Physics
Scientific paper
Dec 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998phdt.........4p&link_type=abstract
Thesis (PHD). THE PENNSYLVANIA STATE UNIVERSITY , Source DAI-B 59/06, p. 2803, Dec 1998, 208 pages.
Physics
Time Averaged Spectra
Scientific paper
The origin of Gamma Ray Bursts (GRB) is still embedded in mystery. There is, however, good evidence that, irrespective of the trigger mechanism and the progenitor's identity, GRBs involve ultra-relativistic flows. It has been suggested that such outflows develop shocks due to their deceleration by the surrounding medium (external shocks) and, possibly, due to variability within the flow (internal shocks). Such shocks are believed to act as particle accelerators and magnetic field amplifiers. In this thesis, we study the spectral properties of external and internal shocks. We employ an extensive parameterization of the uncertain physical processes (electron injection and acceleration, magnetic field amplification) in the shocks and calculate the time averaged spectra that result from synchrotron emission and its inverse Compton scattered counterpart. Overall, the resulting spectra share the defining properties of the observed ones: they are non-thermal, they show a break (whose value is not fixed by the model), and spectral slopes in the range that was revealed by fitting BATSE spectra. The hardness-duration anti-correlation and the brightness-hardness correlation are properties inherent to the model spectra (both in external and internal shocks). The spectra are, in general, very broad and counterparts in higher and lower frequencies are predicted. Behaviors such as X-ray deficiency and occasional X-ray excess are common. We discuss the broad-band properties of the spectra and the spectral differences between internal and external shocks bursts. We also examine the spectral properties arising from the deceleration of an unsteady wind that results in hard and delayed emission from external shocks following the main burst from internal ones. We conduct a parameter search in order to identify the environments external shock bursts take place in, as well as the radiative properties of the shocks. Internal shocks are semi-relativistic (v≃0.6c), but one of the external shocks is ultra-relativistic (v ~ > 0.99995c). The properties of very relativistic shocks are poorly understood. Our parameter space covers a wide range of values intended to describe these shocks' capabilities as these are suggested by the spectral properties of GRBs.
No associations
LandOfFree
Spectral Properties of Relativistic Shocks in Gamma-Ray Bursts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spectral Properties of Relativistic Shocks in Gamma-Ray Bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectral Properties of Relativistic Shocks in Gamma-Ray Bursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-764240