5 X-3.

    Both T5 X-3 and T5 X-2 are labeled in the image.

    The work on the rapidly cooling neutron star, led by Nathalie Degenaar of the University of Amsterdam in the Netherlands, was published in the June 2015 issue of the Monthly Notices of the Royal Astronomical Society. The study of the slowly cooling neutron star, led by Laura Ootes, then of the University of Amsterdam, was published in the July 2019 issue of the Monthly Notices of the Royal Astronomical Society.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 8:16 pm on January 6, 2020 Permalink | Reply
    Tags: "Famous Black Hole Has Jet Pushing Cosmic Speed Limit", , , , , , , NASA Chandra   

    From NASA Chandra: “Famous Black Hole Has Jet Pushing Cosmic Speed Limit” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    1
    Credit: NASA/CXC/SAO/B.Snios et al.

    1.6.20

    The Event Horizon Telescope Collaboration released the first image of a black hole with observations of the massive, dark object at the center of Messier 87 last April.

    The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    Now iconic image of Katie Bouman-Harvard Smithsonian Astrophysical Observatory after the image of Messier 87 was achieved. Headed from Harvard to Caltech as an Assistant Professional. On the committee for the next iteration of the EHT .

    EHT map

    This black hole has a mass of about 6.5 billion times that of the sun and is located about 55 million light years from Earth. The black hole has been called M87* by astronomers and has recently been given the Hawaiian name of “Powehi.”

    For years, astronomers have observed radiation from a jet of high energy particles — powered by the black hole — blasting out of the center of Messier 87. They have studied the jet in radio, optical, and X-ray light, including with Chandra. And now by using Chandra observations, researchers have seen that sections of the jet are moving at nearly the speed of light.

    “This is the first time such extreme speeds by a black hole’s jet have been recorded using X-ray data,” said Ralph Kraft of the Center of Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Mass., who presented the study at the American Astronomical Society meeting in Honolulu, Hawaii. “We needed the sharp X-ray vision of Chandra to make these measurements.”

    When matter gets close enough to a black hole, it enters into a swirling pattern called an accretion disk. Some material from the inner part of the accretion disk falls onto the black hole and some of it is redirected away from the black hole in the form of narrow beams, or jets, of material along magnetic field lines. Because this infall process is irregular, the jets are made of clumps or knots that can sometimes be identified with Chandra and other telescopes.

    The researchers used Chandra observations from 2012 and 2017 to track the motion of two X-ray knots located within the jet about 900 and 2,500 light years away from the black hole. The X-ray data show motion with apparent speeds of 6.3 times the speed of light for the X-ray knot closer to the black hole and 2.4 times the speed of light for the other.

    “One of the unbreakable laws of physics is that nothing can move faster than the speed of light,” said co-author Brad Snios, also of the CfA. “We haven’t broken physics, but we have found an example of an amazing phenomenon called superluminal motion.”

    Superluminal motion occurs when objects are traveling close to the speed of light along a direction that is close to our line of sight. The jet travels almost as quickly towards us as the light it generates, giving the illusion that the jet’s motion is much more rapid than the speed of light. In the case of M87*, the jet is pointing close to our direction, resulting in these exotic apparent speeds.

    Astronomers have previously seen such motion in Messier 87*’s jet at radio and optical wavelengths, but they have not been able to definitively show that matter in the jet is moving at very close to the speed of light. For example, the moving features could be a wave or a shock, similar to a sonic boom from a supersonic plane, rather than tracing the motions of matter.

    This latest result shows the ability of X-rays to act as an accurate cosmic speed gun. The team observed that the feature moving with an apparent speed of 6.3 times the speed of light also faded by over 70% between 2012 and 2017. This fading was likely caused by particles’ loss of energy due to the radiation produced as they spiral around a magnetic field. For this to occur the team must be seeing X-rays from the same particles at both times, and not a moving wave.

    3
    Illustration of the Supermassive Black Hole at the Center of Messier 87 (Credit: NASA/CXC/M.Weiss)

    4
    Chandra Wide-field View of Messier 87; box shows the approximate location of the wide-field jet image above (Credit: NASA/CXC)


    A Quick Look at the Black Hole Jet in Messier 87

    “Our work gives the strongest evidence yet that particles in Messier 87*’s jet are actually traveling at close to the cosmic speed limit”, said Snios.

