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  • richardmitnick 2:56 pm on June 22, 2018 Permalink | Reply
    Tags: Basic Research, , , , ,   

    From Scientific American: “Evidence Builds for a New Kind of Neutrino” 

    Scientific American

    From Scientific American

    June 7, 2018
    Clara Moskowitz

    FNAL/MiniBooNE

    Physicists have caught ghostly particles called neutrinos misbehaving at an Illinois experiment, suggesting an extra species of neutrino exists. If borne out, the findings would be nothing short of revolutionary, introducing a new fundamental particle to the lexicon of physics that might even help explain the mystery of dark matter.

    Undeterred by the fact that no one agrees on what the observations actually mean, experts gathered at a neutrino conference this week in Germany are already excitedly discussing these and other far-reaching implications.

    Neutrinos are confusing to begin with. Formed long ago in the universe’s first moments and today in the hearts of stars and the cores of nuclear reactors, the miniscule particles travel at nearly the speed of light, and scarcely interact with anything else; billions pass harmlessly through your body each day, and a typical neutrino could traverse a layer of lead a light-year thick unscathed. Ever since their discovery in the mid–20th century, neutrinos were predicted to weigh nothing at all, but experiments in the 1990s showed they do have some mass—although physicists still do not know exactly how much. Stranger still, they come in three known varieties, or flavors—electron neutrinos, muon neutrinos and tau neutrinos—and, most bizarrely, can transform from one flavor to another. Because of these oddities and others, many physicists have been betting on neutrinos to open the door to the next frontier in physics.

    Now some think the door has cracked ajar. The discovery comes from 15 years’ worth of data gathered by the Mini Booster Neutrino Experiment (MiniBooNE) at Fermi National Accelerator Laboratory in Batavia, Ill. MiniBooNE detects and characterizes neutrinos by the flashes of light they occasionally create when they strike atomic nuclei in a giant vat filled with 800 tons of pure mineral oil. Its design is similar to that of an earlier project, the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos National Laboratory in New Mexico. In the 1990s LSND observed a curious anomaly, a greater-than-expected number of electron neutrinos in a beam of particles that started out as muon neutrinos; MiniBooNE has now seen the same thing, in a neutrino beam generated by one of Fermilab’s particle accelerators.

    Because muon neutrinos could not have transformed directly into electron flavor over the short distance of the LSND experiment, theorists at the time proposed that some of the particles were oscillating into a fourth flavor—a “sterile neutrino”—and then turning into electron neutrinos, producing the mysterious excess. Although the possibility was tantalizing, many physicists assumed the findings were a fluke, caused by some mundane error particular to LSND. But now that MiniBooNE has observed the very same pattern, scientists are being forced to reckon with potentially more profound causes for the phenomenon. “Now you have to really say you have two experiments seeing the same physics effect, so there must be something fundamental going on,” says MiniBooNE co-spokesperson Richard Van de Water of Los Alamos. “People can’t ignore this anymore.”

    The MiniBooNE team submitted its findings on May 30 to the preprint server arXiv, and is presenting them this week at the XXVIII International Conference on Neutrino Physics and Astrophysics in Heidelberg, Germany.

    A Fourth Flavor

    Sterile neutrinos are an exciting prospect, but outside experts say it is too early to conclude such particles are behind the observations. “If it is sterile neutrinos, it’d be revolutionary,” says Mark Thomson, a neutrino physicist and chief executive of the U.K.’s Science and Technology Facilities Council who was not part of the research. “But that’s a big ‘if.’”

    This new flavor would be called “sterile” because the particles would not feel any of the forces of nature, save for gravity, which would effectively block off communication with the rest of the particle world. Even so, they would still have mass, potentially making them an attractive explanation for the mysterious “dark matter” that seems to contribute additional mass to galaxies and galaxy clusters. “If there is a sterile neutrino, it’s not just some extra particle hanging out there, but maybe some messenger to the universe’s ‘dark sector,’” Van de Water says. “That’s why this is really exciting.” Yet the sterile neutrinos that might be showing up at MiniBooNE seem to be too light to account for dark matter themselves—rather they might be the first vanguard of a whole group of sterile neutrinos of various masses. “Once there is one [sterile neutrino], it begs the question: How many?” says Kevork Abazajian, a theoretical physicist at the University of California, Irvine. “They could participate in oscillations and be dark matter.”

    The findings are hard to interpret, however, because if neutrinos are transforming into sterile neutrinos in MiniBooNE, then scientists would expect to measure not just the appearance of extra electron neutrinos, but a corresponding disappearance of the muon neutrinos they started out as, balanced like two sides of an equation. Yet MiniBooNE and other experiments do not see such a disappearance. “That’s a problem, but it’s not a huge problem,” says theoretical physicist André de Gouvêa of Fermilab. “The reason this is not slam-dunk evidence against the sterile neutrino hypothesis is that [detecting] disappearance is very hard. You have to know exactly how much you had at the beginning, and that’s a challenge.”

    Another Mystery?

    Or perhaps MiniBooNE has discovered something big, but not sterile neutrinos. Maybe some other new aspect of the universe is responsible for the unexpected pattern of particles in the experiment’s beam. “Right now people are thinking about whether there are other new phenomena out there that could resolve this ambiguity,” de Gouvêa says. “Maybe the neutrinos have some new force that we haven’t thought about, or maybe the neutrinos decay in some funny way. It kind of feels like we haven’t hit the right hypothesis yet.”

    Unusually, this is one mystery physicists will not have to wait too long to solve. Another experiment at Fermilab called MicroBooNE was designed to follow MiniBooNE and will be able to study the excess more closely.

    FNAL/MicrobooNE

    One drawback of MiniBooNE is that it cannot be sure the flashes of light it sees are truly coming from neutrinos—it is possible that some unknown process is producing an excess of photons that mimic the neutrino signal. MicroBooNE, which should deliver its first data later this year, can distinguish between neutrino signals and impostors. If the signal turns out to be an excess of ordinary photons, rather than electron neutrinos, then all bets are off. “We don’t know what would do that in terms of physics, but if it is due to photons, we know that this sterile neutrino interpretation is not correct,” de Gouvêa says.

    In addition to MicroBooNE, Fermilab is building two other detectors to sit on the same beam of neutrinos and work in concert to study the neutrino oscillations going on there. Known collectively as the Short-Baseline Neutrino Program, the new system should be up and running by 2020 and could deliver definitive data in the early part of that decade, says Steve Brice, head of Fermilab’s Neutrino Division.

    FNAL Short baseline neutrino detector

    Until then physicists will continue to debate the mysteries of neutrinos—a field that is growing in size and excitement every year. The meeting happening now in Heidelberg, for example, is the largest neutrino conference ever. “It’s been a steady ramp-up over the last decade,” Brice says. “It’s an area that’s hard to study, but it’s proving to be a very fruitful field for physics.”

    See the full article here .


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  • richardmitnick 2:32 pm on June 22, 2018 Permalink | Reply
    Tags: A SINFONI of Exoplanets, , , Basic Research, ,   

    From ESOblog: “A SINFONI of Exoplanets” 

    ESO 50 Large

    From ESOblog

    1
    Science Snapshots

    22 June 2018

    Exoplanets have fast become a huge research area and astronomers are now trying to study their atmospheres. The possibility of finding an exoplanet with an atmosphere that may be able to support life is incredibly exciting. We spoke to Jens Hoeijmakers, from the Geneva Observatory and the Center for Space Habitability in Bern, Switzerland, to find out more about these distant worlds.

    Q: Let’s start simple: what is an exoplanet?

    A: Since 1995, we have known that many stars other than the Sun have their own “solar systems,” with the majority of stars hosting one or multiple planets. Exoplanetary systems come in all shapes and colours, meaning that they are very diverse. Astronomers have discovered planets ranging from gas giants to smaller, rocky planets. Some planets orbit far away from their star like the gas and ice giants in our Solar System, and some orbit very closely, with surface temperatures greater than 1000°C.

    Q: Why do you think it’s important and exciting to study exoplanets?

    A: The discovery of the existence of exoplanets has evolved as a major branch of astronomy in the past two decades. We now know of the existence of thousands of exoplanets, and this has shown that planets may even be more common than stars in our Universe! This ubiquitous presence of planets all around us begs the question of whether it’s possible for extraterrestrial life to exist. This is a major driving force behind the continued search for exoplanets and the detailed study of those that we’ve already discovered. But besides the exciting prospect of discovering life, the exoplanet population also gives us a unique window into understanding our own Solar System and the possible outcomes of the same planet formation processes that have made our Solar System the way that we see it today — essentially, studying exoplanets can help us understand how we got to be here.

