Program: GS-2022B-Q-220

Title:Precise estimates of virial masses of 2 Eddington-limited intermediate-mass black holes using GMOS-S IFU observations
PI:Igor Chilingarian
Co-I(s): Ivan Katkov, Victoria Toptun, Kirill Grishin, Vladimir Goradzhanov, Mariia Demyanenko, Dmitrii Matveev, Fedor Kolganov, Evgenii Rubtsov, Ivan Kuzmin

Abstract

Low-mass black holes are the cornerstone for solving puzzles of black hole growth and co-evolution with their hosts. A discovery of a population of 305 intermediate-mass BHs (IMBHs) in 2018 opened a new window of opportunity in this field. Using dedicated analysis of 1 million optical spectra and archival X-ray from Chandra, Swift, and XMM-Newton, we identified 25 AGN powered by IMBHs confirmed in X-ray. Virial black hole mass estimates remain the largest uncertainty and reason for skepticism. Here we propose GMOS-IFU observations free of slit losses for 2 X-ray confirmed low-redshift IMBHs with X-ray fluxes indicative of extremely high accretion rates close to the Eddington limit. We will measure H-alpha and H-beta broad lines and estimate line-of-sight extinction and improve BH mass estimates by reducing the systematics to 15%. We will also map stellar populations and emission line ratios in the circumnuclear regions of IMBH host galaxies. This project will complete the IFU follow-up campaign on Eddington-limited IMBHs known to date.