Lunch talk on Sep. 18, 2023

Explore the Signature of Non-Rotational Motion in the Morphology of Velocity Fields

Speaker: Shuai Feng (Hebei Normal University)

Venue: SWIFAR Building 2111

Time: 12:30 PM, Monday, Sep. 18, 2023

Abstract: 

In recent decades, the application of integral field spectrographs (IFSs) opens a new window for studying the internal motion of galaxies. The morphology of Halpha velocity fields, which is derived from the cubes of IFSs, provides an intuitive way to characterize gas kinematics. The asymmetric features of these velocity fields reflect the non-rotational component of a galaxy’s internal motion of ionized gas. Based on the SDSS-IV MaNGA survey, we make a census of asymmetric degrees and analyze their general properties. We discuss the physical origin of asymmetric velocity fields in three types of special galaxies, including merging galaxies, barred galaxies, and AGN host galaxies, and suggest that the asymmetric degree of the velocity field is a good indicator of galaxy interaction. For regular galaxies, we find a large number of galaxies with highly asymmetric velocity fields. Through investigating the correlation between asymmetric velocity fields and other physical properties of galaxies, we suggest that their asymmetric velocity field might be raised by the gas inflow and outflow.

Reoprt PPT:  SWIFAR_Shuai Feng.pdf