Mathematics – Logic
Scientific paper
May 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995aas...186.0503p&link_type=abstract
American Astronomical Society, 186th AAS Meeting, #05.03; Bulletin of the American Astronomical Society, Vol. 27, p.819
Mathematics
Logic
Scientific paper
We present spectral calculations for Gamma Ray Bursts (GRB) capable of explaining the bulk-part of the bursts' spectral properties. Relativistic outflows are invoked by many GRB models. Here, we consider the unsteady relativistic wind (Rees and Meszaros, 1994) in a cosmological framework. We stress its ability to produce up to three bursts with distinct spectra, and examine them, in the context of explaining bursts like the exceptional burst of 2/17/1994, as well as the more typical ones. The optically thick wind, that lasts for tw and varies on tvar, consists mainly of radiation with some baryonic contamination. When relativistic expansion (Gamma ~ 10(2) ) turns the flow optically thin, a burst approximating a black body spectrum of Teff ~ 0.1- 10 keV with mbol > 9 occurs, lasts for tw and goes undetected (in most cases). The bulk of the energy will be dissipated and radiated away later, partly when,due to the flow being unsteady, internal shocks develop and partly when the swept-up surrounding material decelerates the flow causing the formation of a blast wave and a reverse shock. The former burst lasts for tw while the latter takes the typical expansion time-scale (tex). Those two bursts will occur with a time difference of 2 tex and will both have non-thermal spectra. The shocks accelerate electrons and carry frozen-in magnetic field and/or turbulently generate it, thus giving rise to radiation via synchrotron and inverse Compton scattering processes. The power indices and spectral break frequencies are in good agreement with observations. The delayed burst will be, in general, brighter and more energetic (up to 10(2) GeV) than the one due to internal shocks (10(2) keV- GeV). The latter only, or both bursts, are expected to have low energy tails (X-ray down to UV) that may be detectable. A steady wind will not produce the 'internal shock' burst, and a flow that is very poor in baryonic contaminants will result in a thermal burst only thus covering the full range of the bursts' observed spectral characteristics.
Meszaros Peter
Papathanassiou Hara
No associations
LandOfFree
Gamma Ray Bursts from Relativistic Outflows: Spectral Characteristics of Multiple Delayed 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 Gamma Ray Bursts from Relativistic Outflows: Spectral Characteristics of Multiple Delayed Bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gamma Ray Bursts from Relativistic Outflows: Spectral Characteristics of Multiple Delayed Bursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1057101