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  • richardmitnick 11:47 am on July 14, 2020 Permalink | Reply
    Tags: "Breakthrough in deciphering birth of supermassive black holes", A galaxy that is familiarly known as “Mirach’s Ghost”, , , , Cardiff University,   

    From Cardiff University: “Breakthrough in deciphering birth of supermassive black holes” 

    From Cardiff University

    14 July 2020

    1

    A research team led by Cardiff University scientists say they are closer to understanding how a supermassive black hole (SMBH) is born thanks to a new technique that has enabled them to zoom in on one of these enigmatic cosmic objects in unprecedented detail.

    Scientists are unsure as to whether SMBHs were formed in the extreme conditions shortly after the big bang, in a process dubbed a ‘direct collapse’, or were grown much later from ‘seed’ black holes resulting from the death of massive stars.

    If the former method were true, SMBHs would be born with extremely large masses – hundreds of thousands to millions of times more massive than our Sun – and would have a fixed minimum size.

    If the latter were true then SMBHs would start out relatively small, around 100 times the mass of our Sun, and start to grow larger over time by feeding on the stars and gas clouds that live around them.

    Astronomers have long been striving to find the lowest mass SMBHs, which are the missing links needed to decipher this problem.

    In a study published today [MNRAS], the Cardiff-led team has pushed the boundaries, revealing one of the lowest-mass SMBHs ever observed at the centre of a nearby galaxy, weighing less than one million times the mass of our sun.

    The SMBH lives in a galaxy that is familiarly known as “Mirach’s Ghost”, due to its close proximity to a very bright star called Mirach, giving it a ghostly shadow.

    The findings were made using a new technique with the Atacama Large Millimeter/submillimeter Array (ALMA), a state-of-the-art telescope situated high on the Chajnantor plateau in the Chilean Andes that is used to study light from some of the coldest objects in the Universe.

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

    “The SMBH in Mirach’s Ghost appears to have a mass within the range predicted by ‘direct collapse’ models,” said Dr Tim Davis from Cardiff University’s School of Physics and Astronomy.

    3
    Mirach’s Ghost. ©Anthony Ayiomamitis (TWAN)

    “We know it is currently active and swallowing gas, so some of the more extreme ‘direct collapse’ models that only make very massive SMBHs cannot be true.

    Black holes are objects that have collapsed under the weight of gravity, leaving behind small but incredibly dense regions of space from which nothing can escape, not even light.

    An SMBH is the largest type of black hole that can be hundreds of thousands, if not billions, of times the mass of the Sun.

    It is believed that nearly all large galaxies, such as our own Milky Way, contain an SMBH located at its centre.

    “SMBHs have also been found in very distant galaxies as they appeared just a few hundred million years after the big bang”, said Dr Marc Sarzi, a member of Dr. Davis’ team from the Armagh Observatory & Planetarium.

    “This suggest that at least some SMBHs could have grown very massive in a very short time, which is hard to explain according to models for the formation and evolution of galaxies.”

    “All black holes grow as they swallow gas clouds and disrupt stars that venture too close to them, but some have more active lives than others.”

    “Looking for the smallest SMBHs in nearby galaxies could therefore help us reveal how SMBHs start off,” continued Dr. Sarzi.

    In their study, the international team used brand new techniques to zoom further into the heart of a small nearby galaxy, called NGC404, than ever before, allowing them to observe the swirling gas clouds that surrounded the SMBH at its centre.

    The ALMA telescope enabled the team to resolve the gas clouds in the heart of the galaxy, revealing details only 1.5 light years across, making this one of the highest resolution maps of gas ever made of another galaxy.

    Being able to observe this galaxy with such high resolution enabled the team to overcome a decade’s worth of conflicting results and reveal the true nature of the SMBH at the galaxy’s centre.

    “Our study demonstrates that with this new technique we can really begin to explore both the properties and origins of these mysterious objects,” continued Dr Davis.

    “If there is a minimum mass for a supermassive black hole, we haven’t found it yet.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Cardiff Unversity is and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 10:45 am on December 23, 2019 Permalink | Reply
    Tags: "Scientists find evidence of missing neutron star", , , , , Cardiff University, ,   

    From Cardiff University: “Scientists find evidence of missing neutron star” 

    Cardiff University

    From Cardiff University

    19 November 2019

    1
    The location of the recently discovered neutron star at the core of the Supernova 1987A remnant. Image via Cardiff University.

