Resolving the Cosmic X-ray Background with NuSTAR and Chandra
Abstract
Although its origin was long mysterious, the cosmic X-ray background (CXB) is now known to be primarily the sum of emission from large number of active galactic nuclei (AGN). With the advent of NuSTAR, the first focusing high-energy X-ray observatory, we can now directly identify the sources that contribute to the bulk of the CXB at energies > 10 keV where the CXB spectrum peaks. I will present an analysis using data from the NuSTAR extragalactic survey program in which we using stacking techniques to determine the fraction of the CXB that is produced by X-ray sources identified at softer energies by deep Chandra observations. These results provide important constraints on AGN synthesis models fo the CXB and point toward a further "missing" population of obscured AGN. This work is supported in part by NASA award NNX15AP24G.
- Publication:
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AAS/High Energy Astrophysics Division #15
- Pub Date:
- April 2016
- Bibcode:
- 2016HEAD...1540001H