Open Access. Powered by Scholars. Published by Universities.®
Science and Technology Studies Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 1 of 1
Full-Text Articles in Science and Technology Studies
A Physical Model For The Hard X-Ray Background, R J. Wilman, A C. Fabian, Paul E J Nulsen
A Physical Model For The Hard X-Ray Background, R J. Wilman, A C. Fabian, Paul E J Nulsen
Faculty of Engineering and Information Sciences - Papers: Part A
We combine a semi-analytic galaxy formation model with a prescription for the obscured growth of massive black holes, to reproduce the hard X-ray background (XRB), the local 2–10 keV active galactic nuclei (AGN) luminosity function and the source counts, including recent Chandra results. The model also complies with constraints on the AGN contribution to the far-infrared and submillimetre backgrounds.
The comoving density of luminous AGN [L(2-10keV) > 1044 erg s-1, in the unabsorbed rest-frame] in the model declines sharply since z=2, mimicking the observed evolution of the quasar population. The abundance of lower luminosity AGN simultaneously increases, and …