    Scientists claim to have found evidence of the location of a neutron star that was left behind when a massive star ended its life in a gigantic explosion, leading to a famous supernova dubbed Supernova 1987A.

    2
    Composite image of Supernova 1987A, via NASA/ ESA/ NRAO.

    For more than 30 years astronomers have been unable to locate the neutron star – the collapsed leftover core of the giant star – as it has been concealed by a thick cloud of cosmic dust.

    Using extremely sharp and sensitive images taken with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in the Atacama Desert of northern Chile, the team have found a particular patch of the dust cloud that is brighter than its surroundings, and which matches the suspected location of the neutron star.

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

    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.

    ALMA is funded by the European Southern Observatory (ESO) (representing its member states, including UK), National Science Foundation (NSF; USA) and National Institutes of Natural Science (NINS; Japan), together with National Research Council Canada (NRC; Canada), Ministry of Science and Technology (MOST) and Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan), and Korea Astronomy and Space Science Institute (KASI, Republic of Korea), in cooperation with the Republic of Chile.

    The findings have been published in The Astrophysical Journal.

    Lead author of the study Dr Phil Cigan, from Cardiff University’s School of Physics and Astronomy, said: “For the very first time we can tell that there is a neutron star inside this cloud within the supernova remnant. Its light has been veiled by a very thick cloud of dust, blocking the direct light from the neutron star at many wavelengths like fog masking a spotlight.”

    Dr Mikako Matsuura, another leading member of the study, added: “Although the light from the neutron star is absorbed by the dust cloud that surrounds it, this in turn makes the cloud shine in sub-millimetre light, which we can now see with the extremely sensitive ALMA telescope.”

    Supernova 1987A was first spotted by astronomers on Feb 23, 1987, when it blazed in the night sky with the power of 100 million suns, and continuing to shine brightly for several months.

    The supernova was discovered in a neighbouring galaxy, the Large Magellanic Cloud, only 160,000 light years away.

    Large Magellanic Cloud. Adrian Pingstone December 2003

    It was the nearest supernova explosion observed in over 400 years and, since its discovery, has continued to fascinate astronomers who have been presented with the perfect opportunity to study the phases before, during, and after the death of a star.

    The supernova explosion that took place at the end of this star’s life resulted in huge amounts of gas with a temperature of over a million degrees, but as the gas began to cool down quickly below zero degrees centigrade, some of the gas transformed into a solid, i.e. dust.

    The presence of this thick cloud of dust has long been the main explanation as to why the missing neutron star has not been observed, but many astronomers were sceptical about this and began to question whether their understanding of a star’s life was correct.

    “Our new findings will now enable astronomers to better understand how massive stars end their lives, leaving behind these extremely dense neutron stars,” continued Dr Matsuura.

    “We are confident that this neutron star exists behind the cloud and that we know its precise location. Perhaps when the dust cloud begins to clear up in the future, astronomers will be able to directly see the neutron star for the very first time.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Cardiff Unversity is and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 8:12 am on May 3, 2019 Permalink | Reply
    Tags: "Have scientists observed a black hole swallowing a neutron star?", , , , , Cardiff University, , , ,   

    From Cardiff University: “Have scientists observed a black hole swallowing a neutron star?” 

    Cardiff University

    From Cardiff University

    3 May 2019

    Professor Mark Hannam
    Head of Gravitational Physics Group
    Director of the Gravity Exploration Institute

    1
    Now iconic image NSF/LIGO/Sonoma State University/A. Simonnet

    Within weeks of switching their machines back on to scour the sky for more sources of gravitational waves, scientists are poring over data in an attempt to further understand an unprecedented cosmic event.

    Astronomers working at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the European-based Virgo detector have reported the possible detection of gravitational waves emanating from the collision of a neutron star and a black hole.


