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  • richardmitnick 11:29 am on July 21, 2019 Permalink | Reply
    Tags: , , , , , , FRB's Fast radio Bursts, Is anyone out there?, , , Shelley Wright of UCSD and Niroseti at UCSC Lick Observatory's Nickel Telescope,   

    From WIRED: “An Alien-Hunting Tech Mogul May Help Solve a Space Mystery” 

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    From WIRED

    07.21.19
    Katia Moskvitch

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    Yuri Milner. Billy H.C. Kwok/Getty Images

    In spring 2007, David Narkevic, a physics student at West Virginia University, was sifting through reams of data churned out by the Parkes telescope—a dish in Australia that had been tracking pulsars, the collapsed, rapidly spinning cores of once massive stars.

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    His professor, astrophysicist Duncan Lorimer, had asked him to search for a recently discovered type of ultra-rapid pulsar dubbed RRAT. But buried among the mountain of data, Narkevic found an odd signal that seemed to come from the direction of our neighboring galaxy, the Small Magellanic Cloud.

    smc

    Small Magellanic Cloud. NASA/ESA Hubble and ESO/Digitized Sky Survey 2

    The signal was unlike anything Lorimer had encountered before. Although it flashed only briefly, for just five milliseconds, it was 10 billion times brighter than a typical pulsar in the Milky Way galaxy. It was emitting in a millisecond as much energy as the sun emits in a month.

    What Narkevic and Lorimer found was the first of many bizarre, ultra-powerful flashes detected by our telescopes. For years the flashes first seemed either improbable or at least vanishingly rare. But now researchers have observed more than 80 of these Fast Radio Bursts, or FRBs. While astronomers once thought that what would be later dubbed the “Lorimer Burst” was a one-off, they now agree that there’s probably one FRB happening somewhere in the universe nearly every second.

    And the reason for this sudden glut of discoveries? Aliens. Well, not aliens per se, but the search for them. Among the scores of astronomers and researchers working tirelessly to uncover these enigmatic signals is an eccentric Russian billionaire who, in his relentless hunt for extraterrestrial life, has ended up partly bankrolling one of the most complex and far-reaching scans of our universe ever attempted.

    Ever since Narkevic spotted the first burst, scientists have been wondering what could produce these mesmerizing flashes in deep space. The list of possible sources is long, ranging from the theoretical to the simply unfathomable: colliding black holes, white holes, merging neutron stars, exploding stars, dark matter, rapidly spinning magnetars, and malfunctioning microwaves have all been proposed as possible sources.

    While some theories can now be rejected, many live on. Finally though, after more than a decade of searching, a new generation of telescopes is coming online that could help researchers to understand the mechanism that is producing these ultra-powerful bursts. In two recent back-to-back papers, one published last week and one today, two different arrays of radio antennas—the Australian Square Kilometer Array Pathfinder (ASKAP) and Caltech’s Deep Synoptic Array 10 at the Owens Valley Radio Observatory (OVRO) in the US—have for the first time ever been able to precisely locate two different examples of these mysterious one-off FRBs.

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    Caltech’s Deep Synoptic Array 10 dish array at Owens Valley Radio Observatory, near Big Pine, California USA, Altitude 1,222 m (4,009 ft

    Physicists are now expecting that two other new telescopes—Chime (the Canadian Hydrogen Intensity Mapping Experiment) in Canada and MeerKAT in South Africa—will finally tell us what produces these powerful radio bursts.

    CHIME Canadian Hydrogen Intensity Mapping Experiment -A partnership between the University of British Columbia, the University of Toronto, McGill University, Yale and the National Research Council in British Columbia, at the Dominion Radio Astrophysical Observatory in Penticton, British Columbia, CA Altitude 545 m (1,788 ft)

    SKA Meerkat telescope(s), 90 km outside the small Northern Cape town of Carnarvon, SA

    But Narkevic’s and Lorimer’s discovery nearly got binned. For a few months after they first spotted the unusually bright burst, it looked like the findings wouldn’t make it any further than Lorimer’s office walls, just beyond the banks of the Monongahela River that slices through the city of Morgantown in West Virginia.

    Soon after detecting the burst, Lorimer asked his former graduate adviser Matthew Bailes, an astronomer at Swinburne University in Melbourne, to help him plot the signal—which to astronomers is now a famous and extremely bright energy peak, rising well above the power of any known pulsar. The burst seemed to come from much, much further away than where the Parkes telescope would usually find pulsars; in this case, probably from another galaxy, potentially billions of light-years away.

    “It just looked beautiful. I was like, ‘Whoa, that’s amazing.’ We nearly fell off our chairs,” recalls Bailes. “I had trouble sleeping that night because I thought if this thing is really that far away and that insanely bright, it’s an amazing discovery. But it better be right.”

    Within weeks, Lorimer and Bailes crafted a paper and sent it to Nature—and swiftly received a rejection. In a reply, a Nature editor raised concerns that there had been only one event, which appeared way brighter than seemed possible. Bailes was disappointed, but he had been in a worse situation before. Sixteen years earlier, he and fellow astronomer Andrew Lyne had submitted a paper claiming to have spotted the first ever planet orbiting another star—and not just any star but a pulsar. The scientific discovery turned out to be a fluke of their telescope. Months later, Lyne had to stand up in front of a large audience at an American Astronomical Society conference and announce their mistake. “It’s science. Anything can happen,” says Bailes. This time around, Bailes and Lorimer were certain that they had it right and decided to send their FRB paper to another journal, Science.

    After it was published, the paper immediately stirred interest; some scientists even wondered whether the mysterious flash was an alien communication. This wasn’t the first time that astronomers had reached for aliens as the answer for a seemingly inexplicable signal from space; in 1967, when researchers detected what turned out to be the first pulsar, they also wondered whether it could be a sign of intelligent life.

    Just like Narkevic decades later, Cambridge graduate student Jocelyn Bell had stumbled across a startling signal in the reams of data gathered by a radio array in rural Cambridgeshire.

    Women in STEM – Dame Susan Jocelyn Bell Burnell

    Dame Susan Jocelyn Bell Burnell, discovered pulsars with radio astronomy. Jocelyn Bell at the Mullard Radio Astronomy Observatory, Cambridge University, taken for the Daily Herald newspaper in 1968. Denied the Nobel.

    Dame Susan Jocelyn Bell Burnell at work on first plusar chart 1967 pictured working at the Four Acre Array in 1967. Image courtesy of Mullard Radio Astronomy Observatory.

    Dame Susan Jocelyn Bell Burnell 2009

    Dame Susan Jocelyn Bell Burnell (1943 – ), still working from http://www. famousirishscientists.weebly.com

    Not much of the array is left today; in the fields near the university where it once stood, there’s an overgrown hedge, hiding a collection of wonky, sad-looking wooden poles that were once covered in a web of copper wire designed to detect radio waves from faraway sources. The wire has long been stolen and sold on to scrap metal dealers.

    “We did seriously consider the possibility of aliens,” Bell says, now an emeritus professor at Oxford University. Tellingly, the first pulsar was half-jokingly dubbed LGM-1 —for little green men. With only half a year left until the defense of her PhD thesis, she was less than thrilled that “some silly lot of little green men” were using her telescope and her frequency to signal to planet Earth. Why would aliens “be using a daft technique signaling to what was probably still a rather inconspicuous planet?” she once wrote in an article for Cosmic Search Magazine.

    Just a few weeks later, however, Bell spotted a second pulsar, and then a third just as she got engaged, in January 1968. Then, as she was defending her thesis and days before her wedding, she discovered a fourth signal in yet another part of the sky. Proof that pulsars had to be a natural phenomenon of an astrophysical origin, not a signal from intelligent life. Each new signal made the prospect even more unlikely that groups of aliens, separated by the vastness of the space, were somehow coordinating their efforts to send a message to an uninteresting hunk of rock on the outskirts of the Milky Way.

    Lorimer wasn’t so lucky. After the first burst, six years would pass without another detection. Many scientists began to lose interest. The microwave explanation persisted for a while, says Lorimer, as skeptics sneered at the notion of finding a burst that was observed only once. It didn’t help that in 2010 Parkes detected 16 similar pulses, which were quickly proven to be indeed caused by the door of a nearby microwave oven that had been opened suddenly during its heating cycle.

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    Yuri Milner on stage with Mark Zuckerberg at a Breakthrough Prize event in 2017. Kimberly White/Getty Images

    When Avi Loeb first read of Lorimer’s unusual discovery, he too wondered if it was nothing more than the result of some errant wiring or miscalibrated computer. The chair of the astronomy department at Harvard happened to be in Melbourne in November 2007, just as Lorimer’s and Bailes’ paper appeared in Science, so he had a chance to discuss the odd burst with Bailes. Loeb thought the radio flash was a compelling enigma—but not much more than that.

