The MBHBM* Project -- I: Measurement of the Central Black Hole Mass in Dwarf Galaxy NGC 3504 Using Molecular Gas Kinematics

Understand

We present the first measurement of the mass of a supermassive black hole (SMBH) in the nearby double-barred spiral galaxy NGC 3504 as part of the Measuring Black Holes Below the Milky Way ($M_{\star}$) mass galaxies (MBHBM$_{\star}$) Project.

• Our analysis is based on Atacama Large Millimeter/submillimeter Array (ALMA) Cycle-5 observations of the ${\rm ^{12}CO(2-1)}$ emission line.
• NGC 3504 has a circumnuclear gas disk (CND), which has a relatively high-velocity dispersion of 30 \kms.
• Our dynamical models of the CND yield a \Mbh~of $M_{\rm BH}=1.02^{+0.18}_{-0.15}\times10^7$\Msun and a mass-to-light ratio in $H$-band of \ml$_{\rm H}=0.66^{+1.44}_{-0.65}$ (\Msun/\Lsun).