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  • richardmitnick 11:56 am on October 13, 2019 Permalink | Reply
    Tags: A triple merger in the early Universe, ALPINE program-ALMA Large Program to INvestigate CII at Early times, , , , , Kavli Institute for Cosmology Cambridge   

    From Kavli Institute for Cosmology, Cambridge: “A triple merger in the early Universe” 

    KavliFoundation

    The Kavli Foundation

    From Kavli Institute for Cosmology, Cambridge

    Oct 11, 2019

    As part of the multinational ALPINE collaboration, scientists at the Kavli Institute have discovered a system of three galaxies merging together when the universe was only 1.3 billion years old.

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    The total brightness (contours), velocity along our line of sight (colors of top panel), and speed of random motions (colors of bottom panel) of DEIMOS COSMOS 818760.

    The ALPINE program (ALMA Large Program to INvestigate CII at Early times) is an extensive project using the Atacama Large Millimetre Array (ALMA) to look at the ionized carbon emission (tracing regions that are actively forming stars) from 118 galaxies as they were ~1-1.5 billion years after the Big Bang. One of the primary goals is to characterize the dynamics of each galaxy in the sample, including how many are merging with other galaxies and how many feature regular rotating disks.

    One of the galaxies in this sample (named DEIMOS COSMOS 818760), features three clumps of emission. From the way the clumps are distributed, how they are moving, and by comparing them with simulations, they are interpreted as three galaxies that are merging together in the early Universe. The two brightest sources are close together and show signs of interaction, while the third source is slightly weaker and more distant. The discovery of such complex interactions between galaxies in the early Universe provides information for understanding the early formation of galaxies and of their subsequent evolution.

    Only a handful of triple mergers have been detected in the early universe, and further analysis of the ALPINE data is sure to reveal more.

    The investigation of this galaxy was led by Gareth Jones, a postdoctoral research associate at the Kavli Institute, and the results were published in this week’s issue of Monthly Notices of the Royal Astronomical Society: Letters

    his is the very first paper published by the ALPINE collaboration and it is opening a sequence of several other papers that will be published in the coming months presenting various other important results that provide new important information on the primeval stages of galaxy evolution. The ALPINE project is led by Olivier Le Fèvre.

    See the full article here .

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    Kavli Institute for Cosmology, Cambridge

    For centuries, the University of Cambridge has been pushing back the frontiers of knowledge about the Universe. Joining this rich tradition of inquiry is the Kavli Institute for Cosmology, founded in 2006 as the first member of the Kavli network in the UK.

    Cambridge’s long history as a center for astronomy and cosmology includes Isaac Newton’s discovery of the law of gravitation and, in modern times, the discovery of pulsars and crucial contributions to the development of the Big Bang model of the Universe. The Kavli Institute is helping to continue this work by creating a single site at which the University’s cosmologists and astrophysicists from different academic departments can share knowledge and work together on major projects. In particular, KICC brings together scientists from the University’s Institute of Astronomy, the Cavendish Laboratory (the Department of Physics) and the Department of Applied Mathematics and Theoretical Physics.

    The Institute started operations in 2008, thanks to an endowment from the Kavli Foundation, and now has about 50 researchers working on the following themes:

    Cosmic Microwave Background and the Early Universe
    Large Scale Structures and Precision Cosmology
    Epoch of Cosmic Reionization
    Formation and Evolution of Galaxies and Supermassive Black Holes
    Evolution of the Intergalactic Medium
    Gravitational Waves

    The institute offers these scientists the benefit of close interaction as well as advanced technologies, including access to giant telescopes and space satellites. Meanwhile, the Institute’s fellowships program host promising scholars from around the globe for stays of up to five years. They are free to pursue their own independent research as well as taking part in the world-class flagship projects led by distinguished Cambridge scientists.

    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 2:13 pm on September 28, 2019 Permalink | Reply
    Tags: , , , , Greedy Black Holes, Kavli Institute for Cosmology Cambridge   

    From Kavli Institute for Cosmology, Cambridge: “Greedy black holes in the early Universe generate galactic storms” 

    KavliFoundation

    The Kavli Foundation

    From Kavli Institute for Cosmology, Cambridge

    1

    Scientists at the Kavli Institute, in collaboration with researchers at various institutes in Italy, have discovered that in the early Universe, at the time when the first stars and first galaxies formed, the first massive black holes became extremely greedy, by gobbling enormous amount of matter, and generated extremely powerful winds. These winds reached velocities in excess of 1,000 kilometres per second, and certainly affected the galaxies in which the black holes were hosted.

