TY - JOUR
T1 - Diffuse thermal emission from very hot gas in starburst galaxies
T2 - Spatial results
AU - Cappi, M.
AU - Persic, M.
AU - Mariani, S.
AU - Bassani, L.
AU - Danese, L.
AU - Dean, A. J.
AU - Di Cocco, G.
AU - Franceschini, A.
AU - Hunt, L. K.
AU - Matteucci, P.
AU - Molendi, S.
AU - Palazzi, E.
AU - Palumbo, G. G.C.
AU - Rephaeli, Y.
AU - Salucci, P.
AU - Spizzichino, A.
PY - 1999
Y1 - 1999
N2 - New BeppoSAX observations of the nearby prototypical starburst galaxies NGC 253 and M82 are presented. A companion paper (Cappi et al. 1998) 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.
AB - New BeppoSAX observations of the nearby prototypical starburst galaxies NGC 253 and M82 are presented. A companion paper (Cappi et al. 1998) 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.
UR - http://www.scopus.com/inward/record.url?scp=0040912931&partnerID=8YFLogxK
U2 - 10.1016/S0273-1177(99)00230-6
DO - 10.1016/S0273-1177(99)00230-6
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AN - SCOPUS:0040912931
SN - 0273-1177
VL - 23
SP - 905
EP - 909
JO - Advances in Space Research
JF - Advances in Space Research
IS - 5-6
ER -