An Achromatic Break in the Afterglow of the Short GRB 140903A: Evidence for a Narrow Jet
We report the results of our observing campaign on GRB 140903A, a nearby (z = 0.351) short-duration (T ∼ 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 ≈ 1 day. Continued m...
| Autores: | , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/380189 |
| Acceso en línea: | http://hdl.handle.net/10261/380189 |
| Access Level: | acceso abierto |
| Palabra clave: | Gamma-ray burst: individual (GRB 140903A) X-rays: bursts |
| Sumario: | We report the results of our observing campaign on GRB 140903A, a nearby (z = 0.351) short-duration (T ∼ 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 ≈ 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 ≈ 5° and a collimation-corrected total energy release E ≈ 2 × 10 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. © 2016. The American Astronomical Society. All rights reserved. |
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