Gamma-Ray Burst in a Binary System
| Autor: | Xiao-Hong Zhao, Yong-Feng Huang, Bin-Bin Zhang, Ze-Cheng Zou |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Brightness Jet (fluid) Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astronomy and Astrophysics Astrophysics Radius Observer (special relativity) Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics::Solar and Stellar Astrophysics Binary system Astrophysics::Earth and Planetary Astrophysics Gamma-ray burst Astrophysics - High Energy Astrophysical Phenomena Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.2106.12838 |
| Popis: | Regardless of their different types of progenitors and central engines, gamma-ray bursts (GRBs) were always assumed to be standalone systems after they formed. Little attention has been paid to the possibility that a stellar companion can still accompany a GRB itself. This paper investigates such a GRB-involved binary system and studies the effects of the stellar companion on the observed GRB emission when it is located inside the jet opening angle. Assuming a typical emission radius of $\sim10^{15}\,$cm, we show that the blockage by a companion star with a radius of $R_\mathrm{c}\sim67\,\mathrm{R_\odot}$ becomes non-negligible when it is located within a typical GRB jet opening angle (e.g., $\sim10$ degrees) and beyond the GRB emission site. In such a case, an on-axis observer will see a GRB with a similar temporal behavior but 25% dimmer. On the other hand, an off-axis observer outside the jet opening angle (hence missed the original GRB) can see a delayed "reflected" GRB, which is much fainter in brightness, much wider in the temporal profile and slightly softer in energy. Our study can naturally explain the origin of some low-luminosity GRBs. Moreover, we also point out that the companion star may be shocked if it is located inside the GRB emission site, which can give rise to an X-ray transient or a GRB followed by a delayed X-ray bump on top of X-ray afterglows. Comment: 11 pages, 6 figures, 1 table, accepted by ApJ |
| Databáze: | OpenAIRE |
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