    2
    This composite image represents the close environment of Beta Pictoris as seen in near-infrared light. A very careful subtraction of the much bright stellar halo reveals this very faint environment. The outer part of the image shows the reflected light on the dust disc, as observed with ADONIS on ESO 3.6-metre telescope. The inner part is the innermost part of the system, as seen with NACO on the Very Large Telescope.
    Credit: ESO/A.-M. Lagrange et al.

    3
    ADONIS Infrared Cameras

    ESO/NACO

    Q: Your research looked at one exoplanet in particular: Beta Pictoris b. Why did you choose to look at this system?

    A: Beta Pictoris b is maybe the most famous directly-imaged exoplanet, meaning that astronomers have managed to actually take a snapshot of the planet rather than infer its existence through its indirect effect on its star, as is most commonly done. Beta Pictoris b orbits a bright star about 70 light-years away from Earth, is in a system about 20 to 25 million years old and has a fairly hot surface, about 1700°C.

    Beta Pictoris b is one of the easier (but still challenging) planets to image directly because it’s young and hot enough to be observed at infrared wavelengths. When stars and planets form in a large disk of gas and dust, known as the protoplanetary disk, the material from which the planets form is very hot. This means that newborn planets start off with very high temperatures, and throughout the first tens of millions of years of their lives, they slowly cool down as they radiate this heat away, making these planets visible at infrared wavelengths. This is the class of planets that we can directly image, and Beta Pictoris b is a typical example of such a young planet, which is why we chose to observe it — and, indeed, why it is one of the most famous directly imaged exoplanets.

    Q: How did you observe Beta Pictoris b and what were you aiming to find?

    A: We used existing data of the planet from the SINFONI spectrograph on ESO’s Very Large Telescope located at the Paranal Observatory in Chile. Our aim was actually to test out the instrument — to investigate to what extent an adaptive-optics-assisted integral field spectrograph like SINFONI can be used to study an exoplanet’s atmosphere.

    ESO/SINFONI

    SINFONI is a special instrument. Not only does it perform the high-contrast imaging necessary to separately image the planet from its brighter host star, but it also simultaneously generates a spectrum of each pixel in that image at a high enough resolution. This allows us to see absorption lines in the spectrum of the planet. These absorption lines are what tell us about the chemicals in the planet’s atmosphere, and also about the planet’s temperature and other physical parameters. In fact, our new technique relies on the fact that the planet’s spectrum has absorption lines that are not present in the star that it orbits. This helps us disentangle the planet from its much brighter star, effectively increasing the contrast on top of the already high-contrast imaging from SINFONI. The instrument was not actually designed to be used in this way, so we’re the first to apply this technique.

    The only other instrument in the world that can currently perform this type of research is the OSIRIS spectrograph at the Keck Observatory in Hawaii.

    UCO Keck OSIRIS being installed

    It is very similar to SINFONI but is located at a much more northern latitude, meaning that SINFONI and OSIRIS can access complementary parts of the sky.

    3
    Molecular maps of carbon dioxide (left) and water (right) around Beta Pictoris. Beta Pictoris b is starkly visible in the lower right side of both maps. The left-side scale is the y-position and the bottom-side scale is the x-position. The scale is in arcseconds. Credit: J. Hoeijmakers.

    4
    Yepun, the fourth Unit Telescope of the VLT, is angled at a very low altitude, revealing the cell holding its main mirror and the SINFONI integral-field spectrograph.
    Credit: ESO

    Q: So what did you and your team find out?

    A: First of all, our analysis of the existing dataset confidently shows the presence of water and carbon monoxide in the atmosphere of Beta Pictoris b. This in itself is not a new result because both species were known (and expected) to be present. However, it is the first time that a high-contrast imaging instrument has been used to directly detect these absorption lines in an exoplanet’s atmosphere, thereby uniquely and robustly confirming their presence.

    Q: Did you face any challenges during your research?

    A: Our analysis was quite challenging because these observations were experimental. SINFONI is not tuned for these kinds of observations, so when the data was initially taken in 2014, it was quickly deemed too challenging even for the detection of the planet, let alone a measurement of its spectrum. In the case of this dataset, our method is more sensitive to the planet, but we also had to overcome the fact that the instrument is simply not designed to image a very faint planet next to a very bright star. This is why we strongly advocate that future, SINFONI-like instruments (such as the planned HARMONI instrument on ESO’s Extremely Large Telescope) should be outfitted with a coronagraph, which blocks out much of the starlight, making such observations even more powerful.

    5
    This composite image shows the movement of Beta Pictoris b around its star, observed by the NACO on the VLT over six years.
    Credit: ESO/A.-M. Lagrange

    Q: What do you personally find most exciting about this research?

    A: This is a clear example of using an existing dataset and instrument in a completely new way and finding exciting results. I think that there is no reason why the same analysis and observations couldn’t have been carried out 10 years ago, achieving the same results — and something similar is true for the entire field of exoplanets! The first exoplanets could have been discovered with technology that was already available over a decade earlier if only astronomers had taken the possibility of the existence of hot Jupiters seriously. That’s why I sometimes wonder what other new discoveries or applications of existing facilities are still hiding under our noses right now.

    Q: What might this research lead to in the future? And what are the next big steps in the field?

    A: The strength of our signal spells good news for the future, when new instruments will come online that are similar to SINFONI but much more powerful in terms of contrast and spectral resolution. For instance, our result came from over two hours of observations with SINFONI, but we calculated that the same result could be obtained using the Extremely Large Telescope in only 90 seconds — for a planet like Beta Pictoris that is five times closer to its host star! In this sense, our result is a clear demonstration of this analysis technique and should encourage ongoing development of these future instruments, especially for making them suitable for the high-contrast imaging of exoplanets.

    See the full article here .


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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

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    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

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    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

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    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

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    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

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    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 1:25 pm on June 22, 2018 Permalink | Reply
    Tags: , Basic Research, , , , , ,   

    From Brookhaven Lab: “Upgrades to ATLAS and LHC Magnets for Run 2 and Beyond” 

    From Brookhaven Lab

    6.22.18

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    The following news release was issued by CERN, the European Organization for Nuclear Research, home to the Large Hadron Collider (LHC). Scientists from the U.S. Department of Energy’s Brookhaven National Laboratory play multiple roles in the research at the LHC and are making major contributions to the high-luminosity upgrade described in this news release, including the development of new niobium tin superconducting magnets that will enable significantly higher collision rates; new particle tracking and signal readout systems for the ATLAS experiment that will allow scientists to capture and analyze the most significant details from vastly larger data sets; and increases in computing capacity devoted to analyzing and sharing that data with scientists around the world. Brookhaven Lab also hosts the Project Office for the U.S. contribution to the HL-LHC detector upgrades of the ATLAS experiment. For more information about Brookhaven’s roles in the high-luminosity upgrade or to speak with a Brookhaven/LHC scientist, contact Karen McNulty Walsh, (631) 344-8350, kmcnulty@bnl.gov.

    Brookhaven physicists play critical roles in LHC restart and plans for the future of particle physics.

    1
    The ATLAS detector at the Large Hadron Collider, an experiment with large involvement from physicists at Brookhaven National Laboratory. Image credit: CERN

    July 6, 2015

    At the beginning of June, the Large Hadron Collider at CERN, the European research facility, began smashing together protons once again. The high-energy particle collisions taking place deep underground along the border between Switzerland and France are intended to allow physicists to probe the furthest edges of our knowledge of the universe and its tiniest building blocks.

    The Large Hadron Collider returns to operations after a two-year offline period, Long Shutdown 1, which allowed thousands of physicists worldwide to undertake crucial upgrades to the already cutting-edge particle accelerator. The LHC now begins its second multi-year operating period, Run 2, which will take the collider through 2018 with collision energies nearly double those of Run 1. In other words, Run 2 will nearly double the energies that allowed researchers to detect the long-sought Higgs Boson in 2012.

    CERN CMS Higgs Event

    CERN ATLAS Higgs Event

    The U.S. Department of Energy’s Brookhaven National Laboratory is a crucial player in the physics program at the Large Hadron Collider, in particular as the U.S. host laboratory for the pivotal ATLAS experiment, one of the two large experiments that discovered the Higgs. Physicists at Brookhaven were busy throughout Long Shutdown 1, undertaking projects designed to maximize the LHC’s chances of detecting rare new physics as the collider reaches into a previous unexplored subatomic frontier.

