Asymmetric Star Formation Triggered by Gas Inflow in a Barred Lenticular Galaxy PGC 34107

Comparing the inactive and gas-poor normal lenticular galaxies (S0s) in the local universe, we study a barred star-forming S0 galaxy, PGC 34107, which has been observed by the Centro Astronomico Hispano Aleman 3.5 m telescope and the Northern Extended Millimeter Array. The spatially resolved ionized gas and molecular gas traced by (CO)-C-12(1-0), hereafter CO(1-0), show similar distribution and kinematics to the stellar component with an off-center star-forming region, similar to 380 pc away from the center. The resolved kinematics of molecular CO(1-0) emission reveals that there is a blueshifted (redshifted) velocity component on the receding (approaching) side of the galaxy along the stellar bar. This might provide plausible evidence of noncircular motion, such as the bar-induced molecular gas inflow. The velocity of the molecular gas inflow decreases when approaching toward the peak of the off-center star formation in the north, which might be associated with the inner Lindblad resonance. In addition to CO(1-0), we also detect the isotopic line of (CO)-C-13(1-0). For most H alpha, CO(1-0) and (CO)-C-13(1-0) emissions are concentrated on this northern star-forming region. We find that PGC 34107 follows the local stellar mass-metallicity relation, star-forming main sequence, and the Kennicutt-Schmidt law. The resolved and integrated molecular gas main sequence suggests that there is a higher gas fraction in the central region of the galaxy, which supports a scenario that the bar-induced gas reservoir provides the raw material, and subsequently triggers the central star formation.