    However, despite being so mighty, such winds were probably not capable of suppressing the birth of new stars in their host galaxies. These galaxies may therefore have survived these catastrophic events by continuing their evolution and forming new generations of stars.

    The result was obtained by investigating the signal emitted by ionized carbon of 48 quasars, which are supermassive accreting black holes, observed at an epoch when the Universe was younger than one billion years (that is less than 7% of the Universe current age).

    The data was collected by the Atacama Large Millimetre Array (ALMA) in Chile.

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

    The project was led by Manuela Bischetti, former student at the Kavli Institute, and the results were published in this week’s issue of the journal Astronomy and Astrophysics.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 4:43 pm on April 16, 2019 Permalink | Reply
    Tags: , , , , , , Kavli Institute for Cosmology Cambridge   

    From Kavli Institute for Cosmology, Cambridge: “Variations in the ‘fogginess’ of the universe identify a milestone in cosmic history” 

    KavliFoundation

    The Kavli Foundation

    From Kavli Institute for Cosmology, Cambridge

    Apr 16, 2019

    1

    Large differences in the ‘fogginess’ of the early universe were caused by islands of cold gas left behind when the universe heated up after the big bang, according to an international team of astronomers.

    The results, reported in the Monthly Notices of the Royal Astronomical Society, have enabled astronomers to zero in on the time when reionization ended and the universe emerged from a cold and dark state to become what it is today: full of hot and ionised hydrogen gas permeating the space between luminous galaxies.

    Hydrogen gas dims light from distant galaxies much like streetlights are dimmed by fog on a winter morning. By observing this dimming in the spectra of a special type of bright galaxies, called quasars, astronomers can study conditions in the early universe.

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    In the last few years, observations of this specific dimming pattern (called the Lyman-alpha Forest) suggested that the fogginess of the universe varies significantly from one part of the universe to another, but the reason behind these variations was unknown.

    “We expected the light from quasars to vary from place to place at most by factor of two at this time, but it is seen to vary by factor of about 500,” said lead author Girish Kulkarni, who completed the research while a postdoctoral researcher at the Kavli Institute, University of Cambridge. “Some hypotheses were put forward for why this is so, but none were satisfactory.”

    The new study concludes that these variations result from large regions full of cold hydrogen gas present in the universe when it was just one billion years old, a result which enables researchers to pinpoint when reionization ended.

    During reionization, when the universe transitioned out of the cosmic ‘dark ages’, the space between galaxies was filled with a plasma of ionised hydrogen with a temperature of about 10,000˚C. This is puzzling because fifty million years after the big bang, the universe was cold and dark. It contained gas with temperature only a few degrees above absolute zero, and no luminous stars and galaxies. How is it then that today, about 13.6 billion years later, the universe is bathed in light from stars in a variety of galaxies, and the gas is a thousand times hotter?

    Answering this question has been an important goal of cosmological research over the last two decades. The conclusions of the new study suggests that reionization occurred 1.1 billion years after the big bang (or 12.7 billion years ago), quite a bit later than previously thought.

    The team of researchers from India, the UK, Canada, Germany, and France drew their conclusions with the help of state-of-the-art computer simulations performed on supercomputers based at the Universities of Cambridge, Durham, and Paris, funded by the UK Science and Technology Facilities Council (STFC) and the Partnership for Advanced Computing in Europe (PRACE).

    “When the universe was 1.1 billion years old there were still large pockets of the cosmos where the gas between galaxies was still cold and it is these neutral islands of cold gas that explain the puzzling observations,” said Martin Haehnelt of the Kavli Institute, University of Cambridge, who led the group that conducted this research, supported by funding from the European Research Council (ERC).

    “This finally allows us to pinpoint the end of reionization much more accurately than before,” said Laura Keating of the Canadian Institute of Theoretical Astrophysics.

    The new study suggests that the universe was reionized by light from young stars in the first galaxies to form.

    “Late reionization is also good news for future experiments that aim to detect the neutral hydrogen from the early universe,” said Kulkarni, who is now based at the Tata Institute of Fundamental Research in India. “The later the reionisation, the easier it will be for these experiments to succeed.”

