학술논문
IPTF14yb: The first discovery of a gamma-ray burst afterglow independent of a high-energy trigger
Document Type
article
Author
Cenko, SB; Urban, AL; Perley, DA; Horesh, A; Corsi, A; Fox, DB; Cao, Y; Kasliwal, MM; Lien, A; Arcavi, I; Bloom, JS; Butler, NR; Cucchiara, A; Diego, JAD; Filippenko, AV; Gal-Yam, A; Gehrels, N; Georgiev, L; González, JJ; Graham, JF; Greiner, J; Kann, DA; Klein, CR; Knust, F; Kulkarni, SR; Kutyrev, A; Laher, R; Lee, WH; Nugent, PE; Xavier Prochaska, J; Ramirez-Ruiz, E; Richer, MG; Rubin, A; Urata, Y; Varela, K; Watson, AM; Wozniak, PR
Source
Astrophysical Journal Letters. 803(2)
Subject
Language
Abstract
We report here the discovery by the Intermediate Palomar Transient Factory (iPTF) of iPTF14yb, a luminous(Mr ≈ -27.8 mag), cosmological (redshift 1.9733), rapidly fading optical transient. We demonstrate, based onprobabilistic arguments and a comparison with the broader population, that iPTF14yb is the optical afterglow ofthe long-duration gamma-ray burst GRB 140226A. This marks the first unambiguous discovery of a GRBafterglow prior to (and thus entirely independent of) an associated high-energy trigger. We estimate the rate ofiPTF14yb-like sources (i.e., cosmologically distant relativistic explosions) based on iPTF observations, inferringan all-sky value of Rrel = 610 yr?1 (68% confidence interval of 1102000 yr?1). Our derived rate is consistent(within the large uncertainty) with the all-sky rate of on-axis GRBs derived by the Swift satellite. Finally, webriefly discuss the implications of the nondetection to date of bona fide orphan afterglows (i.e., those lackingdetectable high-energy emission) on GRB beaming and the degree of baryon loading in these relativistic jets.