Speaker
Description
It is well known that galaxy interactions will trigger star formation, due to the tidal effect. With the observations from ALFALFA and SDSS samples, we show that galaxies with close companions tend to exihibit single-peaked integrated HI profiles, indicating that galaxy interactions lead to more centrally concentrated HI distribution, and trigger star formation.
Besides, it was found that the star formation enhancement only occurs in galaxies with spiral companions. We examine this phenomenon beyond the limited small sample in previous work, with the large galaxy sample from SDSS. We confirm that the star formation enhancement is more pronounced in galaxies with spiral companions and inner regions of galaxies. We also find that host galaxies with spiral companions show lower relative velocity and tend to reside in low-mass halos and under-dense regions. However, after matching halo mass and local density between the two pair samples, the difference in star formation enhancement remains significant. Our analysis indicates that the phenomenon may not be fully explained by the coplanar interaction mentioned in Xu et al. 2021.
