Diffuse Thermal Emission from Very Hot Gas in Starburst Galaxies: Spatial Results
Abstract
New BeppoSAX observations of the nearby prototypical starburst galaxies NGC 253 and M82 are presented. A companion paper (Cappi et al. 1998;astro-ph/9809325) shows that the hard (2-10 keV) spectrum of both galaxies, extracted from the source central regions, is best described by a thermal emission model with kT ~ 6-9 keV and abundances ~ 0.1-0.3 solar. The spatial analysis yields clear evidence that this emission is extended in NGC 253, and possibly also in M82. This quite clearly rules out a LLAGN as the main responsible for their hard X-ray emission. Significant contribution from point-sources (i.e. X-ray binaries (XRBs) and Supernovae Remnants (SNRs)) cannot be excluded; neither can we at present reliably estimate the level of Compton emission. However, we argue that such contributions shouldn't affect our main conclusion, i.e., that the BeppoSAX results show, altogether, compelling evidence for the existence of a very hot, metal-poor interstellar plasma in both galaxies.
Cite
@article{arxiv.astro-ph/9902021,
title = {Diffuse Thermal Emission from Very Hot Gas in Starburst Galaxies: Spatial Results},
author = {M. Cappi and M. Persic and S. Mariani and L. Bassani and L. Danese and A. J. Dean and G. DiCocco and A. Franceschini and L. K. Hunt and F. Matteucci and S. Molendi and E. Palazzi and G. G. C. Palumbo and Y. Rephaeli and P. Salucci and A. Spizzichino},
journal= {arXiv preprint arXiv:astro-ph/9902021},
year = {2019}
}
Comments
5 Latex pages, 4 figures, uses psfig.sty. Accepted for publication in Advances in Space Research, in Proceedings of 32nd Sci. Ass. of COSPAR