Fermi lat Discovery of Extended Gamma-ray Emissions in the Vicinity of the hb 3 Supernova Remnant

H. Katagiri , K. Yoshida , J. Ballet (1) , M.H. Grondin (2) , Y. Hanabata , J.W. Hewitt , H. Kubo , M. Lemoine-Goumard (2)

1 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
2 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

We report the discovery of extended gamma-ray emission measured by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) HB 3 (G132.7+1.3) and the W3 II complex adjacent to the southeast of the remnant. W3 is spatially associated with bright (12)CO (J = 1–0) emission. The gamma-ray emission is spatially correlated with this gas and the SNR. We discuss the possibility that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields. The decay of neutral pions produced in nucleon–nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray emission. The emission from W3 is consistent with irradiation of the CO clouds by the cosmic rays accelerated in HB 3.

Mots clés: acceleration of particles; cosmic rays; gamma rays: ISM; ISM: individual objects; ISM: supernova remnants; gamma ray: emission; nucleon nucleon: interaction; gas; supernova; GLAST; cosmic radiation; irradiation; hadron; cloud

Domaines: Astrophysique [astro-ph]

H. Katagiri, K. Yoshida, J. Ballet, M.H. Grondin, Y. Hanabata, et al.. Fermi lat Discovery of Extended Gamma-ray Emissions in the Vicinity of the hb 3 Supernova Remnant. Astrophys.J., 2016, 818 (2), pp.114. ⟨10.3847/0004-637X/818/2/114⟩. ⟨hal-03626448⟩