    While the technology needed to produce a new particle is a marvel on its own terms, equally remarkable is everything the team at ATLAS and other experiments must do to detect these potentially world-changing discoveries. Because the production of such particles is a rare phenomenon, it isn’t enough to just be able to smash one proton into another. The LHC needs to be able to collide proton bunches, each bunch consisting of hundreds of billions of particles, every 50 nanoseconds—eventually rising to every 25 nanoseconds in Run 2—and be ready to sort through the colossal amounts of data that all those collisions produce.

    It is with those interwoven challenges—maximizing the number of collisions within the LHC, capturing the details of potentially noteworthy collisions, and then managing the gargantuan amount of data those collisions produce—that scientists at Brookhaven National Laboratory are making their mark on the Large Hadron Collider and its search for new physics—and not just for the current Run 2, but looking forward to the long-term future operation of the collider.

    Restarting the Large Hadron Collider

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    2
    Brookhaven physicist Srini Rajagopalan, operation program manager for U.S. ATLAS, works to keep manageable the colossal amounts of data that are generated by the Large Hadron Collider and sent to Brookhaven’s RHIC and ATLAS Computing Facility.

    The Large Hadron Collider is the largest single machine in the world, so it’s tempting to think of its scale just in terms of its immense size. The twin beamlines of the particle accelerator sit about 300 to 600 feet underground in a circular tunnel more than 17 miles around. Over 1,600 magnets, each weighing more than 25 tons, are required to keep the beams of protons focused and on the correct paths, and nearly 100 tons of liquid helium is necessary to keep the magnets operating at temperatures barely above absolute zero. Then there are the detectors, each of which stand several stories high.

    But the scale of the LHC extends not just in space, but in time as well. A machine of this size and complexity doesn’t just switch on or off with the push of a button, and even relatively simple maintenance can require weeks, if not months, to perform. That’s why the LHC recently completed Long Shutdown 1, a two-year offline period in which physicists undertook the necessary repairs and upgrades to get the collider ready for the next three years of near-continuous operation. As the U.S. host laboratory for the ATLAS experiment, Brookhaven National Laboratory was pivotal in upgrading and improving one of the cornerstones of the LHC apparatus.

    “After having run for three years, the detector needs to be serviced much like your car,” said Brookhaven physicist Srini Rajagopalan, operation program manager for U.S. ATLAS. “Gas leaks crop up that need to be fixed. Power supplies, electronic boards and several other components need to be repaired or replaced. Hence a significant amount of detector consolidation work occurs during the shutdown to ensure an optimal working detector when beam returns.”

    Beyond these vital repairs, the major goal of the upgrade work during Long Shutdown 1 was to increase the LHC’s center of mass energies from the previous 8 trillion electron volts (TeV) to 13 TeV, near the operational maximum of 14 TeV.

    “Upgrading the energy means you’re able to probe much higher mass ranges, and you have access to new particles that might be substantially heavier,” said Rajagopalan. “If you have a very heavy particle that cannot be produced, it doesn’t matter how much data you collect, you just cannot reach that. That’s why it was very important to go from 8 to 13 TeV. Doubling the energy allows us to access the new physics much more easily.”

    As the LHC probes higher and higher energies, the phenomena that the researchers hope to observe will happen more and more rarely, meaning the particle beams need to create many more collisions than they did before. Beyond this increase in collision rates, or luminosity, however, the entire infrastructure of data collection and management has to evolve to deal with the vastly increased volume of information the LHC can now produce.

    “Much of the software had to be evolved or rewritten,” said Rajagopalan, “from patches and fixes that are more or less routine software maintenance to implementing new algorithms and installing new complex data management systems capable of handling the higher luminosity and collision rates.”

    Making More Powerful Magnets

    3
    Brookhaven physicist Peter Wanderer, head of the laboratory’s Superconducting Magnet Division, stands in front of the oven in which niobium tin is made into a superconductor.

    The Large Hadron Collider works by accelerating twin beams of protons to speeds close to that of light. The two beams, traveling in opposite directions along the path of the collider, both contain many bunches of protons, with each bunch containing about 100 billion protons. When the bunches of protons meet, not all of the protons inside of them are going to interact and only a tiny fraction of the colliding bunches are likely to yield potentially interesting physics. As such, it’s absolutely vital to control those beams to maximize the chances of useful collisions occurring.

    The best way to achieve that and the desired increase in luminosity—both during the current Run 2, and looking ahead to the long-term future of the LHC—is to tighten the focus of the beam. The more tightly packed protons are, the more likely they’ll smash into each other. This means working with the main tool that controls the beam inside the accelerator: the magnets.

    FNAL magnets such as this one, which is mounted on a test stand at Fermilab, for the High-Luminosity LHC Photo Reidar Hahn

    “Most of the length of the circumference along a circular machine like the LHC is taken up with a regular sequence of magnets,” said Peter Wanderer, head of Brookhaven Lab’s Superconducting Magnet Division, which made some of the magnets for the current LHC configuration and is working on new designs for future upgrades. “The job of these magnets is to bend the proton beams around to the next point or region where you can do something useful with them, like produce collisions, without letting the beam get larger.”

    A beam of protons is a bunch of positively charged particles that all repel one another, so they want to move apart, he explained. So physicists use the magnetic fields to keep the particles from being able to move away from the desired path.

    “You insert different kinds of magnets, different sequences of magnets, in order to make the beams as small as possible, to get the most collisions possible when the beams collide,” Wanderer said.

    The magnets currently in use in the LHC are made of the superconducting material niobium titanium (NbTi). When the electromagnets are cooled in liquid helium to temperatures of about 4 Kelvin (-452.5 degrees Fahrenheit), they lose all electric resistance and are able to achieve a much higher current density compared with a conventional conductor like copper. A magnetic field gets stronger as its current is more densely packed, meaning a superconductor can produce a much stronger field over a smaller radius than copper.

    But there’s an upper limit to how high a field the present niobium titanium superconductors can reach. So Wanderer and his team at Brookhaven have been part of a decade-long project to refine the next generation of superconducting magnets for a future upgrade to the LHC. These new magnets will be made from niobium tin (Nb3Sn).

    “Niobium tin can go to higher fields than niobium titanium, which will give us even stronger focusing,” Wanderer said. “That will allow us to get a smaller beam, and even more collisions.” Niobium tin can also function at a slightly higher temperature, so the new magnets will be easier to cool than those currently in use.

    There are a few catches. For one, niobium tin, unlike niobium titanium, isn’t initially superconducting. The team at Brookhaven has to first heat the material for two days at 650 degrees Celsius (1200 degrees Fahrenheit) before beginning the process of turning the raw materials into the wires and cables that make up an electromagnet.

    “And when niobium tin becomes a superconductor, then it’s very brittle, which makes it really challenging,” said Wanderer. “You need tooling that can withstand the heat for two days. It needs to be very precise, to within thousandths of an inch, and when you take it out of the tooling and want to put it into a magnet, and wrap it with iron, you have to handle it very carefully. All that adds a lot to the cost. So one of the things we’ve worked out over 10 years is how to do it right the first time, almost always.”

    Fortunately, there’s still time to work out any remaining kinks. The new niobium tin magnets aren’t set to be installed at the LHC until around 2022, when the changeover from niobium titanium to niobium tin will be a crucial part of converting the Large Hadron Collider into the High-Luminosity Large Hadron Collider (HL-LHC).

    Managing Data at Higher Luminosity

    As the luminosity of the LHC increases in Run 2 and beyond, perhaps the biggest challenge facing the ATLAS team at Brookhaven lies in recognizing a potentially interesting physics event when it occurs. That selectivity is crucial, because even CERN’s worldwide computing grid—which includes about 170 global sites, and of which Brookhaven’s RHIC and ATLAS Computing Facility is a major center—can only record the tiniest fraction of over 100 million collisions that occur each second. That means it’s just as important to quickly recognize the millions of events that don’t need to be recorded as it is to recognize the handful that do.

    “What you have to do is, on the fly, analyze each event and decide whether you want to save it to disk for later use or not,” said Rajagopalan. “And you have to be careful you don’t throw away good physics events. So you’re looking for signatures. If it’s a good signature, you say, ‘Save it!’ Otherwise, you junk it. That’s how you bring the data rate down to a manageable amount you can write to disk.”

    Physicists screen out unwanted data using what’s known as a trigger system. The principle is simple: as the data from each collision comes in, it’s analyzed for a preset signature pattern, or trigger, that would mark it as potentially interesting.

