Showing 2000 · astro-phShow all
3 papers · 2 filters
astro-ph2000
Sub-mm and X-ray background: two unrelated phenomena?
P. Severgnini, R. Maiolino, M. Salvati +9
Obscured AGNs are thought to contribute a large fraction of the hard X-ray background (2-10 keV), and have also been proposed as the powerhouse of a fraction of the SCUBA sources w…
astro-ph2000
The Elusive Active Nucleus of NGC 4945
A. Marconi, E. Oliva, P. P. van der Werf +4
We present new HST NICMOS observations of NGC 4945, a starburst galaxy hosting a highly obscured active nucleus that is one of the brightest extragalactic sources at 100 keV. The H…
astro-ph2000
The variability of the Seyfert galaxy NGC 2992: the case for a revived AGN
R. Gilli, R. Maiolino, A. Marconi +4
We report the transition to an active state of the nucleus in the Seyfert 1.9 galaxy NGC 2992, discovered by means of new hard X-ray data. While the 2-10 keV flux declined by a fac…