One more surprise from the Circinus Galaxy: BeppoSAX discovery of a transmission component in hard X-rays

Authors
Matt, G Guainazzi, M Maiolino, R Molendi, S Perola, GC Antonelli, LA Bassani, L Brandt, WN Fabian, AC Fiore, F Iwasawa, K Malaguti, G Marconi, A Poutanen, J
Citation
G. Matt et al., One more surprise from the Circinus Galaxy: BeppoSAX discovery of a transmission component in hard X-rays, ASTRON ASTR, 341(2), 1999, pp. L39-L42
Citations number
26
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
00046361 → ACNP
Volume
341
Issue
2
Year of publication
1999
Pages
L39 - L42
Database
ISI
SICI code
0004-6361(199901)341:2<L39:OMSFTC>2.0.ZU;2-1
Abstract
The Circinus Galaxy has been observed, for the first time above 10 keV, by BeppoSAX. An excess emission above the extrapolation of the best fit 0.1-10 keV spectrum is apparent in the PDS data. The most likely explanation is th at we are observing the nucleus through a column density of similar to 4 x 10(24) cm(-2), i.e. large enough to completely block the radiation below 10 keV but small enough to permit partial transmission above this energy.