    Still, that same year Loeb wrote a theoretical paper arguing that radio telescopes built to detect very specific hydrogen emissions from the early universe would also be able to eavesdrop on radio signals from alien civilizations up to about 10 light-years away. “We have been broadcasting for a century—so another civilization with the same arrays can see us from a distance out to 50 light-years,” was Loeb’s reasoning. He followed up with another paper on the search for artificial lights in the solar system. There, Loeb showed that a city as bright as Tokyo could be detected with the Hubble Space Telescope even if it was located right at the edge of the solar system. In yet another paper he argued how to detect industrial pollution in planetary atmospheres.

    Ever since he was a little boy growing up in Israel, Loeb has been fascinated with life—on Earth and elsewhere in the universe. “Currently, the search for microbial life is part of the mainstream in astronomy—people are looking for the chemical fingerprints of primitive life in the atmosphere of exoplanets,” says Loeb, who first dabbled in philosophy before his degree in physics.

    But the search for intelligent life beyond Earth should also be part of the mainstream, he argues. “There is a taboo, it’s a psychological and sociological problem that people have. It’s because there is the baggage of science fiction and UFO reports, both of which have nothing to do with what actually goes on out there in space,” he adds. He’s frustrated with having to explain—and defend—his point of view. After all, he says, billions have been poured into the search for dark matter over decades with zero results. Should the search for extraterrestrial intelligence, more commonly known as SETI, be regarded as even more fringe than this fruitless search?

    Lorimer didn’t follow Loeb’s SETI papers closely. After six long and frustrating years, his luck turned in 2013, when a group of his colleagues—including Bailes—spotted four other bright radio flashes in Parkes’ data. Lorimer felt vindicated and relieved. More detections followed and the researchers were on a roll: At long last, FRBs had been confirmed as a real thing. After the first event was dubbed “Lorimer’s Burst,” it swiftly made it onto the physics and astronomy curricula of universities around the globe. In physics circles, Lorimer was elevated to the position of a minor celebrity.

    Keeping an eye on events from a distance was Loeb. One evening in February 2014, at a dinner in Boston, he started chatting to a charismatic Russian-Israeli called Yuri Milner, a billionaire technology investor with a background in physics and a well-known name in Silicon Valley. Ever since he could remember, Milner had been fascinated with life beyond Earth, a subject close to Loeb’s heart; the two instantly hit it off.

    Milner came to see Loeb again in May the following year, at Harvard, and asked the academic how long it would take to travel to Alpha Centauri, the star system closest to Earth.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    Loeb replied he would need half a year to identify the technology that would allow humans to get there in their lifetime. Milner then asked Loeb to lead Breakthrough Starshot, one of five Breakthrough Initiatives the Russian oligarch was about to announce in a few weeks—backed by $100 million of his own money and all designed to support SETI.

    Breakthrough Starshot Initiative

    Breakthrough Starshot

    ESO 3.6m telescope & HARPS at LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    SPACEOBS, the San Pedro de Atacama Celestial Explorations Observatory is located at 2450m above sea level, north of the Atacama Desert, in Chile, near to the village of San Pedro de Atacama and close to the border with Bolivia and Argentina

    SNO Sierra Nevada Observatory is a high elevation observatory 2900m above the sea level located in the Sierra Nevada mountain range in Granada Spain and operated maintained and supplied by IAC

    Teide Observatory in Tenerife Spain, home of two 40 cm LCO telescopes

    Observatori Astronòmic del Montsec (OAdM), located in the town of Sant Esteve de la Sarga (Pallars Jussà), 1,570 meters on the sea level

    Bayfordbury Observatory,approximately 6 miles from the main campus of the University of Hertfordshire

    Fast-forward six months, and at the end of December 2015 Loeb got a call asking him to prepare a presentation summarizing his recommended technology for the Alpha Centauri trip. Loeb was visiting Israel and about to head on a weekend trip to a goat farm in the southern part of the country. “The following morning, I was sitting next to the reception of the farm—the only location with internet connectivity—and typing the PowerPoint presentation that contemplated a lightsail technology for Yuri’s project,” says Loeb. He presented it at Milner’s home in Moscow two weeks later, and the Breakthrough Initiatives were announced with fanfare in July 2015.

    The initiatives were an adrenaline shot in the arm of the SETI movement—the largest ever private cash injection into the search for aliens. One of the five projects is Breakthrough Listen, which was championed, among others, by the famous astronomer Stephen Hawking (who has died since) and British astronomer royal Martin Rees.

    Breakthrough Listen Project

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    UC Observatories Lick Autmated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA




    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia


    SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    Newly added

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four 12m optical reflectors for gamma-ray astronomy in the GeV – TeV energy range. Located at Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona, US in AZ, USA, Altitude 2,606 m (8,550 ft)

    Echoing the film Contact, with Jodie Foster playing an astronomer listening out for broadcasts from aliens (loosely based on real-life SETI astronomer Jill Tarter), the project uses radio telescopes around the world to look for any signals from extraterrestrial intelligence.

    Jill Tarter Image courtesy of Jill Tarter

    After the Breakthrough Initiatives were announced, Milner’s money quickly got invested into the deployment of cutting-edge technology—such as computer storage and new receivers—at existing radio telescopes, including Green Bank in West Virginia and Parkes in Australia; whether the astronomers using these observatories believed in alien life or not, they welcomed the investment with open arms. It didn’t take long to receive the first scientific returns.

    After the Breakthrough Initiatives were announced, Milner’s money quickly got invested into the deployment of cutting-edge technology—such as computer storage and new receivers—at existing radio telescopes, including Green Bank in West Virginia and Parkes in Australia; whether the astronomers using these observatories believed in alien life or not, they welcomed the investment with open arms. It didn’t take long to receive the first scientific returns.

    In August 2015 one of the previously spotted FRBs decided to make a repeat appearance, triggering headlines worldwide because it was so incredibly powerful, brighter than the Lorimer Burst and any other FRB. It was dubbed “the repeater” and is also known as the Spitler Burst, because it was first discovered by astronomer Laura Spitler of the Max Planck Institute for Radio Astronomy in Bonn, Germany.

    Max Planck Institute for Radio Astronomy

    Max Planck Institute for Radio Astronomy Bonn Germany

    Over the next few months, the burst flashed many more times, not regularly, but often enough to allow researchers to determine its host galaxy and consider its possible source—likely a highly magnetized, young, rapidly spinning neutron star (or magnetar).

    This localization was done with the Very Large Array (VLA), a group of 27 radio dishes in New Mexico that feature heavily in the film Contact. But the infrastructure at Green Bank Telescope upgraded by Breakthrough Listen caught the repeating flashes many more times, says Lorimer—allowing researchers to study its host galaxy more in detail. “It’s wonderful—they have a mission to find ET, but along the way they want to show that this is producing other useful results for the scientific community,” he adds. Detecting FRBs has quickly become one of the main objectives of Breakthrough Listen.

    Netting the repeater was both a boon and a hindrance—on the one hand, it eliminated models that cataclysmic events such as supernova explosions were causing FRBs; after all, these can happen only once. On the other hand, it deepened the mystery. The repeater lives in a small galaxy with a lot of star formation—the kind of environment where a neutron star could be born, hence the magnetar model. But what about all the other FRBs that don’t repeat?

    Researchers started to think that perhaps there were different types of these bursts, each with its own source. Scientific conferences still buzz with talks of mights and might-nots, with physicists eagerly debating possible sources of FRBs in corridors and at conference bars. In March 2017, Loeb caused a media frenzy by suggesting that FRBs could actually be of alien origin—solar-powered radio transmitters that might be interstellar light sails pushing huge spaceships across galaxies.

    That Parkes is part of the SETI project is obvious to any visitor. Walking up the flight of stairs to the circular operating tower below the dish, every button, every door, and every wall nostalgically screams 1960s, until you reach the control room full of modern screens where astronomers remotely control the antenna to observe pulsars.

    Up another flight of stairs is the data storage room, stacked with columns and columns of computer drives full of blinking lights. One thick column of hard drives is flashing neon blue, put there by Breakthrough Listen as part of a cutting-edge recording system designed to help astronomers search for every possible radio signal in 12 hours of data, much more than ever before. Bailes, who now splits his time between FRB search and Breakthrough Listen, takes a smiling selfie in front of Milner’s drives.

    While many early FRB discoveries were made with veteran telescopes—single mega dishes like Parkes and Green Bank—new telescopes, some with the financial backing of Breakthrough Listen, are now revolutionizing the FRB field.

    Deep in South African’s semi-desert region of the Karoo, eight hours by car from Cape Town, stands an array of 64 dishes, permanently tracking space. They are much smaller than their mega-dish cousins, and all work in unison. This is MeerKAT [above], another instrument in Breakthrough Listen’s growing worldwide network of giant telescopes. Together with a couple of other next-generation instruments, this observatory might hopefully tell us one day, probably in the next decade, what FRBs really are.

    The name MeerKAT means “More KAT,” a follow up to KAT 7, the Karoo Array Telescope of seven antennas—although real meerkats do lurk around the remote site, sharing the space with wild donkeys, horses, snakes, scorpions and kudus, moose-sized mammals with long, spiraling antlers. Visitors to MeerKAT are told to wear safety leather boots with steel toes as a precaution against snakes and scorpions. They’re also warned about the kudus, which are very protective of their calves and recently attacked the pickup truck of a security guard, turning him and his car over. Around MeerKAT there is total radio silence; all visitors have to switch off their phones and laptops. The only place with connectivity is an underground “bunker” shielded by 30-centimeter-thick walls and a heavy metal door to protect the sensitive antennas from any human-made interference.

    MeerKAT is one of the two precursors to a much bigger future radio observatory—the SKA, or Square Kilometer Array.

    SKA Square Kilometer Array

    SKA South Africa

    Once SKA is complete, scientists will have added another 131 antennas in the Karoo. The first SKA dish has just been shipped to the MeerKAT site from China. Each antenna will take several weeks to assemble, followed by a few more months of testing to see whether it actually works the way it should. If all goes well, more will be commissioned, built, and shipped to this faraway place, where during the day the dominant color is brown; as the sun sets, however, the MeerKAT dishes dance in an incredible palette of purples, reds, and pinks, as they welcome the Milky Way stretching its starry path just above. MeerKAT will soon be an incredible FRB machine, says Bailes.

    There is another SKA precursor—ASKAP in Australia.

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    Back in 2007, when Lorimer was mulling over the Nature rejection, Ryan Shannon was finishing his PhD in physics at Cornell University in New York—sharing the office with Laura Spitler, who would later discover the Spitler Burst. Shannon had come to the US from Canada, growing up in a small town in British Columbia. About half an hour drive from his home is the Dominion and Radio Astronomical Observatory (DRAO)—a relatively small facility that was involved in building equipment for the VLA.

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

    Subconsciously, says Shannon, DRAO must have impacted his choice of career. And it was at DRAO that a few years later a totally new telescope—Chime [above]—would be built that would greatly impact the nascent field of FRB research. But in 2007 that was still to come. After graduating from Cornell in 2011, Shannon decided not to stay close to home—“something my mum would’ve wanted.” Instead, he moved to Australia and ultimately to Swinburne University on the outskirts of Melbourne.

    Shannon joined Bailes’ team in 2017—and by then astronomers had begun to understand why they weren’t detecting more FRBs, even though they were already estimating that these flashes were happening hundreds of times every day, if not more. “Our big radio telescopes don’t have wide fields of view, they can’t see the entire sky—that’s why we missed nearly all FRBs in the first decade of realizing these things exist,” says Shannon.

    When he, Bailes, and other FRB hunters saw the ultra-bright repeater, the Spitler Burst, they understood that there were fast radio bursts which could be found even without gigantic telescopes like Parkes, by using instruments that have a wider field of view. So they started building ASKAP [above]—a new observatory conceived in 2012 and recently completed in the remote Australian outback. It sports 36 dishes with a 12-meter diameter each, and just like with MeerKAT, they all work together.

    To get to ASKAP, in a very sparsely populated area in the Murchison Shire of Western Australia, one has to first fly to Perth, change for a smaller plane bound for Murchison, then squeeze into a really tiny single propeller plane, or drive for five hours across 150 kilometers of dirt roads. “When it rains, it turns to mud, and you can’t drive there,” says Shannon, who went to the ASKAP site twice, to introduce the local indigenous population to the new telescope constructed—with permission—on their land and see the remote, next-generation ultra-sensitive radio observatory for himself.

    MeerKAT and ASKAP bring two very different technological approaches to the hunt for FRBs. Both observatories look at the southern sky, which makes it possible to see the Milky Way’s bright core much better than in the northern hemisphere; they complement old but much upgraded observatories like Parkes and Arecibo in South America. But the MeerKAT dishes have highly sensitive receivers which are able to detect very distant objects, while ASKAP’s novel multi-pixel receivers on each dish offer a much wider field of view, enabling the telescope to find nearby FRBs more often.

    “ASKAP’s dishes are less sensitive, but we can observe a much larger portion of the sky,” says Shannon. “So ASKAP is going to be able to see things that are usually intrinsically brighter.” Together, the two precursors will be hunting for different parts of the FRB population—since “you want to understand the entire population to know the big picture.”

    MeerKAT only started taking data in February, but ASKAP has been busy scanning the universe for FRBs for a few years now. Not only has it already spotted about 30 new bursts, but in a new paper just released in Science, Shannon and colleagues have detailed a new way to localize them despite their short duration, which is a big and important step toward being able to determine what triggers this ultra-bright radiation. Think of ASKAP’s antennas as the eye of a fly; they can scan a wide patch of the sky to spot as many bursts as possible, but the antennas can all be made to point instantly in the same direction. This way, they make an image of the sky in real time, and spot a millisecond-long FRB as it washes over Earth. That’s what Shannon and his colleagues have done, and for the first time ever, managed to net one burst they named FRB 180924 and pinpoint its host galaxy, some 4 billion light-years away, all in real time.

    Another team, at Caltech’s Owens Valley Radio Observatory (OVRO) in the Sierra Nevada mountains in California, have also just caught a new burst and traced it back to its source, a galaxy 7.9 billion light years away.

    Caltech’s Deep Synoptic Array 10 dish array at Owens Valley Radio Observatory, near Big Pine, California USA, Altitude 1,222 m (4,009 ft

    And just like Shannon, they didn’t do it with a single dish telescope but a recently built array of 10 4.5-meter antennas called the Deep Synoptic Array-10. The antennas act together like a mile-wide dish to cover an area on the sky the size of 150 full moons. The telescope’s software then processes an amount of data equivalent to a DVD every second. The array is a precursor for the Deep Synoptic Array that, when built by 2021, will sport 110 radio dishes, and may be able to detect and locate more than 100 FRBs every year.

    What both ASKAP’s and OVRO’s teams found was that their presumably one-off bursts originated in galaxies very different from the home of the first FRB repeater. Both come from galaxies with very little star formation, similar to the Milky Way and very different from the home of the repeater, where stars are born at a rate of about a hundred times faster. The discoveries show that “every galaxy, even a run-of-the-mill galaxy like our Milky Way, can generate an FRB,” says Vikram Ravi, an astronomer at Caltech and part of the OVRO team.

    But the findings also mean that the magnetar model, accepted by many as the source of the repeating burst, does not really work for these one-off flashes. Perhaps, Shannon says, ASKAP’s burst could be the result of a merger of two neutron stars, similar to the one spotted two years ago by the gravitational wave detectors LIGO and Virgo in the US and Italy, because both host galaxies are very similar. “It’s a bit spooky that way,” says Shannon. One thing is clear though, he adds: The findings show that there is likely more than one type of FRBs.

    Back in Shannon’s hometown in Canada, the excitement has also been growing exponentially because of CHIME. Constructed at the same time as MeerKAT and ASKAP, this is a very different observatory; it has no dishes but antennas in the form of long buckets designed to capture light. In January, the CHIME team reported the detection of the second FRB repeater and 12 non-repeating FRBs. CHIME is expected to find many, many more bursts, and with ASKAP, MeerKAT and CHIME working together, astronomers hope to understand the true nature of the enigmatic radio flashes very soon.

    But will they fulfill Milner’s dream and successfully complete SETI, the search for extraterrestrial intelligence? Lorimer says that scientists hunting for FRBs and pulsars have for decades been working closely with colleagues involved in SETI projects.

    After all, Loeb’s models for different—alien—origins of FRBs are not fundamentally wrong. “The energetics when you consider what we know from the observations are consistent and there’s nothing wrong with that,” says Lorimer. “And as part of the scientific method, you definitely want to encourage those ideas.” He personally prefers to find the simplest natural explanation for the phenomena he observes in space—but until we manage to directly observe the source of these FRBs, all theoretical ideas should stand, as long as they are scientifically sound—whether they involve aliens or not.

    Any image repeats in this post were required for complete coverage.

    See the full article here .

    Totally missing from this article on SETI-

    SETI Institute


    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA, Altitude 986 m (3,235 ft)

    UCSC alumna Shelley Wright, now an assistant professor of physics at UC San Diego, discusses the dichroic filter of the NIROSETI instrument. (Photo by Laurie Hatch).jpg

    Shelley Wright of UC San Diego, with NIROSETI, developed at U Toronto, at the 1-meter Nickel Telescope at Lick Observatory at UC Santa Cruz

    Laser SETI, the future of SETI Institute research

    SETI@home, a BOINC project originated in the Space Science Lab at UC Berkeley

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 10:16 am on July 6, 2019 Permalink | Reply
    Tags: , , Australian Square Kilometre Array Pathfinder (ASKAP), , Caltech Owens Valley Long Wavelength Array, , , FRB's Fast radio Bursts, FRBs are surprisingly common with perhaps 2000 of them pinpricking the sky every day, One of the big issues in astrophysics he adds is that most of the matter in the universe is invisible to us., , The vast majority are one-off events   

    From COSMOS Magazine: “A decade waiting (and working), then two FRBs nailed in a week” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    06 July 2019
    Richard A Lovett

    But Australian and US astronomers took different approaches.

    1
    An artist’s impression of Australia’s ASKAP radio telescope observing fast radio bursts.
    OZGRAV, SWINBURNE UNIVERSITY OF TECHNOLOGY.

    In less than a week as June became July, two teams of radio astronomers – one in Australia, the other in the US – announced they had independently accomplished a decade-long astronomical quest: identifying the sources of powerful blasts of intergalactic radiation known as fast radio bursts (FRBs).

    FRBs are enormous blazes of radio energy that in a few milliseconds can broadcast as much energy in radio waves as the monthly output of the sun in all forms combined.

    What causes them is unknown, but it can only be something dramatic, such as a collision between neutron stars, or even a neutron stars falling into a black hole. “For a long time, there were more theories than [known] bursts,” says Keith Bannister, an astronomer with CSIRO’s Australia Telescope National Facility (ATNF) and leader of the Australian team.

    FRBs are surprisingly common, with perhaps 2000 of them pinpricking the sky every day, Bannister says, but only a tiny fraction are detectable, “because traditional radio telescopes only see a small fraction of the sky”.

    Also, the vast majority are one-off events, making it incredibly difficult to figure out what galaxy they are coming from, once they are spotted.

    In an effort to solve this problem, Bannister’s team equipped 36 identical 12-metre radio telescopes that together form the Australian Square Kilometre Array Pathfinder (ASKAP) in Western Australia with a “phased array feed” that allowed each dish to see 36 distinct patches of the sky at once, each about 200 times larger than the full moon.

    They also upgraded their software to rapidly triangulate on an FRB via 0.1 nanosecond differences in the time it takes the signal to reach the various telescopes in the array: a method, Bannister says, that allowed them to pinpoint its origin to a precision of 1/50,000th of a degree – the width of a human hair, 200 metres away.

    The US team took a different approach. Rather than retrofitting an existing telescope array, it built a new one from the ground up.

    Due to the extreme brightness of FRBs, “Keith Bannister and I both realised that we can utilise relatively insensitive but wide field-of view telescopes to try to localise them,” says its leader, Vikram Ravi, a radio astronomer at California Institute of Technology, Pasadena.

    His team therefore purchased 10 broad-field-of-view 4.5-meter radio antennas – instruments not much larger than the best satellite TV dishes – and laid them out in the Owens Valley of eastern California, at a total cost of under $US500,000.

    Caltech Owens Valley Long Wavelength Array-currently hosts LEDA, the largest correlator ever built, Owens Valley, California, Altitude 1,222 m (4,009 ft)

    “It was a shoestring experiment,” Ravi says. “I literally moved them in place and focused them by hand.” The ultimate goal, he adds, is to expand the project to include 110 such dishes.

    Finding the sources of FRBs is important for two reasons. One is simply that it helps us figure out what causes them. The FRB located by Bannister’s team, for example, came not from the centre of its galaxy, but from its outskirts – “or at least its suburbs”, Bannister says. “This means our FRB wasn’t produced by a gigantic black hole at the galaxy’s centre.”

    Ravi adds that both the FRBs come from mature, Milky Way style galaxies. That’s interesting because the only other FRB whose source has ever been identified – a repeating burster whose repeated bursts made it easier to localise – came from a very different type of galaxy. That one had 1000 times less mass but was in a “starburst” stage, in which it was forming new stars at an extremely rapid pace.

    Based on that, one theory had been that FRBs came from the deaths of such galaxies’ most giant youthful stars, which live fast and die in blazes of glory known as superluminous supernovae.

    But such gigantic explosions are uncommon in more mature galaxies, suggesting that in the case of the two FRBs identified by Bannister’s team and Ravi’s, superluminous supernovae probably didn’t play a role.

    Localising the sources of FRBs is also important, Ravi says, because FRBs can be used as probes of the distribution of matter in the universe.

    One of the big issues in astrophysics, he adds, is that most of the matter in the universe is invisible to us.

    Much of that is dark matter, an enigmatic substance to date is detected only by its gravity, but the vast bulk of normal matter is also invisible, Ravi says. All that’s known is that it’s very hot – on the order of a million degrees or more – and very diffuse, partly contained in tenuous halos around galaxies, but possibly also dispersed throughout the intergalactic medium.

    FRBs, Ravi says, offer a way to figure out where this unseen matter lies, and how it is distributed.

    That’s because as the radio burst travels through this diffuse medium, different frequencies travel at slightly different speeds. It’s not a big difference, but it’s enough that an FRB signal can become stretched as it travels, with higher frequencies travelling faster, and lower frequencies travelling slower.

    “We observe the burst arriving first at the high frequencies, then later at the low frequencies,” Ravi says, an effect that can stretch a millisecond FRB to nearly a second.

    Different parts of the signal can also reach us by different paths, in which they start out travelling in a slightly different direction than the main part of the signal, then are refracted back into our own line of sight.

    “It’s sort of like why stars twinkle,” Ravi says.

    The effect is small, but it’s a sign that the medium through which the FRB signal propagated might have been “clumpy”, rather than uniformly distributed.

    To figure all of this out, Ravi says, it’s really useful to know how far an FRB signal has been travelling before it reaches us (and to know how many other galaxies it has passed close to. That’s another reason why it’s useful to locate the source galaxies of as many such signals as possible.

    Shami Chatterjee, a radio astronomer at Cornell University, Ithaca, New York, and leader of the team that located the source of the repeating FRB, agrees.

    Bannister’s find (and by extension, Ravi’s), he says, is “a magnificent technical achievement” that should, among other things, open the floodgates to more such findings, allowing FRBs to live up to their promise as probes of the intergalactic medium.

    “Once we have a few dozen,” he says, “FRBs will be one of the only viable probes of the intergalactic medium.”

    See the full article here .


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  • richardmitnick 2:10 pm on March 10, 2019 Permalink | Reply
    Tags: , , , CHIME Canadian Hydrogen Intensity Mapping Experiment -A partnership between the University of British Columbia Dunlap Institute/CHIME Collaboration at University of Toronto McGill University Yale and , , FRB's Fast radio Bursts,   

    From Columbia University via WIRED: “Astronomers Think They Can Explain Mysterious Cosmic Bursts” 

    Columbia U bloc

    From Columbia University

    via

    Wired logo

    WIRED

    03.10.19
    Joshua Sokol

    CHIME Canadian Hydrogen Intensity Mapping Experiment -A partnership between the University of British Columbia, Dunlap Institute/CHIME Collaboration at University of Toronto, McGill University, Yale and the National Research Council in British Columbia, at the Dominion Radio Astrophysical Observatory in Penticton, British Columbia, CA

    Between this past Christmas and New Year’s Day, Brian Metzger realized he had his home to himself—no emails coming in, no classes to teach—and maybe, just maybe, the glimmer of an answer to one of astronomy’s most stubborn mysteries.

    1
    Brian Metzger and his wife, Stacey Thomas, at the 2019 Breakthrough Prize awards ceremony, where he was recognized with the New Horizons in Physics Prize. Breakthrough Prize.

    He chased hard after the lead, worried a little error could unravel everything or that someone else would put together the same pieces first. “You’re racing a little bit against the clock, because other people probably see this as well,” said Metzger, an astrophysicist at Columbia University. “It can kind of become all-consuming.”

    Along with scores of other researchers around the world, Metzger has spent the last few years brainstorming ways to understand fast radio bursts (FRBs). These are millisecond-long blips of intense and unexplained radio signals that pop up all over the sky, temporarily outshining radio pulsars in our galaxy despite being perhaps a million times farther away. Before 2013, many astrophysicists doubted that they even existed. In the years since, researchers have invented dozens of possible explanations for what might be causing them. One catalog counts 48 separate theories, a tally that until recently outnumbered the events themselves.

    An FRB theory needs two parts, roughly akin to a suspect and a weapon in a cosmic game of Clue. The suspect is an astrophysical beast that can unleash vast sums of energy. The weapon is something that will transform that energy into a bright, head-scratchingly unusual radio signal.

    Now Metzger and his colleagues think they have reconstructed the crime scene. Earlier this month they released a paper that sketched out a way for FRBs to arise from explosions in regions of space cluttered with dense clouds of particles and magnetic fields.

    The model favors, but doesn’t require, a magnetar as the source of the explosions. A magnetar is a young neutron star that sometimes burps out charged particles in a supersize version of the coronal mass ejections that erupt on the sun. Each new blast plows into the surrounding clutter. When it does, it creates a shock wave, which in turn beams a short, laserlike flash of radio waves halfway across the universe.

    “In just very general terms, this makes a ton of sense,” said James Cordes, an astrophysicist at Cornell University, adding that while further details still need to be worked out, “I would say it’s a good horse to bet on.”

    What the astronomers really like, though, is that Metzger’s theory generates very specific predictions for what future FRBs should look like, predictions that will soon be put to make-or-break tests. A new Canadian radio telescope called CHIME is expected to find between one and 10 FRBs each day after it becomes fully operational later this year. During initial testing last summer it detected a baker’s dozen of the bursts, results that were published in January. “I think that over the next year or so we’ll be able to test this very well,” said Shriharsh Tendulkar, an astrophysicist at McGill University and a member of CHIME’s FRB team.

    At Shock Wave Speed

    The theory developed by Metzger and his colleagues Ben Margalit and Lorenzo Sironi builds on the biggest break in the FRB case so far. In 2016, a team led by Laura Spitler at the Max Planck Institute for Radio Astronomy in Bonn, Germany, published their results on the first-ever FRB known to repeat. Previously, each event had been a one-off. As a consequence, astronomers were unable to track down where they were in the sky, so while they suspected FRBs came from far beyond our galaxy, they knew nothing about where. But this one blared out burst after enigmatic burst at unpredictable intervals.

    Radio astronomers soon pinpointed its origin to a small, misshapen dwarf galaxy. Trying to squeeze out every clue from these radio signals, they found that it came from a dense region of plasma gripped by extreme magnetic fields. They also found that the burst was surrounded by a fainter, constant radio glow. And last November, the astronomer Jason Hessels (with Spitler and others) noticed something else strange: Each split-second burst actually contains a few sub-bursts that, without fail, shift downward from higher to lower radio frequencies.

    To Metzger’s team, this last clue seemed oddly familiar. In the 1950s, physicists studied the blast waves of nuclear weapons to estimate their yields. In these models, the shock fronts from nuclear explosions sweep up more gas as they expand outward. That extra weight slows down the shock, and because it slows, radiation released from the shock front shifts downward in frequency thanks to the Doppler effect.

    Metzger had been thinking this blast wave effect might hint at the true nature of FRBs when suddenly, in early January, the haul from the CHIME telescope included another repeating event. This one’s repeating radio signals showed the same downward frequency drift. “The idea was there with the first repeater,” Metzger said, “but seeing that feature of FRBs reinforced sort of put me on overdrive.”

    Now Metzger, Margalit and Sironi have released their full model, based mostly on explaining the ins and outs of the first repeater. Imagine a magnetar, a city-sized neutron star forged in a supernova only a few years or decades earlier, its surface roiling and churning. Like the sun on a bad day, this young magnetar releases occasional flares that blast out electrons, positrons and maybe heavier ions at near the speed of light.

    When this material launches, it runs into older particles vomited out during previous flares. Where the new ejecta meets the older debris, it piles up into a shock, inside which magnetic fields soar. As the shock presses outward, the electrons inside gyrate around along magnetic field lines, and that motion produces a burst of radio waves. That signal then shifts from higher to lower frequencies as the shock slows. (And presumably, far away and eons later, Earth’s astronomers get a very exciting email alert from radio telescopes.)

    3
    Lucy Reading-Ikkanda/Quanta Magazine

    All this is still tenuous, but the idea is ready to pass or flunk based on what happens next in the FRB story. It’s the most quantitative, deeply thought-out scenario yet. “They’ve done the most-detailed calculations, and they’ve been able to make the most-specific observational predictions,” Spitler said.

    Metzger’s model predicts a number of specific features that future FRBs should share. For one: All future FRBs should follow the same downward shift in frequency. They might show gamma-ray or X-ray emission, which astronomers such as Spitler have already started to hunt for. They should live in galaxies that are forming lots of new stars and producing fresh magnetars. And when they do repeat, they should take breaks from bursting after astronomers observe a major flare. At that point, the system is so choked with material that subsequent flashes can’t make it out.

    Metzger’s model now faces a crowded bracket of other, still-viable theories. FRBs could be a consequence of merging neutron stars, which lit up both telescopes and gravitational-wave detectors for the first time in 2017.

    https://sciencesprings.wordpress.com/2017/10/16/from-ucsc-a-uc-santa-cruz-special-report-neutron-stars-gravitational-waves-and-all-the-gold-in-the-universe/

    Neutron stars might also make FRBs when they crash into other objects like black holes or white dwarfs, when they themselves collapse into black holes, or when their magnetic field lines are plucked by fierce winds of plasma.

    And it’s not even clear if FRBs all come from a single kind of event. While Metzger’s model has a “stranglehold” on observations of the first repeater, said the astrophysicist Victoria Kaspi, also at McGill, “I personally am always a little nervous when something is so tailored to one source.” Compared with the repeaters, perhaps one-off bursts come from entirely different sources. Or, as Spitler and others pointed out last November, all FRBs might turn out to repeat if astronomers only waited around for long enough.

    The data are about to pour in, ready to narrow the field. During the past five months, while CHIME has been in a commissioning phase, researchers have found more bursts that they haven’t publicly released. Team members hope to start the official observing run in April. The Australian Square Kilometer Array, a network of 36 radio dishes in western Australia, is also trawling for more examples and working to pinpoint their exact homes. And within a few years, so will HIRAX: an array of dishes in South Africa, Botswana and Rwanda that will hunt FRBs in an environment free from ambient radio signals.

    After years of sparse data and theoretical daydreaming, a solution finally seems within reach. In mid-February, FRB-curious astronomers met in Amsterdam to share new, please-don’t-post-this-on-Twitter discoveries and discuss the idea that neutron stars are in some way responsible. “That is what is so nice about his theory coming out just recently,” wrote Amanda Weltman, a theoretical astrophysicist at the University of Cape Town, in an email. “It is a perfect time.” The researchers debated Metzger’s model, presented at the meeting by his coauthor Margalit, but wouldn’t yet commit to it. “We are on the verge of convergence,” Tendulkar said. “Let’s just put it that way.”

    See the full article here .

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    Columbia U Campus

    Columbia University was founded in 1754 as King’s College by royal charter of King George II of England. It is the oldest institution of higher learning in the state of New York and the fifth oldest in the United States.

     
  • richardmitnick 9:00 am on January 29, 2019 Permalink | Reply
    Tags: , , , FRB's Fast radio Bursts,   

    From CERN: “Solving the next mystery in astrophysics” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    1
    Stellar stats for FRB’s

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    UTMOST-Molonglo Observatory Synthesis Telescope (MOST) a radio telescope operating at 843 mhz, operated by the school of physics of U Sidney, AU

    Green Bank Radio Telescope, West Virginia, USA, now the center piece of the GBO, Green Bank Observatory, being cut loose by the NSF


    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft).

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    In 2007, while studying archival data from the Parkes radio telescope in Australia, Duncan Lorimer and his student David Narkevic of West Virginia University in the US found a short, bright burst of radio waves. It turned out to be the first observation of a fast radio burst (FRB), and further studies revealed additional events in the Parkes data dating from 2001. The origin of several of these bursts, which were slightly different in nature, was later traced back to the microwave oven in the Parkes Observatory visitors centre. After discarding these events, however, a handful of real FRBs in the 2001 data remained, while more FRBs were being found in data from other radio telescopes.

    The cause of FRBs has puzzled astronomers for more than a decade. But dedicated searches under way at the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and the Australian Square Kilometre Array Pathfinder (ASKAP) [above], among other activities, are intensifying the search for their origin.

    CHIME Canadian Hydrogen Intensity Mapping Experiment -A partnership between the University of British Columbia, the University of Toronto, McGill University, Yale and the National Research Council in British Columbia, at the Dominion Radio Astrophysical Observatory in Penticton, British Columbia, CA

    Recently, while still in its pre-commissioning phase, CHIME detected no less than 13 new FRBs – one of them classed as a “repeater” on account of its regular radio output – setting the field up for an exciting period of discovery.

    Dispersion

    All FRBs have one thing in common: they last for a period of several milliseconds and have a relatively broad spectrum where the radio waves with the highest frequencies arrive first followed by those with lower frequencies. This dispersion feature is characteristic of radio waves travelling through a plasma in which free electrons delay lower frequencies more than the higher ones. Measuring the amount of dispersion thus gives an indication of the number of free electrons the pulse has traversed and therefore the distance it has travelled. In the case of FRBs, the measured delay cannot be explained by signals travelling within the Milky Way alone, strongly indicating an extragalactic origin.

    The size of the emission region responsible for FRBs can be deduced from their duration. The most likely sources are compact km-sized objects such as neutron stars or black holes. Apart from their extragalactic origin and their size, not much more is known about the 70 or so FRBs that have been detected so far. Theories about their origin range from the mundane, such as pulsar or black-hole emission, to the spectacular – such as neutron stars travelling through asteroid belts or FRBs being messages from extraterrestrials.

    For one particular FRB, however, its location was precisely measured and found to coincide with a faint unknown radio source within a dwarf galaxy. This shows clearly that the FRB was extragalactic. The reason this FRB could be localised is that it was one of several to come from the same source, allowing more detailed studies and long-term observations. For a while, it was the only FRB found to do so, earning it the title “The Repeater”. But the recent detection by CHIME has now doubled the number of such sources. The detection of repeater FRBs could be seen as evidence that FRBs are not the result of a cataclysmic event, since the source must survive in order to repeat. However, another interpretation is that there are actually two classes of FRBs: those that repeat and those that come from cataclysmic events.

    Until recently the number of theories on the origin of FRBs outnumbered the number of detected FRBs, showing how difficult it is to constrain theoretical models based on the available data. Looking at the experience of a similar field – that of gamma-ray burst (GRB) research, which aims to explain bright flashes of gamma rays discovered during the 1960s – an increase in the number of detections and searches for counterparts in other wavelengths or in gravitational waves will enable quick progress. As the number of detected GRBs started to go into the thousands, the number of theories (which initially also included those with extraterrestrial origins) decreased rapidly to a handful. The start of data taking by ASKAP and the increasing sensitivity of CHIME means we can look forward to an exponential growth of the number of detected FRBs, and an exponential decrease in the number of theories on their origin.
    Further reading

    CHIME/FRB Collaboration 2019 Nature https://www.nature.com/articles/s41586-018-0867-7.

    CHIME/FRB Collaboration 2019 Nature https://www.nature.com/articles/s41586-018-0864-x

    E F Keane 2018 Nat. Astron. 2 865.https://www.nature.com/articles/s41550-018-0603-0

    D Lorimer 2018 Nat. Astron. 2 860. [Unfound]

    See the full article here.


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA


    CERN ALPHA-g Detector

    CERN ALPHA-g Detector


    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN GBAR

    CERN GBAR

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

     
  • richardmitnick 10:13 am on January 17, 2019 Permalink | Reply
    Tags: , Are Fast Radio Bursts from Flaring Magnetars?, , , , , FRB's Fast radio Bursts   

    From AAS NOVA: “Are Fast Radio Bursts from Flaring Magnetars?” 

    AASNOVA

    From AAS NOVA

    16 January 2019
    Susanna Kohler

    1
    Artist’s impression of a magnetized neutron star. Could these objects be responsible for fast radio bursts? [ESO/L. Calçada]

    Could the mysterious fast-radio-burst signal FRB 121102 be emitted from a flaring, strongly magnetic neutron star? In a new study, two scientists explore the evidence.

    Mysterious Signals

    More than a decade ago, a powerful burst of coherent radio emission lasting only a few milliseconds mystified astronomers. The dispersion of the signal — the delay of its component frequencies by different amounts of time, depending on the wavelength — indicated that this pulse came from beyond our galaxy. But what was it?

    2
    Artist’s impression of a fast radio burst observed by the Parkes Radio Telescope. [Swinburne Astronomy Productions]

    Today, we’ve detected many dozens of these odd fast radio bursts (FRBs), including two sources that appear to repeat. The repetition has allowed scientists to learn more about the best studied of these, FRB 121102: this burst has been localized to a star-forming dwarf galaxy that lies three billion light-years from Earth. Upon closer inspection of the region, scientists found that in addition to FRB 121102’s repeating bursts, a dim and steady source of radio emission lies nearby.

    These accumulating clues all address a broad mystery: what object could be responsible for the bursting and steady emission we observe? What is the source of an FRB?

    A Magnetized Solution

    Two scientists at Columbia University, former graduate student Ben Margalit (now a NASA Einstein Postdoctoral Fellow at UC Berkeley) and advisor Brian Metzger, recently proposed an explanation for FRB 121102: perhaps this source is a young, flaring, highly magnetized neutron star that is embedded in a decades-old supernova remnant.

    Neutron stars are dense cores left behind after a star’s spectacular death in a supernova or a gamma-ray burst. In particular, a magnetar is a type of neutron star with an extremely powerful magnetic field that causes flares and bursts early in the object’s life. Such flares from a distant young magnetar, Margalit and Metzger argue, could explain the FRB signals we observe.

    3
    Schematic of the authors’ model, in which a young, flaring magnetar is embedded in a magnetized nebula trapped behind the shell of supernova ejecta. Electrons in the magnetized nebula emit the persistent radio radiation, and the nebula leaves an imprint on the burst emission — which originates from the magnetar — as well. [Margalit & Metzger 2018]

    In addition, the newly-formed magnetar may rest in the center of a compact, magnetized nebula that’s trapped behind the expanding shell of supernova ejecta created when the magnetar was born. This magnetized nebula could power persistent radio emission like what we observed near FRB 121102.

    As a final piece of the puzzle, the authors point out that the identified home for FRB 121102 is consistent with the type of galaxy in which magnetars often form. Such small galaxies with high specific star formation rates are known to preferentially host long gamma-ray bursts and superluminous supernovae, events in which magnetars are born.

    Predicting the Future

    To test their theory, Margalit and Metzger develop a detailed time-dependent model of an expanding, magnetized electron-ion nebula inflated by a flaring, young magnetar. They then show that the energetics of their model beautifully match the properties of both the bursting and persistent radio emission from FRB 121102.

    Does this mean the mystery’s solved? We can’t say for sure yet — but the authors make specific predictions for future observations of FRB 121102 that will provide a robust test of their model. In addition, the very recent discovery of a second repeating burst, FRB 180814.J0422+73, will hopefully allow us to further explore these mysterious sources and confirm their origin.

    Citation

    “A Concordance Picture of FRB 121102 as a Flaring Magnetar Embedded in a Magnetized Ion–Electron Wind Nebula,” Ben Margalit and Brian D. Metzger 2018 ApJL 868 L4.
    http://iopscience.iop.org/article/10.3847/2041-8213/aaedad/meta

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Societyis 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 1:36 pm on January 12, 2019 Permalink | Reply
    Tags: , , , Bevy of Mysterious Radio Bursts Finds Second Repeating Source, Both repeaters give important clues about their origins-they cannot be produced by some one-off cataclysmic event, , , FRB's Fast radio Bursts, The highlight of the bounty is the single burst that flared time and again   

    From Sky & Telescope: “Bevy of Mysterious Radio Bursts Finds Second Repeating Source” 

    SKY&Telescope bloc

    From Sky & Telescope

    January 9, 2019
    Shannon Hall

    CHIME Canadian Hydrogen Intensity Mapping Experiment -A partnership between the University of British Columbia, the University of Toronto, McGill University, Yale and the National Research Council in British Columbia, at the Dominion Radio Astrophysical Observatory in Penticton,British Columbia

    More than a decade ago, astronomers discovered that every day the sky sparkles with thousands of bursts of radio waves. These flashes are hundreds of millions of times more energetic than the sun but so fleeting that astronomers miss them time and again.

    That has made it hard to pin down the origins of these so-called “fast radio bursts,” or FRBs for short. Yet there are tantalizing hints that they could represent an entirely new class of astrophysical objects. As such, they’re arguably one of the most intriguing mysteries in astrophysics, which makes their often-missed detection even more infuriating.

    Luckily, the tides are turning.

    A new telescope known as the Canadian Hydrogen Intensity Mapping Experiment (CHIME), nestled in the mountains of British Columbia, has already spotted 13 bursts. And of those bursts, reported January 9th in Nature and at a meeting of the American Astronomical Society, one appears to repeat — an advance that might help astronomers settle its exotic origin.

    A Baker’s Dozen

    The bursts were detected over a period of just three weeks last summer, while CHIME was running at only a fraction of its full capacity. “Immediately, it was clear that this is good news,” said Victoria Kaspi (McGill University) at the meeting.

    First, it’s a resounding endorsement of the telescope’s capabilities. And while Kaspi was hesitant to say just how many bursts might become visible once the telescope is in full swing, early estimates suggest that CHIME might ultimately detect anywhere from 2 to 50 bursts per day — a feat that would truly revolutionize the field.

    Second, Kaspi noted that the radio waves from many of these bursts appear to have been scattered on their journey to Earth. That means that the FRBs likely originated in special environments that contain a lot of turbulent gas, such as near a supermassive black hole, a young supernova remnant, or a star-forming region, she said.

    1
    A composite image of the field around the first repeating fast radio burst, FRB 121102 (indicated), showed that the burst came from a dwarf galaxy.
    Gemini Observatory / AURA / NSF / NRC

    The Gift That Keeps on Giving

    The highlight of the bounty is the single burst that flared time and again. First detected on August 14th, CHIME saw it pop up five additional times. The only other known repeating FRB was detected in 2012 and has reappeared hundreds of times since. So, a second “suggests that these repeaters are not as rare as we might have thought previously,” Kaspi said.

    What’s more: Both repeaters give important clues about their origins. The sheer fact that the bursts repeat, for example, suggest that they cannot be produced by some one-off cataclysmic event, like a core-collapse supernova or a merger of neutron stars. Both events would only occur once and a second burst would be impossible.

    But that’s not all. Both FRBs have another intriguing characteristic: Their frequencies drift downward over time. That means that the first few bursts arrived at the telescope with much higher frequencies than the final few bursts. “This is quite bizarre,” says Jason Hessels (Netherlands Institute for Radio Astronomy) who was not involved in the recent study. “But it’s also exciting because it’s a clue to determining what kind of physics creates this burst.”

    So what might cause such a downward drift? Late last year, Hessels attempted to answer that very question with regards to the first repeating radio burst. He argued that the drift could be intrinsic to the burst, meaning the burst starts very close to an energetic source (say, a supermassive black hole) and then moves farther away over time. Such a pattern has been seen before. As solar flares propagate outward, for example, the Sun’s magnetic field strength drops — an effect that causes the flare’s radio emission to similarly drop.

    Alternatively, the drift could come from something around the burst. A cloud of extremely hot and electrically charged gas, or plasma, for example, might act as a lens, which would bend the radio waves in much the same way that water bends rays of light.

    The fact that the two events look so similar is what most excites Hessels about the newest repeater. “It really suggests they’re of the same ilk,” he says. And while Kaspi agrees that the similarity is “striking,” she notes that we can’t draw any firm conclusions yet.

    Astronomers are keeping their eyes on the mysterious burst with the hope that they will be able to tie it to the galaxy it lives in, enabling them to better understand its environment. And of course, they’re also eagerly awaiting the scores of radio bursts that CHIME will soon detect.

    References:

    CHIME/FRB Collaboration “A second source of repeating fast radio bursts.” Nature, available online on 9 January 2019.

    CHIME/FRB Collaboration “Observations of fast radio bursts at frequencies down to 400 megahertz.” Nature, available online on 9 January 2019.

    J.W.T. Hessels et al. “FRB 121102 Bursts Show Complex Time-Frequency Structure.” Submitted to The Astrophysical Journal.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 1:55 pm on November 11, 2018 Permalink | Reply
    Tags: ASKAP-Australia Square Kilometre Array Pathfinder, , , , , , FRB's Fast radio Bursts, , Murchison Radio-astronomy Observatory (MRO) in Western Australia,   

    From International Centre for Radio Astronomy Research: “Aussie telescope almost doubles known number of mysterious ‘fast radio bursts’” 

    ICRAR Logo
    From International Centre for Radio Astronomy Research

    October 11, 2018
    Dr Ryan Shannon
    Swinburne University of Technology
    & OzGrav ARC Centre of Excellence
    +61 3 9214 5205
    rshannon@swin.edu.au

    Dr Jean-Pierre Macquart —
    ICRAR / Curtin University
    +61 8 9266 9248
    jean-pierre.macquart@icrar.org

    Dr Keith Bannister
    CSIRO
    +61 2 9372 4295
    keith.bannister@csiro.au

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

    October 11, 2018

    Australian researchers using a CSIRO radio telescope in Western Australia have nearly doubled the known number of ‘fast radio bursts’— powerful flashes of radio waves from deep space.
    The team’s discoveries include the closest and brightest fast radio bursts ever detected. Their findings were reported today in the journal Nature.

    Fast radio bursts come from all over the sky and last for just milliseconds. Scientists don’t know what causes them but it must involve incredible energy—equivalent to the amount released by the Sun in 80 years. “We’ve found 20 fast radio bursts in a year, almost doubling the number detected worldwide since they were discovered in 2007,” said lead author Dr Ryan Shannon, from Swinburne University of Technology and the OzGrav ARC Centre of Excellence.

    “Using the new technology of the Australia Square Kilometre Array Pathfinder (ASKAP), we’ve also proved that fast radio bursts are coming from the other side of the Universe rather than from our own galactic neighbourhood.”

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    1
    For each burst, the top panels show what the FRB signal looks like when averaged over all frequencies. The bottom panels show how the brightness of the burst changes with frequency. The bursts are vertical because they have been corrected for dispersion. Credit: Ryan Shannon and the CRAFT collaboration.

    Co-author Dr Jean-Pierre Macquart, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), said bursts travel for billions of years and occasionally pass through clouds of gas. “Each time this happens, the different wavelengths that make up a burst are slowed by different amounts,” he said. “Eventually, the burst reaches Earth with its spread of wavelengths arriving at the telescope at slightly different times, like swimmers at a finish line. “Timing the arrival of the different wavelengths tells us how much material the burst has travelled through on its journey. “And because we’ve shown that fast radio bursts come from far away, we can use them to detect all the missing matter located in the space between galaxies—which is a really exciting discovery.”

    CSIRO’s Dr Keith Bannister, who engineered the systems that detected the bursts, said ASKAP’s phenomenal discovery rate is down to two things. “The telescope has a whopping field of view of 30 square degrees, 100 times larger than the full Moon,” he said. “And, by using the telescope’s dish antennas in a radical way, with each pointing at a different part of the sky, we observed 240 square degrees all at once—about a thousand times the area of the full Moon. “ASKAP is astoundingly good for this work.”

    Dr Shannon said we now know that fast radio bursts originate from about halfway across the Universe but we still don’t know what causes them or which galaxies they come from.
    The team’s next challenge is to pinpoint the locations of bursts on the sky. “We’ll be able to localise the bursts to better than a thousandth of a degree,” Dr Shannon said.
    “That’s about the width of a human hair seen ten metres away, and good enough to tie each burst to a particular galaxy.”

    ASKAP is located at CSIRO’s Murchison Radio-astronomy Observatory (MRO) in Western Australia, and is a precursor for the future Square Kilometre Array (SKA) telescope.

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

    The SKA could observe large numbers of fast radio bursts, giving astronomers a way to study the early Universe in detail.

    CSIRO acknowledges the Wajarri Yamaji as the traditional owners of the MRO site.

    A fast radio burst leaves a distant galaxy, travelling to Earth over billions of years and occasionally passing through clouds of gas in its path. Each time a cloud of gas is encountered, the different wavelengths that make up a burst are slowed by different amounts. Timing the arrival of the different wavelengths at a radio telescope tells us how much material the burst has travelled through on its way to Earth and allows astronomers to to detect “missing” matter located in the space between galaxies. Credit: CSIRO/ICRAR/OzGrav/Swinburne University of Technology

    Dr Ryan Shannon (Swinburne/OzGrav), Dr Jean-Pierre Macquart (Curtin/ICRAR) and Dr Keith Bannister (CSIRO) describe their discovery of 20 new fast radio bursts (FRBs) and how the Phased Array Feed (PAF) receiver technology in CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope enabled this breakthrough science. Credit: CSIRO.

    More Information:
    ASKAP

    The Australian Square Kilometre Array Pathfinder (ASKAP) is the world’s fastest survey radio telescope. Designed and engineered by CSIRO, ASKAP is made up of 36 ‘dish’ antennas, spread across a 6km diameter, that work together as a single instrument called an interferometer. The key feature of ASKAP is its wide field of view, generated by its unique phased array feed (PAF) receivers. Together with specialised digital systems, the PAFs create 36 separate (simultaneous) beams on the sky which are mosaicked together into a large single image.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

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

    A Small part of the Murchison Widefield Array

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

     
  • richardmitnick 2:06 pm on October 31, 2018 Permalink | Reply
    Tags: , , , , CSIRO’s Australian Square Kilometre Array Pathfinder, , , FRB's Fast radio Bursts   

    From CSIROscope: “The search for the source of a mysterious fast radio burst comes relatively close to home” 

    CSIRO bloc

    From CSIROscope

    31 October 2018
    Elizabeth Mahony

    1
    Antennas of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope first picked up the Fast Radio Burst. CSIRO/Alex Cherney, Author provided.

    Fast radio bursts (FRBs) are just that – enormous blasts of radio waves from space that only last for a fraction of a second. This makes pinpointing their source a huge challenge.

    Our team recently discovered 20 new FRBs using CSIRO’s Australian Square Kilometre Array Pathfinder in the Western Australian outback, almost doubling the known number of FRBs.

    In follow-up research, published today in The Astrophysical Journal Letters, we have taken one of these new detections – known as FRB 171020 (the day the radio waves arrived at Earth: October 20, 2017) – and narrowed down the location to a galaxy close to our own.

    This is the closest FRB detected (so far) but we still don’t know what causes these mysterious radio bursts that can contain more energy than our Sun produces in decades.

    Waves in space

    As radio waves travel through the universe they pass through other galaxies and our own Milky Way before arriving at our telescopes.

    The longer radio wavelengths are slowed down more than the shorter wavelengths, meaning that there is a slight delay in the arrival time of longer wavelengths.

    This difference in arrival times is called the dispersion measure and indicates the amount of matter the radio emission has travelled through.

    FRB 171020 has the lowest dispersion measure of any FRB detected to date, meaning that it hasn’t travelled from half way across the universe like most of the other FRBs detected so far. That means it originated from relatively nearby (by astronomical standards).By using models of the distribution of matter in the universe we can put a hard limit on how far the radio signal has travelled. For this particular FRB, we estimate that it could not have originated from further than a billion light years away, and likely occurred much closer. (Our Milky Way galaxy is about 100,000 light years across.)This distance limit, combined with the sky area we know the FRB came from (an area half a square degree – or roughly two full Moons across) enormously narrows down the search volume to look for the host galaxy.

    Closing in

    A region of the sky this size typically contains hundreds of galaxies. We used giant optical telescopes in Chile – including the appropriately named Very Large Telescope and Gemini South – to derive distances to these galaxies by either measuring their redshifts directly, or by using their optical colours to estimate their distance.

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


    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

    This allowed us to drastically reduce the number of possible galaxies within the distance limit to just 16.

    By far the closest, and we believe most likely to host the FRB, is a nearby spiral galaxy called ESO 601-G036. This is 120 million light years away – making this FRB host almost our next door neighbour.

    3
    Optical image of the search area from the Digitized Sky Survey (DSS). The circles mark possible host galaxies for FRB 171020, but these are all much further away than the most likely galaxy ESO 601-G036, shown in the lower left as a three-colour image from the VLT Survey Telescope (VST) ATLAS survey. ESO, Digitized Sky Survey and VST-ATLAS, Author provided.

    Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light.
    Credit: ESO/Y. Beletsky, with an elevation of 2,635 metres (8,645 ft) above sea level

    What is particularly striking about this galaxy is that it shares many similar features to the only galaxy known to produce FRBs: FRB 121102.

    This FRB is also known as the repeating FRB due to its – so far unique – property of producing multiple bursts. This helped astronomers locate it to a small galaxy about more than 3 billion light years away.

    ESO 601-G036 is similar in size, and forming new stars at about the same rate, as the host galaxy of the repeating FRB.

    But there is one intriguing feature of the repeating FRB that we don’t see in ESO 601-G036.

    Other emissions

    In addition to repeat bursts of radio emission, the repeating FRB emits lower energy radio emission continuously.

    Using CSIRO’s Australia Telescope Compact Array (ATCA) in Narrabri, NSW, we have searched for this persistent radio emission in ESO 601-G036. If it was anything like the repeater’s galaxy, it should have a boomingly bright radio source in it. We saw nothing.

    5
    The Australia Telescope Compact Array (ATCA) used in the follow-up observations. CSIRO, Author provided

    Not only did we find that ESO 601-G036 doesn’t have any persistent radio emission, but there are no other galaxies in our search volume that show similar properties to that seen in the repeating FRB.

    This points to the possibility that there are different types of fast radio bursts that may even have different origins.

    Finding the galaxies that FRBs originate from is a big step towards solving the mystery of what produces these extreme bursts. Most FRBs travel much further distances so finding one so close to Earth allows us to study the environments of FRBs in unprecedented detail.

    The hunt for more

    Unfortunately, we can’t say with absolute certainty that ESO 601-G036 is the galaxy that FRB 171020 came from.

    The next big hurdle in understanding what causes FRBs is to pinpoint more of them. If we can do that we’ll be able to work out not only exactly which galaxy an FRB occurred in, but even where within the galaxy it occurred.

    If FRBs occur within the central nuclei of galaxies, this could perhaps point to black holes as their source. Or do they prefer the outskirts of galaxies? Or regions where a lot of new stars have recently formed? There are still so many unknowns about FRBs.

    Several radio telescopes around the world are commissioning systems to pinpoint bursts. Our study has shown that by combining observations from radio and optical telescopes we’ll be able to paint a complete picture of FRB host galaxies, and be able to finally determine what causes these FRBs.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    So what can we expect these new radio projects to discover? We have no idea, but history tells us that they are almost certain to deliver some major surprises.

    Making these new discoveries may not be so simple. Gone are the days when astronomers could just notice something odd as they browse their tables and graphs.

    Nowadays, astronomers are more likely to be distilling their answers from carefully-posed queries to databases containing petabytes of data. Human brains are just not up to the job of making unexpected discoveries in these circumstances, and instead we will need to develop “learning machines” to help us discover the unexpected.

    With the right tools and careful insight, who knows what we might find.

    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 3:58 pm on October 10, 2018 Permalink | Reply
    Tags: ASKAP is located at CSIRO’s Murchison Radio-astronomy Observatory (MRO) in Western Australia, ASKAP telescopes to rule fast radio-burst hunt, , , , , , CSIRO acknowledges the Wajarri Yamaji as the traditional owners of the MRO site, FRB's Fast radio Bursts, ,   

    From Commonwealth Scientific and Industrial Research Organisation CSIRO: “CSIRO telescope almost doubles known number of mysterious ‘fast radio bursts'” 

    CSIRO bloc

    From Commonwealth Scientific and Industrial Research Organisation CSIRO

    Australian researchers using a CSIRO radio telescope in Western Australia have nearly doubled the known number of ‘fast radio bursts’— powerful flashes of radio waves from deep space.

    1
    Antennas of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope. Credit: CSIRO/Alex Cherney

    2
    An artist’s impression of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope observing ‘fast radio bursts’ in ‘fly’s-eye mode’. Each antenna points in a slightly different direction, giving maximum sky coverage. ©OzGrav, Swinburne University of Technology

    3
    (L-R) Lead author Dr Ryan Shannon (Swinburne/OzGrav), with co-authors Dr Keith Bannister (CSIRO) and Dr Jean-Pierre Macquart (Curtin/ICRAR). ©Inspireworks

    4
    Dishes of CSIRO’s Australian Square Kilometre Array Pathfinder in ‘fly’s-eye mode’ ©Kim Steel

    The team’s discoveries include the closest and brightest fast radio bursts ever detected.

    Their findings were reported today in the journal Nature .

    Fast radio bursts come from all over the sky and last for just milliseconds.

    Scientists don’t know what causes them but it must involve incredible energy—equivalent to the amount released by the Sun in 80 years.

    “We’ve found 20 fast radio bursts in a year, almost doubling the number detected worldwide since they were discovered in 2007,” lead author Dr Ryan Shannon, from Swinburne University of Technology and the OzGrav ARC Centre of Excellence said.

    “Using the new technology of the Australia Square Kilometre Array Pathfinder (ASKAP), we’ve also proved that fast radio bursts are coming from the other side of the Universe rather than from our own galactic neighbourhood.”

    Co-author Dr Jean-Pierre Macquart, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), said bursts travel for billions of years and occasionally pass through clouds of gas.

    “Each time this happens, the different wavelengths that make up a burst are slowed by different amounts,” he said.

    “Eventually, the burst reaches Earth with its spread of wavelengths arriving at the telescope at slightly different times, like swimmers at a finish line.

    “Timing the arrival of the different wavelengths tells us how much material the burst has travelled through on its journey.

    “And because we’ve shown that fast radio bursts come from far away, we can use them to detect all the missing matter located in the space between galaxies—which is a really exciting discovery.”

    CSIRO’s Dr Keith Bannister, who engineered the systems that detected the bursts, said ASKAP’s phenomenal discovery rate is down to two things.

    “The telescope has a whopping field of view of 30 square degrees, 100 times larger than the full Moon,” he said.

    “And, by using the telescope’s dish antennas in a radical way, with each pointing at a different part of the sky, we observed 240 square degrees all at once—about a thousand times the area of the full Moon.

    “ASKAP is astoundingly good for this work.”

    Dr Shannon said we now know that fast radio bursts originate from about halfway across the Universe but we still don’t know what causes them or which galaxies they come from.

    The team’s next challenge is to pinpoint the locations of bursts on the sky.

    “We’ll be able to localise the bursts to better than a thousandth of a degree,” Dr Shannon said.

    “That’s about the width of a human hair seen 10 metres away, and good enough to tie each burst to a particular galaxy.”

    ASKAP is located at CSIRO’s Murchison Radio-astronomy Observatory (MRO) in Western Australia, and is a precursor for the future Square Kilometre Array (SKA) telescope.

    The SKA could observe large numbers of fast radio bursts, giving astronomers a way to study the early Universe in detail.

    CSIRO acknowledges the Wajarri Yamaji as the traditional owners of the MRO site.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 1:44 pm on October 1, 2018 Permalink | Reply
    Tags: , , , , , , FRB's Fast radio Bursts,   

    From AAS NOVA: “Featured Image: A CHIME Search for Fast Radio Bursts” 

    AASNOVA

    From AAS NOVA

    1
    The Canadian Hydrogen Intensity Mapping Experiment, or CHIME, is a novel radio telescope originally intended to map features in hydrogen gas to measure dark energy. It has an additional mission now, however: CHIME will search the sky for signs of new fast radio bursts (FRBs). FRBs — energetic transient radio pulses that last only a few milliseconds — were first discovered about a decade ago, and though we’ve only observed ~30 of them so far, some estimates suggest they occur at a rate of several hundred to a few thousand per day across the sky! CHIME’s large field of view, high sensitivity, and wide bandwidth will help us hunt for these explosive events. In a new report by the CHIME/FRB collaboration, the team details this unique telescope, located in British Columbia. CHIME is made up of four 20-m x 100-m semicylindrical paraboloid reflectors, giving it its unusual appearance. The team expects that when CHIME begins science operations, it will detect FRBs at a rate of 2–42 FRBs per sky per day. For more information, check out the article below!

    Citation

    “The CHIME Fast Radio Burst Project: System Overview,” The CHIME/FRB Collaboration et al 2018 ApJ 863 48. http://iopscience.iop.org/article/10.3847/1538-4357/aad188/meta

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

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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

     
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