    The Chandra data are an excellent complement to the EHT data. The size of the ring around the black hole seen with the Event Horizon Telescope is about a hundred million times smaller than the size of the jet seen with Chandra.

    Another difference is that the EHT observed Messier 87 over six days in April 2017, giving a recent snapshot of the black hole. The Chandra observations investigate ejected material within the jet that was launched from the black hole hundreds and thousands of years earlier.

    “It’s like the Event Horizon Telescope is giving a close-up view of a rocket launcher,” said the CfA’s Paul Nulsen, another co-author of the study, “and Chandra is showing us the rockets in flight.”

    In addition to being presented at the AAS meeting, these results are also described in a paper in The Astrophysical Journal led by Brad Snios.
    Other materials about the findings are available at:
    http://chandra.si.edu

    For more Chandra images, multimedia and related materials, visit:
    http://www.nasa.gov/chandra

    Media contacts:
    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 12:07 am on January 6, 2020 Permalink | Reply
    Tags: "NASA's Great Observatories Help Astronomers Build a 3D Visualization of Exploded Star", , , , , NASA Chandra, ,   

    From NASA/ESA Hubble Telescope: “NASA’s Great Observatories Help Astronomers Build a 3D Visualization of Exploded Star” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    January 05, 2020

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Frank Summers
    Space Telescope Science Institute, Baltimore, Maryland
    summers@stsci.edu

    1

    Summary
    Movie Dissects the Nebula’s Intricate Nested Structure

    In the year 1054 AD, Chinese sky watchers witnessed the sudden appearance of a “new star” in the heavens, which they recorded as six times brighter than Venus, making it the brightest observed stellar event in recorded history.

    2
    Crab Nebula

    This “guest star,” as they described it, was so bright that people saw it in the sky during the day for almost a month. Native Americans also recorded its mysterious appearance in petroglyphs.

    Observing the nebula with the largest telescope of the time, Lord Rosse in 1844 named the object the “Crab” because of its tentacle-like structure. But it wasn’t until the 1900s that astronomers realized the nebula was the surviving relic of the 1054 supernova, the explosion of a massive star.

    Now, astronomers and visualization specialists from the NASA’s Universe of Learning program have combined the visible, infrared, and X-ray vision of NASA’s Great Observatories to create a three-dimensional representation of the dynamic Crab Nebula.

    The multiwavelength computer graphics visualization is based on images from the Chandra X-ray Observatory and the Hubble and Spitzer space telescopes.

    NASA/Chandra X-ray Telescope

    NASA/Spitzer Infrared Telescope

    Astronomers and visualization specialists from the NASA’s Universe of Learning program
    have combined the visible, infrared, and X-ray vision of NASA’s Great Observatories to create a three-dimensional representation of the dynamic Crab Nebula, the tattered remains of an exploded star.

    The multiwavelength computer graphics visualization is based on images from the Chandra X-ray Observatory and the Hubble
    and Spitzer space telescopes.

    The approximately four-minute video dissects the intricate nested structure that makes up this stellar corpse, giving viewers a better understanding of the extreme and complex physical processes powering the nebula. The powerhouse “engine” energizing the entire system is a pulsar, a rapidly spinning neutron star, the super-dense crushed core of the exploded star. The tiny dynamo is blasting out blistering pulses of radiation 30 times a second with unbelievable clockwork precision.

    The visualization was produced by a team at the Space Telescope Science Institute (STScI) in Baltimore, Maryland; the Caltech/IPAC in Pasadena, California; and the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts. It will debut at the American Astronomical Society meeting in Honolulu, Hawaii. The movie is available to planetariums and other centers of informal learning worldwide.

    “Seeing two-dimensional images of an object, especially of a complex structure like the Crab Nebula, doesn’t give you a good idea of its three-dimensional nature,” explained STScI’s visualization scientist Frank Summers, who led the team that developed the movie. “With this scientific interpretation, we want to help people understand the Crab Nebula’s nested and interconnected geometry. The interplay of the multiwavelength observations illuminate all of these structures. Without combining X-ray, infrared, and visible light, you don’t get the full picture.”

