2021MNRAS.502.3769I

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 N_H = (1.02^+0.76_–0.41) x 10²⁴ cm^–2, a near edge-on geometry with the line-of-sight inclination angle of θ_i = 85°, and a scattering fraction of f_sc ∼ 3 per cent. The absorption-corrected, intrinsic 2-10 keV X-ray luminosity of L_2–10= (1.4⁺¹_–1) x 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 n_e ∼ 7.5 x (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.