    “We can change the trigger, or make the trigger more sophisticated to be more selective,” said Brookhaven’s Howard Gordon, a leader in the ATLAS physics program. “If we don’t select the right events, they are gone forever.”

    The current trigger system can handle the luminosities of Run 2, but with future upgrades it will no longer be able to screen out and reject enough collisions to keep the number of recorded events manageable. So the next generation of ATLAS triggers will have to be even more sophisticated in terms of what they can instantly detect—and reject.

    A more difficult problem comes with the few dozen events in each bunch of protons that look like they might be interesting, but aren’t.

    “Not all protons in a bunch interact, but it’s not necessarily going to be only one proton in a bunch that interacts with a proton from the opposite bunch,” said Rajagopalan. “You could have 50 of them interact. So now you have 50 events on top of each other. Imagine the software challenge when just one of those is the real, new physics we’re interested in discovering, but you have all these 49 others—junk!—sitting on top of it.”

    “We call it pileup!” Gordon quipped.

    Finding one good result among 50 is tricky enough, but in 10 years that number will be closer to 1 in 150 or 200, with all those additional extraneous results interacting with each other and adding exponentially to the complexity of the task. Being able to recognize instantly as many characteristics of the desired particles as possible will go a long way to keeping the data manageable.

    Further upgrades are planned over the next decade to cope with the ever-increasing luminosity and collision rates. For example, the Brookhaven team and collaborators will be working to develop an all-new silicon tracking system and a full replacement of the readout electronics with state-of-the-art technology that will allow physicists to collect and analyze ten times more data for LHC Run 4, scheduled for 2026.

    The physicists at CERN, Brookhaven, and elsewhere have strong motivation for meeting these challenges. Doing so will not only offer the best chance of detecting rare physics events and expanding the frontiers of physics, but would allow the physicists to do it within a reasonable timespan.

    As Rajagopalan put it, “We are ready for the challenge. The next few years are going to be an exciting time as we push forward to explore a new unchartered energy frontier.”

    Brookhaven’s role in the LHC is supported by the DOE Office of Science.

    See the full article here .


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    BNL Campus

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 3:29 pm on June 21, 2018 Permalink | Reply
    Tags: ALMA Discover Exciting Structures in a Young Protoplanetary Disk That Support Planet Formation, , , Basic Research, , ,   

    From ALMA: “ALMA Discover Exciting Structures in a Young Protoplanetary Disk That Support Planet Formation” 

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

    From ALMA

    20 June, 2018

    Ruobing Dong
    Steward Observatory, University of Arizona, USA
    Institute of Astronomy and Astrophysics, Academia Sinica, Taiwan
    +1 609 423 5625
    rbdong@gmail.com

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    +81 422 34 3630
    hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Phone: +1 434 296 0314
    Cell phone: +1 202 236 6324
    cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO
    Garching bei München, Germany
    Phone: +49 89 3200 6655
    Cell phone: +49 151 1537 3591
    rhook@eso.org

    1
    ALMA image of the 0.87 mm continuum emission from the MWC 758 disk. Credit: ALMA (ESO/NAOJ/NRAO)/Dong et al.

    Since early 2000, rich structures, including gaps and rings, dust clumps, and spiral arm-like features, have been discovered in a few tens of disks surrounding newborn stars. With the belief that planets are forming inside, astronomers named these disks protoplanetary disks.

    The origin of these structures is in hot debate among astronomers. In one scenario, they are thought to be produced by unseen planets forming inside and gravitationally interacting with the host disks, as planets open gaps, shepherd dust clumps, and excite spiral arms.

    Alternative ways to produce observed disk structures that do not invoke planets have also been raised. For examples, large central cavities may be the outcome of photoevaporation, as high energy radiations from the central star evaporate the inner disk. Also, under certain conditions shadows in disks may mimic the spiral arms seen in reflected light.

    The protoplanetary disk around a young star MWC 758 is located at 500 light years from us. In 2012, a pair of near symmetric giant spiral arms was discovered in reflected light. In dust thermal and molecular gas line emission at millimeter wavelengths, a big inner hole and two major dust clumps have been found, too.

    Now with the new ALMA image, the previously known cavity of MWC 758 is shown to be off-centered from the star with its shape well described by an ellipse with one focus on the star. Also, a millimeter dust emission feature corresponds nicely with one of the two spiral arms previously seen in reflected light. Both discoveries are the first among protoplanetary disks.

    “MWC 758 is a rare breed!”, says Sheng-Yuan Liu at ASIAA, co-author of this study, “All major types of disk structures have been found in this system. It reveals to us one of the most comprehensive suites of evidence of planet formation in all protoplanetary disks.”

    Previously in 2015, Dr. Dong and his collaborators proposed that the two arms in the MWC 758 disk can be explained as driven by a super-Jupiter planet just outside the disk.

    “Our new ALMA observations lend crucial support to planet-based origins for all the structures.”, says Dr. Takayuki Muto at Kogakuin University, Japan, co-author of this research, “For example, it’s exciting to see ellipses with one focus on the star. That’s Kepler’s first law! It’s pointing to a dynamical origin, possibly interacting with planets.”

    The off-centered cavity strongly, on the other hand, disfavors alternative explanations such as photoevaporation, which does not have an azimuthal dependence.

    2
    Various disk structures are marked. The green dotted contours mark the boundaries of the disk; the small circle at the center roughly marks the location of the star; the two green solid contours represent the extent of the two bright clumps; the solid, dotted and dashed white arcs trace out the inner, middle, and outer rings, respectively; and the arrow points out the spiral arm. The resolution (beam size, ~6.5 AU) of the image is labeled at the lower left corner. Credit: ALMA (ESO/NAOJ/NRAO)/Dong et al.

    The fact that the south spiral branch is present in the millimeter emission tracing the dust rules that it’s a density arm. Other scenarios, such as shadows, which view the spiral arms as surface features, are not expected to reproduce the observations. The ultra-high resolution achieved in the new ALMA dataset also enables the detection of a slight offset between the arm locations in reflected light and in dust emission, which is consistent with models of planet-induced density wave.

    “These fantastic new details are only made possible thanks to the amazing angular resolution delivered by ALMA”, says co-author Eiji Akiyama at Hokkaido University, Japan, “We took full advantage of ALMA’s long baseline capabilities, and now the MWC 758 disk joins the elite club of ultra-high-resolution ALMA disks alongside only a handful of others.”

    Additional information

    This research was presented in a paper “The Eccentric Cavity, Triple Rings, Two-Armed Spirals, and Double Clumps of the MWC 758 Disk” by Dong et al. to appear in The Astrophysical Journal.

    The team is composed of Ruobing Dong (U. of Arizona, USA; ASIAA, Taiwan), Sheng-yuan Liu (ASIAA, Taiwan), Josh Eisner (University of Arizona, USA), Sean Andrews (Harvard-Smithsonian Center for Astrophysics, USA), Jeffrey Fung (UC Berkeley, USA), Zhaohuan Zhu (UNLV, USA) Eugene Chiang (UC Berkeley, USA), Jun Hashimoto (Astrobiology Center, NINS, Japan), Hauyu Baobab Liu (European Southern Observatory, Germany), Simon Casassus (University of Chile, Chile), Thomas Esposito (UC Berkeley, USA), Yasuhiro Hasegawa (JPL/Caltech, USA), Takayuki Muto (Kogakuin University, Japan), Yaroslav Pavlyuchenkov (Russian Academy of Sciences, Russia), David Wilner (Harvard-Smithsonian Center for Astrophysics, USA), Eiji Akiyama (Hokkaido University, Japan), Motohide Tamura (The University of Tokyo; Astrobiology Center, NINS, Japan), and John Wisniewski (U. of Oklahoma, USA).

    See the full article here .


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

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

    NRAO Small
    ESO 50 Large
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  • richardmitnick 3:05 pm on June 21, 2018 Permalink | Reply
    Tags: Basic Research, , Muon antineutrino oscillation spotted by NOvA, ,   

    From physicsworld.com: “Muon antineutrino oscillation spotted by NOvA” 

    physicsworld
    From physicsworld.com

    07 June 2018
    Hamish Johnston

    FNAL NOvA detector in northern Minnesota

    NOvA Far Detector Block

    The best evidence yet that muon antineutrinos can change into electron antineutrinos has been found by the NOvA experiment in the US. The measurement involved sending a beam of muon antineutrinos more than 800 km through the Earth from Fermilab near Chicago to a detector in northern Minnesota. After running for about 14 months, NOvA found that at least 13 of the muon antineutrinos had changed type, or “flavour”, during their journey.

