Slim-disk self-shadowing plus accretion-rate-dependent BLR density enhancement explains the observed offsets of high-Eddington AGNs below the canonical R-L relation.
The tight relation between X-ray and ultraviolet luminosity of quasars
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abstract
The observed relation between the soft X-ray and the optical-ultraviolet emission in active galactic nuclei (AGN) is non-linear and it is usually parametrized as a dependence between the logarithm of the monochromatic luminosity at 2500 {\AA} and at 2 keV. Previous investigations have found that the dispersion of this relation is rather high (~0.35-0.4 in log units), which may be caused by measurement uncertainties, variability, and intrinsic dispersion due to differences in the AGN physical properties (e.g. different accretion modes). We show that, once optically-selected quasars with homogeneous SED and X-ray detection are selected, and dust reddened and/or gas obscured objects are not included, the measured dispersion drops to significantly lower values (i.e. ~0.21-0.24 dex). We show that the residual dispersion is due to some extent to variability, and to remaining measurement uncertainties. Therefore, the real physical intrinsic dispersion should be <0.21 dex. Such a tight relation, valid over 4 decades in luminosity, must be the manifestation of an intrinsic (and universal) physical relation between the disk, emitting the primary radiation, and the hot electron corona emitting X-rays.
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Galaxy cluster observations yield two preferred directions with cosmic anisotropy amplitude of about 5.3 times 10 to the minus 4 at roughly 1 sigma overall significance, though higher in the XMM-Newton subsample.
Expanding HST observations of intermediate-redshift quasars can deliver the first systematic rest-frame EUV census of QSOs and warm-hot gas in the CGM/IGM as a low-redshift anchor for future UV missions.
citing papers explorer
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Understanding the Broad-line Region of Active Galactic Nuclei with Photoionization. II. Slim disks, Self-shadowing, and BLR sizes
Slim-disk self-shadowing plus accretion-rate-dependent BLR density enhancement explains the observed offsets of high-Eddington AGNs below the canonical R-L relation.
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New constraints on cosmic anisotropy from galaxy clusters using an improved dipole fitting method
Galaxy cluster observations yield two preferred directions with cosmic anisotropy amplitude of about 5.3 times 10 to the minus 4 at roughly 1 sigma overall significance, though higher in the XMM-Newton subsample.
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Closing the UV Gap: Rest-frame EUV science from high-redshift QSOs as a legacy-defining capability
Expanding HST observations of intermediate-redshift quasars can deliver the first systematic rest-frame EUV census of QSOs and warm-hot gas in the CGM/IGM as a low-redshift anchor for future UV missions.