    VIRGO Gravitational Wave interferometer, near Pisa, Italy


    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger

    Gravity is talking. Lisa will listen. Dialogos of Eide

    ESA/eLISA the future of gravitational wave research

    Localizations of gravitational-wave signals detected by LIGO in 2015 (GW150914, LVT151012, GW151226, GW170104), more recently, by the LIGO-Virgo network (GW170814, GW170817). After Virgo came online in August 2018


    Skymap showing how adding Virgo to LIGO helps in reducing the size of the source-likely region in the sky. (Credit: Giuseppe Greco (Virgo Urbino group)

    The signal, detected on 26 April, came just weeks after the teams turned the updated detectors back on to start their third observation run, named “O3”.

    “The universe is keeping us on our toes,” says Patrick Brady, spokesperson for the LIGO Scientific Collaboration and a professor of physics at the University of Wisconsin-Milwaukee. “We’re especially curious about the April 26 candidate. Unfortunately, the signal is rather weak. It’s like listening to somebody whisper a word in a busy café; it can be difficult to make out the word or even to be sure that the person whispered at all. It will take some time to reach a conclusion about this candidate.”

    The possible detection not only throws light on an event that up until now has never been observed, but also confirms the unprecedented accuracy with which the gravitational wave detectors are now operating.

    Included in the latest batch of discoveries is another possible merger between two neutron stars – potentially the second time this has been observed by the LIGO and Virgo teams – as well as a further three interesting black hole mergers.

    Professor Mark Hannam, a member of the LIGO team and Director of Cardiff University’s Gravity Exploration Institute said: “Yet again the LIGO and Virgo detectors have surpassed expectations. Our most optimistic estimates were for a detection every week, and the first month of the run gave us five candidates.”

    Dr Vivien Raymond, from Cardiff University’s Gravity Exploration Institute, said: “LIGO-Virgo’s third observing run has already proven to be more interesting than we expected, barely a month after it started. It’s exciting to think about the next surprises in the Universe for us to discover.”

    Gravitational waves are ripples in space produced by massive cosmic events such as the collision of black holes or the explosion of supernovae.

    Research undertaken by Cardiff University’s Gravity Exploration Institute has laid the foundations for how we go about detecting gravitational waves with the development of novel algorithms and software that have now become standard tools for detecting the elusive signals.

    The Institute also includes world-leading experts in the collision of black holes, who have produced large-scale computer simulations of what is to be expected and observed when these violent events occur, as well as experts in the design of gravitational-wave detectors.

    The twin detectors of LIGO—one in Washington and one in Louisiana—along with Virgo, located at the European Gravitational Observatory (EGO) in Italy, resumed operations on 1 April , after undergoing a series of upgrades to increase their sensitivities to gravitational waves—ripples in space and time.

    Each detector now surveys larger volumes of the universe than before, searching for extreme events such as smash-ups between black holes and neutron stars.

    In total, since making history with the first-ever direct detection of gravitational waves in 2015, the network has spotted evidence for two neutron star mergers; 13 black hole mergers; and one possible black hole-neutron star merger.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Cardiff Unversity is an ambitious and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 4:59 pm on December 21, 2017 Permalink | Reply
    Tags: A century of galaxy discrimination revealed by giant European astronomy survey, , , , Cardiff University, ,   

    From Cardiff: “A century of galaxy discrimination revealed by giant European astronomy survey” Revised for science papers 

    Cardiff University

    Cardiff University

    21 December 2017

    A huge European astronomy survey, whose results are released today (21 December 2017), has revealed that the view of the Universe provided by traditional optical telescopes is seriously biased.

    ESA/Herschel spacecraft

    Why Herschel

    The Herschel ATLAS (H-ATLAS) was a survey carried out by an international team led by researchers at Cardiff University with European Herschel Space Observatory in the far-infrared waveband, which consists of electromagnetic waves with wavelengths 200 times greater than optical light.

