Magnetically and Baryonically Dominated Photospheric Gamma-Ray Burst Model Fits to Fermi LAT Observations

Abstract

We consider gamma-ray burst models where the radiation is dominated by a photospheric region providing the MeV Band spectrum, and an external shock region responsible for the GeV radiation via inverse Compton scattering. We parametrize the initial dynamics through an acceleration law Gamma \propto r^μ, with μbetween 1/3 and 1 to represent the range between an extreme magnetically dominated and a baryonically dominated regime. We compare these models to several bright Fermi LAT bursts, and show that both the time integrated and the time resolved spectra, where available, can be well described by these models. We discuss the parameters which result from these fits, and discuss the relative merits and shortcomings of the two models.

8 pages, 14 figures, corrected version, accepted by ApJ

References in corpus (3)

• Detection of a Thermal Spectral Component in the Prompt Emission of GRB 100724B
• A Comprehensive Analysis of Fermi Gamma-Ray Burst Data. I. Spectral Components and Their Possible Physical Origins of LAT/GBM GRBs
• The extremely high peak energy of GRB 110721A in the context of a dissipative photosphere synchrotron emission model

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• Gamma-ray Bursts Induced by Turbulent Reconnection
• An Observed Correlation Between Thermal and Non-Thermal Emission in Gamma-Ray Bursts
• Ultra-high Energy Cosmic Rays and Neutrinos from Gamma-Ray Bursts, Hypernovae and Galactic Shocks
• Physics of non-dissipative ultrarelativistic photospheres
• Statistical properties of Fermi GBM GRBs' spectra
• A Small, Rapid Optical-IR Response Gamma-Ray Burst Space Observatory (The NGRG)
• Polarization of gamma-ray burst afterglows in the synchrotron self-Compton process from a highly relativistic jet