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Photons and Particle Production in Cassiopeia A: Predictions from Nonlinear Diffusive Shock Acceleration

Donald C. Ellison·Philippe Goret·Matthew G. Baring·Isabelle A. Grenier·Pierre-Olivier Lagage
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Abstract

We calculate particle spectra and continuum photon emission from the Cassiopeia A supernova remnant (SNR). The particle spectra, ion and electron, result from diffusive shock acceleration at the forward SNR shock and are determined with a nonlinear Monte Carlo calculation. The calculation self-consistently determines the shock structure under the influence of ion pressure, and includes a simple parameterized treatment of electron injection and acceleration. Our results are compared to photon observations, concentrating on the connection between the Radio and GeV-TeV gamma-ray range, and to cosmic ray ion observations. We include new upper limits from the Cherenkov Array at Themis (CAT) imaging Cherenkov telescope and the Whipple 10m gamma-ray telescope at > 400 GeV. These new limits support the suggestion (e.g. Cowsik & Sarkar 1980; Allen et. al. 1997) that energetic electrons are emitting synchrotron radiation in an extremely high magnetic field (~ 1000 microGauss), far greater than values routinely assigned to the ISM, and help to constrain our model. The large magnetic field allows acceleration of cosmic ray ions to well above $10^{15}$ eV per nucleon in the ~ 300 yr lifetime of Cas A.

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Donald C. Ellison, Philippe Goret, Matthew G. Baring, Isabelle A. Grenier, Pierre-Olivier Lagage. 1999-10-07. Photons and Particle Production in Cassiopeia A: Predictions from Nonlinear Diffusive Shock Acceleration. https://arxiv.org/abs/astro-ph/9910125

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