Fermi Gamma-ray Space Telescope

Cosmic-ray acceleration in RCW 86 : new clues from HESS and Fermi-LAT Pass 8 data

B. Condon
M. Caragiulo, J. W. Hewitt, M. Lemoine-Goumard, I. Jung-Richardt

Abstract:

RCW 86 is a young supernova remnant detected as a shell in radio, optical, infrared and X-rays. The latest X-ray observations suggest that this remnant may be an efficient cosmic-ray accelerator. We will show the results of a deep morphological and spectral analysis, using more than 6 years of data acquired by the Fermi Large Area Telescope with the new Pass 8 event reconstruction. These studies reveal a significant extended source at GeV energies (r = 0.37) and a hard spectrum (Index = 1.4 between 100 MeV and 500 GeV). In addition, complementary results obtained with the High Energy Stereoscopic System (H.E.S.S.) provide the first evidence of a shell in TeV gamma-rays and precise measurements of the spectral energy distribution. Using all the available data from radio to VHE gamma-rays, we perform broadband modeling of the nonthermal emission of RCW 86 which constrains key parameters such as the magnetic field and the total energy in accelerated particles.