Proton-synchrotron as the radiation mechanism of the prompt emission of GRBs?. (arXiv:1912.02185v1 [astro-ph.HE])

Proton-synchrotron as the radiation mechanism of the prompt emission of GRBs?. (arXiv:1912.02185v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ghisellini_G/0/1/0/all/0/1">G. Ghisellini</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Ghirlanda_G/0/1/0/all/0/1">G. Ghirlanda</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Oganesyan_G/0/1/0/all/0/1">G. Oganesyan</a> (2,3,4), <a href="http://arxiv.org/find/astro-ph/1/au:+Ascenzi_S/0/1/0/all/0/1">S. Ascenzi</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Nava_L/0/1/0/all/0/1">L. Nava</a> (1,5,6,7), <a href="http://arxiv.org/find/astro-ph/1/au:+Celotti_A/0/1/0/all/0/1">A. Celotti</a> (8,1,6,7), <a href="http://arxiv.org/find/astro-ph/1/au:+Salafia_O/0/1/0/all/0/1">O.S. Salafia</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Ravasio_E/0/1/0/all/0/1">E.M. Ravasio</a> (1,9), <a href="http://arxiv.org/find/astro-ph/1/au:+Ronchi_M/0/1/0/all/0/1">M. Ronchi</a> (1) (1:OA Brera, 2: GSSI, 3: INFN L&#x27;Aquila, 4: OA Teramo, 5: OA Trieste, 6: INFN 7: IFPU Trieste, 8: SISSA Trieste, 9: Univ. Bicocca Milano)

We discuss the new surprising observational results that indicate quite
convincingly that the prompt emission of Gamma-Ray Bursts (GRBs) is due to
synchrotron radiation produced by a particle distribution that has a low energy
cut-off. The evidence of this is provided by the low energy part of the
spectrum of the prompt emission, that shows the characteristic F(nu) propto
nu^(1/3) shape followed by F(nu) propto nu^(-1/2) up to the peak frequency.
This implies that although the emitting particles are in fast cooling, they do
not cool completely. This poses a severe challenge to the basic ideas about how
and where the emission is produced, because the incomplete cooling requires a
small value of the magnetic field, to limit synchrotron cooling, and a large
emitting region, to limit the self-Compton cooling, even considering
Klein-Nishina scattering effects. Some new and fundamental ingredient is
required for understanding the GRBs prompt emission. We propose
proton-synchrotron as a promising mechanism to solve the incomplete cooling
puzzle.

We discuss the new surprising observational results that indicate quite
convincingly that the prompt emission of Gamma-Ray Bursts (GRBs) is due to
synchrotron radiation produced by a particle distribution that has a low energy
cut-off. The evidence of this is provided by the low energy part of the
spectrum of the prompt emission, that shows the characteristic F(nu) propto
nu^(1/3) shape followed by F(nu) propto nu^(-1/2) up to the peak frequency.
This implies that although the emitting particles are in fast cooling, they do
not cool completely. This poses a severe challenge to the basic ideas about how
and where the emission is produced, because the incomplete cooling requires a
small value of the magnetic field, to limit synchrotron cooling, and a large
emitting region, to limit the self-Compton cooling, even considering
Klein-Nishina scattering effects. Some new and fundamental ingredient is
required for understanding the GRBs prompt emission. We propose
proton-synchrotron as a promising mechanism to solve the incomplete cooling
puzzle.

http://arxiv.org/icons/sfx.gif

Comments are closed.