Chih-Teng Ling (NTHU); Tomotsugu Goto (NTHU); Tetsuya Hashimato (NTHU)
Galaxies are hosted by huge dark matter halos in general. In contrast to this consensus, dark matter-deficient galaxies (DMDGs) have been discovered recently. The existence of DMDGs challenges our understanding of galaxy formation, suggesting that DMDGs may be a key to revealing the galaxy formation and the nature of dark matter. While several theories have attempted to solve the puzzle of the origin of DMDGs, the current DMDG sample is too small to test the theories. To overcome this problem, we aim to search for more observational evidence of DMDGs from the Sloan Digital Sky Survey data and constrain their properties. In this work, a DMDG is defined as a galaxy with a higher stellar mass to dynamical mass ratio. We report environmental effects on our DMDG sample in various stellar-mass and redshift ranges. Additionally, opposite populations to the DMDG, i.e., dark matter-rich galaxies, will be discussed in the presentation.