Lunch talk on Apr. 17, 2023

Multiple gas acquisition events in the local universe

Speaker:Xiao Cao (Nanjing University)

Venue:SWIFAR Building 2111

Time:12:30 PM, Monday, Apr. 17, 2023

Abstract:

Gas acquisition plays an important role in galaxy assembly, while the evidence of gas inflow from environment is absent in the local universe. As the integral-field units (IFU) survey developed, we obtain spatially resolved kinematics of stars and gas, covering the galactic bulge and disk. Ubiquitous kinematically misaligned galaxies have been observed in the IFU surveys (including MUSE, SAMI and MaNGA), which are the key laboratories to explore the external processes in galaxy evolution. However, almost all known kinematically misaligned galaxies identify only one gas disk misaligned with the stellar component implying a single gas acquisition event. In this talk, I will report a new configuration of two galaxies from the MaNGA survey, where both contain two gas disks misaligned with each other and also with the stellar component, indicating at least twice gas acquisition events in galaxies. The star formation is enhanced at the interface of the two gas disks compared with the other regions within the same galaxy. Such systems illustrate that low-redshift galaxies can still experience multiple gas acquisition events, and provide a new view into the origins of galactic gas.

Report PPT:SWIFAR_Xiao Cao.pdf