A Demonstration of Extremely Low Latency \(\gamma\)-ray, X-Ray & UV Follow-Up of a Millisecond Radio Transient

• Published in: arXiv.org 2020-06
• Main Authors: Tohuvavohu, Aaron, Law, Casey J, Kennea, Jamie A, Adams, Elizabeth A K, Aggarwal, Kshitij, Bower, Geoffrey, Burke-Spolaor, Sarah, Butler, Bryan J, Cannon, John M, S Bradley Cenko, DeLaunay, James, Demorest, Paul, Drout, Maria R, Evans, Philip A, Hirschauer, Alec S, Lazio, T J W, Linford, Justin, Marshall, Francis E, McQuinn, K, Petroff, Emily, Skillman, Evan D
• Format: Article
• Language: English
• Subjects: Fluence; Gamma rays; Radio bursts; Soft x rays
• ISSN: 2331-8422

We report results of a novel high-energy follow-up observation of a potential Fast Radio Burst. The radio burst was detected by VLA/realfast and followed-up by the Neil Gehrels Swift Observatory in very low latency utilizing new operational capabilities of Swift (arXiv:2005.01751), with pointed soft X-ray and UV observations beginning at T0+32 minutes, and hard X-ray/gamma-ray event data saved around T0. These observations are \(>10\)x faster than previous X-ray/UV follow-up of any radio transient to date. No emission is seen coincident with the FRB candidate at T0, with a 0.2s fluence \(5\sigma\) upper limit of \(1.35\times10^{-8}\) erg cm\(^{-2}\) (14-195 keV) for a SGR 1935+2154-like flare, nor at T0+32 minutes down to \(3\sigma\) upper limits of 22.18 AB mag in UVOT u band, and \(3.33\times10^{-13}\) erg cm\(^{-2}\) s\(^{-1}\) from 0.3-10 keV for the 2 ks observation. The candidate FRB alone is not significant enough to be considered astrophysical, so this note serves as a technical demonstration. These new Swift operational capabilities will allow future FRB detections to be followed up with Swift at even lower latencies than demonstrated here: 15-20 minutes should be regularly achievable, and 5-10 minutes occasionally achievable. We encourage FRB detecting facilities to release alerts in low latency to enable this science.