| 1. |
- Kirsten, Franz, 1983, et al.
(författare)
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A repeating fast radio burst source in a globular cluster
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 602:7898, s. 585-589
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Tidskriftsartikel (refereegranskat)abstract
- Fast radio bursts (FRBs) are flashes of unknown physical origin1. The majority of FRBs have been seen only once, although some are known to generate multiple flashes2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission4,5. Recently, the discovery6 of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths6. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system7. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.
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| 2. |
- Nimmo, K., et al.
(författare)
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Burst timescales and luminosities as links between young pulsars and fast radio bursts
- 2022
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Ingår i: Nature Astronomy. - : Springer Science and Business Media LLC. - 2397-3366. ; 6:3, s. 393-401
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Tidskriftsartikel (refereegranskat)abstract
- Fast radio bursts (FRBs) are extragalactic radio flashes of unknown physical origin. Their high luminosities and short durations require extreme energy densities, such as those found in the vicinity of neutron stars and black holes. Studying the burst intensities and polarimetric properties on a wide range of timescales, from milliseconds down to nanoseconds, is key to understanding the emission mechanism. However, high-time-resolution studies of FRBs are limited by their unpredictable activity levels, available instrumentation and temporal broadening in the intervening ionized medium. Here we show that the repeating FRB 20200120E can produce isolated shots of emission as short as about 60 nanoseconds in duration, with brightness temperatures as high as 3 × 1041 K (excluding relativistic effects), comparable with ‘nano-shots’ from the Crab pulsar. Comparing both the range of timescales and luminosities, we find that FRB 20200120E observationally bridges the gap between known Galactic young pulsars and magnetars and the much more distant extragalactic FRBs. This suggests a common magnetically powered emission mechanism spanning many orders of magnitude in timescale and luminosity. In this Article, we probe a relatively unexplored region of the short-duration transient phase space; we highlight that there probably exists a population of ultrafast radio transients at nanosecond to microsecond timescales, which current FRB searches are insensitive to.
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