- 3.1 2007 (Lorimer Burst)
- 3.2 2010
- 3.3 2011
- 3.4 2012
- 3.5 2013
- 3.6 2014
<When the FRBs are polarized, it indicates that they are emitted from a source contained within an extremely powerful magnetic field.[14] The exact origin and cause of the FRBs is still the subject of investigation; proposals for their origin range from a rapidly rotating neutron star and a black hole, to extraterrestrial intelligence.[15][16] In 2020, astronomers reported narrowing down the source of Fast Radio Bursts, which may now plausibly include "compact-object mergers and magnetars arising from normal core collapse supernovae".[17][18][19]
The localization and characterization in 2012 of FRB 121102, one of the three repeating sources, has improved the understanding of the source class. FRB 121102 is identified with a galaxy at a distance of approximately three billion light-years and is embedded in an extreme environment.[20][14] The first host galaxy identified for a non-repeating burst, FRB 180924, was identified in 2019 and is a much larger and more ordinary galaxy, nearly the size of the Milky Way. In August 2019, astronomers reported the detection of eight more repeating FRB signals.[21][22] In January 2020, astronomers reported the precise location of a second repeating burst, FRB 180916.[23][24] One FRB seems to have been in the same location as a known gamma-ray burst.[25][13]
On 28 April 2020, a pair of millisecond-timescale bursts (FRB 200428) consistent with observed fast radio bursts, with a fluence of >1.5 million Jy/ms, was detected from the same area of sky as the magnetar SGR 1935+2154.[26][27] Furthermore, the dispersion measure was too low to have originated anywhere outside of the Milky Way. Although it was thousands of times less intrinsically bright than previously observed fast radio bursts, its comparative proximity rendered it the most powerful fast radio burst yet observed, reaching a peak flux of either a few thousand or several hundred thousand janskys, comparable to the brightness of the radio sources Cassiopeia A and Cygnus A at the same frequencies. This established magnetars as at least one ultimate source of fast radio bursts,[28][29][30] although the exact cause remains unknown.[31][32][33]
The first fast radio burst to be described, the Lorimer Burst FRB 010724, was detected in 2007 in archived data recorded by the Parkes Observatory on 24 July 2001. Since then, many FRBs have been found in previously recorded data. On 19 January 2015, astronomers at Australia's national science agency (CSIRO) reported that a fast radio burst had been observed for the first time live, by the Parkes Observatory.[34] Many FRBs have been detected in real time by the CHIME radio telescope since it became operational in 2018, including the first FRB detected from within the Milky Way in April 2020.[29][35]
Features
Fast radio bursts are bright, unresolved (pointsource-like), broadband (spanning a large range of radio frequencies), millisecond flashes found in parts of the sky. Unlike many radio sources, the signal from a burst is detected in a short period of time with enough strength to stand out from the noise floor. The burst usually appears as a single spike of energy without any change in its strength over time. The bursts last for several milliseconds (thousandths of a second). The bursts come from all over the sky, and are not concentrated on the plane of the Milky Way. Known FRB locations are biased by the parts of the sky that the observatories can image.
Many have radio frequencies detected around 1400 MHz; a few have been detected at lower frequencies in the range of 400–800 MHz.[36] The component frequencies of each burst are delayed by different amounts of time depending on the wavelength. This delay is described by a value referred to as a dispersion measure (DM).[37] This results in a received signal that sweeps rapidly down in frequency, as longer wavelengths are delayed more.
The interferometer UTMOST has put a lower limit of 10,000 kilometers for the distance to the FRBs it has detected, supporting the case for an astronomical, rather than terrestrial, origin (because signal sources on Earth are ruled out as being closer than this limit). This limit can be determined from the fact that closer sources would have a curved wave front that could be detected by the multiple antennas of the interferometer.[38]
Fast radio bursts have pulse dispersion measurements > 100 pc cm−3[39], much larger than expected for a source inside the Milky Way galaxy[40] and consistent with propagation through an ionized plasma.[37] Furthermore, their distribution is isotropic (not especially coming from the galactic plane);[38]:fig 3 consequently they are conjectured to be of extragalactic origin.
Bursts observed
Fast radio bursts are named by the date the signal was recorded, as "FRB YYMMDD".
2007 (Lorimer Burst)
The first FRB detected, the Lorimer Burst FRB 010724, was discovered in 2007 when Duncan Lorimer of West Virginia University assigned his student David Narkevic to look through archival data taken in 2001 by the Parkes radio dish in Australia.[41]
Analysis of the survey data found a 30-jansky dispersed burst which occurred on 24 July 2001,[37] less than 5 milliseconds in duration, located 3° from the Small Magellanic Cloud. The reporte
Fast radio bursts are bright, unresolved (pointsource-like), broadband (spanning a large range of radio frequencies), millisecond flashes found in parts of the sky. Unlike many radio sources, the signal from a burst is detected in a short period of time with enough strength to stand out from the noise floor. The burst usually appears as a single spike of energy without any change in its strength over time. The bursts last for several milliseconds (thousandths of a second). The bursts come from all over the sky, and are not concentrated on the plane of the Milky Way. Known FRB locations are biased by the parts of the sky that the observatories can image.
