Open AccessConstraints on the emission mechanisms of gamma‐ray bursts
Author(s) -
Ghisellini Gabriele,
Celotti Annalisa,
Lazzati Davide
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03354.x
Subject(s) - physics , astrophysics , equipartition theorem , synchrotron , compton scattering , synchrotron radiation , particle acceleration , adiabatic process , electron , gamma ray burst , gamma ray , shock (circulatory) , bremsstrahlung , radius , relativistic particle , magnetic field , nuclear physics , quantum mechanics , medicine , computer security , computer science
If the emission of gamma‐ray bursts were as a result of the synchrotron process in the standard internal shock scenario, then the typical observed spectrum should have a slope F ∝ ν −1/2 , which strongly conflicts with the much harder spectra observed. This directly follows from the cooling time being much shorter than the dynamical time. Particle re‐acceleration, deviations from equipartition, quickly changing magnetic fields and adiabatic losses are found to be inadequate to account for this discrepancy. We also find that in the internal shock scenario the relativistic inverse Compton scattering is always as important as the synchrotron process, and faces the same problems. This indicates that the burst emission is not produced by relativistic electrons emitting synchrotron and inverse Compton radiation.