Confronting hierarchical clustering models with observations of galaxy pairs

Perez, J.
Referencia bibliográfica

The Fabulous Destiny of Galaxies: Bridging Past and Present. Marseille International Cosmology Conference (5 : 2005: Marseille, France) Proceedings of the Vth Marseille International Cosmology conference, June 20-24, 2005, Marseille, France. Edited by V. LeBrun, A. Mazure, S. Arnouts and D. Burgarella. ISBN 2914601190. Paris: Frontier Group, 2006, p.557

Fecha de publicación:
1
2006
Número de autores
1
Número de autores del IAC
0
Número de citas
1
Número de citas referidas
1
Descripción
We investigate the star formation activity in galaxy pairs in chemical hydrodynamical simulations consistent with a Lambda-CDM scenario. A statistical analysis of the effects of galaxy interactions on the star formation activity as a function of orbital parameters shows that close encounters (r < 30 kpc/h) can be effectively correlated with an enhancement of star formation activity with respect to galaxies without a close companion. Our results suggest that the stability properties of systems are also relevant in this process. We found that the passive star forming galaxies pairs tend to have deeper potential wells, older stellar populations, and less leftover gas than active star forming ones. In order to assess the effects that projection and interlopers could introduce in observational samples, we have also constructed and analysed projected simulated catalogs of galaxy pairs. In good agreement with observations, our results show a threshold (rp < 25 kpc/h) for interactions to enhance the star formation activity with respect to galaxies without a close companion. Finally, analysing the environmental effect, we detect the expected SFR-local density relation for both pairs and isolated galaxy samples, although the density dependence is stronger for galaxies in pairs suggesting a relevant role for interactions in driving this relation.