Volume 427, Number 3, December I 2004
|Page(s)||L21 - L24|
|Published online||16 November 2004|
Letter to the Editor
Hard X-ray emission clumps in the γ-Cygni supernova remnant: An INTEGRAL-ISGRI view
A. F. Ioffe Institute for Physics and Technology, 26 Polytechnicheskaia, 194021 St. Petersburg, Russia e-mail: firstname.lastname@example.org
2 SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
3 Department of Astronomy, University of Virginia, PO Box 3818, Charlottesville, VA 22903, USA
4 CEA – Saclay, DSM/DAPNIA/Service d'Astrophysique, 91191 Gif-sur-Yvette Cedex, France
5 Sternberg Astronomical Institute, Moscow State University, 13 Universitetskij, 119899 Moscow, Russia
6 Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bât. B5c, 4000 Liège, Belgium
7 Astro Space Center of the Lebedev Physics Institute, 84/32 Profsoyuznaia, 117810 Moscow, Russia
8 NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771, USA
Accepted: 9 October 2004
Spatially resolved images of the galactic supernova remnant G78.2+2.1 (γ-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 ( in the 25–40 keV band. The observed X-ray fluxes are in agreement with extrapolations of soft X-ray imaging observations of γ-Cyg 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.
Key words: gamma rays: observations / X rays: ISM: supernova remnants / individual: G78.2+2.1 (γ-Cygni) / radiation mechanisms: nonthermal / cosmic rays
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.