Monitoring AGNs with H${\hat{I}}^2$ Asymmetry. V. Long-term Variation and Evolution of the Broad H${\hat{I}}^2$ Emission-Line Profiles

Feng-Na Fang, Pu Du, Michael S. Brotherton +40

The physical origins of the diverse emission-line asymmetries observed in the spectra of active galactic nuclei (AGNs) remain incompletely understood. Monitoring the temporal varia…