Hadronic emission in middle-aged SNRs
Abstract
Recent gamma-rays observations of Supernova Remnants revealed the existence of a class of objects characterized by an age older than some thousands of years, interacting with massive molecular clouds and with a soft spectral energy distribution peaked at some hundreds of MeV. This class includes the well known SNRs W44, IC 443, W28, W51C and others. Here we present the AGILE observations of this class of SNRs in the band 50 MeV - 10 GeV. The observations in this range (especially in the lowest part, 50-100 MeV) are crucial in constraining the emission models of these objects and can be used to study the diffusion of particles in the ISM around the source. Probably the most relevant object in this class is SNR W44, for which, combining gammarays and radio observations, we demonstrated that lepton-dominated models fail to explain simultaneously the well-constrained multiwavelenght spectrum, leading to the first unambiguous evidence of gamma-rays emission from neutral-pions decay in a SNR.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E1001G