The synchrotron-self-Compton spectrum of relativistic blast waves at large Y
Aug 31, 201513 pages
Published in:
- Mon.Not.Roy.Astron.Soc. 453 (2015) 4, 3772-3784
- Published: Nov 11, 2015
e-Print:
- 1508.07830 [astro-ph.HE]
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Abstract: (Oxford University Press)
Recent analyses of multiwavelength light curves of gamma-ray bursts afterglows point to values of the magnetic turbulence well below the canonical ∼1 per cent of equipartition, in agreement with theoretical expectations of a microturbulence generated in the shock precursor, which then decays downstream of the shock front through collisionless damping. As a direct consequence, the Compton parameter Y can take large values in the blast. In the presence of decaying microturbulence and/or as a result of the Klein–Nishina suppression of inverse Compton cooling, the Y parameter carries a non-trivial dependence on the electron Lorentz factor, which modifies the spectral shape of the synchrotron and inverse Compton components. This paper provides detailed calculations of this synchrotron self-Compton spectrum in this large Y regime, accounting for the possibility of decaying microturbulence. It calculates the expected temporal and spectral indices α and β customarily defined by in various spectral domains. This paper also makes predictions for the very high energy photon flux; in particular, it shows that the large Y regime would imply a detection rate of gamma-ray bursts at >10 GeV several times larger than currently anticipated.Note:
- 13 pages, 6 figures, to appear in MNRAS
- acceleration of particles
- shock waves
- gamma-ray burst: general
- gamma ray: burst
- turbulence: magnetic
- photon: flux
- spectral
- suppression
- synchrotron
- blast wave
References(63)
Figures(6)