SIMBAD references

2016ApJ...819..154L - Astrophys. J., 819, 154 (2016/March-2)

The tight relation between X-ray and ultraviolet luminosity of quasars.


Abstract (from CDS):

The observed relation between the soft X-ray and the optical-ultraviolet emission in active galactic nuclei (AGNs) is nonlinear and it is usually parametrized as a dependence between the logarithm of the monochromatic luminosity at 2500 Å 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 four 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.

Abstract Copyright:

Journal keyword(s): galaxies: active - galaxies: evolution - methods: statistical - quasars: general

VizieR on-line data: <Available at CDS (J/ApJ/819/154): table1.dat table2.dat>

CDS comments: Among the 2153 objects in Table 1, 383 given detection IDs are not found in the 3XMM-DR5 catalog, and thus not added in Simbad.

Simbad objects: 2687

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