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We present new X-ray observations of luminous heavily dust-reddened quasars (HRQs) selected from infrared (IR) sky surveys. HRQs appear to be a dominant population at high redshifts and the highest luminosities, and may be associated with a transitional 'blowout' phase of black hole and galaxy co-evolution models. Despite this, their high-energy properties have been poorly known. We use the overall sample of 10 objects with XMM–Newton coverage to study the high-energy properties of HRQs at $\langle$ Lbol $\rangle$  =1047.5 erg s−1 and $\langle$ z $\rangle$  =2.5. For seven sources with strong X-ray detections, we perform spectral analyses. These find a median X-ray luminosity of $\left\langle L_{\rm 2\!-\!10\, keV} \right\rangle = 10^{45.1}$  erg s−1, comparable to the most powerful X-ray quasars known. The gas column densities are NH = (1–8) × 1022 cm−2, in agreement with the amount of dust extinction observed. The dust-to-gas ratios are sub-Galactic, but are higher than found in local AGN. The intrinsic X-ray luminosities of HRQs are weak compared to the mid-IR ($L_{\rm 6\, \mu m}$) and bolometric luminosities (Lbol), in agreement with findings for other luminous quasar samples. For instance, the X-ray to bolometric corrections range from κbol ≈ 50 to 3000. The moderate absorption levels and accretion rates close to the Eddington limit ($\langle$ λEdd $\rangle$  =1.06) are in agreement with a quasar blowout phase. Indeed, we find that the HRQs lie in the forbidden region of the NH–λEdd plane, and therefore that radiation pressure feedback on the dusty interstellar medium may be driving a phase of blowout that has been ongoing for a few 105 yr. The wider properties, including [O iii] narrow-line region kinematics, broadly agree with this interpretation. [ABSTRACT FROM AUTHOR]

The goal of this work is to study the obscuration properties of mid-infrared (mid-IR)-selected active galactic nuclei (AGN). For that purpose, we use Wide-field Infrared Survey Explorer (WISE) sources in the Stripe 82– XMM area to identify mid-IR AGN candidates, applying the Assef et al. criteria. Stripe 82 has optical photometry ≈2 times deeper than any single-epoch Sloan Digital Sky Survey (SDSS) region. XMM–Newton observations cover ∼26 deg2. Applying the aforementioned criteria, 1946 IR AGN are selected. |${\sim} 78{{\, \rm per\, cent}}$| have SDSS detection, while 1/3 of them are detected in X-rays, at a flux limit of |$\rm {\sim} 5 \times 10^{-15}\, erg\, s^{-1}\, cm^{-2}$|⁠. Our final sample consists of 507 IR AGN with X-ray detection and optical spectra. Applying a |$r-W2 > 6$| colour criterion, we find that the fraction of optically red AGN drop from 43 per cent for those sources with SDSS detection to |$23{{\, \rm per\, cent}}$| for sources that also have X-ray detection. X-ray spectral fitting reveals 40 (⁠|${\sim} 8{{\, \rm per\, cent}}$|⁠) X-ray absorbed AGN (⁠|$N_\mathrm{ H} > 10^{22}\,{\rm cm}^{-2}$|⁠). Among the X-ray unabsorbed AGN, there are 70 red systems. To further investigate the absorption of these sources, we construct spectral energy distributions (SEDs) for the total IR AGN sample. SED fitting reveals that |${\sim} 20{{\, \rm per\, cent}}$| of the optically red sources have such colours because the galaxy emission is a primary component in the optical part of the SED, even though the AGN emission is not absorbed at these wavelengths. SED fitting also confirms that |$12{{\, \rm per\, cent}}$| of the X-ray unabsorbed IR AGN are optically obscured. [ABSTRACT FROM AUTHOR]