    The results were presented at the Neutrino 2018 conference, which is being held in Heidelberg, Germany, this week. Although the measurement is still below the threshold required to claim a “discovery”, the result means that fundamental properties of neutrinos and antineutrinos can be compared in detail. This could shed light on important mysteries of physics, such as why there is very little antimatter in the universe.

    Neutrinos and antineutrinos come in three flavours: electron, muon and tau. The subatomic particles also exist in three mass states, which means that neutrinos (and antineutrinos) will continuously change flavour (or oscillate). Neutrino oscillation came as a surprise to physicists, who had originally thought that neutrinos have no mass. Indeed, the origins of neutrino mass are not well-understood and a better understanding of neutrino oscillation could point to new physics beyond the Standard Model.
    Pion focusing

    NOvA has been running for more than three years and comprises two detectors – one located at Fermilab and the other in Minnesota near the border with Canada.

    FNAL Near Detector

    The muon antineutrinos in the beam are produced at Fermilab’s NuMI facility by firing a beam of protons at a carbon target. This produces pions, which then decay to produce either muon neutrinos or muon antineutrinos – depending upon the charge of the pion. By focusing pions of one charge into a beam, researchers can create a beam of either neutrinos or antineutrinos.

    The beam is aimed on a slight downward trajectory so it can travel through the Earth to the detector in Minnesota, which weighs in at 14,000 ton. Electron neutrinos and antineutrinos are detected when they very occasionally collide with an atom in a liquid scintillator, which produces a tiny flash of light. This light is converted into electrical signals by photomultipler tubes and the type of neutrino (or antineutrino) can be worked-out by studying the pattern of signal produced.

    The experiment’s first run with antineutrino began in February 2017 and ended in April 2018. The first results were presented this week in Heidelberg by collaboration member Mayly Sanchez of Iowa State University, who reported that a total of 18 electron antineutrinos had been seen by the Minnesota detector. If muon antineutrinos did not oscillate to electron antineutrinos, then only five detections should have been made.
    “Strong evidence”

    “The result is above 4σ level, which is strong evidence for electron antineutrino appearance,” Sanchez told Physics World, adding that this is the first time that the appearance of electron antineutrinos has been seen in a beam of muon antineutrinos. While this is below the 5σ level normally accepted as a discovery in particle physics, it is much stronger evidence than found by physicists working on the T2K detector in Japan – which last year reported seeing hints of the oscillation.

    In 2014-2017 NOvA detected 58 electron neutrinos that have appeared in a muon neutrino beam. This has allowed NOvA physicists to compare the rates at which muon neutrinos and antineutrinos oscillate to their respective electron counterparts. According to Sanchez, the team has seen a small discrepancy that has a statistical significance of just 1.8σ. While this difference is well within the expected measurement uncertainty, if it persists as more data are collected it could point towards new physics.

    Sanchez says that NOvA is still running in antineutrino mode and the amount of data taken will double by 2019.

    See the full article here .


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    PhysicsWorld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
    IOP Institute of Physics

     
  • richardmitnick 2:22 pm on June 21, 2018 Permalink | Reply
    Tags: 'Red Nuggets' are Galactic Gold for Astronomers, , , Basic Research, ,   

    From NASA Chandra: “‘Red Nuggets’ are Galactic Gold for Astronomers” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    June 21, 2018

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

    1
    Credit: X-ray: NASA/CXC/MTA-Eötvös University/N. Werner et al.; Illustration: NASA/CXC/M.Weiss
    Press Image, Caption, and Videos

    The central black holes may be the driving force in how much star formation occurs in a certain type of rare galaxy.

    ‘Red nuggets’ are the relics of the first massive galaxies that formed within a billion years after the Big Bang.

    While most red nuggets merged with other galaxies, some remained untouched throughout the history of the Universe.

    Astronomers used Chandra to learn more about how the black holes in these galaxies affect star formation.

    About a decade ago, astronomers discovered a population of small, but massive galaxies called “red nuggets.” A new study using NASA’s Chandra X-ray Observatory indicates that black holes have squelched star formation in these galaxies and may have used some of the untapped stellar fuel to grow to unusually massive proportions.

    Red nuggets were first discovered by the Hubble Space Telescope at great distances from Earth, corresponding to times only about three or four billion years after the Big Bang. They are relics of the first massive galaxies that formed within only one billion years after the Big Bang. Astronomers think they are the ancestors of the giant elliptical galaxies seen in the local Universe. The masses of red nuggets are similar to those of giant elliptical galaxies, but they are only about a fifth of their size.

    While most red nuggets merged with other galaxies over billions of years, a small number managed to slip through the long history of the cosmos untouched. These unscathed red nuggets represent a golden opportunity to study how the galaxies, and the supermassive black hole at their centers, act over billions of years of isolation.

    For the first time, Chandra has been used to study the hot gas in two of these isolated red nuggets, MRK 1216, and PGC 032673. They are located only 295 million and 344 million light years from Earth respectively, rather than billions of light years for the first known red nuggets. This X-ray emitting hot gas contains the imprint of activity generated by the supermassive black holes in each of the two galaxies.

    “These galaxies have existed for 13 billion years without ever interacting with another of its kind,” said Norbert Werner of MTA-Eötvös University Lendület Hot Universe and Astrophysics Research Group in Budapest, Hungary, who led the study. “We are finding that the black holes in these galaxies take over and the result is not good for new stars trying to form.”

    Astronomers have long known that the material falling towards black holes can be redirected outward at high speeds due to intense gravitational and magnetic fields. These high-speed jets can tamp down the formation of stars. This happens because the blasts from the vicinity of the black hole provide a powerful source of heat, preventing the galaxy’s hot interstellar gas from cooling enough to allow large numbers of stars to form.

    The temperature of the hot gas is higher in the center of the MRK 1216 galaxy compared to its surroundings, showing the effects of recent heating by the black hole. Also, radio emission is observed from the center of the galaxy, a signature of jets from black holes. Finally, the X-ray emission from the vicinity of the black hole is about a hundred million times lower than a theoretical limit on how fast a black hole can grow — called the “Eddington limit” — where the outward pressure of radiation is balanced by the inward pull of gravity. This low level of X-ray emission is typical for black holes producing jets. All these factors provide strong evidence that activity generated by the central supermassive black holes in these red nugget galaxies is suppressing the formation of new stars.

    The black holes and the hot gas may have another connection. The authors suggest that much of the black hole mass may have accumulated from the hot gas surrounding both galaxies. The black holes in both MRK 1216 and PGC 032873 are among the most massive known, with estimated masses of about five billion times that of the Sun, based on optical observations of the speeds of stars near the galaxies’ centers. Furthermore, the masses of the MRK 1216 black hole and possibly the one in PGC 032873 are estimated to be a few percent of the combined masses of all the stars in the central regions of the galaxies, whereas in most galaxies, the ratio is about ten times less.

    In the latest research, astronomers used Chandra to study the hot gas in two of these isolated red nuggets, Mrk 1216, and PGC 032673. (The Chandra data, colored red, of Mrk 1216 is shown in the inset.) These two galaxies are located only 295 million and 344 million light years from Earth respectively, rather than billions of light years for the first known red nuggets, allowing for a more detailed look. The gas in the galaxy is heated to such high temperatures that it emits brightly in X-ray light, which Chandra detects. This hot gas contains the imprint of activity generated by the supermassive black holes in each of the two galaxies.

    An artist’s illustration (main panel) shows how material falling towards black holes can be redirected outward at high speeds due to intense gravitational and magnetic fields. These high-speed jets can tamp down the formation of stars. This happens because the blasts from the vicinity of the black hole provide a powerful source of heat, preventing the galaxy’s hot interstellar gas from cooling enough to allow large numbers of stars to form.

    “Apparently, left to their own devices, black holes can act a bit like a bully,” said co-author Kiran Lakhchaura, also of MTA-Eötvös University.

    “Not only do they prevent new stars from forming,” said co-author Massimo Gaspari, an Einstein fellow from Princeton University, “they may also take some of that galactic material and use it to feed themselves.”

    In addition, the hot gas in and around PGC 032873 is about ten times fainter than the hot gas around MRK 1216. Because both galaxies appear to have evolved in isolation over the past 13 billion years, this difference might have arisen from more ferocious outbursts from PGC 032873’s black hole in the past, which blew most of the hot gas away.

    “The Chandra data tell us more about what the long, solitary journey through cosmic time has been like for these red nugget galaxies,” said co-author Rebecca Canning of Stanford University. “Although the galaxies haven’t interacted with others, they’ve shown plenty of inner turmoil.”