    Science papers:

    Valiante et al. 2016 MNRAS
    The Herschel-ATLAS Data Release 1 Paper I: Maps, Catalogues and Number Counts

    Bourne et al. 2016 MNRAS
    The Herschel-ATLAS Data Release 1 Paper II: Multi-wavelength counterparts to submillimetre sources

    MNRAS
    The Herschel-ATLAS: a sample of 500 μm-selected lensed galaxies over 600 deg

    Science
    The Detection of a Population of Submillimeter-Bright, Strongly Lensed Galaxies

    ApJ
    HERSCHEL-ATLAS: A BINARY HyLIRG PINPOINTING A CLUSTER OF STARBURSTING PROTOELLIPTICALS

    MNRAS
    Revealing the complex nature of the strong gravitationally lensed system H-ATLAS J090311.6+003906 using ALMA

    Although Herschel stopped observing in 2013, the Herschel-ATLAS team has spent the last five years analysing their results, and today they released their final images and catalogues, which consist of half-a-million galaxies emitting far-infrared radiation. While the optical light from galaxies is starlight, the far-infrared radiation is from interstellar dust, tiny solid grains of material between the stars.

    Deeply mysterious

    Galaxies, assemblies of stars ranging from 40,000 to thousand billion stars (ours contains about one billion) are the basic building blocks of our Universe. Since they were discovered about a century ago, most of what we know about them has come from optical telescopes. However, when looked at in far-infrared light, the galaxy population looks very different.

    Initially, the team used their results to measure how much dust there is in galaxies today. Cardiff University PhD student Rosie Beeston who led this work said: “Before, astronomers were trying to understand how much dust there is billions of light years away but didn’t really have a handle on how much dust resides in our own astronomical backyard because only a couple of hundred measurements existed. Now we’ve created a census of dust in over 15,000 galaxies.”

    Puzzlingly, the team also found a mysterious class of galaxy with lots of gas and a bigger ratio of dust to star mass than any other type of galaxy. Dubbed BADGERS (Blue and Dusty Gas Rich Galaxies), these galaxies are deeply mysterious, since the huge amounts of dust should hide most of the optical light, and the dust is also very cold.

    Dr Loretta Dunne, a research fellow at the University’s School of Physics and Astronomy, was amazed to discover these odd new galaxies: “I remember checking the optical images of our brightest 300 galaxies and being amazed that they were mostly these really messy looking blue galaxies with no obvious signs of dust. It was totally not at all what I was expecting to see, and the funny thing was I having this eureka moment in Sydney airport on my way to an H-ATLAS meeting in Cardiff.”

    ‘Green valley’ galaxies

    Another discovery made by the team has overturned astronomers’ ideas about how galaxies evolve. All current theories of how galaxies evolve are based on the fundamental assumption that there are two classes of galaxy: galaxies in which stars are actively forming and ‘quiescent galaxies’ in which star formation has essentially stopped. This assumption is based on decades of optical surveys, which have found that most galaxies are either blue (star-forming) or red (quiescent). The existence of these two classes means that all theories need to include a catastrophic process that suddenly (in cosmic terms) converts a star-forming galaxy into a quiescent galaxy.

    Most of the galaxies detected in the Herschel ATLAS, however, fall in the ‘green valley’ between the red and the blue galaxies. According to Professor Steve Eales, of the University’s School of Physics and Astronomy: “This discovery has overturned all the current theories for how galaxies evolve. Our results show that there really is only a single galaxy class…”

    ________________________________________________________

    “There is no longer any need for a violent process that moves a galaxy rapidly from one class to the other.
    Herschel has shown that galaxy evolution is actually quite a gentle process.”

    Professor Stephen Eales,
    ________________________________________________________

    The catalogues and images released by the team today will be a treasure trove for the worldwide community of astronomers. Apart from revolutionising our view of galaxies, the catalogues contain galaxies ranging from ones nearby to ones being seen only a billion years after the big bang, tens of thousands of galaxies magnified by ‘gravitational lensing’, and even tiny clouds of dust in our own galaxy. Since there is no similar mission on the drawing board for either the European Space Agency or NASA, the results from the survey will be a fundamental resource for astronomers for decades to come.

    2
    One of the gravitationally lensed sources found in the survey. The ring is a map made with the Atacama Large Millimetre Array of one of the sources detected in the survey.

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

    The ring is an ‘Einstein ring’ made as the result of the bending of light from the distant Herschel source as the result of the gravitational field from a nearby galaxy (the galaxy in the centre, which was not detected by Herschel).

    Dr Elisabetta Valiante, also of the School, who led the team that produced the galaxy catalogues: “The H-ATLAS survey is a milestone in the history of far-infrared astronomy and I expect it to be a reference for the next generation of researchers studying the formation of stars and galaxies.”

