出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We have found empirically that the radio loudness of AGN can be understood as function of both
the X-ray and optical luminosity. This way of considering the radio loudness was inspired by
the hardness-intensity diagrams for X-ray binaries, in which objects follow a definite track with
changes to their radio properties occurring in certain regions. We generalize the hardness-intensity
diagram to a disk-fraction luminosity diagram, which can be used to classify the accretion states
both of X-ray binaries and of AGN. Using a sample of nearly 5000 SDSS quasars with ROSAT
matches, we show that an AGN is more likely to have a high radio:optical flux ratio when it has a
high total luminosity or a large contribution from X-rays. Thus, it is necessary to take into account
both the optical and the X-ray properties of quasars in order to understand their radio loudness.
The success of categorizing quasars in the same way as X-ray binaries is further evidence for the
unification of accretion onto stellar-mass and supermassive compact objects.
