Post by Andrei Tchentchik on Aug 20, 2020 18:26:44 GMT 2
(.#485).- No, rapid radio bursts do not come from E.T.
No, rapid radio bursts do not come from E.T.
Article by Laurent Sacco
Published on 06/01/2017
Archives
The track of an E.T. technosignature seems to be fading as regards the investigations into the nature of the mysterious rapid radio bursts. By locating one of the 18 known sources in a distant dwarf galaxy, radio astronomers have just made this hypothesis very unlikely.
Are we about to unravel the mystery of rapid radio bursts? One may wonder after the publication by an astronomer group of an article in the famous journal Nature. They announced that they had determined for the first time the location of a rapid radio burst (Fast Radio Burst or FRB in English) first observed in 2012 in the constellation of the Coachman (Auriga in Latin) with the Arecibo radio telescope. The peculiarity of FRB 121102, which, as its name suggests, was detected on November 2, 2012, is that it occurred several times, which allowed a battery of instruments on Earth to associate it with a dwarf galaxy located about 3 billion light years from the Milky Way. In 2015, researchers already thought they had located an FRB, the one called FRB 150418, but its nature of rapid radio burst has since been called into question and today, it is the observations concerning FRB 121102 that are taken seriously.
By making aperture synthesis by interferometry, it is possible to combine several radio telescopes as if we had a giant of several tens of kilometers, and even a thousand times more. This artist's drawing thus represents the antennas of the VLA, whose observations at high resolutions made it possible to specify the location of a rapid radio burst. © Danielle Futselaar
It should be recalled that the FRBs were identified for the first time in 2007 thanks to new analyzes of archive data collected by the Parkes radio telescope, in Australia. They are also called "Lorimer bursts", from the name of their discoverer. They are extremely brief, a few thousandths of a second at most. But it is estimated that they come from violent events which release, perhaps during this brief period of time and in the radio domain, as much energy as the Sun in a day.
Astronomers find it difficult to make them part of conventional astrophysical explanations, just as was the case in the past for the famous gamma-ray bursts. This is why it is important to determine the places of their occurrences. Are they located in the Milky Way or are they properly cosmological objects associated with extragalactic phenomena? Can we associate them with stars and other energetic events in other wavelengths, for example in the visible or in the field of X and gamma rays? This information is vital for sorting out several hypotheses that range from the technosignature of E.T. civilizations to that of the Planck star explosion.
The Gemini North telescope finally made it possible to flush out the counterpart of the rapid radio burst FRB 121102. © Gemini Observatory, AURA, NSF, NRC
FRBs, magnetars, Planck stars or AGNs?
In this case therefore, FRB 121102, whose first approximate location had been obtained in 2012, appeared again nine times during the 83 hours of observations devoted to it for 6 months with time allocated to radio astronomers for the famous Very Large Array (VLA) and its 27 branches in New Mexico. It is thanks to their combination that the resolution of the observations has been able to increase and that the mystery of the location of at least one FRB has been partly solved. Indeed, at the same time, researchers were able to know where to point exactly on the sky, the 8 m Gemini North telescope at the top of Mauna Kea in Hawaii.
A small galaxy containing at most 1% of the mass of our Milky Way then appeared and we could have access to a measurement of spectral shift, therefore of distance. FRB 121102 is therefore an extragalactic object, which at least in this specific case does not easily agree with the hypothesis that it may be a technosignature AND since it was supposed, to be credible, being given the released energy, with a source in our Galaxy.
By refining the study of the galaxy containing the FRB, astronomers were able to locate it in a region of a hundred light years in diameter. The galaxy also appears as a very specific continuous radio source, which in fact suggests that it has an active nucleus (AGN) whose activity comes from matter falling on a supermassive black hole. FRB 121102 could have come from an event associated with this active nucleus, which suggests that it seems to be located in a region of 100 light years in diameter surrounding the heart of the dwarf galaxy. We know that supermassive black holes can generate jets of matter that become sources of radio waves.
But among the other hypotheses put forward, there is that of a magnetar which is always in contention. The radio waves could there also come from the instability of the accretion of matter by this type of neutron star having a particularly intense magnetic field. But according to astrophysicist Jason Hessel, it would be necessary to involve an atypical magnetar, of a kind never detected before among those that we know in the Milky Way. Observations in the field of X-rays or gamma may perhaps allow us to see more clearly in the future.
What is certain, at least in the case of FRB 121102, is that what causes a rapid radio burst is not destroyed by the transmission process, which does not agree with the idea that it could be a supernova or a long gamma-ray burst and maybe not with a Planck star either.