    See the full article here .

    Please help promote STEM in your local schools

    stem

    STEM Education Coalition

    We are an ambitious and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 1:40 pm on September 8, 2017 Permalink | Reply
    Tags: , Cardiff University, , Scientists make methanol using air around us   

    From Cardiff: “Scientists make methanol using air around us” 

    Cardiff University

    Cardiff University

    7 September 2017

    1
    Scientists at Cardiff University have created methanol from methane using oxygen from the air.

    Methanol is currently produced by breaking down natural gas at high temperatures into hydrogen gas and carbon monoxide before reassembling them – expensive and energy-intensive processes known as ‘steam reforming’ and ‘methanol synthesis.’

    But researchers at Cardiff Catalysis Institute have discovered they can produce methanol from methane through simple catalysis that allows methanol production at low temperatures using oxygen and hydrogen peroxide.

    The breakthrough, published today in Science, has major implications for cleaner, greener industrial processes worldwide.

    2
    Professor Graham Hutchings, Director of Cardiff Catalysis Institute, said: “The quest to find a more efficient way of producing methanol is a hundred years old. Our process uses oxygen – effectively a ‘free’ product in the air around us – and combines it with hydrogen peroxide at mild temperatures which require less energy.

    “We have already shown that gold nanoparticles supported by titanium oxide could convert methane to methanol, but we simplified the chemistry further and took away the titanium oxide powder. The results have been outstanding…”

    “At present global natural gas production is ca. 2.4 billion tons per annum and 4% of this is flared into the atmosphere – roughly 100 million tons. Cardiff Catalysis Institute’s approach to using natural gas could use this “waste” gas saving CO2 emissions. In the US there is now a switch to shale gas, and our approach is well suited to using this gas as it can enable it to be liquefied so it can be readily transported.”

    Research of significant value

    Dr. James J. Spivey, Professor of Chemical Engineering at Louisiana State University and Editor-in-Chief of Catalysis Today, said: “This research is of significant value to the scientific and industrial communities. The conversion of our shale resources into higher value intermediates like methanol provide new routes for chemical intermediates.”

    Cardiff Catalysis Institute has a world-wide reputation for outstanding science. The Institute works with industry to develop new catalytic processes and promote the use of catalysis as a sustainable 21st century technology.

    See the full article here .

    Please help promote STEM in your local schools

    stem

    STEM Education Coalition

    We are an ambitious and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 11:17 am on August 6, 2015 Permalink | Reply
    Tags: , , Cardiff University   

    From Cardiff: “New test to help diagnose autism in adults” 

    Cardiff University

    Cardiff University

    06 August 2015
    No Writer Credit

    1
    Professor Sue Leekam, Cardiff Autism Centre

    University psychologists have developed the first self-assessment test designed to help clinicians diagnose autism in adults

    Published in the Journal of Autism and Developmental Disorders, the test measures the extent to which adults are affected by repetitive behaviours – one of the criteria used to diagnose autism.

    These behaviours include common habits and routines, such as lining up objects or arranging them in patterns, fiddling obsessively with objects, or insisting that aspects of a daily routine remain exactly the same.

    Researchers say that the test is a reliable method of measuring these behaviours to indicate when they are unusually frequent or severe.

    To determine how reliable this adult self-assessment is, University autism experts and La Trobe University, Melbourne, trialled the test on British and Australian adults (229 participants in total) with and without an autism diagnosis.

    While adults without an autism diagnosis showed a high tendency for repetitive behaviours the individuals with an autism diagnosis consistently scored significantly higher on this measure.

    Autism is found in more than 1 in 100 of the population. It is hoped that the test will contribute to improvements in the diagnosis of autism.

    “Many measures used for research and diagnoses of autism rely on parents, teachers or caregivers to report the behaviours of individuals with the condition,” said Professor Sue Leekam, Chair of Autism and Director of the University’s Wales Autism Research Centre.

    “What our research has done is develop a test where individuals can report on their own behaviours, for both research and clinical purposes, ensuring we get a fuller picture of the way that these behaviours affect people.”

