Hard X-ray Emission Clumps in the gamma-Cygni Supernova Remnant: an INTEGRAL-ISGRI View

Abstract

Spatially resolved images of the galactic supernova remnant G78.2+2.1 (gamma-Cygni) in hard X-ray energy bands from 25 keV to 120 keV are obtained with the IBIS-ISGRI imager aboard the International Gamma-Ray Astrophysics Laboratory INTEGRAL. The images are dominated by localized clumps of about ten arcmin in size. The flux of the most prominent North-Western (NW) clump is (1.7 +/- 0.4) 10^{-11} erg/cm^2/s in the 25-40 keV band. The observed X-ray fluxes are in agreement with extrapolations of soft X-ray imaging observations of gamma-Cygni by ASCA GIS and spatially unresolved RXTE PCA data. The positions of the hard X-ray clumps correlate with bright patches of optical line emission, possibly indicating the presence of radiative shock waves in a shocked cloud. The observed spatial structure and spectra are consistent with model predictions of hard X-ray emission from nonthermal electrons accelerated by a radiative shock in a supernova interacting with an interstellar cloud, but the powerful stellar wind of the O9V star HD 193322 is a plausible candidate for the NW source as well.

5 pages, 5 figures, Astronomy and Astrophysics Letters

References in corpus (8)

• ISGRI: the INTEGRAL Soft Gamma-Ray Imager
• Supernova Remnants in Molecular Clouds
• The INTEGRAL/IBIS Scientific Data Analysis
• Nonthermal Emission from a Supernova Remnant in a Molecular Cloud
• Gamma-ray production in supernova remnants
• ASCA View of the Supernova Remnant Gamma Cygni (G78.2+2.1): Bremsstrahlung X-ray Spectrum from Loss-flattened Electron Distribution
• RXTE, ROSAT and ASCA Observations of G347.3-0.5 (RX J1713.7-3946): Probing Cosmic Ray Acceleration by a Galactic Shell-Type Supernova Remnant
• Faint Hard X-ray Sources in the Galactic Center Region: Supernova Ejecta Fragments Population

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• X-ray and Radio Observations of the gamma Cygni Supernova Remnant G78.2+2.1
• The GeV counterpart of VER J2019+407 in the northern shell of the supernova remnant G78.2+2.1 ($\gamma$ Cygni)
• A search for a counterpart of the unidentified gamma-ray source 3EG J2020+4017 (2CG078+2)
• Study of the gamma-ray source 1AGL J2022+4032 in the Cygnus Region
• On the nature of the hard X-ray source IGR J2018+4043
• High frequency VLBI observations of the scatter broadened quasar B2005+403
• Exploring the region encompassing gamma Cygni SNR and MAGIC J2019+408 with the GMRT at 325 and 610 MHz
• Fermi LAT observation of VER J2019+407