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Are quasars reliable standard candles?
Elisabeta Lusso, Guido Risaliti, Emanuele Nardini
In this paper we address the question whether the non-linear relation between the X-ray and UV emission of quasars can be used to derive their distances. In previous works of our g…
Building the high-redshift Hubble Diagram with quasars
Matilde Signorini, Guido Risaliti, Andrea Sacchi +2
Proceeding of the "HACK100" Conference, 6-10 June 2022, Trieste, Italy - In recent years, quasars have been shown to be reliable standardizable candles, thanks to the non-linear re…
Quasars as Standard Candles V. Evaluation of a 0.06 dex intrinsic dispersion in the LX-LUV relation
Matilde Signorini, Guido Risaliti, Elisabeta Lusso +4
A characteristic feature of quasars is the observed non-linear relationship between their monochromatic luminosities at rest-frame 2500 Å and 2 keV. This relationship is evident ac…
Quasars as Standard Candles IV. Analysis of the X-ray and UV indicators of the disc-corona relation
Matilde Signorini, Guido Risaliti, Elisabeta Lusso +4
Context: A non-linear relation between quasar monochromatic luminosities at 2500A and 2 keV holds at all observed redshifts and luminosities, and it has been used to derive quasar…
Quasars as high-redshift standard candles
Guido Risaliti, Elisabeta Lusso, Emanuele Nardini +5
In the past few years, we built a Hubble diagram of quasars up to redshift z7, based on the nonlinear relation between quasars' x-ray and UV luminosities. Such a Hubble diagr…
Quasars as high-redshift standard candles
A. Sacchi, G. Risaliti, M. Signorini +10
The non-linear relation between the X-ray and ultraviolet (UV) luminosity in quasars has been used to derive quasar distances and to build a Hubble diagram at redshifts up to $z\si…