Title: Cosmic-Ray Acceleration in SN1006: Synchrotron Radiation and Nonthermal Bremsstrahlung in Hard X-Rays


Proposal ID: 0120133
Subject category: Others
Principal investigator: Reynolds
Institute: North Carolina State University


Abstract

We propose a 900 ksec observation of the remnant of the supernova of 1006 AD, the Rosetta Stone object for the study of electron acceleration to very high energies. The combination of IBIS and Jem-X spatial and spectral coverage should allow testing of the hyposthesis that the emission above 3 keV is dominantly synchrotron, and should either detect, or put limits on, a contribution from nonthermal bremsstrahlung. The angular diameter of SN 1006, 30', is large enough that IBIS will have sufficient spatial resolution to perform a simple discrimination on the highest-energy detectable hard X-rays: synchrotron emission should come from two opposing limbs, while bremsstrahlung should have a more uniform ring morphology. Jem-X will resolve SN 1006 with about 10 beams across its diameter, ample to search for a bremsstrahlung contribution and comparable to ASCA resolution at thermal X-ray energies. The energy range of 5 to 50 keV shows the lowest-energy suprathermal cosmic-ray electrons, through bremsstrahlung, and the highest-energy electrons, through synchrotron radiation. Quantitative inferences from detections or limits can include the efficiency of shock acceleration of electrons, the maximum energies to which electrons can be accelerated, and indirect constraints on the mean remnant magnetic field strength. INTEGRAL can make a major contribution to the understanding of nonthermal emission from this important object, and through it, to the understanding acceleration of particles at shocks anywhere in astrophysics.