Centre-Outskirt Kinematic Misalignment of Each Galaxy Depending on Environments

Leader: Joon Hyeop Lee

Collaborators: Hyunjin Jeong, Mina Pak, Jiwon Chung

Topic: The kinematic properties of Milky Way analogues

Status: under review by Science Committee

Abstract: In our recent studies (Lee et al. 2019, ApJ, 872, 78; Lee et al. 2020, ApJ, 893, 154), we have discovered observational evidence supporting the coherence between galaxy rotation and the average line-of-sight motion of neighbors, utilizing data from the CALIFA survey. The significance of this coherence reaches up to 3.5σ for each galaxy’s outskirt rotation (at Re < R < 2Re), while being less evident for central rotation (at R < Re). Faint, blue, or kinematically misaligned galaxies exhibit stronger coherence with neighbor motions than bright, red, or kinematically well-aligned galaxies. Furthermore, galaxy pairs demonstrating strong kinematic coherence tend to share similar optical colors. These findings suggest that the centre-outskirt kinematic misalignment of each galaxy can serve as an indicator of recent interactions with a massive neighbor. We propose to systematically investigate such centre-outskirt misalignments of Hector galaxies embedded in various environments, such as fields, filaments, and clusters, to directly trace their recent kinematic histories and the influence of large-scale environments on them.

Needed data products: stellar velocity and stellar mass (out to 2 effective radius of each galaxy)

Publication Date: 02/02/2024