1. A candidate coherent radio flash following a neutron star merger.
- Author
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Rowlinson, A, Ruiter, I de, Starling, R L C, Rajwade, K M, Hennessy, A, Wijers, R A M J, Anderson, G E, Mevius, M, Ruhe, D, Gourdji, K, Horst, A J van der, Veen, S ter, and Wiersema, K
- Subjects
RADIO sources (Astronomy) ,GAMMA ray bursts ,NEUTRON stars ,STELLAR mergers ,REDSHIFT ,MAGNETARS - Abstract
In this paper, we present rapid follow-up observations of the short GRB 201006A, consistent with being a compact binary merger, using the LOw Frequency ARray (LOFAR). We have detected a candidate 5.6 |$\sigma$| , short, coherent radio flash at 144 MHz at 76.6 min post-GRB with a 3 |$\sigma$| duration of 38 s. This radio flash is 27 arcsec offset from the GRB location, which has a probability of being co-located with the GRB of |$\sim$| 0.05 per cent (3.8 |$\sigma$|) when accounting for measurement uncertainties. Despite the offset, we show that the probability of finding an unrelated transient within 40 arcsec of the GRB location is |$\lt 10^{-6}$| and conclude that this is a candidate radio counterpart to GRB 201006A. We performed image plane dedispersion and the radio flash is tentatively (2.4 |$\sigma$|) shown to be highly dispersed, allowing a distance estimate, corresponding to a redshift of |$0.58\pm 0.06$|. The corresponding luminosity of the event at this distance is |$6.7^{+6.6}_{-4.4} \times 10^{32}$| erg s |$^{-1}$| Hz |$^{-1}$|. If associated with GRB 201006A, this emission would indicate prolonged activity from the central engine that is consistent with being a newborn, supramassive, likely highly magnetized, millisecond spin neutron star (a magnetar). [ABSTRACT FROM AUTHOR]
- Published
- 2024
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