The MBHBM_⋆ Project. I. Measurement of the Central Black Hole Mass in Spiral Galaxy NGC 3504 Using Molecular Gas Kinematics

Author(s)

Dieu D. Nguyen, Mark den Brok, Anil C. Seth, Timothy A. Davis, Jenny E. Greene, Michelle Cappellari, Joseph B. Jensen, Sabine Thater, Satoru Iguchi, Masatoshi Imanishi, Takuma Izumi, Kristina Nyland, Nadine Neumayer, Kouichiro Nakanishi, Phuong M. Nguyen, Takafumi Tsukui, Martin Bureau, Kyoko Onishi, Quang L. Nguyen, Ngan M. Le

Abstract

We present a dynamical mass measurement of the supermassive black hole (SMBH) in the nearby double-barred spiral galaxy NGC 3504 as part of the Measuring Black Holes in below Milky Way (M_⋆) Mass Galaxies Project. Our analysis is based on Atacama Large Millimeter/submillimeter Array cycle 5 observations of the ¹²CO(2-1) emission line. These observations probe NGC 3504's circumnuclear gas disk (CND). Our dynamical model of the CND simultaneously constrains a black hole (BH) mass of 1.6_-0.4^+0.6 × 10^7} M_☉, which is consistent with the empirical BH-galaxy scaling relations and a mass-to-light ratio in the H band of 0.44 ± 0.12 (M_☉/L_☉). This measurement also relies on our new estimation of the distance to the galaxy of 32.4 ± 2.1 Mpc using the surface brightness fluctuation method, which is much further than the existing distance estimates. Additionally, our observations detect a central deficit in the ¹²CO(2-1) integrated intensity map with a diameter of 6.3 pc at the putative position of the SMBH. However, we find that a dense gas tracer CS(5 - 4) peaks at the galaxy center, filling in the ¹²CO(2 - 1)-attenuated hole. Holes like this one are observed in other galaxies, and our observations suggest these may be caused by changing excitation conditions rather than a true absence of molecular gas around the nucleus....

Organisation(s)

Department of Astrophysics

External organisation(s)

Cardiff University, National Institutes of Natural Sciences (NINS), Leibniz-Institut für Astrophysik Potsdam, University of Utah, Princeton University, University of Oxford, Utah Valley State College, Graduate University for Advanced Studies , U.S. Naval Research Laboratory, Max-Planck-Institut für Astronomie, Quy Nhon University, Ehime University, Nagoya City University, Hanoi University of Science and Technology

Journal

The Astrophysical Journal

Volume

892

No. of pages

22

ISSN

0004-637X

DOI

https://doi.org/10.3847/1538-4357/ab77aa

Publication date

03-2020

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/0ab53ad0-a617-48e1-a846-a0b9cb25e089