July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

A detailed study of gamma-ray emission from Cassiopeia A using VERITAS

Aug 1, 2015, 3:16 PM
World Forum Theater (World Forum)

World Forum Theater

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Oral contribution GA-EX Parallel GA10 VERITAS


Mr Sajan Kumar (for the VERITAS collaboration)


Supernova remnants (SNRs) have long been considered the leading candidate sites for the acceleration of cosmic rays within the Galaxy through the process of diffusive shock acceleration. The connection between SNRs and cosmic rays is supported by the detection of high energy (HE; 100 MeV to 100 GeV) and very high energy (VHE; 100 GeV to 100 TeV) gamma rays from young and middle-aged SNRs. However, the interpretation of the gamma-ray observations is not unique. This is due to the fact that gamma rays can be produced by electrons through non-thermal Bremsstrahlung and inverse Compton scattering, and by protons through proton-proton collisions and subsequent neutral pion decay. To disentangle and quantify the contributions of electrons and protons to the gamma-ray flux, it is necessary to measure precisely the spectra and morphology of SNRs over a broad range of gamma-ray energies. Cassiopeia A (Cas A) is one such young SNR (~350 years) which is bright in radio and X-rays. It has been detected as a bright point source in HE gamma rays by Fermi-LAT and in VHE gamma rays by HEGRA, MAGIC and VERITAS. Cas A has been observed with VERITAS for more than 60 hours - three times the published exposure. The observations were taken between 2007 to 2013 over a wide range of zenith angles. In particular, half of the total data was taken under large zenith angle to boost the effective area above few TeV. Here, we will present the detailed spectral and morphological results from the complete dataset.
Collaboration VERITAS
Registration number following "ICRC2015-I/" 492

Primary author

Mr Sajan Kumar (for the VERITAS collaboration)

Presentation materials