The MBHBM* Project - II. Molecular gas kinematics in the lenticular galaxy NGC 3593 reveal a supermassive black hole
- Author(s)
- Dieu D. Nguyen, Martin Bureau, Sabine Thater, Kristina Nyland, Mark den Brok, Michelle Cappellari, Timothy A. Davis, Jenny E. Greene, Nadine Neumayer, Masatoshi Imanishi, Takuma Izumi, Taiki Kawamuro, Shunsuke Baba, Phuong M. Nguyen, Satoru Iguchi, Takafumi Tsukui, N. T. Lam, Than Ho
- Abstract
As part of the Measuring Black Holes in Below Milky Way-mass (M$^\star$) galaxies (MBHBM$^\star$) Project, we present a dynamical measurement of the supermassive black hole (SMBH) mass in the nearby lenticular galaxy NGC 3593, using cold molecular gas $^{12}$CO(2-1) emission observed at an angular resolution of $\approx0''.3$ ($\approx10$ pc) with the Atacama Large Millimeter/submillimeter Array (ALMA). Our ALMA observations reveal a circumnuclear molecular gas disc (CND) elongated along the galaxy major axis and rotating around the SMBH. Using dynamical modelling, the molecular gas kinematics allow us to infer a SMBH mass $M_{\rm BH}=2.40_{-1.05}^{+1.87}\times10^6$ M$_\odot$ (only statistical uncertainties at the $3\sigma$ level). We also detect a massive core of cold molecular gas (CMC) of mass $M_{\rm CMC}=(5.4\pm1.2)\times10^6$ M$_\odot$ and effective (half-mass) radius $r_{\rm CMC,e}=11.2\pm2.8$ pc, co-spatial with a nuclear star cluster (NSC) of mass $M_{\rm NSC}=(1.67\pm0.48)\times10^7$ M$_\odot$ and effective radius $r_{\rm NSC,e}=5.0\pm1.0$~pc (or $0''.15\pm0''.03$). The mass profiles of the CMC and NSC are well described by S\'{e}rsic functions with indices $1-1.4$. Our $M_{\rm BH}$ and $M_{\rm NSC}$ estimates for NGC 3593 agree well with the recently compiled $M_{\rm BH}$-$M_{\rm NSC}$ scaling relation. Although the $M_{\rm NSC}$ uncertainty is twice the inferred $M_{\rm BH}$, the rapid central rise of the rotation velocities of the CND (as the radius decreases) clearly suggests a SMBH. Indeed, our dynamical models show that even if $M_{\rm NSC}$ is at the upper end of its allowed range, the evidence for a black hole does not vanish, but remains with a lower limit of $M_{\rm BH}>3\times10^5$ M$_\odot$.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Vietnam National University Ho Chi Minh City, National Institutes of Natural Sciences (NINS), University of Oxford, U.S. Naval Research Laboratory, Leibniz-Institut für Astrophysik Potsdam, Cardiff University, Princeton University, Max-Planck-Institut für Astronomie, Graduate University for Advanced Studies , Quy Nhon University, Paris Observatory, Mientrung University of Civil Engineering, Yonsei University
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 509
- Pages
- 2920-2939
- No. of pages
- 20
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stab3016
- Publication date
- 01-2022
- 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/aa80aba9-0885-45c7-9c56-a24e9943fa5a