Mysterious radio bursts from far away
Tea Cosmic-Zoo–our Universe–is the strange domain of various strange beasts, many of which are unlike anything we are familiar with on our own little planet lost in Space. Oddities of many kinds are accumulating in remote and darkly mysterious regions of our Universe, and some of these bizarre occurrences are violent in nature, such as the collisions of fiery stars that blow up each other, and the cataclysmic explosive deaths of massive stars that blow up into the sky. forget when they go supernova. In July 2013, astronomers reported that they had detected a rare population of short radio bursts coming from far beyond our Milky Way galaxy, the first detected short radio bursts emanating from other galaxies. The sources of these mysterious outbursts are unknown, but cataclysmic events such as stellar collisions and supernova explosions are thought to be the most likely triggers.
“This is one of the most important radio discoveries in the last two decades,” commented Dr. Scott Ransom on July 4, 2013. News of nature. Dr. Ransom, US astronomer National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, was not part of the study.
IN radio burst it is a short wave of light emanating from a point in the sky, made up of longer electromagnetic wavelengths in the radio portion of the light spectrum. A-single radio burst It was discovered in 2007, but astronomers weren’t sure if it came from our Milky Way or from somewhere beyond our Galaxy.
The objects with which we are familiar: our own planet, our Moon, the Sun, the Solar System and the visible and luminous objects that inhabit the Universe, such as the stars, as well as the galaxies that they light up with their silvery fires. –compose the portions of the Cosmic-Zoo that we have been aware of for a long time, and that we are now beginning to explore.
But Cosmic-Zoo it is also the domicile of many strange beasts, belonging to strange species that have never been observed before, and whose identity has yet to be determined and defined. Most of our Universe is mysterious, inscrutable, maybe. But, being a curious species, we seem to have the need explore the unknown in our Cosmos.
Radio bursts from a long time ago and far away
The new radio bursts— four in all — have been traveling toward us from billions of light-years away, indicating that they do in fact originate from unknown and mysterious sources beyond our own Galaxy. The discovery of this quartet of strangers explodes was reported in the July 5, 2013 edition of Science by an international team of astronomers using the Parkes Observatory in Australia. The article is titled A population of fast radio bursts at cosmological distances.
“Short radio bursts are really hard to identify. Our team had to search 11 months of data covering a large area of the sky,” Dr. Sarah Burke Spolaor explained in a July 8, 2013 report. Press release from NASA’s Jet Propulsion Laboratory (JPL). Dr. Spolaor, who is from JPL located in Pasadena, California, developed the software used by the team. The software was designed to search for unique pulses in the radio data and then determine which of them were genuine signals rather than local interference. Local interference, for example, can come from spark plugs, airplanes, and cell phones. Obviously, this amounts to a huge and very difficult computational task.
Although radio signals traveling to Earth from remote galaxies, ranging from days to months, have been detected for decades, such short bursts from beyond our Milky Way have never been definitively detected before, according to Dr. Dan Thornton, co-author of the study. author. Dr. Thornton is an astronomer at the University of Manchester in the UK and with the Australian Commonwealth Scientific and Industrial Research Organization. He and his team set out to search for extragalactic radio bursts, following an event observed in 2007 that indicated that one such signal had possibly been found. Using archived 64 meter data Parkes Using the telescope, the same instrument that had detected the first candidate outburst six years earlier, Dr. Thornton and his team discovered outbursts that appeared to be traveling toward us from beyond our Milky Way.
“Radio bursts last only a few milliseconds and the furthest we detected was 11 billion light-years away,” Dr. Thornton explained on July 8, 2013. JPL press release.
As radio waves make their long journey through ionized material in space, they encounter a vast sea of electrons that slows down the low-frequency components of the signals, but leaves the high-frequency components almost completely alone. This causes a narrow radio signal, which travels a very long distance, to spread out or scatter. The quartet of radio signals detected by Dr. Thornton and his colleagues are so spread out that the distribution of electrons in our galaxy may only account for a mere 3-6% of their spread. This strongly suggests that the four radio bursts originate from beyond the Milky Way. The signals also come from different regions of the sky.
Our sky is literally filled with countless bursts and flares of various descriptions and origins. Gamma rays, for example, are thought to be caused by the death throes of massive, giant stars as they collapse into stellar-mass black holes. Gamma rays are routinely observed by a network of ‘scopes both on the ground and in space, including NASA’s. Closed and Fast. When one of this vast network of telescopes detects an outburst, it can signal the others to quickly turn to the site for coordinated observations.
The recently discovered quartet of radio bursts likely have a different origin than gamma-ray bursts, although both types of bursts consist of light waves produced by violent and catastrophic events that occur over great distances. The brightness and shortness of the quartet of radio bursts suggest that they were emitted by some type of relatively small but highly energetic body, such as a magnetar. IN magnetar it’s a neutron star It sports an extremely strong magnetic field. Radio bursts “signal the existence of a catastrophic event involving large amounts of mass or energy,” Dr. Thornton said on July 4, 2013. News of nature. However, their source remains a mystery because astronomers were unable to pinpoint where the extremely brief signals were coming from.
The burst quartet is similar to the observed pulses emanating from press, neutron stars whose rapid rotations regularly sweep, like the headlights of a lighthouse, the blackness of space. Due to its weak emission, most of the known press dwell within our Galaxy or in one of its nearby satellite dwarf galaxies, the Broad and Small Magellanic Clouds. However, the newly discovered burst quartet is different because they originate from greater distances, far beyond the Milky Way. The sources of the radio bursts are undoubtedly exotic by our familiar standards: strange beasts, indeed, that inhabit our strange Cosmic zoo! The range of suspects includes emissions from evaporating black holes, sources involving supernova explosions, and magnetars. The outbursts could also originate from the hearts of galaxies where compact stars dance around.—before they howl into the hungry mouths of supermassive black holes that weigh millions to billions of times more than our Sun.
But these mysterious outbursts could also represent an entirely new and previously unknown species of exotic beast.
Models of the electron content of intergalactic space indicate that the remote burst quartet traveled between 5.5 billion and 10 billion light-years of space to reach our planet, far beyond our galaxy. But their origin remains shrouded in a fascinating mystery because astronomers could not determine where these brief signals came from.
If astronomers can finally pinpoint the distances, they can use the scattering of radio signals to measure the number of electrons in intergalactic space. The number of electrons is representative of the number of baryons–protons and neutrons that make up the nuclei of atoms–that swim in Space between galaxies.
This number is of great interest because it could help solve a longstanding cosmic mystery about why the abundance of protons and neutrons within galaxies is so much less than the total number that observations of the ancient Universe indicate should be swimming around today. This Newly Discovered Burst Species Could Finally Locate the Missing baryons of the Cosmic Zoo.