The Bulletin of The Korean Astronomical Society (천문학회보)
- Volume 38 Issue 2
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- Pages.51.2-51.2
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- 2013
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- 1226-2692(pISSN)
Statistical Analysis of Fly-by interactions between Galaxies via Cosmological Simulations
- An, Sung-Ho (Department of Astronomy & Center of Galaxy Evolution Research, Yonsei University) ;
- Kim, Jeonghwan (Department of Astronomy & Center of Galaxy Evolution Research, Yonsei University) ;
- Yun, Kiyun (Department of Astronomy & Center of Galaxy Evolution Research, Yonsei University) ;
- Kim, Juhan (Korea Institute for Advanced Study) ;
- Yoon, Suk-Jin (Department of Astronomy & Center of Galaxy Evolution Research, Yonsei University)
- Published : 2013.10.08
Abstract
Galactic fly-by interactions are believed to be far more frequent than direct mergers, acting as hidden drivers of galaxy evolution. We perform a tree-particle-mesh code GOTPM, and investigate the statistical properties of the fly-by interactions as functions of halo masses and ambient environments. Based on the total energy of the two halos of interest, impulsive fly-by pairs are identified from eventual merger candidates. We find three obvious results as follows: (1) Halos in the high-dense environment experience more frequent mergers and fly-by encounters than those in the low-dense region; (2) In the massive halos, both merger and fly-by fractions evolve more dramatically with time than those in dwarfs; and (3) The fly-by fraction decreases as approaching the present epoch, in contrast to the increase of the merger fraction.
Keywords