    A paper describing these results in the latest issue of the Monthly Notices of the Royal Astronomical Society. The authors of the paper are Norbert Werner (MTA-Eötvös University Lendület Hot Universe and Astrophysics Research Group in Budapest, Hungary), Kiran Lakhchaura (MTA-Eötvös University), Rebecca Canning (Stanford University), Massimo Gaspari (Princeton University), and Aurora Simeonescu (ISAS/JAXA).

    See the full article here .


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

     
  • richardmitnick 4:34 pm on June 20, 2018 Permalink | Reply
    Tags: , , , Basic Research, , Exploring Jets from a Supermassive Black Hole   

    From AAS NOVA: “Exploring Jets from a Supermassive Black Hole” 

    AASNOVA

    From AAS NOVA

    1
    The double-sided jets of the active galaxy NGC 4261, shown here in this composite optical (white) and radio (orange) image, span around 88,000 light-years across. A new study explores the structure and properties of these jets. [HST/NASA/ESA/NRAO]

    What are the feeding — and burping — habits of the supermassive black holes peppering the universe? In a new study, observations of one such monster reveal more about the behavior of its powerful jets.

    Beams from Behemoths

    Across the universe, supermassive black holes of millions to billions of solar masses lie at the centers of galaxies, gobbling up surrounding material. But not all of the gas and dust that spirals in toward a black hole is ultimately swallowed! A large fraction of it can instead be flung out into space again, in the form of enormous, powerful jets that extend for thousands or even millions of light-years in opposite directions.

    2
    Messier 87, shown in this Hubble image, is a classic example of a nearby (55 million light-years distant) supermassive black hole with a visible, collimated jet. Its counter-jet isn’t seen because relativistic effects make the receding jet appear less bright. [The Hubble Heritage Team (STScI/AURA) and NASA/ESA]

    What causes these outflows to be tightly beamed — collimated — in the form of jets, rather than sprayed out in all directions? Does the pressure of the ambient medium — the surrounding gas and dust that the jet is injected into — play an important role? In what regions do these jets accelerate and decelerate? There are many open questions that scientists hope to understand by studying some of the active black holes with jets that live closest to us.

    Eyes on a Nearby Giant

    In a new study led by Satomi Nakahara (The Graduate University for Advanced Studies in Japan), a team of scientists has used multifrequency Very Long Baseline Array (VLBA) and Very Large Array (VLA) images to explore jets emitted from a galaxy just 100 million light-years away: NGC 4261.

    NRAO/VLBA

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

    This galaxy’s (relatively) close distance — as well as the fact that we’re viewing it largely from the side, so we can clearly see both of its polar jets — allows us to observe in detail the structure and intensity of its jets as a function of their distance from the black hole. Nakahara and collaborators’ observations span the enormous radial distance of a thousand to a billion times the radius of the black hole, or about 54 light-days to more than a million light-years.

    3
    The width of the jet as a function of radial distance from the black hole, for NGC 4261 (red) compared to the few other jets from nearby supermassive black holes that we’ve measured. NGC 4261’s jets transition from parabolic to conical at around 10,000 times the radius of the black hole (RS). [Nakahara et al. 2018]

    Scale for Change

    The authors’ observations of NGC 4261’s jets indicate that a transition occurs at ~10,000 times the radius of the black hole (that’s a little over a light-year from the black hole). At this point, the jets’ structures change from parabolic (becoming more tightly beamed) to conical (expanding freely). Around the same location, Nakahara and collaborators also see the radiation profile of one of the jets change, suggesting the physical conditions in the jets transition here as well.

    This is the first time we’ve been able to examine jet width this closely for both of the jets emitted from a supermassive black hole. The fact that the structure changes at the same distance for both jets indicates that the shape of these powerful streams is likely governed by global properties of the environment surrounding the galaxy’s nucleus, or properties of the jets themselves, rather than by a local condition.

    The authors next hope to pin down velocities inside NGC 4261’s jets to determine where the jets accelerate and decelerate. This nearby powerhouse is clearly going to be a useful laboratory in the future, helping to unveil the secrets of more distant, feeding monsters.

    Bonus

    Curious what these hungry supermassive black holes look like? Check out this artist’s imagining of NGC 4261, which shows how it feeds from a large, swirling accretion disk and emits fast-moving, collimated jets. [Original video credit to Dana Berry, Space Telescope Science Institute]

    Citation

    Satomi Nakahara et al 2018 ApJ 854 148. http://iopscience.iop.org/article/10.3847/1538-4357/aaa45e/meta The Astrophysical Journal

    Related journal articles
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    See the full article for further references with links.

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    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 2:48 pm on June 20, 2018 Permalink | Reply
    Tags: A Strange Type of Matter Might Lie Inside Neutron Stars, Basic Research, It Breaks The Periodic Table, , ,   

    From University of Toronto via Science Alert: “A Strange Type of Matter Might Lie Inside Neutron Stars, And It Breaks The Periodic Table” 

    U Toronto Bloc

    From University of Toronto

    via

    Science Alert

    1
    (gremlin/istock)

    20 JUN 2018
    MIKE MCRAE

    This is amazing and we are freaking out.

    A group of physicists are questioning our understanding of how quarks – a type of elementary particle – arrange themselves under extreme conditions. And their quest is revealing that elements beyond the edge of the periodic table might be far more weird than we thought.

    Periodic table Sept 2017. Wikipedia

    Deep in the depths of the periodic table there are monsters made of a unique arrangement of subatomic particles. As far as elements go, they come no bigger than oganesson – a behemoth that contains 118 protons and has an atomic mass of just under 300.

    1

    That’s not to say protons and neutrons can’t be arranged into even bigger clumps and still remain somewhat stable for longer than an eye blink. But for all practical purposes, nobody has discovered it yet.

    While scientists speculate over how far the frontiers of the periodic table stretch, it’s becoming clear that as atoms get bigger, the usual rules governing their behaviour change.

    In this latest study, physicists from the University of Toronto argue that the constituent particles making up an atom’s protons and neutrons could break their usual bonds under extreme conditions and still retain enough stability for the atom to stick around.

    There are six types of these particles, called quarks, with the rather odd names of up, down, charm, strange, top, and bottom. Protons contain two up types and a down type. Neutrons, on the other hand, are made of two downs and a single up.

    Quarks aren’t limited to these configurations, though finding other arrangements is often rare thanks to the fact few stay stable very long.

    A little over thirty years ago, a physicist named Edward Witten proposed that the energy keeping combinations of quarks in triplets could achieve something of a balance if put under sufficient pressure, such as that inside a neutron star.

    This ‘strange quark matter’ (or SQM) would be a relatively equal mix of up, down, and strange quarks arranged not in threes, but as a liquid of numerous buzzing particles.

    Given the fact up and down quarks get along well enough to form teams inside protons and neutrons, the possibility of making quark matter without strange quarks to mix things up has been generally dismissed.

    According to physicists Bob Holdom, Jing Ren, and Chen Zhang, doing the actual sums reveals up-down quark matter, or udQM, might not only be possible, but preferable.

    “Physicists have been searching for SQM for decades,” the researchers told Lisa Zyga at phys.org. “From our results, many searches may have been looking in the wrong place.”

    The team went back to basics and question the lowest energy state of a big bunch of squirming quarks.

    They discovered that the ground state – that comfortable lobby of energy levels for particles – for udQM could actually be lower than both SQM and the ground state of the triplets inside protons and neutrons.

    So if bunches of quarks are given enough of a push, they could force the ups and downs to pool into a liquid mess at energies that don’t need the help of strange quarks.

    Neutron stars could provide just such a squeeze, but it’s no secret that the hearts of atoms themselves are pretty intense places as far as forces go.

    The team suggest elements with atomic masses greater than 300 might also provide the right conditions to force up and down quarks to loosen up and party.

    Making these elements would be a challenge that would require some way to pile on the neutrons to make supermassive elements stable enough.

    But the lower ground states of udQM point the way to stable regions beyond the edges of the periodic table.

    Exactly what these heavy elements look like or how they behave is hard to say for now, but it’s unlikely they’d be following the usual rules.

    There’s also a chance that udQM could shoot across the Universe in the form of cosmic rays, and potentially be caught here on Earth. Or even produced inside particle accelerators.

    “Knowing better where to look for udQM might then help to achieve an old idea: that of using quark matter as a new source of energy,” the researchers claim.

