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  • richardmitnick 11:01 am on September 13, 2018 Permalink | Reply
    Tags: , , , BUFFALO charges towards the earliest galaxies, Caltech Buffalo, , Durham University, , ,   

    From NASA/ESA Hubble Telescope: “BUFFALO charges towards the earliest galaxies” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    New Hubble project provides wide-field view of the galaxy cluster Abell 370.

    13 September 2018
    Charles Steinhardt
    Niels Bohr Institute
    Copenhagen, Denmark
    Tel: +45 35 33 50 10
    Email: Steinhardt@nbi.ku.dk

    Mathilde Jauzac
    Durham University
    Durham, UK
    Tel: +44 7445218614
    Email: mathilde.jauzac@durham.ac.uk

    Mathias Jäger
    ESA/Hubble, Public Information Officer
    Garching, Germany
    Tel: +49 176 62397500
    Email: mjaeger@partner.eso.org

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

    1
    The NASA/ESA Hubble Space Telescope has started a new mission to shed light on the evolution of the earliest galaxies in the Universe. The BUFFALO survey will observe six massive galaxy clusters and their surroundings. The first observations show the galaxy cluster Abell 370 and a host of magnified, gravitationally lensed galaxies around it.

    The universe is a big place. The Hubble Space Telescope’s views burrow deep into space and time, but cover an area a fraction the angular size of the full Moon. The challenge is that these “core samples” of the sky may not fully represent the universe at large. This dilemma for cosmologists is called cosmic variance. By expanding the survey area, such uncertainties in the structure of the universe can be reduced.

    A new Hubble observing campaign, called Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO)[Caltech], will boldly expand the space telescope’s view into regions that are adjacent to huge galaxy clusters previously photographed by NASA’s Spitzer and Hubble space telescopes under a program called Frontier Fields.

    The six massive clusters were used as “natural telescopes,” to look for amplified images of galaxies and supernovas that are so distant and faint that they could not be photographed by Hubble without the boost of light caused by a phenomenon called gravitational lensing. The clusters’ large masses, mainly composed of dark matter, magnify and distort the light coming from distant background galaxies that otherwise could not be detected. The BUFFALO program is designed to identify galaxies in their earliest stages of formation, less than 800 million years after the big bang.

    2

    BUFFALO’s view on Abell 370
    The galaxy cluster Abell 370 was the first target of the BUFFALO survey, which aims to search for some of the first galaxies in the Universe.
    This remarkable cluster in the constellation of Cetus is located approximately four billion light-years away. Its mass, consisting of both hundreds of galaxies and dark matter, bends and distorts the light coming from even more distant objects behind it. This effect is known as strong gravitational lensing.
    The most stunning demonstration of gravitational lensing can be seen just below the centre of the image. Nicknamed “the Dragon”, this extended feature is made up of a multitude of duplicated images of a spiral galaxy in the background of Abell 370 — all lying five billion light-years away. Credit: NASA, ESA, A. Koekemoer, M. Jauzac, C. Steinhardt, and the BUFFALO team

    3
    The last of the Frontier Fields — Abell 370
    With the final observation of the distant galaxy cluster Abell 370 — some five billion light-years away — the Frontier Fields program came to an end.
    Abell 370 is one of the very first galaxy clusters in which astronomers observed the phenomenon of gravitational lensing, the warping of spacetime by the cluster’s gravitational field that distorts the light from galaxies lying far behind it. This manifests as arcs and streaks in the picture, which are the stretched images of background galaxies.
    Credit: NASA/ESA Hubble, HST Frontier Fields

    4
    Comparison between Frontier Fields and BUFFALO
    This image composite shows the new observations of Abell 370 made for the BUFFALO project, as well as the old observation made for the Frontier Fields programme. The composition clearly shows the extended field of view in the new observations. Credit: NASA, ESA, A. Koekemoer, M. Jauzac, C. Steinhardt, the BUFFALO team and HST Frontier Fields.

