TY - JOUR
T1 - The NuSTAR Extragalactic Survey
T2 - Average Broadband X-Ray Spectral Properties of the NuSTAR-detected AGNs
AU - Del Moro, A.
AU - Alexander, D. M.
AU - Aird, J. A.
AU - Bauer, F. E.
AU - Civano, F.
AU - Mullaney, J. R.
AU - Ballantyne, D. R.
AU - Brandt, W. N.
AU - Comastri, A.
AU - Gandhi, P.
AU - Harrison, F. A.
AU - Lansbury, G. B.
AU - Lanz, L.
AU - Luo, B.
AU - Marchesi, S.
AU - Puccetti, S.
AU - Ricci, C.
AU - Saez, C.
AU - Stern, D.
AU - Treister, E.
AU - Zappacosta, L.
N1 - Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - We present a study of the average X-ray spectral properties of the sources detected by the NuSTAR extragalactic survey, comprising observations of the Extended Chandra Deep Field South (E-CDFS), Extended Groth Strip (EGS), and the Cosmic Evolution Survey (COSMOS). The sample includes 182 NuSTAR sources (64 detected at 8-24 keV), with 3-24 keV fluxes ranging between and 6 10-13 erg cm-2 s-1 (erg cm-2 s-1) and redshifts in the range of We produce composite spectra from the Chandra + NuSTAR data (rest frame) for all the sources with redshift identifications (95%) and investigate the intrinsic, average spectra of the sources, divided into broad-line (BL) and narrow-line (NL) active galactic nuclei (AGNs), and also in different bins of X-ray column density and luminosity. The average power-law photon index for the whole sample is, flatter than the typically found for AGNs. While the spectral slope of BL and X-ray unabsorbed AGNs is consistent with the typical values a significant flattening is seen in NL AGNs and heavily absorbed sources (and , respectively), likely due to the effect of absorption and to the contribution from the Compton reflection component to the high-energy flux ( keV). We find that the typical reflection fraction in our spectra is (for), with a tentative indication of an increase of the reflection strength with X-ray column density. While there is no significant evidence for a dependence of the photon index on X-ray luminosity in our sample, we find that decreases with luminosity, with relatively high levels of reflection for erg s-1 and for erg s-1 AGNs, assuming a fixed spectral slope of .
AB - We present a study of the average X-ray spectral properties of the sources detected by the NuSTAR extragalactic survey, comprising observations of the Extended Chandra Deep Field South (E-CDFS), Extended Groth Strip (EGS), and the Cosmic Evolution Survey (COSMOS). The sample includes 182 NuSTAR sources (64 detected at 8-24 keV), with 3-24 keV fluxes ranging between and 6 10-13 erg cm-2 s-1 (erg cm-2 s-1) and redshifts in the range of We produce composite spectra from the Chandra + NuSTAR data (rest frame) for all the sources with redshift identifications (95%) and investigate the intrinsic, average spectra of the sources, divided into broad-line (BL) and narrow-line (NL) active galactic nuclei (AGNs), and also in different bins of X-ray column density and luminosity. The average power-law photon index for the whole sample is, flatter than the typically found for AGNs. While the spectral slope of BL and X-ray unabsorbed AGNs is consistent with the typical values a significant flattening is seen in NL AGNs and heavily absorbed sources (and , respectively), likely due to the effect of absorption and to the contribution from the Compton reflection component to the high-energy flux ( keV). We find that the typical reflection fraction in our spectra is (for), with a tentative indication of an increase of the reflection strength with X-ray column density. While there is no significant evidence for a dependence of the photon index on X-ray luminosity in our sample, we find that decreases with luminosity, with relatively high levels of reflection for erg s-1 and for erg s-1 AGNs, assuming a fixed spectral slope of .
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U2 - 10.3847/1538-4357/aa9115
DO - 10.3847/1538-4357/aa9115
M3 - Article
AN - SCOPUS:85033598740
SN - 0004-637X
VL - 849
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 57
ER -