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Lecture 4: Light extinction : Compton scattering Gamma-Ray Bursts. GRBs are brief flashes of soft -ray radiation ( 100 keV), discovered in the 1970’s, the origin of which was not known until 1997. CGRO-BATSE. Compton thick sources
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Lecture 4: Light extinction: Compton scattering Gamma-Ray Bursts
GRBs are brief flashes of soft -ray radiation (100 keV), discovered in the 1970’s, the origin of which was not known until 1997 CGRO-BATSE
Compton thick sources In Seyfert 2 galaxies there is evidence of cold material around the nucleus and of absorption caused by this material in excess of the Galactic one. The local column density of this material is optically thick to Compton scattering Bassani et al. 1999, ApJS, 121, 473 Matt et al. 1999, New Astronomy, 4, 191
CGRO-BATSE (Fishman & Meegan 1995) Light curves of GRBs Fluence ~ if cosmological relativistic conditions are implied: Lorentz factor