    Repetitive behaviours are not just common in autism, they are also a symptom associated with Obsessive-Compulsive Disorder (OCD), Parkinson’s disease and Tourette syndrome.

    The test on its own cannot diagnose autism because repetitive behaviours are common to other conditions and because repetitive behaviours are only one criterion for a diagnosis of autism. The test has been designed to help clinicians in the diagnostic process.

    What is remarkable is that increased behaviours normally assessed in infancy can also be measured in a self report form in adulthood.

    The next phase of the research will be to trial the test on people of all ages with autism before implementing its use in clinics across the UK.

    Funded by an ESRC studentship to PhD student Sarah Barrett, the research remains ongoing. People aged over 18 can participate in the research by visiting: http://sites.cardiff.ac.uk/rbq2a/online/.

    See the full article here.

    Please help promote STEM in your local schools

    stem

    STEM Education Coalition

    We are an ambitious and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

     
  • richardmitnick 12:37 pm on November 16, 2014 Permalink | Reply
    Tags: , , , Cardiff University,   

    From Cardiff University: “Cardiff scientists help unlock secrets of the Universe” 

    Cardiff University

    Cardiff University

    13 November 2014
    No Writer Credit

    A team of Cardiff University researchers have made a breakthrough in helping scientists discover hundreds of black holes throughout the universe.

    When two detectors are switched on in the US next year, the Cardiff team hope their research will help scientists pick up the faint ripples of black hole collisions millions of years ago, known as gravitational waves.

    1
    No image credit

    Black holes cannot be seen, but scientists hope the revamped detectors – which act like giant microphones – will find remnants of black hole collisions.

    Led by Dr Mark Hannam from the School of Physics and Astronomy, the researchers have built a theoretical model which aims to predict all potential gravitational-wave signals that might be found by the detectors.

    The Cardiff researchers hope it will act as a ‘spotters’ guide’ to help scientists working with the giant LIGO detectors recognise the right waveforms and reveal the secrets of how black holes orbit into each other and collide.

    Dr Hannam said: “The rapid spinning of black holes will cause the orbits to wobble, just like the last wobbles of a spinning top before it falls over. These wobbles can make the black holes trace out wild paths around each other, leading to extremely complicated gravitational-wave signals. Our model aims to predict this behaviour and help scientists find the signals in the detector data.”

    The Cardiff team, which includes postdoctoral researchers, PhD students, and collaborators from universities in Europe and the United States, will work with scientists across the world as they attempt to unravel the origins of the Universe.

    Dr Hannam added: “Sometimes the orbits of these spinning black holes look completely tangled up, like a ball of string. But if you imagine whirling around with the black holes, then it all looks much clearer, and we can write down equations to describe what is happening. It’s like watching a kid on a high-speed spinning amusement park ride, apparently waving their hands around. From the side lines, it’s impossible to tell what they’re doing. But if you sit next to them, they might be sitting perfectly still, just giving you the thumbs up.”

    The new model has been programmed into the computer codes that LIGO scientists all over the world are preparing to use to search for black-hole mergers when the detectors switch on. But there is still more work to do.

    “So far we’ve only included these precession effects while the black holes spiral towards each other,” said Dr Hannam. “We still need to work our exactly what the spins do when the black holes collide.”

    For that they need to perform large computer simulations to solve [Albert]Einstein’s equations for the moments before and after the collision. They’ll need to produce many simulations to capture enough combinations of black-hole masses and spin directions to understand the overall behaviour of these complicated systems.

    Dr Hannam is optimistic. “For years we were stumped on how to untangle the black-hole motion. Now that we’ve solved that, we know what to do next.”

    Time is running out. Once the detectors switch on, it will only be a matter of time before the first gravitational-wave detections are made. The calculations that Dr Hannam and his colleagues are producing have to be ready in time to make the most of them.

    School of Physics and Astronomy

    See the full article here.

    Please help promote STEM in your local schools
    stem

    STEM Education Coalition

    We are an ambitious and innovative university with a bold and strategic vision located in a beautiful and thriving capital city. Our research is world-leading and we provide an educationally outstanding experience for our students.

    Driven by creativity and curiosity, we strive to fulfil our social, cultural and economic obligations to Cardiff, Wales, and the world.

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