A revisited study of the unidentified $\gamma$-ray emission towards the SNR Kes 41

JORGE L. SUPÁN; GABRIELA CASTELLETTI; DANIEL SUPANITSKY; MICHAEL G. BURTON

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2018

0004-6361

Kes 41 is among the Galactic supernova remnants (SNRs) proposed to be physically linked to gamma-ray emission at GeV energies. Although not conclusively, the nature of the gamma-ray photons has been explained by means of hadronic collisions of particles accelerated at the SNR blast wave with target protons in an adjacent molecular clump. We performed an analysis of Fermi-Large Area Telescope (LAT) data of about 9 years to assess the origin of the gamma-ray emission. To investigate this matter we also used spectral modelling constraints from the physical properties of the interstellar medium towards the gamma-ray emitting region along with a revised radio continuum spectrum of Kes 41 (alpha = -0.54 +/- 0.10, S proportional to freq^alpha). We demonstrated that the gamma-ray fluxes in the GeV range can be explained through bremsstrahlung emission from electrons interacting with the surrounding medium. We also consider a model in which the emission is produced by pion-decay after hadronic collisions, and confirmed that this mechanism cannot be excluded.