Fossati, Giovanni

What is truly the relationship between jet, accretion disk and BLR intensity changes in FSRQs?.

Author list: G. Fossati

Studies of the relationship between variations in the jet continuum emission and those of broad emission lines (and disk emission) can provide new clues about the structure of the central regions of jetted AGNs and properties of the outflow, such as the location of the active region. Thanks to Fermi and the large multiwavelength coverage that it stimulated (and supported) there are now high quality data for several blazars and this type of investigation is becoming possible and slowly beginning to bear fruit. The interpretation of the correlated (or not) variability requires to look more in depth at the relationship between the various "radiative signals", some of which may be responsible for causing variations in other components, examples being BLR radiation seeding EC in the jet, disk emission increasing BLR power, or jet emission ionizing part of the BLR as recently discussed. Because the jet "blob" moves nearly at the same speed of the "signals", the actual relationships are somewhat at odds with the naive intuition. I will present results of our study of the observational implications/appearance of variations originating in different components and discuss the implications for the interpretation of recent novel observational work.