Yan-Rong Li

A Decade-scale Ionization Echo of Black Hole Accretion in Galactic Nuclei

Abstract Circumnuclear structures in active galactic nuclei (AGN) respond to accretion variability over different spatial and temporal scales, but whether compact narrow-line gas responds on decade timescales has not been systematically established. We use repeat Sloan Digital Sk...

On the Probability Distribution and Null-hypothesis Testing of Cross Correlation for Light Curves in Active Galactic Nuclei

Abstract Cross correlation is crucial in studies of multiwavelength flux variability in active galactic nuclei (AGNs), especially for reverberation mapping analysis, where an interpolated cross-correlation function is widely used to measure time lags between light curves. While t...