X-ray analysis of SDSS J165202.60+172852.4, an obscured quasar with outflows at peak galaxy formation epoch

Abstract

We report on deep XMM-Newton and NuSTAR observations of the high redshift, z = 2.94, extremely red quasar (ERQ), SDSS J165202.60+172852.4, with known galactic ionized outflows detected via spatially resolved [O iii] emission lines. X-ray observations allow us to directly probe the accretion disc luminosity and the geometry and scale of the circumnuclear obscuration. We fit the spectra from the XMM-Newton/EPIC and NuSTAR detectors with a physically motivated torus model and constrain the source to exhibit a near Compton-thick column density of NH = (1.02+0.76-0.41) × 1024 cm-2, a near edge-on geometry with the line-of-sight inclination angle of θi = 85°, and a scattering fraction of fsc ∼3 per cent. The absorption-corrected, intrinsic 2-10 keV X-ray luminosity of L2-10= (1.4 +1-1) × 1045 erg s-1 reveals a powerful quasar that is not intrinsically X-ray weak, consistent with observed trends in other ERQs. We also estimate the physical properties of the obscuration, although highly uncertain: the warm ionized scattering density of ne ∼7.5 × (102-103) cm-3 and the obscuration mass of M obsc∼ 1.7× (104-106 M⊙. As previously suggested with shallower X-ray observations, optical and infrared selection of ERQ has proved effective in finding obscured quasars with powerful outflow signatures. Our observations provide an in-depth view into the X-ray properties of ERQs and support the conclusions of severely photon-limited studies of obscured quasar populations at high redshifts.