Rapid-response radio observations of short GRB 181123B with the Australia Telescope Compact Array
| Autor: | Antonia Rowlinson, Jamie Stevens, Richard M. Plotkin, Ralph A. M. J. Wijers, G. E. Anderson, Jean-Pierre Macquart, Paul Hancock, M. D. Aksulu, James Miller-Jones, Martin Bell, Arash Bahramian, A. J. van der Horst, Stuart D. Ryder |
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| Přispěvatelé: | High Energy Astrophys. & Astropart. Phys (API, FNWI) |
| Rok vydání: | 2021 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Gravitational wave FOS: Physical sciences Flux Astronomy and Astrophysics Astrophysics Electron Radio spectrum LIGO Afterglow law.invention Telescope Space and Planetary Science law Astrophysics - High Energy Astrophysical Phenomena Gamma-ray burst |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 503(3), 4372-4386. Oxford University Press |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab727 |
| Popis: | We introduce the Australia Telescope Compact Array (ATCA) rapid-response mode by presenting the first successful trigger on the short-duration gamma-ray burst (GRB) 181123B. Early-time radio observations of short GRBs may provide vital insights into the radio afterglow properties of Advanced LIGO- and Virgo-detected gravitational wave events, which will in turn inform follow-up strategies to search for counterparts within their large positional uncertainties. The ATCA was on target within 12.6 hr post-burst, when the source had risen above the horizon. While no radio afterglow was detected during the 8.3 hr observation, we obtained force-fitted flux densities of $7 \pm 12$ and $15 \pm 11~\mu$Jy at 5.5 and 9 GHz, respectively. Afterglow modelling of GRB 181123B showed that the addition of the ATCA force-fitted radio flux densities to the Swift X-ray Telescope detections provided more stringent constraints on the fraction of thermal energy in the electrons (log$\epsilon_e = -0.75^{+0.39}_{-0.40}$ rather than log$\epsilon_e = -1.13^{+0.82}_{-1.2}$ derived without the inclusion of the ATCA values), which is consistent with the range of typical $\epsilon_e$ derived from GRB afterglow modelling. This allowed us to predict that the forward shock may have peaked in the radio band $\sim10$ days post-burst, producing detectable radio emission $\gtrsim3-4$ days post-burst. Overall, we demonstrate the potential for extremely rapid radio follow-up of transients and the importance of triggered radio observations for constraining GRB blast wave properties, regardless of whether there is a detection, via the inclusion of force-fitted radio flux densities in afterglow modelling efforts. Comment: 15 pages, 7 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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