    Learning about the formation and evolution of the very first galaxies in the Universe is crucial for our understanding of the cosmos. While the NASA/ESA Hubble Space Telescope has already detected some of the most distant galaxies known, their numbers are small, making it hard for astronomers to determine if they represent the Universe at large.

    Galaxy clusters

    The immense mass of galaxy clusters like Abell 370, mainly composed of the mysterious dark matter, bends and magnifies the light of these faraway objects, turning these clusters into natural telescopes.

    This gravitational lensing effect allows scientists to see further into space beyond the cluster, by capturing the light emitted by very distant and faint objects.

    The most stunning demonstration of gravitational lensing in Abell 370 can be seen just below the centre of the cluster. Nicknamed “The Dragon” this feature is a combination of five gravitationally lensed images of the same spiral galaxy that lies beyond the cluster.

    Although Hubble has already detected some of the Universe’s earliest galaxies through its Frontier Fields programme, these fields are relatively small and might not fully represent the number of early galaxies in the wider Universe.

    BUFFALO builds upon these observations using gravitational lensing, and will expand the search area around the six Frontier Fields previously observed by Hubble. Abell 370 is the first cluster to be observed.

    Dark matter assembly

    BUFFALO will investigate how and when the most massive and luminous galaxies in the Universe formed and how they are linked to dark matter assembly – the constraining effects of which are an essential factor in how the Universe looks today. The survey will also learn more about the evolution of lensing galaxy clusters and will give clues on the nature of dark matter.

    The first step is making a detailed a dark matter mass map of these massive galaxy clusters in order to measure exactly by how much the lensed galaxies are being magnified. The programme will determine how rapidly galaxies formed in the first 800 million years after the Big Bang – paving the way for observations with the upcoming NASA/ESA/CSA James Webb Space Telescope.

    NASA/ESA/CSA Webb Telescope annotated

    Massive galaxy clusters like Abell 370, which is visible in this new image, can help astronomers find more of these distant objects. The immense masses of galaxy clusters make them act as cosmic magnifying glasses. A cluster’s mass bends and magnifies light from more distant objects behind it, uncovering objects otherwise too faint for even Hubble’s sensitive vision. Using this cosmological trick — known as strong gravitational lensing — Hubble is able to explore some of the earliest and most distant galaxies in the Universe.

    Numerous galaxies are lensed by the mass of Abell 370. The most stunning demonstration of gravitational lensing can be seen just below the centre of the cluster. Nicknamed “the Dragon”, this extended feature is made up of a multitude of duplicated images of a spiral galaxy which lies beyond the cluster.

    This image of Abell 370 and its surroundings was made as part of the new Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO) survey. This project, led by European astronomers from the Niels Bohr Institute (Denmark) and Durham University (UK), was designed to succeed the successful Frontier Fields project [1]. 101 Hubble orbits — corresponding to 160 hours of precious observation time — have been dedicated to exploring the six Frontier Field galaxy clusters. These additional observations focus on the regions surrounding the galaxy clusters, allowing for a larger field of view.

    BUFFALO’s main mission, however, is to investigate how and when the most massive and luminous galaxies in the Universe formed and how early galaxy formation is linked to dark matter assembly. This will allow astronomers to determine how rapidly galaxies formed in the first 800 million years after the Big Bang — paving the way for observations with the upcoming NASA/ESA/CSA James Webb Space Telescope.

    Driven by the Frontier Fields observations, BUFFALO will be able to detect the most distant galaxies approximately ten times more efficiently than its progenitor. The BUFFALO survey will also take advantage of other space telescopes which have already observed the regions around the clusters. These datasets will be included in the search for the first galaxies.

    The extended fields of view will also allow better 3-dimensional mapping of the mass distribution — of both ordinary and dark matter — within each galaxy cluster. These maps help astronomers learn more about the evolution of the lensing galaxy clusters and about the nature of dark matter.
    Notes

    [1] Frontier Fields was a Hubble programme that ran from 2013 to 2017. Hubble spent 630 hours of observation time probing six notable galaxy clusters, all of which showed effects of strong gravitational lensing.


