PROBABLE SPECTRAL STEEPENING OF UHE GAMMA-RAYS OF NUCLEAR-ORIGIN AND ITS CONSEQUENCES

Authors
Citation
A. Mitra, PROBABLE SPECTRAL STEEPENING OF UHE GAMMA-RAYS OF NUCLEAR-ORIGIN AND ITS CONSEQUENCES, Journal of astrophysics and astronomy, 15(2), 1994, pp. 179-186
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
0250-6335
Volume
15
Issue
2
Year of publication
1994
Pages
179 - 186
Database
ISI
SICI code
0250-6335(1994)15:2<179:PSSOUG>2.0.ZU;2-C
Abstract
Recent accelerator data based parameterization of the inclusive cross section (c - s) for pi0 production in hadronic collisions and an expli cit incorporation of the finiteness of the relevant projectile hadron spectrum suggest a significant steepening in the spectrum (by as much as 0.4 in the spectral index) of the secondary gamma-ray towards the e nd of the spectrum. We emphasize here that this spectral steepening in conjunction with the possibility that in the bright X-ray binaries th e maximum energy to which the gamma-ray producing progenitor protons m ay be accelerated is only approximately 10 PeV, may imply an effective efficiency for gamma-ray production, epsilon, as reckoned by the PeV arrays, one or two orders smaller than the previous estimates. To expl ain the genesis of a given PeV photon flux from an X-ray binary, one, therefore, has to accordingly consider a much higher value of the prog enitor proton beam luminosity, L(p). This requirement may raise furthe r questions regarding the actual genesis of PeV gamma-rays in X-ray bi naries, or alternatively, on the veracity of the high values of the Pe V photon fluxes reported by earlier experiments.