The Most Luminous H$\beta$ Reverberation Mapping of E1821+643 Indicates the Lower Boundary of the Radius-Luminosity Relation

Sha-Sha Li, Hai-Cheng Feng, Jiancheng Wu +5

The radius-luminosity ($R_{\mathrm{BLR}}$-$L_{5100}$) relation is fundamental to active galactic nucleus (AGN) studies, enabling supermassive black hole (SMBH) mass estimates and AGN-ba…