2005/10/11 by M. Josefa Perez, P. B. Tissera, Perez, M. Josefa +5 · 1 citation
Chemistry · Decision Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Innovation Diffusion and Forecasting #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.astro-ph/0510327
openalex publication_date 2005/10/11 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
We carried out a statistical analysis of galaxy pairs in hydrodynamical\nLambda-CDM simulations. We focused on the triggering of star formation by\ninteractions and analysed the enhancement of star formation activity in terms\nof orbital parameters. By comparing to a suitable sample of simulated galaxies\nwithout a nearby companion, we find that close encounters (r<30 kpc/h) may\neffectively induce star formation. However, our results suggest that the\nstability properties of systems and the spatial proximity are both relevant\nfactors in the process of triggering star formation by tidal interactions. In\norder to assess the effects of projection and spurious pairs in observational\nsamples, we also constructed and analysed samples of pairs of galaxies in the\nsimulations obtained in projection. We found a good agreement with\nobservational results with a threshold at rp ~ 25 kpc/h for interactions to\neffectively enhance star formation activity.\n For pairs within rp < 100 kpc/h, we estimated a ~27% contamination by\nspurious pairs, reduced to ~19% for close systems. We also found that spurious\npairs affect more strongly high density regions with 17% of spurious pairs\ndetected for low density regions compared to 33% found in high density ones.\nAlso, we analysed the dependence of star formation on environment by defining\nthe usual projected density parameter for both pairs and isolated galaxies in\nthe simulations. We find the expected star formation-local density relation for\nboth galaxies in pairs and without a close companion, with a stronger density\ndependence for close pairs which suggests a relevant role for interactions in\ndriving this relation.\n