Fermi LAT Observation of Supernova Remnant HB9

Abstract

A 5.5-year Fermi LAT gamma-ray observation shows significant extended emission at the position of the supernova remnant HB9 (G160.9+2.6). The significance of the detection above the background for photon energies above 0.2 GeV is 16$\sigma$. The gamma-ray flux above 0.2 GeV is (2.23E-8) photons/cm${}^2$ s, and the corresponding luminosity above 1 GeV is 1.4E33 erg/s (for a source distance of 1 kpc). The spectrum of the source is best described by a curved power-law (log-parabola). The gamma-ray spectrum of the source is consistent with both leptonic and hadronic models, and the relevant physical parameters in each case are derived. More studies on the ambient density in the region of HB9 should be carried out to rule out or confirm hadronic and non-thermal bremsstrahlung scenarios for the gamma-ray emission.

15 pages, 2 figures. Accepted for publication in MNRAS. The new analysis uses the recently released (June 2014) Fermi LAT Galactic diffuse background, which affects the region around the source leading to a change in results with respect to the previous analysis

References in corpus (4)

• Detection of the Characteristic Pion-Decay Signature in Supernova Remnants
• Fermi Large Area Telescope Bright Gamma-ray Source List
• Radio Spectrum and Distance of the SNR HB9
• Modeling the Multi-Wavelength Emission of Shell-Type Supernova Remnant RX J1713.7-3946

Cited by in corpus (8)

• Perspective on the cosmic-ray electron spectrum above TeV
• Gamma-ray upper limits on magnetars with 6 years of Fermi-LAT observations
• Observational constraints on the maximum energies of accelerated particles in supernova remnants: low maximum energies and a large variety
• Search for new cosmic-ray acceleration sites within the 4FGL catalog Galactic plane sources
• Detection of gamma rays around SNR HB9 and its implication to the diffusive shock-acceleration history
• X-ray emission from the mixed-morphology supernova remnant HB 9
• Optical observations of the Galactic SNR HB9 and H II region G159.2+3.3
• Magnetic field properties of the SNR HB 9