Speaker
Description
The structure and physical properties of accretion discs in quasars remain poorly understood. A primary challenge lies in disentangling the degenerate roles of various physical parameters—such as black hole mass and spin, accretion rate, inclination, and environment—within the observed emission. A powerful method to mitigate these limitations is the analysis of variable quasars through multi-epoch observations, where spectral transitions are expected to be driven primarily by fluctuations in the accretion rate. In this study, I analyze the relationship between line and continuum luminosity using variable quasars with multiple SDSS spectroscopic observations. I focus on two primary samples: the first data release from the Black Hole Mapper project and sources observed by both the SDSS and BOSS spectrographs. Our findings indicate that an increase in continuum luminosity does not necessarily correspond to a proportional increase in line emission. Furthermore, we observe that objects with higher accretion rates appear, on average, cooler. These results suggest that elevated accretion rates may trigger disc truncation at larger inner radii—potentially driven by radiation-driven winds—resulting in lower disc temperatures while maintaining a constant ionizing
luminosity.