    Certain structures and processes, driven by the pulsar engine at the heart of the nebula, are best seen at particular wavelengths.

    The movie begins by showing the Crab Nebula in context, pinpointing its location in the constellation Taurus. This view zooms in to present the Hubble, Spitzer, and Chandra images of the Crab Nebula, each highlighting one of the nested structures in the system. The video then begins a slow buildup of the three-dimensional X-ray structure, showing the pulsar and a ringed disk of energized material, and adding jets of particles firing off from opposite sides of the energetic dynamo.

    Appearing next is a rotating infrared view of a cloud enveloping the pulsar system, and glowing from synchrotron radiation. This distinctive form of radiation occurs when streams of charged particles spiral around magnetic field lines. There is also infrared emission from dust and gas.

    The visible-light outer shell of the Crab Nebula appears next. Looking like a cage around the entire system, this shell of glowing gas consists of tentacle-shaped filaments of ionized oxygen (oxygen missing one or more electrons). The tsunami of particles unleashed by the pulsar is pushing on this expanding debris cloud like an animal rattling its cage.

    The X-ray, infrared, and visible-light models are combined at the end of the movie to reveal both a rotating three-dimensional multiwavelength view and the corresponding two-dimensional multiwavelength image of the Crab Nebula.

    The three-dimensional structures serve as scientifically informed approximations for imagining the nebula. “The three-dimensional views of each nested structure give you an idea of its true dimensions,” Summers said. “To enable viewers to develop a complete mental model, we wanted to show each structure separately, from the ringed disk and jets in stark relief, to the synchrotron radiation as a cloud around that, and then the visible light as a cage structure surrounding the entire system.”

    These nested structures are particular to the Crab Nebula. They reveal that the nebula is not a classic supernova remnant as once commonly thought. Instead, the system is better classified as a pulsar wind nebula. A traditional supernova remnant consists of a blast wave, and debris from the supernova that has been heated to millions of degrees. In a pulsar wind nebula, the system’s inner region consists of lower-temperature gas that is heated up to thousands of degrees by the high-energy synchrotron radiation.

    “It is truly via the multiwavelength structure that you can more cleanly comprehend that it’s a pulsar wind nebula,” Summers said. “This is an important learning objective. You can understand the energy from the pulsar at the core moving out to the synchrotron cloud, and then further out to the filaments of the cage.”

    Summers and the STScI visualization team worked with Robert Hurt, lead visualization scientist at IPAC, on the Spitzer images; and Nancy Wolk, imaging processing specialist at the Chandra X-ray Center at the CfA, on the Chandra images. Their initial step was reviewing past research on the Crab Nebula, an intensely studied object that formed from a supernova seen in 1054 by Chinese astronomers.

    Starting with the two-dimensional Hubble, Spitzer, and Chandra images, the team worked with experts to analyze the complex nested structures comprising the nebula and identify the best wavelength to represent each component. The three-dimensional interpretation is guided by scientific data, knowledge, and intuition, with artistic features filling out the structures.

    The visualization is one of a new generation of products and experiences being developed by the NASA’s Universe of Learning program. The effort combines a direct connection to the science and scientists of NASA’s Astrophysics missions with attention to audience needs to enable youth, families, and lifelong learners to explore fundamental questions in science, experience how science is done, and discover the universe for themselves.

    This video demonstrates the power of multiwavelength astronomy. It helps audiences understand how and why astronomers use multiple regions of the electromagnetic spectrum to explore and learn about our universe.

    NASA’s Universe of Learning materials are based upon work supported by NASA under cooperative agreement award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Jet Propulsion Laboratory, CfA, and Sonoma State University.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

    ESA50 Logo large

    AURA Icon

     
  • richardmitnick 2:22 pm on December 17, 2019 Permalink | Reply
    Tags: "Galaxy Gathering Brings Warmth", , , , , NASA Chandra, NGC 6338, Two groups of galaxies are slamming into each other at about 4 million miles per hour.   

    From NASA Chandra: “Galaxy Gathering Brings Warmth” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    December 17, 2019

    1
    Composite

    2
    X-ray

    3
    Optical

    4
    Temperature Map

    Two groups of galaxies are slamming into each other at about 4 million miles per hour.

    Galaxies often exist in groups or clusters that can contain many individual galaxies bound together by gravity.

