The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV

We acknowledge support from a Herchel Smith Postdoctoral Research Fellowship of the University of Cambridge (G.B.L.); the Science and Technology Facilities Council (STFC) grants ST/I001573/1 (D.M.A.) and ST/J003697/2 (P.G.); the ERC Advanced Grant FEEDBACK 340442 at the University of Cambridge (J.A.); the NASA Earth and Space Science Fellowship Program, grant NNX14AQ07H (M.B.); CONICYT-Chile grants FONDECYT Regular 1141218 (F.E.B.), FONDECYT 1120061 and 1160999 (E.T.), and Anillo ACT1101 (F.E.B. and E.T.); the Center of Excellence in Astrophysics and Associated Technologies (PFB 06; F.E.B. and E.T.); the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC120009, awarded to the Millennium Institute of Astrophysics, MAS (F.E.B.); ASI/INAF contract I/037/12/0-011/13 (A.C., A.M., and L.Z.); and Chandra grants GO5-16154X and GO6-17135X (J.A.T.). We thank Yoshihiro Ueda and Roberto Gilli for providing number counts predictions. This work was supported under NASA contract No. NNG08FD60C and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). Facilities: Chandra, ESO La Silla, Keck, Magellan, NuSTAR, Palomar, Pan-STARRS, SDSS, Swift, WISE, XMM-Newton.