    This zoom starts with a ground-based view of the sky and zooms in on the distant galaxy cluster Abell 370, as seen by the NASA/ESA Hubble Space Telescope. The mass of the cluster is large enough to bend the light of more distant objects along the line of sight. This creates interesting distortions, fascinating arcs and it even magnifies objects which would otherwise be to faint and tiny to be seen by Hubble.
    More information and download options: http://www.spacetelescope.org/videos/… Credit: ESA/Hubble Music: Richard Hasbia “Stan Dart”


    To many, Hubble is best known for its stunning images of celestial objects, but among astronomers it is admired for the valuable data it delivers. Hubble has helped revolutionise astronomy, including shedding light on dark matter and dark energy, lifting the veil on black holes, and peering into the dusty regions around stars to image exoplanets.
    This new Hubblecast is the second part of an exploration of some of Hubble’s most important discoveries throughout its history. More information and download options: http://www.spacetelescope.org/videos/… Subscribe to Hubblecast in iTunes!
    https://itunes.apple.com/gb/podcast/h…
    Receive future episodes on YouTube by pressing the Subscribe button above or follow us on Vimeo: https://vimeo.com/hubbleesa Watch more Hubblecavideo.web_category.allst episodes: http://www.spacetelescope.org/videos/… Credit: Directed by: Mathias Jäger Visual design and editing: Martin Kornmesser Written by: Lauren Fuge, Tom Barratt, Mathias Jäger Narration: Sara Mendes da Costa Images: NASA, ESA/Hubble, M. Kornmesser, HST Frontier Fields team (STScI, Risinger, Guisard, Digitized Sky Survey 2, G. Bacon (STScI) Videos: NASA, ESA/Hubble, Hubble Heritage Team, CLUES – Constrained Local Universe Evolution Simulation Animations: NASA, ESA/Hubble, M. Kornmesser, L. Calçada, G. Bacon, L. Frattare, Z. Levay, F. Summers, J. Anderson Music: Johan B. Monell (www.johanmonell.com) Web and technical support: Mathias André and Raquel Yumi Shida Executive producer: Lars Lindberg Christensen

    See the Caltech BUFFALO Project Website here.

    See the full ESA article here .
    See the full NASA article here .
    See the full Durham University 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.

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    AURA Icon

     
  • richardmitnick 3:29 pm on August 17, 2018 Permalink | Reply
    Tags: , , , , Durham University, Physicists reveal oldest galaxies   

    From Durham University: “Physicists reveal oldest galaxies” 

    Durham U bloc

    From Durham University

    17 August 2018

    1

    2
    The distribution of satellite galaxies orbiting a computer-simulated galaxy, as predicted by the Lambda-cold-dark-matter cosmological model. The blue circles surround the brighter satellites, the white circles the ultrafaint satellites (so faint that they are not readily visible in the image).Credit: Institute for Computational Cosmology, Durham University, UK/ Heidelberg Institute for Theoretical Studies, Germany / Max Planck Institute for Astrophysics, Germany.

    Some of the faintest satellite galaxies orbiting our own Milky Way galaxy are amongst the very first that formed in our Universe, physicists have found.

    Findings by a team of academics, including physicists Professor Carlos Frenk and Dr Alis Deason from the Institute for Computational Cosmology (ICC) at Durham University and Dr Sownak Bose from the Harvard-Smithsonian Center for Astrophysics in America, suggest that galaxies including Segue-1, Bootes I, Tucana II and Ursa Major I are over 13 billion years old.

    Their findings are published in The Astrophysical Journal.

    Professor Carlos Frenk, Director of Durham University’s ICC, said: “Finding some of the very first galaxies that formed in our Universe orbiting in the Milky Way’s own backyard is the astronomical equivalent of finding the remains of the first humans that inhabited the Earth. It is hugely exciting.

