Shallow Decay of Early X-Ray Afterglows from Inhomogeneous Gamma-Ray Burst Jets
Abstract
Almost all the X-ray afterglows of γ-ray bursts (GRBs) observed by the Swift satellite have a shallow decay phase in their first few thousand seconds. We show that in an inhomogeneous-jet model (multiple-subjet or patchy-shell), the superposition of the afterglows of off-axis subjets (patchy shells) can produce the shallow decay phase. The necessary condition for obtaining the shallow decay phase is that γ-ray–bright subjets (patchy shells) have γ-ray efficiencies higher than previously estimated and that they be surrounded by γ-ray–dim subjets (patchy shells) with low γ-ray efficiency. Our model predicts that events with dim prompt emission will have a conventional afterglow light curve without a shallow decay phase, like GRB 050416A.
Journal
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- The Astrophysical Journal
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The Astrophysical Journal 640 (2), L139-L142, 2006-04
The American Astronomical Society
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Details
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- CRID
- 1050296265988045568
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- NII Article ID
- 120000882222
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- Text Lang
- en
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- Article Type
- journal article
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- Data Source
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- IRDB
- CiNii Articles