Observations of fast radio bursts at frequencies down to 400 megahertz

© 2019, Springer Nature Limited. Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio flashes probably arriving from far outside the Milky Way1,2. This phenomenon was discovered at radio frequencies near 1.4 gigahertz and so far has been observed in one case3 at as high as 8 giga...

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Format: Article
Language:English
Published: Springer Science and Business Media LLC 2021
Online Access:https://hdl.handle.net/1721.1/132481
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description © 2019, Springer Nature Limited. Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio flashes probably arriving from far outside the Milky Way1,2. This phenomenon was discovered at radio frequencies near 1.4 gigahertz and so far has been observed in one case3 at as high as 8 gigahertz, but not at below 700 megahertz in spite of substantial searches at low frequencies4–7. Here we report detections of 13 FRBs at radio frequencies as low as 400 megahertz, on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) using the CHIME/FRB instrument8. They were detected during a telescope pre-commissioning phase, when the sensitivity and field of view were not yet at design specifications. Emission in multiple events is seen down to 400 megahertz, the lowest radio frequency to which the telescope is sensitive. The FRBs show various temporal scattering behaviours, with the majority detectably scattered, and some apparently unscattered to within measurement uncertainty even at our lowest frequencies. Of the 13 reported here, one event has the lowest dispersion measure yet reported, implying that it is among the closest yet known, and another has shown multiple repeat bursts, as described in a companion paper9. The overall scattering properties of our sample suggest that FRBs as a class are preferentially located in environments that scatter radio waves more strongly than in the diffuse interstellar medium in the Milky Way.
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spelling mit-1721.1/1324812022-04-01T17:20:50Z Observations of fast radio bursts at frequencies down to 400 megahertz © 2019, Springer Nature Limited. Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio flashes probably arriving from far outside the Milky Way1,2. This phenomenon was discovered at radio frequencies near 1.4 gigahertz and so far has been observed in one case3 at as high as 8 gigahertz, but not at below 700 megahertz in spite of substantial searches at low frequencies4–7. Here we report detections of 13 FRBs at radio frequencies as low as 400 megahertz, on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) using the CHIME/FRB instrument8. They were detected during a telescope pre-commissioning phase, when the sensitivity and field of view were not yet at design specifications. Emission in multiple events is seen down to 400 megahertz, the lowest radio frequency to which the telescope is sensitive. The FRBs show various temporal scattering behaviours, with the majority detectably scattered, and some apparently unscattered to within measurement uncertainty even at our lowest frequencies. Of the 13 reported here, one event has the lowest dispersion measure yet reported, implying that it is among the closest yet known, and another has shown multiple repeat bursts, as described in a companion paper9. The overall scattering properties of our sample suggest that FRBs as a class are preferentially located in environments that scatter radio waves more strongly than in the diffuse interstellar medium in the Milky Way. 2021-09-20T18:22:39Z 2021-09-20T18:22:39Z 2020-11-03T15:32:01Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/132481 en 10.1038/s41586-018-0867-7 Nature Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Springer Science and Business Media LLC arXiv
spellingShingle Observations of fast radio bursts at frequencies down to 400 megahertz
title Observations of fast radio bursts at frequencies down to 400 megahertz
title_full Observations of fast radio bursts at frequencies down to 400 megahertz
title_fullStr Observations of fast radio bursts at frequencies down to 400 megahertz
title_full_unstemmed Observations of fast radio bursts at frequencies down to 400 megahertz
title_short Observations of fast radio bursts at frequencies down to 400 megahertz
title_sort observations of fast radio bursts at frequencies down to 400 megahertz
url https://hdl.handle.net/1721.1/132481