Work

Variabilities of Gamma‐Ray Burst Afterglows: Long‐acting Engine, Anisotropic Jet, or Many Fluctuating Regions?

Year: 2005

Type: article

Abstract: We show that simple kinematic arguments can give limits on the timescale and amplitude of variabilities in gamma-ray burst (GRB) afterglows, especially when the variability timescale is shorter than the observed time since the burst, Δ t < t . These limits help us to identify the sources of afterglow variability. The afterglows of GRB 011211 and GRB 021004 marginally violate these limits. If such violation is confirmed by the Swift satellite, a possible explanation is that (1) the compact objects that power GRB jets continue to eject an intermittent outflow for a very long timescale (≳1 day), (2) the GRB jet from the central engine has a temporal anisotropy with a large brightness contrast ≳10 and small angular structure ≲10 -2 , or (3) many (≳10 3 ) regions fluctuate simultaneously in the emitting site.

Source: The Astrophysical Journal

DOI: 10.1086/432567

Authors: Kunihito Ioka, Shiho Kobayashi, Bing Zhang

Institutions: Pennsylvania State University, University of Nevada, Las Vegas

Language: English

Topic: Gamma-ray bursts and supernovae

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Aeronautics and Space Administration, Pennsylvania State University

Award: MULTI-WAVELENGTH STUDY OF GAMMA-RAY BURSTS & THEIR AFTERGLOWS