Speaker
Igor Oya
(DESY Zeuthen)
Description
HESS J1641-463 is a unique source discovered by the H.E.S.S. telescope array in the very-high energy (VHE, E >= 0.1 TeV) domain. The source had been previously hidden in the extended tail of emission from the bright nearby source HESS J1640-465. However, the analysis of the VHE data from the region at energies above 4 TeV revealed this new source at a significance level of 8.5 sigma. HESS J1641-463 showed a moderate flux level F(E > 1 TeV) = (3.64 +/- 0.44_stat +/- 0.73_sys) x 10^-13 cm^-2s^-1, corresponding to 1.8% of the Crab Nebula flux above the same energy, and a hard spectrum with a photon index Gamma = 2.07 +/- 0.11_stat +/- 0.20_sys. The light curve was investigated for evidence of variability, but none was found on both short (28-min observation) timescales and long (yearly) timescales. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1. There is no clear X-ray counterpart of the SNR, although Chandra and XMM-Newton data reveal some weak emission that may be associated. If the emission from HESS J1641-463 is produced by cosmic ray protons colliding with the ambient gas, then the proton spectrum extends up to at least 0.1 PeV (99% confidence limit. If this is the case, then HESS J1641-463 may be a member of a larger source population contributing to the Galactic cosmic-ray flux around the knee.
| Registration number following "ICRC2015-I/" | 310 |
|---|---|
| Collaboration | H.E.S.S. |
Author
Igor Oya
(DESY Zeuthen)
Co-authors
Felix Aharonian
(Max Planck fuer Kernphysik)
Matthiew Dalton
(Université Bordeaux 1, CNRS/IN2P3, Centre d'Études Nucléaires de Bordeaux Gradignan)
Sabrina Casanova
(Max Planck fuer Kernphysik)
