Origin of gamma-ray emission in the shell of Cassiopeia A

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Saha L., Ergin T., Majumdar P., Bozkurt M., Ercan E. N.

ASTRONOMY & ASTROPHYSICS, vol.563, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 563
  • Publication Date: 2014
  • Doi Number: 10.1051/0004-6361/201323218
  • Journal Name: ASTRONOMY & ASTROPHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: acceleration of particles, radiation mechanisms: non-thermal, supernovae: individual: Cassiopeia A, SUPERNOVA REMNANT CASSIOPEIA, DIFFUSIVE SHOCK ACCELERATION, MAGNETIC-FIELD, 3-DIMENSIONAL STRUCTURE, CARBON-MONOXIDE, COSMIC-RAYS, HIGH-ENERGY, ELECTRONS, TEV, AMPLIFICATION
  • Middle East Technical University Affiliated: Yes

Abstract

Context. Non-thermal X-ray emission from the shell of Cassiopeia A (Cas A) has been an interesting subject of study, as it provides information about relativistic electrons and their acceleration mechanisms in shocks. The Chandra X-ray observatory revealed the detailed spectral and spatial structure of this supernova remnant in X-rays. The spectral analysis of the Chandra X-ray data of Cas A shows unequal flux levels for different regions of the shell, which can be attributed to different magnetic fields in those regions. Additionally, the GeV gamma-ray emission observed by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope showed that the hadronic processes are dominating in Cas A, which is a clear signature of acceleration of protons.