A hard X-ray view of the distant active galactic nucleus (AGN) population with NuSTAR
Abstract
New insights into AGNs are being provided by the Nuclear Spectroscopic Telescope Array (NuSTAR), the first focusing telescope with high sensitivity at hard X-ray energies (E>10 keV), and therefore at the peak energies of the cosmic X-ray background (CXB). I will present results from the NuSTAR 40-month serendipitous survey (20 Ms total exposure; 13 sq. degrees), which has yielded a large sample of ≈ 500 hard X-ray sources (primarily AGNs), and will compare with results from targeted NuSTAR samples. A crucial part of the AGN census is to identify and characterise the most highly obscured (Compton-thick) AGNs, which may contribute a large fraction of the overall cosmic growth of black holes, but are normally hidden from view by gas and dust. I will show that NuSTAR is identifying new Compton-thick AGNs, which wouldn't have been identified at other wavelengths. These can inform us about the prevalence of such extreme systems in the general AGN population.
- Publication:
-
The X-ray Universe 2017
- Pub Date:
- October 2017
- Bibcode:
- 2017xru..conf..126L