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 11:45 am on April 6, 2019 Permalink | Reply
    Tags: "Maximum earthquake: test successfully passed for first MOONS Camera", , , , , Kavli Institute for Cosmology Cambridge   

    From Kavli Institute for Cosmology, Cambridge: “Maximum earthquake: test successfully passed for first MOONS Camera” 

    KavliFoundation

    The Kavli Foundation

    From Kavli Institute for Cosmology, Cambridge

    Apr 05, 2019

    Institutes at the University of Cambridge, and specifically the Cavendish Laboratory, the Kavli Institute for Cosmology, and the Institute of Astronomy, are in charge of designing, assembling, aligning and testing the six cameras of MOONS, the next generation optical/near-infrared multi-object spectrograph for ESO’s Very Large Telescope.

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    Image: Assembled MOONS camera in the clean room.

    Among the tests that the cameras have to pass is to endure “maximum earthquake” conditions (earthquakes are unfortunately not uncommon on Cerro Paranal -Atacama Desert-, where the VLT telescope is located). This test has been performed on the first of the six cameras, currently assembled in the Cavendish clean room. The test (heartstopping for those of us who have worked so long on this project) has implied essentially hitting the camera with the equivalent of a massive soft-headed hammer to produce an impulse characteristic of an earthquake. The camera was subject to an acceleration of more than 3 g (three times stronger than gravity acceleration on Earth). After the multiple shocks the optics (lenses and mirror) returned to their original position within a few microns, greatly exceeding the requirements.

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    Image: MOONS camera during earthquake test with multiple sensors wired to the monitoring system.

    Congratulations to David Sun for having designed such an excellent mechanical housing of the optics, resilient to such extreme shocks, and many thanks to Martin Fisher for successfully performing such a difficult test.

    Depiction of ESO Moons- a multi-objects spectrograph mounted at a Nasmyth focus at the VLT-Location Nasmyth focus at UT1, VLT

    ESO MOONS depiction

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 2:32 pm on March 2, 2019 Permalink | Reply
    Tags: , , , Cambridge is responsible for designing the optomechanics and assembling aligning and testing the six cameras of the spectrograph, , including a lens nested into a larger aspherical lens, Kavli Institute for Cosmology Cambridge, MOONS- the next generation near-IR multi-object spectrograph for ESO's Very Large Telescope in Chile, The camera will be aligned and tested at cryogenic temperatures (-140 C) and also tested for resilience to simulated earthquake conditions., The first set of optics for the first camera have been delivered and mounted in their housing, These cameras use an innovative optical design   

    From Kavli Institute for Cosmology: “First MOONS camera delivered and mounted” 

    KavliFoundation

    The Kavli Foundation

    From Kavli Institute for Cosmology, Cambridge

    Mar 01, 2019

    The Kavli institute for Cosmology, Cambridge is heavily involved, together with the Cavendish Laboratory and the Institute of Astronomy, in the development of MOONS, the next generation near-IR multi-object spectrograph for ESO’s Very Large Telescope in Chile.

    1

    Cambridge is responsible for designing the optomechanics and assembling, aligning and testing the six cameras of the spectrograph. The first set of optics for the first camera have been delivered and mounted in their housing.

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    Image: Camera assembled showing the primary aspherical lens with the smaller lens nested inside it (the detector will be located behind the central lens). An aspherical mirror is located at the bottom of the camera. David Sun, the engineer who has designed the optomechanics and led the assembly of the camera together with Martin Fisher, is pictured here (centre) together with Philippa Downing (left) and Steve Brereton (right).

    These cameras use an innovative optical design, including a lens nested into a larger aspherical lens. The camera will be aligned and tested at cryogenic temperatures (-140 C) and also tested for resilience to simulated earthquake conditions.

    2
    Image: Large cryogenic test chamber that will host the optical bench (in the front) on which the camera and the alignment/testing optics are being mounted for cryogenic testing and alingment. David Sun (left) is pictured together with Roberto Maiolino (right).