    Astronomers studied this collision using Chandra, XMM-Newton, the Giant Metrewave Radio Telescope, and the Apache Point Observatory.

    By studying mergers like this, astronomers can learn more about galaxy groups grow and evolve over time.

    As the holiday season approaches, people in the northern hemisphere will gather indoors to stay warm. In keeping with the season, astronomers have studied two groups of galaxies that are rushing together and producing their own warmth.

    The majority of galaxies do not exist in isolation. Rather, they are bound to other galaxies through gravity either in relatively small numbers known as “galaxy groups,” or much larger concentrations called “galaxy clusters” consisting of hundreds or thousands of galaxies. Sometimes, these collections of galaxies are drawn toward one another by gravity and eventually merge.

    Using NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton, the Giant Metrewave Radio Telescope (GMRT), and optical observations with the Apache Point Observatory in New Mexico, a team of astronomers has found that two galaxy groups are smashing into each other at a remarkable speed of about 4 million miles per hour. This could be the most violent collision yet seen between two galaxy groups.

    ESA/XMM Newton

    Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft)

    The system is called NGC 6338, which is located about 380 million light years from Earth. This composite image contains X-ray data from Chandra (displayed in red) that shows hot gas with temperatures upward of about 20 million degrees Celsius, as well as cooler gas detected with Chandra and XMM (shown in blue) that also emits X-rays. The Chandra data have been combined with optical data from the Sloan Digital Sky Survey, showing the galaxies and stars in white.

    The researchers estimate that the total mass contained in NGC 6338 is about 100 trillion times the mass of the Sun. This significant heft, roughly 83% of which is in the form of dark matter, 16% is in the form of hot gas, and 1% in stars, indicates that the galaxy groups are destined to become a galaxy cluster in the future. The collision and merger will complete, and the system will continue to accumulate more galaxies through gravity.

    Previous studies of NGC 6338 have provided evidence for the regions of cooler, X-ray emitting gas around the centers of the two galaxy groups (known as “cool cores”). This information has helped astronomers to reconstruct the geometry of the system, revealing that the collision between the galaxy groups happened almost along the line of sight to Earth. This finding has been confirmed with the new study.

    The new Chandra and XMM-Newton data also show that the gas to the left and right of the cool cores, and in between them, appears to have been heated by shock fronts — similar to the sonic booms created by supersonic aircraft — formed by the collision of the two galaxy groups. This pattern of shock-heated gas has been predicted by computer simulations, but NGC 6338 may be the first merger of galaxy groups to clearly show it. Such heating will prevent some of the hot gas from cooling down to form new stars.

    A second source of heat commonly found in groups and clusters of galaxies is energy provided by outbursts and jets of high-speed particles generated by supermassive black holes. Currently this source of heat appears to be inactive in NGC 6338 because there is no evidence for jets from supermassive black holes using radio data from the GMRT. This absence may explain the filaments of cooling gas detected in X-ray and optical data around the large galaxy in the center of the cool core in the south. The filters used in the composite image do not show the optical filaments, and the X-ray filaments are the small, finger-like structures emanating from the center of the cool core in the south, at approximately 2 o’clock, 7 o’clock and 8 o’clock.

    A paper describing these results was published in the September 2019 issue of the Monthly Notices of the Royal Astronomical Society. The first author is Ewan O’Sullivan of the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, and the co-authors are Gerrit Schellenberger (CfA), Doug Burke (CfA), Ming Sun (University of Alabama in Huntsville, Alabama), Jan Vrtilek (CfA), Larry David (CfA) and Craig Sarazin (University of Virginia, Virginia).


    A Quick Look at Galaxy Gathering Brings Warmth

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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 5:10 pm on November 26, 2019 Permalink | Reply
    Tags: "Black Hole Nurtures Baby Stars a Million Light Years Away", , , , , NASA Chandra   

    From NASA Chandra: “Black Hole Nurtures Baby Stars a Million Light Years Away” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    November 26, 2019

    One black hole is influencing the rate of star formation in multiple galaxies and across vast distances.

    This is a rare example of “positive feedback” where a black hole is helping to spur star formation, not suppress it.

    Researchers used X-rays from Chandra, radio waves from the VLA, and optical light from ground-based telescopes to make this discovery.

