# An Achromatic Break in the Afterglow of the Short GRB 140903A: Evidence for a Narrow Jet

DOI:
10.3847/0004-637X/827/2/102
Publication date:
01/08/2016
Main author:
Troja, E.
IAA authors:
Castro-Tirado, A. J.;Jeong, S.;Sanchez-Ramirez, R.
Authors:
Troja, E.;Sakamoto, T.;Cenko, S. B.;Lien, A.;Gehrels, N.;Castro-Tirado, A. J.;Ricci, R.;Capone, J.;Toy, V.;Kutyrev, A.;Kawai, N.;Cucchiara, A.;Fruchter, A.;Gorosabel, J.;Jeong, S.;Levan, A.;Perley, D.;Sanchez-Ramirez, R.;Tanvir, N.;Veilleux, S.
Journal:
The Astrophysical Journal
Refereed:
Yes
Publication type:
Article
Volume:
827
Pages:
102
Abstract:
We report the results of our observing campaign on GRB 140903A, a nearby (z = 0.351) short-duration (T <SUB>90</SUB> ∼ 0.3 s) gamma-ray burst discovered by Swift. We monitored the X-ray afterglow with Chandra up to 15 days after the burst and detected a steeper decay of the X-ray flux after t <SUB> j </SUB> ≈ 1 day. Continued monitoring at optical and radio wavelengths showed a similar decay in flux at nearly the same time, and we interpret it as evidence of a narrowly collimated jet. By using the standard fireball model to describe the afterglow evolution, we derive a jet opening angle θ <SUB> j </SUB> ≈ 5° and a collimation-corrected total energy release E ≈ 2 × {10}<SUP>50</SUP> erg. We further discuss the nature of the GRB progenitor system. Three main lines disfavor a massive star progenitor: the properties of the prompt gamma-ray emission, the age and low star formation rate of the host galaxy, and the lack of a bright supernova. We conclude that this event likely originated from a compact binary merger.
Database:
ADS
SCOPUS
WOK
URL:
https://ui.adsabs.harvard.edu/#abs/2016ApJ...827..102T/abstract
ADS Bibcode:
2016ApJ...827..102T
Keywords:
gamma-ray burst: individual: GRB 140903A;X-rays: bursts;Astrophysics - High Energy Astrophysical Phenomena