Many have radio frequencies detected around 1400 MHz; a few have been detected at lower frequencies in the range of 400–800 MHz.[36]Many have radio frequencies detected around 1400 MHz; a few have been detected at lower frequencies in the range of 400–800 MHz.[36] The component frequencies of each burst are delayed by different amounts of time depending on the wavelength. This delay is described by a value referred to as a dispersion measure (DM).[37] This results in a received signal that sweeps rapidly down in frequency, as longer wavelengths are delayed more.
The interferometer UTMOST has put a lower limit of 10,000 kilometers for the distance to the FRBs it has detected, supporting the case for an astronomical, rather than terrestrial, origin (because signal sources on Earth are ruled out as being closer than this limit). This limit can be determined from the fact that closer sources would have a curved wave front that could be detected by the multiple antennas of the interferometer.[38]
Fast radio bursts have pulse dispersion measurements > 100 pc cm−3[39], much larger than expected for a source inside the Milky Way galaxyFast radio bursts have pulse dispersion measurements > 100 pc cm−3[39], much larger than expected for a source inside the Milky Way galaxy[40] and consistent with propagation through an ionized plasma.[37] Furthermore, their distribution is isotropic (not especially coming from the galactic plane);[38]:fig 3 consequently they are conjectured to be of extragalactic origin.
Fast radio bursts are named by the date the signal was recorded, as "FRB YYMMDD".
2007 (Lorimer Burst)
In 2010 there was a report of 16 similar pulses, clearly of terrestrial origin, detected
In 2010 there was a report of 16 similar pulses, clearly of terrestrial origin, detected by the Parkes radio telescope and given the name perytons.[43] In 2015 perytons were shown to be generated when microwave oven doors were opened during a heating cycle, with detected emission being generated by the microwave oven's magnetron tube as it was being powered off.[44]
2011
In 2015, FRB 110523 was discovered in archival data collected in 2011 from the Green Bank Telescope.[40] It was the first FRB for which linear polarization was detected (allowing a measurement of Faraday rotation). Measurement of the signal's dispersion delay suggested that this burst was of extragalactic origin, possibly up to 6 billion light-years away.[45]
2012
Victoria Kaspi of McGill University estimated that as many as 10,000 fast radio bursts may occur per day over the entire sky.[46]
FRB 121102
In 2014, FRB 140514 was caught 'live' and was found to be 21% (±7%) circularly polarised.[34]
Fast radio bursts discovered up until 2015 had dispersion measures that were close to multiples of 187.5 pc cm−3.[70] However subsequent observations do not fit this pattern.
Fast radio bursts discovered up until 2015 had dispersion measures that were close to multiples of 187.5 pc cm−3.[70] However subsequent observations do not fit this pattern.
On 18 April 2015, FRB 150418 was detected by the Parkes observatory and within hours, several telescopes including the Australia Telescope Compact Array caught an apparent radio "afterglow" of the flash, which took six days to fade.[71][72][73] The Subaru telescope was used to find what was thought to be the host galaxy and determine its redshift and the implied distance to the burst.[74]
However, the association of the burst with the afterglow was soon disputed,[75][76][77] and by April 2016 it was established that the "afterglow" originates from an active galactic nucleus that is powered by a supermassive black hole with dual jets blasting ou
However, the association of the burst with the afterglow was soon disputed,[75][76][77] and by April 2016 it was established that the "afterglow" originates from an active galactic nucleus that is powered by a supermassive black hole with dual jets blasting outward from the black hole.[78] It was also noted that what was thought to be an "afterglow", did not fade away as would be expected, meaning that the variable AGN is unlikely to be associated with the actual fast radio burst.[78]
The upgraded Molonglo Observatory Synthesis Telescope (UTMOST), near Canberra (Australia), reported finding three more FRBs.[79] A 180-day three-part survey in 2015 and 2016 found three FRBs at 843 MHz.[38] Each FRB located with a narrow elliptical 'beam'; the relatively narrow band 828–858 MHz gives a less precise dispersion measure (DM).[38]
A short survey using part of Australian Square Kilometre Array Pathfinder (ASKAP) found one FRB in 3.4 days. FRB170107 was bright with a A short survey using part of Australian Square Kilometre Array Pathfinder (ASKAP) found one FRB in 3.4 days. FRB170107 was bright with a fluence of 58±6 Jy ms.[39][80]
According to Anastasia Fialkov and Abraham Loeb, FRB's could be occurring as often as once per second. Earlier research could not identify the occurrence of FRB's to this degree.[81]
Three FRBs were reported in March 2018 by Parkes Observatory in Australia. One (FRB 180309) had the highest signal to noise ratio yet seen of 411.[83][84]
The unusual CHIME (Canadian Hydrogen Intensity Mapping Experiment) radio telescope, operational from September 2018, will be used to detect "hundreds" of fast radio bursts as a secondary objective to its cosmological observations.[85][47] FRB 180725A was reported by CHIME as the first detection of a FRB under 700 MHz – as low as 580 MHz.[86][87]
