Oral Presentation

Spectroscopic Reverberation Mapping of the Intermediate-Mass AGN in NGC 4395

Author(s): Hojin Cho (Seoul National University) Jong-Hak Woo (Seoul National University) NGC 4395 Collaborations

Presenter: Hojin Cho (Seoul National University)

NGC 4395 harbors the least luminous active galactic nucleus (AGN) known so far, which is powered by an intermediate-mass black hole (IMBH). Despite being only 4 Mpc away, there has been no reliable measurement of reverberation mapping on its Balmer broad lines, leaving its broad line region (BLR) size -- and consequently its mass -- uncertain. Here, we present our latest reverberation mapping results on NGC 4395. Using Gemini GMOS and Keck LRIS, we carried out 3 nights of spectroscopic monitoring observations in 2019. We measured the mass to be less than 20,000 solar masses, which is far smaller than dynamical mass estimate. We will discuss its implications.