    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 Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 4:44 pm on January 4, 2018 Permalink | Reply
    Tags: , , , , , Kavli Institute for Cosmology Cambridge, ultra-low frequency gravitational waves produced by supermassive black hole binaries   

    From The Kavli Foundation Kavli Institute for Cosmology, Cambridge: “Using GAIA to detect low frequency gravitational waves “ 

    KavliFoundation

    The Kavli Foundation

    Kavli Institute for Cosmology, Cambridge

    Jan 04, 2018
    No writer credit

    1
    ESA/GAIA

    A group of Cambridge astronomers, including Anthony Lasenby from the Cavendish Astrophysics Group and Kavli Institute for Cosmology, have made the first investigation of the sensitivity of the GAIA satellite to ultra-low frequency gravitational waves produced by supermassive black hole binaries [Physical Reviw Letters].

    The method is similar to that used in Pulsar Timing Arrays, except that instead of the gravitational wave modifying the apparent frequency of a pulsar, it modifies the apparent positions of stars observed by GAIA, making them oscillate with a characteristic pattern on the sky, An example of this is shown in the figure in which a gravitational wave is travelling from one pole of the celestial sphere, and the black and red lines indicate the induced apparent motions of the stars within a hemisphere (exaggerated by a large factor to make them visible), corresponding to the two possible polarisations of the wave. Using a method which allows the information in the star motions to be compressed by a factor of 10^6, the study shows that it will be possible to search for individually resolvable waves within the full GAIA data set of many billions of stars, and that the sensitivity of GAIA could be comparable to that of current or near-future pulsar timing arrays over a slightly wider frequency band.

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    No image caption or credit.

    The paper was selected as the cover article for a recent issue of Physical Review Letters, and is accompanied by an Editor’s Choice Focus article.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 1:26 pm on March 10, 2017 Permalink | Reply
    Tags: , , , , Kavli Institute for Cosmology Cambridge,   

    From Kavli: “Will a New Discovery Fast-track Our Understanding of the Origins of Galaxies and Gargantuan Black Holes?” 

    KavliFoundation

    The Kavli Foundation

    Kavli Institute for Cosmology, Cambridge

    Mar 10, 2017
    Adam Hadhazy

    Thanks to a record haul of new, ultra-distant quasars—powerhouses of light from the farthest reaches of the universe—astrophysicists can now piece together the rise of mighty objects in the early cosmos.

    THE DISCOVERY OF MORE THAN 60 QUASARS—stupendously bright regions in the cores of galaxies, powered by gargantuan black holes—is a windfall for astrophysicists probing the early universe. At more than 13 billion light-years away, these quasars rank among the farthest objects ever glimpsed by humans.

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    An artist’s iconic impression of an extremely bright quasar. (Credit: ESO/M. Kornmesser)

    That’s important because they take us way back in time, to the first billion years after the Big Bang, and may help explain how the first galaxies and supermassive black holes arose. Guided by their light, astrophysicist hope to understand how the universe transitioned from a dark, featureless expanse into a rich, starry realm loaded with luminous galaxies.

    The Kavli Foundation recently spoke with three astrophysicists about how this haul of ultra-distant quasars will transform what we know about the early universe.

    The participants were:

    ROBERTO MAIOLINO – is a professor of experimental astrophysics at the Cavendish Laboratory of the University of Cambridge and director of the Kavli Institute for Cosmology, Cambridge (KICC). He studies distant quasars to learn about how galaxies and black holes have evolved together throughout cosmic history.
    LINHUA JIANG – is the Youth Qianren Research Professor at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University. An author of two recent studies that discovered dozens of new and extremely distant quasars, Jiang is interested in how the first galaxies changed the universe hundreds of millions of years after the Big Bang.
    MARTA VOLONTERI – is research director at the Institut d’Astrophysique de Paris. A theorist, she is the principal investigator of the BLACK project, which investigates how supermassive black holes formed and influenced their host galaxies, especially as quasars, in the early universe.

    The following is an edited transcript of their roundtable discussion. The participants have been provided the opportunity to amend or edit their remarks.

    THE KAVLI FOUNDATION: Before we talk about the new discovery, what is a quasar and why do you find them so fascinating?

    ROBERTO MAIOLINO: Quasars are the cores of galaxies powered by supermassive black holes gobbling up matter at a high rate. These black holes have masses typically exceeding one million times that of our Sun. The process of consuming matter radiates a lot of energy as light. In fact, most quasars are so bright, they outshine their host galaxy by a large factor. Most quasars are also very far away, and the ones we are particularly interested in are those that developed when the universe was young—less than a billion years old.