F I N .
No, rapid radio bursts do not come from E.T.
Article by Laurent Sacco
Published on 06/01/2017
Archives
The track of an E.T. technosignature seems to be fading as regards the investigations into the nature of the mysterious rapid radio bursts. By locating one of the 18 known sources in a distant dwarf galaxy, radio astronomers have just made this hypothesis very unlikely.
Are we about to unravel the mystery of rapid radio bursts? One may wonder after the publication by an astronomer group of an article in the famous journal Nature. They announced that they had determined for the first time the location of a rapid radio burst (Fast Radio Burst or FRB in English) first observed in 2012 in the constellation of the Coachman (Auriga in Latin) with the Arecibo radio telescope. The peculiarity of FRB 121102, which, as its name suggests, was detected on November 2, 2012, is that it occurred several times, which allowed a battery of instruments on Earth to associate it with a dwarf galaxy located about 3 billion light years from the Milky Way. In 2015, researchers already thought they had located an FRB, the one called FRB 150418, but its nature of rapid radio burst has since been called into question and today, it is the observations concerning FRB 121102 that are taken seriously.
By making aperture synthesis by interferometry, it is possible to combine several radio telescopes as if we had a giant of several tens of kilometers, and even a thousand times more. This artist's drawing thus represents the antennas of the VLA, whose observations at high resolutions made it possible to specify the location of a rapid radio burst. © Danielle Futselaar
It should be recalled that the FRBs were identified for the first time in 2007 thanks to new analyzes of archive data collected by the Parkes radio telescope, in Australia. They are also called "Lorimer bursts", from the name of their discoverer. They are extremely brief, a few thousandths of a second at most. But it is estimated that they come from violent events which release, perhaps during this brief period of time and in the radio domain, as much energy as the Sun in a day.
Astronomers find it difficult to make them part of conventional astrophysical explanations, just as was the case in the past for the famous gamma-ray bursts. This is why it is important to determine the places of their occurrences. Are they located in the Milky Way or are they properly cosmological objects associated with extragalactic phenomena? Can we associate them with stars and other energetic events in other wavelengths, for example in the visible or in the field of X and gamma rays? This information is vital for sorting out several hypotheses that range from the technosignature of E.T. civilizations to that of the Planck star explosion.
The Gemini North telescope finally made it possible to flush out the counterpart of the rapid radio burst FRB 121102. © Gemini Observatory, AURA, NSF, NRC
FRBs, magnetars, Planck stars or AGNs?
In this case therefore, FRB 121102, whose first approximate location had been obtained in 2012, appeared again nine times during the 83 hours of observations devoted to it for 6 months with time allocated to radio astronomers for the famous Very Large Array (VLA) and its 27 branches in New Mexico. It is thanks to their combination that the resolution of the observations has been able to increase and that the mystery of the location of at least one FRB has been partly solved. Indeed, at the same time, researchers were able to know where to point exactly on the sky, the 8 m Gemini North telescope at the top of Mauna Kea in Hawaii.
A small galaxy containing at most 1% of the mass of our Milky Way then appeared and we could have access to a measurement of spectral shift, therefore of distance. FRB 121102 is therefore an extragalactic object, which at least in this specific case does not easily agree with the hypothesis that it may be a technosignature AND since it was supposed, to be credible, being given the released energy, with a source in our Galaxy.
By refining the study of the galaxy containing the FRB, astronomers were able to locate it in a region of a hundred light years in diameter. The galaxy also appears as a very specific continuous radio source, which in fact suggests that it has an active nucleus (AGN) whose activity comes from matter falling on a supermassive black hole. FRB 121102 could have come from an event associated with this active nucleus, which suggests that it seems to be located in a region of 100 light years in diameter surrounding the heart of the dwarf galaxy. We know that supermassive black holes can generate jets of matter that become sources of radio waves.
But among the other hypotheses put forward, there is that of a magnetar which is always in contention. The radio waves could there also come from the instability of the accretion of matter by this type of neutron star having a particularly intense magnetic field. But according to astrophysicist Jason Hessel, it would be necessary to involve an atypical magnetar, of a kind never detected before among those that we know in the Milky Way. Observations in the field of X-rays or gamma may perhaps allow us to see more clearly in the future.
What is certain, at least in the case of FRB 121102, is that what causes a rapid radio burst is not destroyed by the transmission process, which does not agree with the idea that it could be a supernova or a long gamma-ray burst and maybe not with a Planck star either.
F I N .
