Revealing the morphology and kinematics of the double-barred galaxy NGC 3504 using ALMA CO (2-1) data

About one-third of barred galaxies have an inner secondary bar embedded within an outer primary bar (Laine et al. 2002; Erwin & Sparke 2002). They are so called double-barred galaxies. Investigation on inner bars is especially important as they can drive gas inflow to fuel active galactic nuclei (Kormendy 1982; Shlosman, Frank & Begelman 1989). In this poster, we will present results obtained from ALMA CO (2-1) data of the double-barred galaxy NGC 3504 (Wu et al. 2021). This work also serves as the pilot study to build the objectives of our on-going ALMA project to measure CO emission of ten double-barred galaxies. With this project, we hope to provide reliable constraints of the gas mass on theories to shed light on the formation of double-barred galaxies