The Early Time Properties of GRBs - Canonical Afterglows and the Importance of Prolonged Central Engine Activity

Journal Article · Mon May 25 00:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3155885· OSTI ID:21304945

Melandri, A; Mundell, C G; Kobayashi, S; Bersier, D; Steele, I A; Smith, R J; Carter, D; Bode, M F ^[1]; Guidorzi, C ^[1]; Gomboc, A ^[2]

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1. Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom)
2. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana (Slovenia)

Using a new, comprehensive multiwavelength survey of 63 Gamma Ray Bursts (GRBs) with unprecedented temporal coverage, we classify the observed afterglows into four main classes and discuss the underlying physics that can explain them. The presence or absence of temporal breaks in X-ray and optical bands is used to examine the emission in the context of the standard model; a number of GRBs are shown to deviate from the forward shock model even with the inclusion of energy injection or ambient density gradients. We show that additional emission in the early-time X-ray afterglow due to late-time central engine activity is key and may explain both GRBs whose afterglows do not fit the standard model and those GRBs that appear to be optically dark even at early times.

• OSTI ID: 21304945
• Journal Information: AIP Conference Proceedings, Vol. 1133, Issue 1; Conference: 6. Huntsville symposium on gamma-ray burst, Huntsville, AL (United States), 20-23 Oct 2008; Other Information: DOI: 10.1063/1.3155885; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
AFTERGLOW
COSMIC GAMMA BURSTS
COSMIC GAMMA SOURCES
COSMIC PHOTONS
COSMIC X-RAY SOURCES
GAMMA ASTRONOMY
GAMMA DETECTION
PHOTOMETRY
STANDARD MODEL
TELESCOPE COUNTERS
X RADIATION
X-RAY DETECTION