    If confirmed, this result would represent the largest distance over which a black hole has boosted the birth of stars.


    Composite

    2
    X-ray

    3
    Optical

    4
    Radio

    Black holes are famous for ripping objects apart, including stars. But now, astronomers have uncovered a black hole that may have sparked the births of stars over a mind-boggling distance, and across multiple galaxies.

    If confirmed, this discovery, made with NASA’s Chandra X-ray Observatory and other telescopes, would represent the widest reach ever seen for a black hole acting as a stellar kick-starter. The black hole seems to have enhanced star formation more than one million light years away. (One light year is equal to 6 trillion miles.)

    “This is the first time we’ve seen a single black hole boost star birth in more than one galaxy at a time,” said Roberto Gilli of the National Institute of Astrophysics (INAF) in Bologna, Italy, lead author of the study describing the discovery. “It’s amazing to think one galaxy’s black hole can have a say in what happens in other galaxies millions of trillions of miles away.”

    A black hole is an extremely dense object from which no light can escape. The black hole’s immense gravity pulls in surrounding gas and dust, but particles from a small amount of that material can also get catapulted away instead at nearly the speed of light. These fast-moving particles form two narrow beams or “jets” near the poles of the black hole.

    The supermassive black hole scientists observed in the new study is located in the center of a galaxy about 9.9 billion light years from Earth. This galaxy has at least seven neighboring galaxies, according to observations with the European Southern Observatory’s Very Large Telescope (VLT) and the Large Binocular Telescope (LBT).

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    U Arizona 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.

    Using the National Science Foundation’s Karl Jansky Very Large Array, scientists had previously detected radio-wave emission from a jet of high-energy particles that is about a million light years long.

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

    The jet can be traced back to the supermassive black hole, which Chandra detected as a powerful source of X-rays produced by hot gas swirling around the black hole. Gilli and colleagues also detected a diffuse cloud of X-ray emission surrounding one end of the radio jet. This X-ray emission is most likely from a gigantic bubble of hot gas heated by the interaction of the energetic particles in the radio jet with surrounding matter.

    As the hot bubble expanded and swept through four neighboring galaxies, it could have created a shock wave that compressed cool gas in the galaxies, causing stars to form. All four galaxies are approximately the same distance, about 400,000 light years, from the center of the bubble. The authors estimate that the star formation rate is between about two to five times higher than typical galaxies with similar masses and distance from Earth.

    “The story of King Midas talks of his magic touch that can turn metal into gold,” said co-author Marco Mignoli, also of INAF in Bologna, Italy. “Here we have a case of a black hole that helped turn gas into stars, and its reach is intergalactic.”

    Astronomers have seen many cases where a black hole affects its surroundings through “negative feedback” — in other words, curtailing the formation of new stars. This can occur when the black hole’s jets inject so much energy into the hot gas of a galaxy, or galaxy cluster, that the gas can’t cool down enough to make large numbers of stars.

    In this newly discovered collection of galaxies, astronomers have found a less common example of “positive feedback,” where the black hole’s effects increase star formation. Moreover, when astronomers previously encountered positive feedback, it either involved increases in the star formation rate of 30% or less, or it occurred over scales of only about 20,000 to 50,000 light years on a nearby companion galaxy. Whether the feedback is positive or negative depends on a delicate balance between the heating rate and cooling rate of a cloud. That is because clouds that are initially cooler when hit by a shock wave are more prone to experience positive feedback, and form more stars.

    “Black holes have a well-earned reputation for being powerful and deadly, but not always,” said co-author Alessandro Peca, formerly at INAF in Bologna and now a Ph.D. student at the University of Miami. “This is a prime example that they sometimes defy that stereotype and can be nurturing instead.”

    The researchers used a total of six days of Chandra observing time spread out over five months.

    “It’s only because of this very deep observation that we saw the hot gas bubble produced by the black hole,” said co-author Colin Norman of the Johns Hopkins University in Baltimore, Maryland. “By targeting objects similar to this one, we may discover that positive feedback is very common in the formation of groups and clusters of galaxies.”

    A paper describing these results has been published in the most recent issue of the journal Astronomy and Astrophysics.

    Media contacts:
    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
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: