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News Article | February 15, 2017
Site: phys.org

Artist impression of a Fast Radio Burst (FRB) reaching Earth. The colors represent the burst arriving at different radio wavelengths, with long wavelengths (red) arriving several seconds after short wavelengths (blue). This delay is called dispersion and occurs when radio waves travel through cosmic plasma. Credit: Jingchuan Yu, Beijing Planetarium / NRAO Fast radio bursts (FRBs) are brief spurts of radio emission, lasting just one-thousandth of a second, whose origins are mysterious. Fewer than two dozen have been identified in the past decade using giant radio telescopes such as the 1,000-foot dish in Arecibo, Puerto Rico. Of those, only one has been pinpointed to originate from a galaxy about 3 billion light-years away. The other known FRBs seem to also come from distant galaxies, but there is no obvious reason that, every once in a while, an FRB wouldn't occur in our own Milky Way galaxy too. If it did, astronomers suggest that it would be "loud" enough that a global network of cell phones or small radio receivers could "hear" it. "The search for nearby fast radio bursts offers an opportunity for citizen scientists to help astronomers find and study one of the newest species in the galactic zoo," says theorist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA). Previous FRBs were detected at radio frequencies that match those used by cell phones, Wi-Fi, and similar devices. Consumers could potentially download a free smartphone app that would run in the background, monitoring appropriate frequencies and sending the data to a central processing facility. "An FRB in the Milky Way, essentially in our own back yard, would wash over the entire planet at once. If thousands of cell phones picked up a radio blip at nearly the same time, that would be a good sign that we've found a real event," explains lead author Dan Maoz of Tel Aviv University. Finding a Milky Way FRB might require some patience. Based on the few, more distant ones, that have been spotted so far, Maoz and Loeb estimate that a new one might pop off in the Milky Way once every 30 to 1,500 years. However, given that some FRBs are known to burst repeatedly, perhaps for decades or even centuries, there might be one alive in the Milky Way today. If so, success could become a yearly or even weekly event. A dedicated network of specialized detectors could be even more helpful in the search for a nearby FRB. For as little as $10 each, off-the-shelf devices that plug into the USB port of a laptop or desktop computer can be purchased. If thousands of such detectors were deployed around the world, especially in areas relatively free from Earthly radio interference, then finding a close FRB might just be a matter of time. This work has been accepted for publication in the Monthly Notices of the Royal Astronomical Society and is available online. More information: "Searching for Giga-Jansky Fast Radio Bursts from the Milky Way with a Global Array of Low-Cost Radio Receivers," Dan Maoz & Abraham Loeb, 2017, accepted for publication in Monthly Notices of the Royal Astronomical Society arxiv.org/abs/1701.01475


News Article | February 15, 2017
Site: spaceref.com

Astronomers have discovered a cosmic one-two punch unlike any ever seen before. Two of the most powerful phenomena in the Universe, a supermassive black hole, and the collision of giant galaxy clusters, have combined to create a stupendous cosmic particle accelerator. By combining data from NASA's Chandra X-ray Observatory, the Giant Metrewave Radio Telescope (GMRT) in India, the NSF's Karl G. Jansky Very Large Array, and other telescopes, researchers have found out what happens when matter ejected by a giant black hole is swept up in the merger of two enormous galaxy clusters. "We have seen each of these spectacular phenomena separately in many places," said Reinout van Weeren of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., who led the study that appears in the inaugural issue of the journal Nature Astronomy. "This is the first time, however, that we seen them clearly linked together in the same system." This cosmic double whammy is found in a pair of colliding galaxy clusters called Abell 3411 and Abell 3412 located about two billion light years from Earth. The two clusters are both very massive, each weighing about a quadrillion -- or a million billion -- times the mass of the Sun. The comet-shaped appearance of the X-rays detected by Chandra is produced by hot gas from one cluster plowing through the hot gas of the other cluster. Optical data from the Keck Observatory and Japan's Subaru telescope, both on Mauna Kea, Hawaii, detected the galaxies in each cluster. First, at least one spinning, supermassive black hole in one of the galaxy clusters produced a rotating, tightly-wound magnetic funnel. The powerful electromagnetic fields associated with this structure have accelerated some of the inflowing gas away from the vicinity of the black hole in the form of an energetic, high-speed jet. Then, these accelerated particles in the jet were accelerated again when they encountered colossal shock waves -- cosmic versions of sonic booms generated by supersonic aircraft -- produced by the collision of the massive gas clouds associated with the galaxy clusters. "It's almost like launching a rocket into low-Earth orbit and then getting shot out of the Solar System by a second rocket blast," said co-author Felipe Andrade-Santos, also of the CfA. "These particles are among the most energetic particles observed in the Universe, thanks to the double injection of energy." This discovery solves a long-standing mystery in galaxy cluster research about the origin of beautiful swirls of radio emission stretching for millions of light years, detected in Abell 3411 and Abell 3412 with the GMRT. The team determined that as the shock waves travel across the cluster for hundreds of millions of years, the doubly accelerated particles produce giant swirls of radio emission. "This result shows that a remarkable combination of powerful events generate these particle acceleration factories, which are the largest and most powerful in the Universe," said co-author William Dawson of Lawrence Livermore National Lab in Livermore, Calif. "It is a bit poetic that it took a combination of the world's biggest observatories to understand this." These results were presented at the 229th meeting of the American Astronomical Society meeting in Grapevine, TX. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations. A labeled image, a podcast, and a video about the findings are available at: http://chandra.si.edu For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra Please follow SpaceRef on Twitter and Like us on Facebook.


The search for fast radio burst could be bolstered by citizen scientists using their mobile phones. A team of researchers has said a global network of phones and small radio receivers could be used to detect these mystery signals emanating from an unknown source in space. In a report that has been accepted for publication in the Monthly Notices of the Royal Astronomical Society, scientists from the Harvard-Smithsonian Centre for Astrophysics (CfA) and Tel Aviv University say if such a network were in place, it could be used to detect a simultaneous radio blip. This blip would indicate a FRB has been recorded – coming from inside the Milky Way. FRBs are radio signals coming from unknown sources deep in space. Lasting just a few milliseconds, scientists have struggled to identify their origin – the few dozen that have been detected were identified from data after the event, meaning their origin could not be traced back. At present, only one FRB has been found to repeat. In total, scientists have recorded 16 bursts coming from FRB 121102 – meaning they could be tracked to a galaxy three billion light years away. But even though we now know the location, we still do not know what is causing these bursts. The search for more FRBs continues, with astronomers across the globe using huge radio telescopes to detect them. The team say this presents an opportunity to harness a global collective of citizen scientists to look out for FRBs from within our own galaxy. While other FRBs appear to be coming from deep space, there is no reason to think one could not emanate closer to home. "An FRB in the Milky Way, essentially in our own back yard, would wash over the entire planet at once. If thousands of cell phones picked up a radio blip at nearly the same time, that would be a good sign that we've found a real event," said lead author Dan Maoz of Tel Aviv University. How it would work: We propose to search for Galactic FRBs using a global array of low-cost radio receivers. Participating phones would continuously listen for and record candidate FRBs and would periodically upload information to a central data processing website, which correlates the incoming data from all participants, to identify the signature of a real, globe-encompassing, FRB from an astronomical distance. Triangulation of the GPS-based pulse arrival times reported from different locations will provide the FRB sky position, potentially to arc-second accuracy. Pulse arrival times from phones operating at diverse frequencies, or from an on-device de-dispersion search, will yield the dispersion measure (DM) which will indicate the FRB source distance within the Galaxy. FRBs have been detected at frequencies that match those used by mobile phones and Wi-Fi. Potentially, people could download an app that would constantly be running in the background, monitoring frequencies. It could then send data to a central processing facility where any abnormalities could be identified. The researchers calculate there might be FRBs in the Milky Way once every 30 to 1,500 years. But if it is a repeating burst – like FRB 121102 – it may pop up every week. "If FRBs originate from galaxies at cosmological distances, then their all-sky rate implies that the Milky Way may host an FRB on average once every 30 to 1,500 years," they wrote. "If FRBs repeat for decades or centuries, a local FRB could be active now." Avi Loeb, from the CfA, said: "The search for nearby fast radio bursts offers an opportunity for citizen scientists to help astronomers find and study one of the newest species in the galactic zoo."


News Article | February 27, 2017
Site: phys.org

An image of the Taurus Molecular Cloud, about 450 light-years from Earth. Many carbon-chain molecules have been detected towards dark clouds like these, but astronomers have sought HC11N without success. They speculate that chains this large preferentially transform into carbon rings. Credit: ESO; Digitized Sky Survey; Davide De Martin The interstellar medium of the Milky Way contains 5-10% of the total mass of the galaxy (excluding its dark matter) and consists primarily of hydrogen gas. There are small but important contributions from other gases as well, including carbon-bearing molecules both simple, like carbon monoxide and carbon dioxide, and complex like ethene, benzene, propynal, methanol and other alcohols, and cyanides. There are even some very large molecules like polycyclic aromatic hydrocarbons and buckyballs with fifty or more carbon atoms. Some species like the cyanides have relative abundances similar to what is seen in comets in our solar system, suggesting that local carbon chemistry is not unique. Astronomers think complex interstellar molecules are probably produced on dust grains, although some molecules might be produced in the gas phase. About one percent by mass of the interstellar material, these tiny grains are composed predominantly of silicates and provide the gas molecules with surfaces on which to react with other molecules. Carbon chain molecules are particularly interesting because they are thought to be the starting point for a significant fraction of the known complex chemicals in the interstellar medium. It is even suspected that carbon-chain species are a key stage in the formation of polycyclic aromatic hydrocarbons. Carbon-chain molecular chemistry thus provides insight into a large subset of interstellar chemistry. A particularly well-studied family of carbon chains is the cyanopolyynes: linear molecules of the form HCnN, where n = 3, 5, 7, 9, etc. They have been observed in high abundance towards older stars and in cold dark clouds. The presence of the largest known cyanopolyyne, HC11N, however, is in dispute. It was reportedly detected in 1982 towards one dark cloud in Taurus, but that detection has not been confirmed. CfA astronomers Ryan Loomis and Brett McGuire and their colleagues used the Green Bank Telescope to search the Taurus region for HC11N in six of its characteristic radio wavelength transitions, including the two in which it was first reported, but without success. The astronomers argue that the previous detection was an error, and they offer an explanation for the otherwise curious absence of the n=11 species. Laboratory experiments have shown that when carbon-chain molecules get to be longer than about n=9 they begin to curl on themselves and preferentially transform into carbon-ring molecules, which are more stable. A similar process could be occurring in the interstellar medium, siphoning away HC11N to form cyclic species. The non-detection of HC11N thus suggests the importance of this chemical pathway in producing cyclic molecules, although the authors note that further observations and laboratory experiments are needed to confirm the model. Explore further: The formation of carbon-rich molecules in space More information: Ryan A. Loomis et al. Non-detection of HCN towards TMC-1: constraining the chemistry of large carbon-chain molecules, Monthly Notices of the Royal Astronomical Society (2016). DOI: 10.1093/mnras/stw2302


News Article | February 15, 2017
Site: spaceref.com

Fast radio bursts (FRBs) are brief spurts of radio emission, lasting just one-thousandth of a second, whose origins are mysterious. Fewer than two dozen have been identified in the past decade using giant radio telescopes such as the 1,000-foot dish in Arecibo, Puerto Rico. Of those, only one has been pinpointed to originate from a galaxy about 3 billion light-years away. The other known FRBs seem to also come from distant galaxies, but there is no obvious reason that, every once in a while, an FRB wouldn't occur in our own Milky Way galaxy too. If it did, astronomers suggest that it would be "loud" enough that a global network of cell phones or small radio receivers could "hear" it. "The search for nearby fast radio bursts offers an opportunity for citizen scientists to help astronomers find and study one of the newest species in the galactic zoo," says theorist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA). Previous FRBs were detected at radio frequencies that match those used by cell phones, Wi-Fi, and similar devices. Consumers could potentially download a free smartphone app that would run in the background, monitoring appropriate frequencies and sending the data to a central processing facility. "An FRB in the Milky Way, essentially in our own back yard, would wash over the entire planet at once. If thousands of cell phones picked up a radio blip at nearly the same time, that would be a good sign that we've found a real event," explains lead author Dan Maoz of Tel Aviv University. Finding a Milky Way FRB might require some patience. Based on the few, more distant ones, that have been spotted so far, Maoz and Loeb estimate that a new one might pop off in the Milky Way once every 30 to 1,500 years. However, given that some FRBs are known to burst repeatedly, perhaps for decades or even centuries, there might be one alive in the Milky Way today. If so, success could become a yearly or even weekly event. A dedicated network of specialized detectors could be even more helpful in the search for a nearby FRB. For as little as $10 each, off-the-shelf devices that plug into the USB port of a laptop or desktop computer can be purchased. If thousands of such detectors were deployed around the world, especially in areas relatively free from Earthly radio interference, then finding a close FRB might just be a matter of time. This work has been accepted for publication in the Monthly Notices of the Royal Astronomical Society and is available online. Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe. Please follow SpaceRef on Twitter and Like us on Facebook.


News Article | February 20, 2017
Site: phys.org

A photograph of the Andromeda galaxy, a spiral like our Milky Way. Astronomers have discovered white dwarf stars in the disc of the Milky Way galaxy, and measured their properties to obtain an age to the disc of at least eleven billion years. Credit: NOAO and the Local Group Survey Team and T.A. Rector; University of Alaska Anchorage When a star like our sun gets to be very old, after another seven billion years or so, it will no longer be able to sustain burning its nuclear fuel. With only about half of its mass remaining, it will shrink to a fraction of its radius and become a white dwarf star. White dwarfs are common, the most famous one being the companion to the brightest star in the sky, Sirius. As remnants of some of the oldest stars in the galaxy, white dwarfs offer an independent means of dating the lifetimes of different galactic populations. A globular cluster is a roughly spherical ensemble of stars (as many as several million) that are gravitationally bound together and typically located in the outer regions of galaxies. The white dwarf stars in the Milly Way's globular clusters reveal an age spread of between eleven and thirteen billion years. By contrast, the thick disk of the galaxy is thought to be older than ten billion years but that figure is not very well constrained. White dwarfs in the disc can be used to refine those age estimates and, since they are closer and brighter to us than those in globular clusters, they can provide more detailed information. However, they are not located in well-defined regions like clusters and so they are also harder to spot. CfA astronomer Warren Brown and his colleagues used the 6.5-m Multiple Mirror Telescope (MMT) to obtain spectra of fifty-seven white dwarf candidate stars in the disk first discovered in all-sky surveys. Modeling the spectra of these stars revealed a mixture of types (for example, some stars had atmospheres of pure helium and others of pure hydrogen) and also an age for the disc of eleven billion years. The result is consistent with the current age estimates for the thick disc but also suggests that the current minimum age estimate might be increased. Additional measurements are needed to refine the age range, and the scientists predict that large-scale sky surveys now underway will significantly increase the number of non-cluster white dwarfs and enable the determination of their parameters. More information: Kyra Dame et al. New halo white dwarf candidates in the Sloan Digital Sky Survey, Monthly Notices of the Royal Astronomical Society (2016). DOI: 10.1093/mnras/stw2146


News Article | February 15, 2017
Site: www.eurekalert.org

Fast radio bursts (FRBs) are brief spurts of radio emission, lasting just one-thousandth of a second, whose origins are mysterious. Fewer than two dozen have been identified in the past decade using giant radio telescopes such as the 1,000-foot dish in Arecibo, Puerto Rico. Of those, only one has been pinpointed to originate from a galaxy about 3 billion light-years away. The other known FRBs seem to also come from distant galaxies, but there is no obvious reason that, every once in a while, an FRB wouldn't occur in our own Milky Way galaxy too. If it did, astronomers suggest that it would be "loud" enough that a global network of cell phones or small radio receivers could "hear" it. "The search for nearby fast radio bursts offers an opportunity for citizen scientists to help astronomers find and study one of the newest species in the galactic zoo," says theorist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA). Previous FRBs were detected at radio frequencies that match those used by cell phones, Wi-Fi, and similar devices. Consumers could potentially download a free smartphone app that would run in the background, monitoring appropriate frequencies and sending the data to a central processing facility. "An FRB in the Milky Way, essentially in our own back yard, would wash over the entire planet at once. If thousands of cell phones picked up a radio blip at nearly the same time, that would be a good sign that we've found a real event," explains lead author Dan Maoz of Tel Aviv University. Finding a Milky Way FRB might require some patience. Based on the few, more distant ones, that have been spotted so far, Maoz and Loeb estimate that a new one might pop off in the Milky Way once every 30 to 1,500 years. However, given that some FRBs are known to burst repeatedly, perhaps for decades or even centuries, there might be one alive in the Milky Way today. If so, success could become a yearly or even weekly event. A dedicated network of specialized detectors could be even more helpful in the search for a nearby FRB. For as little as $10 each, off-the-shelf devices that plug into the USB port of a laptop or desktop computer can be purchased. If thousands of such detectors were deployed around the world, especially in areas relatively free from Earthly radio interference, then finding a close FRB might just be a matter of time.


News Article | December 12, 2016
Site: phys.org

Equipment deployed at Dome A in Antartica, a site as high as Maunakea and 10 times drier, showed that it would be an ideal location for astronomy at terahertz radio frequencies. Credit: Xue-Fei Gong/Purple Mountain Observatory Antarctica might be one of the most inhospitable regions on the planet, but it is a mecca for astronomers. Its cold, dry air enables observations that can't be done elsewhere on Earth. The South Pole has hosted telescopes for decades. Now, researchers are eyeing a new location - Dome A, which offers a unique opportunity to study the universe at little-explored terahertz radio frequencies. "Dome A is the best site we've found - very flat, very calm winds, and the driest place anywhere on the planet," says Qizhou Zhang of the Harvard-Smithsonian Center for Astrophysics (CfA), co-author of a new study appearing online in the journal Nature Astronomy. Dome A is the highest point in Antarctica, with an elevation of more than 13,000 feet (4,000 meters), comparable to Maunakea in Hawaii. Unlike the South Pole, it isn't visited by aircraft. Instead, researchers must trek inland from the Antarctic coast, a journey of some 750 miles (1,200 km) that takes up to three weeks to complete. As a reward for these herculean efforts, scientists can access a type of light known as terahertz radiation, which has frequencies higher than 1 trillion hertz (1,000 times greater than the frequency used by cell phones). This radiation comes from cold clouds of interstellar gas and dust. By studying it, we can gain new insights into the origins of stars and galaxies. Because water vapor in Earth's atmosphere absorbs this radiation, few places on Earth are suited for terahertz observations. Instead astronomers have relied on aircraft and space missions, which are more costly and less flexible. The solution is to find an extremely dry location. Zhang and CfA co-author Scott Paine joined with their colleagues at China's Purple Mountain Observatory, led by principal investigator Sheng-Cai Shi, to create and deploy instruments to measure the conditions at Dome A over a span of 19 months. The data gathered there will also help inform climate models. "The water vapor in the Earth's atmosphere that obscures our view of the cosmos also blocks infrared radiation escaping from the Earth's surface towards space, which is the essence of the greenhouse effect," says Paine, who studies atmospheric radiation. The team found Dome A is frequently so arid that if all the water vapor in a narrow column stretching straight up from the ground to the edge of space were condensed, it would form a film less than 100 microns thick. That's about 1/250th of an inch, or twice the width of a human hair, and about 10 times less than that over Maunakea, one of the world's best astronomical observing sites. Moreover, Dome A offers a natural laboratory for studying the effects of water vapor on atmospheric absorption at extremely low temperatures. The cold Antarctic atmosphere provides direct access to conditions normally found in the Earth's upper troposphere. Developing Dome A into a permanent observatory for astronomy and atmospheric science will involve significant challenges. In return, researchers stand to gain a unique location for conducting scientific research. Explore further: Polar balloon STO2 to go the edge of space with Dutch instruments More information: Sheng-Cai Shi et al, Terahertz and far-infrared windows opened at Dome A in Antarctica, Nature Astronomy (2016). DOI: 10.1038/s41550-016-0001


News Article | January 6, 2016
Site: motherboard.vice.com

Densely packed stellar balls, known as globular clusters, could be the best places to search for alien life, according to research presented today at the 227th annual meeting of the American Astronomical Society. Globular clusters pack nearly one million stars into an area only 100 light-years across, and are nearly as old as the Milky Way itself. Approximately 150 of these ancient stellar relics lurk on the outskirts of our galaxy. “Globular clusters could be the first place in which intelligent life is found in our galaxy. This research shows they could be great places to look for other intelligent civilizations,” Rosanne DiStefano, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), said during the meeting. Globular clusters are estimated to have formed over 10 billion years ago, and as a result the stars within the cluster contain fewer of the ingredients needed to form planets. However if habitable planets do form within the cluster, they will likely be around for a lot longer than planets that form around massive stars, giving life more time to evolve. Habitable zones—the area around a star that can support liquid water—vary greatly depending on the size of the star. The ones surrounding more massive stars will be further away, while these zones around smaller, dimmer stars will be much closer. This is good news in the crowded, stellar neighborhood of a globular cluster. It means any potential habitable planets would huddle close to their host star and be safe from the gravitational tug of other stars. The majority of stars residing within these clusters are called “red dwarfs.” These types of stars are usually smaller than our Sun, and so they have longer lives and can support planets for billions of years, providing any potential life forms ample time to evolve beyond microbes into intelligent beings. “Once a planet has formed, it can survive for long periods of time, even billions of years,” DiStefano explained. But don’t get too excited yet, so far only one planet has been detected in a globular cluster. Most astronomers think these stellar populations are too crowded for planets to form, and are concerned about the lack of planet-forming ingredients like silicon and iron. DiStefano and her colleagues remain optimistic and think we shouldn’t rule out clusters completely. DiStefano explained that exoplanets have been detected around metal-poor stars, and while massive Jupiter-sized planets seems to prefer metal-rich stars, smaller Earth-sized planets seem to have no preference and can form around a variety of stars. Good news for alien hunters. Life on a planet within one of these clusters would be vastly different than what we experience here on Earth. The closest star to our Solar System is four light-years or 24 trillion miles away. However, within a cluster stellar neighbors are only about one trillion miles away, helping facilitate interstellar communication and exploration. DiStefano refers to this as “the globular cluster opportunity” and believes the close proximity would help support any potential life, making interstellar outposts easier to establish. Travel time within the cluster would take less time, and if there was a civilization at our technological level, sending probes between outposts would definitely be possible, according to DiStefano. So, how do we make contact? The first step is identifying more planets within clusters. Since clusters are densely packed and contain dim stars, detecting planets within the crowded cores of clusters are very difficult to identify, and DiStefano believes that it could be easier to detect planets on the outskirts. Another, more intriguing method might be to partner up with SETI to look for signs of radio communications from the cluster, something DiStefano would like to get more involved with. DiStefano is confident many more planets within these clusters will be discovered; it’s just a matter of time. “In my mind there is no doubt,” she said. “More planets within these clusters are waiting to be found.”


News Article | February 15, 2017
Site: www.renewableenergyworld.com

The Campaign for Accountability (CfA) asked Florida Attorney General Pam Bondi to open up an investigation into companies that offer residential solar panels in Florida. The group claims that some solar companies are using misleading sales practices and targeting elderly consumers, who are particularly susceptible to these tactics. The claims are based on a review of complaints filed with the Florida AG since 2011.

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