    “Our finding supports the current model for the evolution of our Universe, the ‘Lambda-cold-dark-matter model’ in which the elementary particles that make up the dark matter drive cosmic evolution.”

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

    Bursting into light

    Cosmologists believe that when the Universe was about 380,000 years old, the very first atoms formed. These were hydrogen atoms, the simplest element in the periodic table. These atoms collected into clouds and began to cool gradually and settle into the small clumps or “halos” of dark matter that emerged from the Big Bang.

    Dark matter halo. Image credit: Virgo consortium / A. Amblard / ESA

    Caterpillar Project A Milky-Way-size dark-matter halo and its subhalos circled, an enormous suite of simulations . Griffen et al. 2016

    This cooling phase, known as the “cosmic dark ages”, lasted about 100 million years.

    Dark Ages Universe ESO

    Eventually, the gas that had cooled inside the halos became unstable and began to form stars – these objects are the very first galaxies ever to have formed.

    With the formation of the first galaxies, the Universe burst into light, bringing the cosmic dark ages to an end.

    Cosmic dark ages

    The research team identified two populations of satellite galaxies orbiting the Milky Way.

    The first was a very faint population consisting of the galaxies that formed during the cosmic dark ages. The second was a slightly brighter population consisting of galaxies that formed hundreds of millions of years later, once the hydrogen that had been ionized by the intense ultraviolet radiation emitted by the first stars was able to cool into more massive dark matter halos.

    Remarkably, the team found that a model of galaxy formation that they had developed previously agreed perfectly with the data, allowing them to infer the formation times of the satellite galaxies.

    Dr Sownak Bose, who was a PhD student at the ICC when this work began and is now a research fellow at the Harvard-Smithsonian Center for Astrophysics, said: “A nice aspect of this work is that it highlights the complementarity between the predictions of a theoretical model and real data.

    “A decade ago, the faintest galaxies in the vicinity of the Milky Way would have gone under the radar. With the increasing sensitivity of present and future galaxy censuses, a whole new trove of the tiniest galaxies has come into the light, allowing us to test theoretical models in new regimes.”

    Formation of the Milky Way

    The intense ultraviolet radiation emitted by the first galaxies destroyed the remaining hydrogen atoms by ionizing them (knocking out their electrons), making it difficult for this gas to cool and form new stars.

    The process of galaxy formation ground to a halt and no new galaxies were able to form for the next billion years or so.

    Eventually, the halos of dark matter became so massive that even ionized gas was able to cool. Galaxy formation resumed, culminating in the formation of spectacular bright galaxies like our own Milky Way.

    Dr Alis Deason, who is a Royal Society University Research Fellow at the ICC, said: “This is a wonderful example of how observations of the tiniest dwarf galaxies residing in our own Milky Way can be used to learn about the early Universe.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Durham U campus

    Durham University is distinctive – a residential collegiate university with long traditions and modern values. We seek the highest distinction in research and scholarship and are committed to excellence in all aspects of education and transmission of knowledge. Our research and scholarship affect every continent. We are proud to be an international scholarly community which reflects the ambitions of cultures from around the world. We promote individual participation, providing a rounded education in which students, staff and alumni gain both the academic and the personal skills required to flourish.

     
  • richardmitnick 10:18 am on May 14, 2018 Permalink | Reply
    Tags: , , Durham University, , University of Sidney   

    From University of Sidney and Durham University via COSMOS: “Multiverse theory cops a blow after dark energy findings” 

    From

    U Sidney bloc

    University of Sidney

    and

    Durham U bloc

    Durham University

    via

    COSMOS

    14 May 2018
    Andrew Masterson

    1
    Each universe in a multiverse contains different levels of dark energy, according to the dominant theory. Credit: Stolk/Getty Images

    The question of dark energy in one universe does not require others to provide an answer.

    A hypothetical multiverse seems less likely after modelling by researchers in Australia and the UK threw one of its key assumptions into doubt.

