The escape of greater MeV photons from cosmological gamma-ray bursts

Details The escape of greater MeV photons from cosmological gamma-ray bursts The escape of greater MeV photons from cosmological gamma-ray bursts

Mar 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992stin...9230706f&link_type=abstract

Presented at the Recent Advanced in High Energy Astronomy, Toulouse, France, 17-22 Mar. 1992

Astronomy and Astrophysics

Astronomy

Cosmology, Gamma Ray Bursts, Pair Production, Particle Interactions, Photon Density, Photons, Gamma Ray Astronomy, Photosphere, Spectra

Scientific paper

The recent BATSE result indicates that gamma-ray bursts may be at cosmological distances. As such one must reconcile the high photon densities with the observations of spectra to energies well above the pair production threshold. We have investigated two models of relativistic flows that could provide the requiste beaming to allow the escape of 100 MeV photons: a stationary relativistic wind with a photosphere and a relativistic expanding shell. For typical cosmological gamma-ray burst parameters, the expanding shell model requires a Lorentz factor (gamma) of only 102 compared with 3(10)2 to 103 for the relativistic wind. For the expanding shell model, events separated in time at the central source produce peaks observed to be separated by the same time. However, the shape and duration of the peaks are determined by the expansion. The expansion can occur over a much longer time (by gamma2) then the duration that the observer sees so gamma-ray burst could be larger than 102 light-seconds. We have made two crucial assumptions that require further study. The spectrum was assumed to a be a power law and a two component power law or a power law with a high-energy cut-off would decrease the required gamma. The expanding shell model uses an infinitely thin emitting surface and one with a finite thickness could increase the required gamma.

Affiliated with

Also associated with

No associations

Rating

The escape of greater MeV photons from cosmological 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 The escape of greater MeV photons from cosmological gamma-ray bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The escape of greater MeV photons from cosmological gamma-ray bursts will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1491832