    You can think of quasars as lighthouses in the dark of the early universe. Just as a lighthouse’s beam might shine on nearby land forms, making them visible from far away, quasars enable us to investigate the very distant universe and understand the physics of primordial galaxies. We think that quasars indicate special regions in the early universe where matter is particularly dense. As the cosmos developed, these so-called overdense regions probably ended up being populated by a large number of galaxies. So quasars help us to learn about these sites of galaxy formation. We also believe that quasars are tightly connected with the evolution of their young, host galaxies.

    MARTA VOLONTERI: I’m interested in whether quasars can illuminate the origins of supermassive black holes, which can possess less than a million to several billions of times the mass of the Sun. Black holes exist in the center of most galaxies, including the Milky Way, but we don’t know how they got there.

    LINHUA JIANG: What makes distant quasars so interesting to me, as an observational astronomer, is that they are very difficult to find.

    TKF: And we now have twice as many of these lighthouses in deep space to observe. Why is that important?

    MAIOLINO: Until now, we have only had a chance to study a few ultra-distant quasars. What those can teach us about the nature of quasars, and more broadly about the general state of the cosmos long ago, is highly limited. With the newly discovered quasars, we will be able to gauge the variety of these monstrously powerful objects in the universe and how they affect their host galaxies.

    JIANG: Echoing what Roberto just said, now that we have a much larger sample of quasars than ever before, roughly 200, we can study them to learn about their individual variation and how they collectively influenced the primordial cosmos.

    TKF: The more quasars, the merrier, right?

    MAIOLINO: Exactly.

    TKF: Quasars were identified in the early 1960s, and yet the tally remains pretty small compared to the hundreds of billions of galaxies known to exist in our universe. Why are quasars so difficult to find?

    MAIOLINO: Quasars are typically so far away, we generally only see them as point-like sources of light through our telescopes—the same as we see stars. That’s how these objects got their name—“quasars,” for “quasi-stars.” We didn’t know these objects were inside other galaxies, and not just stars, until we measured the light coming from them, which showed they were very far away. The identification of quasars, especially the very distant ones, generally require extensive observing campaigns with large telescopes. Luminous distant quasars are also very rare, hence finding them among the plethora of other celestial objects is often a difficult process.

    TKF: So finding quasars depends heavily on building increasingly powerful and sensitive telescopes?

    JIANG: Yes. To find the most distant quasars, which are not as bright as closer quasars, you really need telescope surveys that take images across a very large part of the sky. My colleagues and I used both the Sloan Digital Sky Survey and the Pan-STARRS survey to find the quasars that we recently reported. Before those surveys began, we really knew very little about distant quasars.


    DSS Telescope at Apache Point Observatory, NM, USA


    Pan-STARRS1 located on Haleakala, Maui, HI, USA

    TKF: And while quasars have been hard to find in the past, do you expect this to change?

    JIANG: Yes. With the next generation of telescopes, we should find many more quasars.

    VOLONTERI: We are probably seeing just the tip of the iceberg. We know that small objects are more common in the universe than big things. We see this when it comes galaxies, stars, planets . . . really everything else! We would therefore expect there to be a lot more quasars out there that are smaller and fainter. Also, the luminosity of the quasars we’ve detected is extremely high, so we are probably only seeing the brightest outliers. That means we are studying quasars with a very limited range of properties.

    TKF: Roberto, you mentioned earlier that quasars outshine their host galaxies. How does all this energy affect their host galaxies?

    MAIOLINO: Quasars can “kill” themselves and their galaxies by completely cleaning out a galaxy’s gas content. This happens because they drive some of the most powerful outflows of gas in the universe that we’ve ever seen, and when they do, they remove the fuel available for star formation.

    VOLONTERI: Right. A quasar dumps so much energy into a host galaxy that it can influence how often stars form.

    TKF: As for black holes, what do quasars reveal about them, and why is this important?

    VOLONTERI: Knowing more about the black holes powering quasars will allow us to know more about how galaxies develop, and knowing about the evolution of galaxies allows us to trace the universe’s history overall. That’s why finding more quasars to study is so fundamental.