    The multiverse concept suggests that our universe is but one of many. It finds support among some of the world’s most accomplished physicists, including Brian Greene, Max Tegmark, Neil deGrasse Tyson and the late Stephen Hawking.

    One of the prime attractions of the idea is that it potentially accounts for an anomaly in calculations for dark energy.

    The mysterious force is thought to be responsible for the accelerating expansion of our own universe. Current theories, however, predict there should be rather more of it around than there appears to be. This throws up another set of problems: if the amount of dark energy around was as much as equations require – and that is many trillions of times the level that seems to exist – the universe would expand so rapidly that stars and planets would not form – and life, thus, would not be possible.

    The multiverse idea to an extent accounts for and accommodates this oddly small – but life-permitting – dark energy quotient. Essentially it permits a curiously self-serving explanation: there are a vast number of universes all with differing amounts of dark energy. We exist in one that has an amount low enough to permit stars and so on to form, and thus life to exist. (And we find ourselves here, runs the logic, because we couldn’t find ourselves anywhere else.)

    So far, so anthropic. But now a group of astronomers, including Luke Barnes from the University of Sydney in Australia and Jaime Salcido from Durham University in the UK, has published two papers in the journal Monthly Notices of the Royal Astronomical Society [Galaxy formation efficiency and the multiverse explanation of the cosmological constant with EAGLE simulations and The impact of dark energy on galaxy formation. What does the future of our Universe hold? that show the dark energy and star formation balance isn’t quite as fine as previous estimates have suggested.

    The team created simulations of the universe using the supercomputer architecture contained within the Evolution and Assembly of GaLaxies and their Environments (EAGLE) project. This is a UK-based collaboration that models some 10,000 galaxies over a distance of 300 million-light years, and compares the results with actual observations from the Hubble Telescope and other observatories.

    The simulations allowed the researchers to adjust the amount of dark energy in the universe and watch what happened.

    The results were a surprise. The research revealed that the amount of dark energy could be increased a couple of hundred times – or reduced equally drastically – without substantially affecting anything else.

    “For many physicists, the unexplained but seemingly special amount of dark energy in our universe is a frustrating puzzle,” says Salcido.

    “Our simulations show that even if there was much more dark energy or even very little in the universe then it would only have a minimal effect on star and planet formation.”

    And this, he suggests, implies that life could potentially exist in many multiverse universes – ironically enough, an uncomfortable conclusion.

    “The multiverse was previously thought to explain the observed value of dark energy as a lottery – we have a lucky ticket and live in the universe that forms beautiful galaxies which permit life as we know it,” says Barnes.

    “Our work shows that our ticket seems a little too lucky, so to speak. It’s more special than it needs to be for life. This is a problem for the multiverse; a puzzle remains.”

    It is a puzzle that goes right to the heart of the matter: if the dark energy assumptions are flawed, does a multiverse even exist? The researchers acknowledge that their results do not preclude it – but they do diminish the likelihood.

    “The formation of stars in a universe is a battle between the attraction of gravity, and the repulsion of dark energy,” says co-author Richard Bower, also from Durham University.

    “We have found in our simulations that universes with much more dark energy than ours can happily form stars. So why such a paltry amount of dark energy in our universe?

    “I think we should be looking for a new law of physics to explain this strange property of our universe, and the multiverse theory does little to rescue physicists’ discomfort.”

    See the full article here .

    Please help promote STEM in your local schools.

    stem

    Stem Education Coalition

    Durham U campus

    Durham University is distinctive – a residential collegiate university with long traditions and modern values. We seek the highest distinction in research and scholarship and are committed to excellence in all aspects of education and transmission of knowledge. Our research and scholarship affect every continent. We are proud to be an international scholarly community which reflects the ambitions of cultures from around the world. We promote individual participation, providing a rounded education in which students, staff and alumni gain both the academic and the personal skills required to flourish.

    U Sidney campus

    Our founding principle as Australia’s first university was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university, University of Sidney, in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
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