Suppression of Star Formation in Galaxy Pairs

Abstract

We investigate the suppression of star formation in galaxy pairs based on the isolated galaxy pair sample derived from the Sloan Digital Sky Survey survey. By comparing the star formation rate between late-type galaxies (LTGs) in galaxy pairs and those in the isolated environment, we detect a signal of the suppression of star formation in galaxy pairs at d p < 100 kpc and 200 kpc < d p < 350 kpc. The occurrence of the suppression of star formation in these LTGs requires their companion galaxies to have an early-type morphology (n s > 2.5). The suppression of star formation in wide galaxy pairs at 200 kpc < d p < 350 kpc mainly occurs in massive LTGs, while in close galaxy pairs at d p < 100 kpc, it only appears in LTGs with a massive companion ( logM⋆>11.0 ), nearly independent of their own stellar mass. Based on these findings, we infer that the suppression of star formation in wide galaxy pairs is actually a result of galaxy conformity, while in close galaxy pairs, it stems from the influence of hot circumgalactic medium surrounding companion galaxies.