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The 'Supercritical Pile' GRB Model: Afterglows and GRB, XRR, XRF UnificationWe present the general notions and observational consequences of the "Supercritical Pile" GRB model; the fundamental feature of this model is a detailed process for the conversion of the energy stored in relativistic protons in the GRB Relativistic Blast Waves (RBW) into relativistic electrons and then into radiation. The conversion is effected through the $p \, \gamma \rightarrow p \, e circumflex + e circumflex -$ reaction, whose kinematic threshold is imprinted on the GRB spectra to provide a peak of their emitted luminosity at energy \Ep $\sim 1$ MeV in the lab frame. We extend this model to include, in addition to the (quasi--)thermal relativistic post-shock protons an accelerated component of power law form. This component guarantees the production of $e circumflex +e circumflex- - $pairs even after the RBW has slowed down to the point that its (quasi-) thermal protons cannot fulfill the threshold of the above reaction. We suggest that this last condition marks the transition from the prompt to the afterglow GRB phase. We also discuss conditions under which this transition is accompanied by a significant drop in the flux and could thus account for several puzzling, recent observations. Finally, we indicate that the same mechanism applied to the late stages of the GRB evolution leads to a decrease in \Ep $\propto \Gamma circumflex 2(t)\propto t circumflex {-3/4}$, a feature amenable to future observational tests.
Document ID
20080031698
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Kazanas, D.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 24, 2013
Publication Date
March 18, 2007
Subject Category
Astronomy
Meeting Information
Meeting: The Next Decade of GRB Afterglows
Location: Amsterdam
Country: Netherlands
Start Date: March 18, 2007
End Date: March 23, 2007
Sponsors: Amsterdam Univ.
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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