    Stable droplets of quarks wouldn’t behave like usual quark clusters found in protons and neutrons, with lower masses that could potentially make them easier to control.

    Quark matter reactors sound like the stuff of science fiction. But if this research is anything to go by, a whole new field of applied physics could be just over the horizon.

    This research was published in Physical Review Letters.

    See the full article here .


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

    Stem Education Coalition

    U Toronto Campus

    Established in 1827, the University of Toronto has one of the strongest research and teaching faculties in North America, presenting top students at all levels with an intellectual environment unmatched in depth and breadth on any other Canadian campus.

    Established in 1827, the University of Toronto has one of the strongest research and teaching faculties in North America, presenting top students at all levels with an intellectual environment unmatched in depth and breadth on any other Canadian campus.

     
  • richardmitnick 2:19 pm on June 20, 2018 Permalink | Reply
    Tags: , , Basic Research, , , The Surprising Reason Why Neutron Stars Don’t All Collapse To Form Black Holes   

    From Ethan Siegel: “The Surprising Reason Why Neutron Stars Don’t All Collapse To Form Black Holes” 

    From Ethan Siegel
    June 20, 2018

    1
    In the aftermath of the creation of a neutron star, it can have a variety of masses, many of which are far in excess of the most massive white dwarf. But there is a limit to how massive they can get before becoming a black hole, and a simple nuclear physics experiment on a single proton may have just discovered why. (NASA)

    There’s something very special inside a proton and neutron that holds the key.

    There are few things in the Universe that are as easy to form, in theory, as black holes are. Bring enough mass into a compact volume and it gets more and more difficult to gravitationally escape from it. If you were to gather enough matter in a single spot and let gravitation do its thing, you’d eventually pass a critical threshold, where the speed you’d need to gravitationally escape would exceed the speed of light. Reach that point, and you’ll create a black hole.

    But real, normal matter will very much resist getting there. Hydrogen, the most common element in the Universe, will fuse in a chain reaction at high temperatures and densities to create a star, rather than a black hole. Burned out stellar cores, like white dwarfs and neutron stars, can also resist gravitational collapse and stave off becoming a black hole. But while white dwarfs can reach only 1.4 times the mass of the Sun, neutron stars can get twice as massive. At long last, we finally understand why [Nature].

    2
    Sirius A and B, a normal (Sun-like) star and a white dwarf star. Even though the white dwarf is much lower in mass, its tiny, Earth-like size ensures its escape velocity is many times larger. For a neutron stars, masses can be even larger, with physical sizes in the tens of kilometers. (NASA, ESA and G. Bacon (STScI))

    In our Universe, the matter-based objects we know of are all made of just a few simple ingredients: protons, neutrons, and electrons. Each proton and neutron is made up of three quarks, with a proton containing two up and one down quark, and a neutron containing one up and two downs. On the other hand, electrons themselves are fundamental particles. Although particles come in two classes — fermions and bosons — both quarks and electrons are fermions.

    3
    The Standard Model of particle physics accounts for three of the four forces (excepting gravity), the full suite of discovered particles, and all of their interactions. Quarks and leptons are fermions, which have a host of unique properties that the other (bosons) particles do not possess. (Contemporary Physics Education Project / DOE / NSF / LBNL)

    Standard Model of Particle Physics from Symmetry Magazine

    Why should you care? It turns out that these classification properties are vitally important when it comes to the question of black hole formation. Fermions have a few properties that bosons don’t, including:

    they have half-integer (e.g., ±1/2, ±3/2, ±5/2, etc.) spins as opposed to integer (0, ±1, ±2, etc.) spins,
    they have antiparticle counterparts; there are no anti-bosons,
    and they obey the Pauli Exclusion Principle, whereas bosons don’t.

    That last property is the key to staving off collapse into a black hole.

    4
    The energy levels and electron wavefunctions that correspond to different states within a hydrogen atom. Because of the spin = 1/2 nature of the electron, only two (+1/2 and -1/2 states) electrons can be in any given state at once. (PoorLeno / Wikimedia Commons)

    The Pauli exclusion principle, which only applies to fermions, not bosons, states, explicitly, that in any quantum system, no two fermions can occupy the same quantum state. It means that if you take, say, an electron and put it in a particular location, it will have a set of properties in that state: energy levels, angular momentum, etc.

    If you take a second electron and add it to your system, however, in the same location, it is forbidden from having those same quantum numbers. It must either occupy a different energy level, have a different spin (+1/2 if the first was -1/2, for example), or occupy a different location in space. This principle explains why the periodic table is arranged as it is.

    This is why atoms have different properties, why they bind together in the intricate combinations that they do, and why each element in the periodic table is unique: because the electron configuration of each type of atom is unlike any other.

    Periodic table Sept 2017. Wikipedia

    5
    The three valence quarks of a proton contribute to its spin, but so do the gluons, sea quarks and antiquarks, and orbital angular momentum as well. The electrostatic repulsion and the attractive strong nuclear force, in tandem, are what give the proton its size.(APS/Alan Stonebraker)

    Protons and neutrons are similar. Despite being composite particles, made up of three quarks apiece, they behave as single, individual fermions themselves. They, too, obey the Pauli Exclusion Principle, and no two protons or neutrons can occupy the same quantum state. The fact that electrons are fermions is what keeps white dwarf stars from collapsing under their own gravity; the fact that neutrons are fermions prevents neutron stars from collapsing further. The Pauli exclusion principle responsible for atomic structure is responsible for keeping the densest physical objects of all from becoming black holes.

    6
    A white dwarf, a neutron star or even a strange quark star are all still made of fermions. The Pauli degeneracy pressure helps hold up the stellar remnant against gravitational collapse, preventing a black hole from forming. (CXC/M. Weiss)

    And yet, when you look at the white dwarf stars we have in the Universe, they cap out at around 1.4 solar masses: the Chandrasekhar mass limit. The quantum degeneracy pressure arising from the fact that no two electrons can occupy the same quantum state is what prevents black holes from forming until that threshold is crossed.

    In neutron stars, there should be a similar mass limit: the Tolman-Oppenheimer-Volkoff limit. Initially, it was anticipated that this would be about the same as the Chandrasekhar mass limit, since the underlying physics is the same. Sure, it’s not specifically electrons that are providing the quantum degeneracy pressure, but the principle (and the equations) are pretty much the same. But we now know, from our observations, that there are neutron stars much more massive than 1.4 solar masses, perhaps rising as high as 2.3 or 2.5 times the mass of our Sun.

    7
    A neutron star is one of the densest collections of matter in the Universe, but there is an upper limit to their mass. Exceed it, and the neutron star will further collapse to form a black hole. (ESO/Luís Calçada)

    And yet, there are reasons for the differences. In neutron stars, the strong nuclear force plays a role, causing a larger effective repulsion than for a simple model of degenerate, cold gases of fermions (which is what’s relevant for electrons). For the past 20+ years, calculations of the theoretical mass limit for neutron stars have varied tremendously: from about 1.5 to 3.0 solar masses. The reason for the uncertainty has been the unknowns surrounding the behavior of extremely dense matter, like the densities you’ll find inside an atomic nucleus, are not well known.

    Or rather, these unknowns plagued us for a long time, until a new paper last month changed all of that. With the publication of their new paper in Nature, The pressure distribution inside the proton, coauthors V. D. Burkert, L. Elouadrhiri, and F. X. Girod may have just achieved the key advance needed to understand what’s happening inside neutron stars.

    8
    A better understanding of the internal structure of a proton, including how the “sea” quarks and gluons are distributed, has been achieved through both experimental improvements and new theoretical developments in tandem. These results apply to neutrons as well. (Brookhaven National Laboratory)

    Our models of nucleons like protons and neutrons have improved tremendously over the past few decades, coincident with improvements in both computational and experimental techniques. The latest research uses an old technique known as Compton scattering, where electrons are fired at the internal structure of a proton to probe its structure. When an electron interacts (electromagnetically) with a quark, it emits a high-energy photon, along with a scattered electron and leads to nuclear recoil. By measuring all three products, you can calculate the pressure distribution experienced by the quarks inside the atomic nucleus. In a shocking find, the average peak pressure, near the center of the proton, comes out to 10³⁵ pascals: a greater pressure than neutron stars experience anywhere.