    MAIOLINO: Observations have shown us that a significant fraction of these primordial black holes is extremely massive. In the local universe, black holes typically have masses of only one-thousandth of their host galaxy. But in the distant, early universe, we now know some black holes can reach masses close to 10 percent of that of their host galaxy. That’s amazing and this tells us that in the early universe, black holes overtake galaxies in terms of forming and growing. Only later in the universe’s history do the galaxies catch up. So observations are already giving us some indications about the early evolutionary path of our universe.

    JIANG: A mystery, though, is that there does not seem to have been enough time for the universe to have grown these supermassive black holes, given how early in cosmic history we begin to see them as quasars. So for a supermassive black hole formation scenario to be right, it has to account for that rapid growth.

    TKF: Shifting gears here, let’s talk about a period in the history of the universe when it literally went from dark to light. Linhua, what role do we think the earliest quasars had in this transformation?

    JIANG: The idea is still controversial, but quasars may have provided the energy that fueled a change in the gas between the galaxies, allowing light to pass through it. That turning point, when the universe was roughly a billion years old, is known as the “epoch of reionization.” It happened when neutral atoms of hydrogen gas became ionized, which is how they had originally been when the universe began in a hot, dense state. The question is, how and why did this happen? Ionization takes a lot of energy. What were the cosmic sources of the high-energy light that drew the universe out of the so-called dark ages, the era before the first stars and galaxies formed? Could quasars be the answer? At the moment, that seems unlikely because there are so few quasars known. But, as Marta said earlier, we are probably seeing only the tip of the quasar iceberg. There could be a lot more that we haven’t seen yet.

    VOLONTERI: We have recently made a theoretical breakthrough that will help us figure out how much of a role quasars played in the epoch of reionization. We can now accurately monitor radiation inside of our computer simulations as galaxies evolve. We should soon be able to count how many light particles can leave a galaxy and start ionizing extragalactic gas, which I think is really awesome.

    TKF: Looking ahead, what are some of the projects and missions that could help us find even more quasars and better characterize them?

    MAIOLINO: I expect that the Large Synoptic Survey Telescope, or LSST, will greatly expand our numbers of distant quasars using visible light, when it opens in 2022.



    LSST/Camera, built at SLAC


    LSST telescope, currently under construction 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.

    If we want to look even further back on time, before the epoch of reionization, then we need to use infrared light. The prime surveys for doing that will both be space-based. One is called EUCLID, launching in 2020, and the other is WFIRST, launching in the mid 2020s.


    ESA/Euclid spacecraft


    NASA/WFIRST

    I’d expect these missions to deliver very distant galaxies and quasars and to help detect quasars hidden by cosmic dust.

    JIANG: Once we find new candidates, we have to confirm them as quasars by looking for chemical signatures in the light observations using a method called spectroscopy. It is very costly to allocate the time on telescopes to take the long observations we need to do spectroscopy. But we will do it, because it allows us to learn a lot about the properties of quasars.

    MAIOLINO: Right. We will want to investigate the physical properties of distant quasars even better than we can do now. The James Webb Space Telescope, the successor to the Hubble Space Telescope, and a few other next-generation facilities, like the Thirty Meter Telescope, the Giant Magellan Telescope, and the European Extremely Large Telescope will enable us to scrutinize what’s happening in the quasars’ host galaxies and with their supermassive black holes.


    NASA/ESA/CSA Webb Telescope annotated


    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA


    Giant Magellan Telescope, Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile


    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile

    TKF: What mysteries about quasars do you still hope to answer?

    MAIOLINO: Observations of the earliest quasars show that their host galaxies are already enriched with huge amounts of heavy elements, such as iron, as well as cosmic dust, small particles that are ejected into space when the stars die. This enrichment process takes time—many hundreds of millions of years.

    Yet, we see these distant galaxies, illuminated by quasars, when the age of the universe was less than one billion years. That suggests that everything in these early galaxies with quasars seems to be going on at a much faster rate than any other galaxies that we know of in the universe, and we don’t know why.

    I’m confident that upcoming observations will shed a lot of light on these amazing objects.

    JIANG: Studying distant quasars will help us gauge the “clumpiness” of gas in the spaces between the galaxies. We’ll learn more about the early history of galaxies and how the cosmos got its shape, so to speak.

    VOLONTERI: As we’ve said, 200 distant quasars is only the tip of the iceberg. We still don’t know about the broader population of quasars and how they can explain the growth of black holes in galaxies, so we need more data.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition
    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
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