Title: Gamma-ray observations of Cas A and Tycho supernova remnants: 44Ti lines and high energy continuum


Proposal ID: 0120198
Subject category: Nucleosynthesis
Principal investigator: Decourchelle
Institute: CEA Saclay

Abstract

We propose to observe the hard X-ray and gamma-ray emission from two young supernova remnants Cas A and Tycho using the instruments onboard the Integral satellite. we will determine the 44Ti line intensities and linewidths at 78.4 keV, 67.9 keV and 1.157 MeV from 44Ti decay as well as the high energy continuum emission of these remnants, which are thought to originate from two different types of supernova explosions. Our two major scientific goals are: - The determination of the mass of 44Ti produced during the explosive nucleosynthesis, which is an essential probe of the type of the supernova, and gives crucial constraints on the model of supernova explosive nucleosynthesis. This requires a precise knowledge of the ionisation structure in the ejecta, which will be constrained in the shocked ejecta by fitting non-equilibrium ionisation hydrodynamics models of these supernova remnants to their XMM-Newton and JEM-X X-ray spectra. The deterrmination of the different mechanisms of thermal and non-thermal continuum emission (bremsstrahlung, non-thermal bremsstrahlung, synchrotron, Inverse Compton) and their implication on the efficiency of acceleration of electrons and protons (and potentially alpha) in these two young supernova remnants.