    9
    At large distances, quarks are confined within a nucleon. But at short distances, there’s a repulsive pressure that prevents other quarks-and-nuclei from getting too close to each individual proton (or, by extension, neutron). (The quark-confinement-induced pressure distribution in the proton by V.D. Burkert, L. Elouadrhiri, and F.X. Girod)

    In other words, by understanding how the pressure distribution inside an individual nucleon works, we can calculate when and under what conditions that pressure can be overcome. Although the experiment was only done for protons, the results should be analogous for neutrons, too, meaning that, in the future, we should be able to calculate a more exact limit for the masses of neutron stars.

    10
    The masses of stellar remnants are measured in many different ways. This graphic shows the masses for black holes detected through electromagnetic observations (purple); the black holes measured by gravitational-wave observations (blue); neutron stars measured with electromagnetic observations (yellow); and the masses of the neutron stars that merged in an event called GW170817, which were detected in gravitational waves (orange). The result of the merger was a neutron star, briefly, that swiftly became a black hole. (LIGO-Virgo/Frank Elavsky/Northwestern)

    The measurements of the enormous pressure inside the proton, as well as the distribution of that pressure, show us what’s responsible for preventing the collapse of neutron stars. It’s the internal pressure inside each proton and neutron, arising from the strong force, that holds up neutron stars when white dwarfs have long given out. Determining exactly where that mass threshold is just got a great boost. Rather than solely relying on astrophysical observations, the experimental side of nuclear physics may provide the guidepost we need to theoretically understand where the limits of neutron stars actually lie.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 12:35 pm on June 20, 2018 Permalink | Reply
    Tags: , , Basic Research, , , XMM-Newton Finds Missing Intergalactic Material   

    From Harvard-Smithsonian Center for Astrophysics: “XMM-Newton Finds Missing Intergalactic Material” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    June 20, 2018
    Megan Watzke
    Harvard-Smithsonian Center for Astrophysics
    +1 617-496-7998
    mwatzke@cfa.harvard.edu

    Peter Edmonds
    Harvard-Smithsonian Center for Astrophysics
    +1 617-571-7279
    pedmonds@cfa.harvard.edu

    ESA/XMM Newton

    1
    This figure shows the filamentary structure of the hot gas that represents part of the warm-hot intergalactic medium (WHIM). It is based on a simulation extending over more than 200 million light years. The red and orange regions have the highest densities & the green regions have lower densities. Princeton University/Renyue Cen

    2
    Astronomers have used ESA’s XMM-Newton space observatory (lower right) to detect the WHIM. The white box encloses the filamentary structure of the hot gas that represents part of the WHIM. It is based on a cosmological simulation extending over more than 200 million light years. The red and orange regions have the highest densities & the green regions have lower densities. The discovery was made using observations of a distant quasar – a supermassive black hole that is actively devouring matter and shining brightly from X-rays to radio waves (upper left). The team found the signature of oxygen in the WHIM lying between the observatory and the quasar, at two different locations along the line of sight (shown in the spectrum in the lower left with green and magenta arrows). The blue arrows are signatures of nitrogen in our Milky Way galaxy.
    Illustrations and composition: ESA / ATG medialab; data: ESA / XMM-Newton / F. Nicastro et al. 2018; cosmological simulation: Princeton University/Renyue Cen

    3
    The mysterious dark matter and dark energy make up about 25 and 70 percent of our cosmos respectively, and ordinary matter, which makes up everything we see, including galaxies, stars and planets – amounts to only about five percent. However, stars in galaxies across the Universe only make up about seven percent of all ordinary matter and the cold and hot interstellar gas that permeates galaxies and galaxy clusters together accounts for only about 11 percent. Most of the Universe’s ordinary matter, or baryons, lurks in the cosmic web, the filamentary distribution of both dark and ordinary matter that extends throughout the Universe. In the past astronomers were able to locate a good chunk of the cool and warm parts of this intergalactic material (about 43 percent of all baryons in total). Astronomers have now used ESA’s XMM-Newton space observatory to detect the hot component of this intergalactic material along the line of sight to a quasar. The amount of hot intergalactic gas detected in these observations amounts up to 40 percent of all baryons in the Universe, closing the gap in the overall budget of ordinary matter in the cosmos. ESA

    After a nearly twenty-year long game of cosmic hide-and-seek, astronomers using ESA’s XMM-Newton space observatory have finally found evidence of hot, diffuse gas permeating the cosmos, closing a puzzling gap in the overall budget of ‘normal’ matter in the Universe.

    While the mysterious dark matter and dark energy make up about 25 and 70 percent of our cosmos respectively, the ordinary matter that makes up everything we see – from stars and galaxies to planets and people – amounts to only about five percent.

    But even this five percent turns out to be hard to track down.

    The total amount of ordinary matter, which astronomers refer to as baryons, can be estimated from observations of the Cosmic Microwave Background [CMB], which is the most ancient light in the history of the Universe, dating back to only about 380,000 years after the Big Bang.

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    Observations of very distant galaxies allow astronomers to follow the evolution of this matter throughout the Universe’s first couple of billions of years. After that, however, more than half of it seemed to have gone missing.

    “The missing baryons represent one of the biggest mysteries in modern astrophysics,” explains Fabrizio Nicastro, lead author of the paper presenting a solution to the mystery, published today in Nature. Nicastro is from the INAF-Osservatorio Astronomico di Roma, Italy, and the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass.

    “We know this matter must be out there, we see it in the early Universe, but then we can no longer get hold of it. Where did it go?”

    Counting the population of stars in galaxies across the Universe, plus the interstellar gas that permeates galaxies – the raw material to create stars – only gets as far as a mere ten percent of all ordinary matter. Adding up the hot, diffuse gas in the haloes that encompass galaxies and the even hotter gas that fills galaxy clusters, which are the largest cosmic structures held together by gravity, raises the inventory to less than twenty percent.

    This is not surprising: stars, galaxies and galaxy clusters form in the densest knots of the cosmic web, the filamentary distribution of both dark and ordinary matter that extends throughout the Universe. While these sites are dense, they are also rare, so not the best spots to look for the majority of cosmic matter.

    Astronomers suspected that the ‘missing’ baryons must be lurking in the ubiquitous filaments of this cosmic web, where matter is, however, less dense and therefore more challenging to observe. Using different techniques over the years, they were able to locate a good chunk of this intergalactic material – mainly its cool and warm components – bringing up the total budget to a respectable 60 percent, but leaving the overall mystery still unsolved.

    Nicastro and many other astronomers around the world have been on the tracks of the remaining baryons for almost two decades, ever since X-ray observatories such as ESA’s XMM-Newton and NASA’s Chandra X-ray Observatory became available to the scientific community.

    Observing in this portion of the electromagnetic spectrum, they can detect hot intergalactic gas, with temperatures around a million degrees or more, that is blocking the X-rays emitted by even more distant sources.

    For this project, Nicastro and his collaborators used XMM-Newton to look at a quasar – a massive galaxy with a supermassive black hole at its center that is actively devouring matter and shining brightly from X-rays to radio waves. They observed this quasar, whose light takes more than four billion years to reach us, for a total of 18 days, split between 2015 and 2017, in the longest X-ray observation ever performed of such a source.

    “After combing through the data, we succeeded at finding the signature of oxygen in the hot intergalactic gas between us and the distant quasar, at two different locations along the line of sight,” says Nicastro.

    “This is happening because there are huge reservoirs of material – including oxygen – lying there, and just in the amount we were expecting, so we finally can close the gap in the baryon budget of the Universe.”

    This extraordinary result is the beginning of a new quest. Observations of different sources across the sky are needed to confirm whether these findings are truly universal, and to further investigate the physical state of this long-sought-for matter.

    Fabrizio and his colleagues are planning to study more quasars with XMM-Newton and Chandra in the coming years. To fully explore the distribution and properties of this so-called warm-hot intergalactic medium, however, more sensitive instruments will be needed, like ESA’s Athena, the Advanced Telescope for High-Energy Astrophysics, scheduled for launch in 2028.

    ESA/Athena spacecraft depiction

    “The discovery of the missing baryons with XMM-Newton is the exciting first step to fully characterize the circumstances and structures in which these baryons are found,” says co-author Jelle Kaastra from the Netherlands Institute for Space Research.

    “For the next steps, we will need the much higher sensitivity of Athena, which has the study of the warm-hot intergalactic medium as one of its main goals, to improve our understanding of how structures grow in the history of the Universe.”

    “It makes us very proud that XMM-Newton was able to discover the weak signal of this long elusive material, hidden in a million-degree hot fog that extends through intergalactic space for hundreds of thousands of light years,” says Norbert Schartel, XMM-Newton project scientist at ESA.

    “Now that we know these baryons are no longer missing, we can’t wait to study them in greater detail.”

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
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