Prevalent non-negligible radiation pressure force exists on broad-line regions of active galactic nucleis

Prof. Liu Hongtao, Ph.D. Feng Haicheng and their cooperators from Yunnan observatories of Chinese Academy of Sciences investigated the virial factor in estimating the virial masses of supermassive black holes in active galactic nucleis (AGNs) through the redward shifted broad emission lines Hβ and Fe II.