In October 2018, astronomers reported 19 more new non-repeating FRB bursts detected by the Australian Square Kilometre Array Pathfinder (ASKAP).[88][89] These included three with dispersion measure (DM) smaller than seen before : FRB 171020 (DM=114.1), FRB 171213 (DM=158.6), FRB 180212 (DM=167.5).[90]
FRB 180814[<The unusual CHIME (Canadian Hydrogen Intensity Mapping Experiment) radio telescope, operational from September 2018, will be used to detect "hundreds" of fast radio bursts as a secondary objective to its cosmological observations.[85][47] FRB 180725A was reported by CHIME as the first detection of a FRB under 700 MHz – as low as 580 MHz.[86][87]
In October 2018, astronomers reported 19 more new non-repeating FRB bursts detected by the Australian Square Kilometre Array Pathfinder (ASKAP).[88][89] These included three with dispersion measure (DM) smaller than seen before : FRB 171020 (DM=114.1), FRB 171213 (DM=158.6), FRB 180212 (DM=167.5).[90]
On 9 January 2019, astronomers announced the discovery of a second repeating FRB source, named FRB 180814, by CHIME. Six bursts were detected between August and October 2018, "consistent with originating from a single position on the sky". The detection was made during CHIME's pre-commissioning phase, during which it operated intermittently, suggesting a "substantial population of repeating FRBs", and that the new telescope would make more detections.[8][91]
Some news media reporting of the discovery speculated that the repeating FRB could be evidence of extraterrestrial intelligence,[92]extraterrestrial intelligence,[92][93] a possibility explored in relation to previous FRBs by some scientists,[94][95] but not raised by the discoverers of FRB 180814.[8][91]
FRB 180916, more formally FRB 180916.J0158+65, is a repeating FRB discovered by CHIME, that later studies found to have originated from a medium-sized spiral galaxy (SDSS J015800.28+654253.0) about 500 million light-years away – the closest FRB discovered to date.[96][23][24] It is also the first FRB observed to have a regular periodicity. Bursts are clustered into a period of about four days, followed by a dormant period of about 12 days, for a total cycle length of 16.35±0.18 days.[12][97][98] Additional followup studies of the repeating FRB by the Swift XRT and UVOT instruments were reported on 4 February 2020;[99] by the Sardinia Radio Telescope (SRT) and Medicina Northern Cross Radio Telescope (MNC), on 17 February 2020;[100] and, by the Galileo telescope in Asiago, also on 17 February 2020.[101] Further observations were made by the Chandra X-ray Observatory on 3 and 18 December 2019, with no significant x-ray emissions detected at the FRB 180916 location, or from the host galaxy SDSS J015800.28+654253.0.[102] On 6 April 2020, followup studies by the Global MASTER-Net were reported on The Astronomer's Telegram.[103]
FRB 181112
FRB 181112 was mysteriously unaffected after believed to have passed through the Halo of an intervening galaxy.[104]
2019
magnetars, the source of FRB 180924 is an older and less active galaxy.[105][106][107]
Because the source was nonrepeating, the astronomers had to scan large areas with the 36 telescopes of ASKAP. Once a signal was found, they used the Very Large Telescope, the Gemini Observatory in Chile, and the W. M. Keck Observatory in Hawaii to identify its host galaxy and determine its distance. Knowing the distance and source galaxy properties, enables a study of the composition of the in
Because the source was nonrepeating, the astronomers had to scan large areas with the 36 telescopes of ASKAP. Once a signal was found, they used the Very Large Telescope, the Gemini Observatory in Chile, and the W. M. Keck Observatory in Hawaii to identify its host galaxy and determine its distance. Knowing the distance and source galaxy properties, enables a study of the composition of the intergalactic medium.[106]
On 28 June 2019, Russian astronomers reported the discovery of nine FRB events (FRB 121029, FRB 131030, FRB 140212, FRB 141216, FRB 151125.1, FRB 151125.2, FRB 160206, FRB 161202, FRB 180321), which include FRB 151125, the third repeating one ever detected, from the direction of the M 31 (Andromeda Galaxy) and M 33 (Triangulum Galaxy) galaxies during the analysis of archive data (July 2012 to December 2018) produced by the BSA/LPI large phased array radio telescope at the Pushchino Radio Astronomy Observatory.[9][10][11]
FRB 190523On 2 July 2019, astronomers reported that FRB 190523, a non-repeating FRB, has been discovered and, notably, localized to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66, nearly 8 billion light-years away from Earth.[108][109]
August 2019In August 2019, the CHIME Fast Radio Burst Collaboration reported the detection of eight more repeating FRB signals.[21][22]
FRB 191223
On 29 December 2019, Australian astronomers from the Molonglo Observatory Synthesis Telescope (MOST), using the UTMOST fast radio burst equipment, reported the detection of FRB 191223 in the Octans constellation (RA = 20:34:14.14, DEC = -75:08:54.19).[110][111]
FRB 191228
On 31 December 2019, Australian astronomers, using the Australian Square Kilometre Array Pathfinder (ASKAP), reported the detection of FRB 191228 in the Piscis Austrinus constellation (RA = 22:57(2), DEC = -29:46(40)).[110][112]
2020