Galaxy pairs in the 2dF survey — I. Effects of interactions on star formation in the field

By D. Lambas, Patricia B. Tissera, M. S. Alonso, G. Coldwell, J. Simon, Guggenheim Fellow. 2002

206 citations recorded by the source corpus.

We study galaxy pairs (GPs) in the field selected from the 100-K public release of the Two Degree Field (2dF) galaxy redshift survey. Our analysis provides a well-defined sample of 1258 GPs, a large data base suitable forstatistical studies of galaxy interactions in the local Universe, z ≤ 0.1. GPs were selected by radial velocity (AV) and projected separation (rp) criteria determined by analysing the star-formation activity within neighbours. We have excluded pairs in high-density regions by removing galaxies in groups and clusters. We analyse the star-formation activity in the pairs as a function of both relative projected distance and relative radial velocity. We found power-law relations for the mean star-formation birth parameter and equivalent widths of the galaxies in pairs as a function of rp and Δ V. We find that star formation in GPs is significantly enhanced over that of isolated galaxies with similar redshifts in the field for r p < 25 h - 1 kpc and AV < 100 km s - 1 . We detected that, when compared to isolated galaxies of similar luminosity and redshift distribution, the effects of having a companion are more significant on the star-formation activity of bright galaxies in pairs, unless the pairs are formed by similar luminosity galaxies. In this case, the star formation is enhanced in both components. The ratio between the fractions of star-forming galaxies in pairs and in isolation is a useful tool to unveil the effects of having a close companion. We found that about 50 per cent of GPs do not show signs of important star-formation activity (independently of their luminosities), supporting the hypothesis that the internal properties of the galaxies play a crucial role in the triggering of star formation by interactions.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/0ce42805d9e71e504d841aa3c66ee93fbeddf25d

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Citations in the corpus

Galaxy pairs in the Sloan Digital Sky Survey – VI. The orbital extent of enhanced star formation in interacting galaxies (2013, unknown): “30 kpc (e.g., Barton, Geller, & Kenyon 2000; Lambas et al. 2003; Ellison etal.”
The effect of galaxy mass ratio on merger-driven starbursts (2007, background): “…(as measured by close pairs or morphology, e.g., Larson & Tinsley 1978; Joseph & Wright 1985; Kennicutt et al. 1987; Barton Gillespie et al. 2003; Lambas et al. 2003; Nikolic et al. 2004), only recently c© 0000 RAS, MNRAS 000, 000–000 has it been possible to specifically address whether or not…”
Galaxy ecology: groups and low-density environments in the SDSS and 2dFGRS (2003, background): “For example, if we believe galaxy-galaxy interactions are important, then perhaps it is only the distance to the nearest neighbour that is relevant (Lambas et al. 2003).”
Galaxy pairs in the Sloan Digital Sky Survey – II. The effect of environment on interactions (2010, background): “It has been well known for many years that galaxy-galaxy interactions can trigger star formation, e.g. Kennicutt et al., (1987); Barton, Geller & Kenyon (2000); Lambas et al (2003); Alonso et al. (2004); Nikolic, Cullen & Alexander (2004).”
Feedback in simulations of disc-galaxy major mergers (2005, background): “…is supported by a variety of observational data which links morphologically disturbed or outright merging galaxies to enhanced levels of star formation (e.g., Larson & Tinsley 1978; Joseph & Wright 1985; Kennicutt et al. 1987; Barton Gillespie et al. 2003; Lambas et al. 2003; Nikolic et al. 2004).”
Galaxy pairs in the Sloan Digital Sky Survey - IV: Interactions trigger AGN (2011, background): “Close pairs have been unequivocally demonstrated to have enhanced star formation rates (Kennicutt et al., 1987; Barton, Geller & Kenyon 2000; Lambas et al 2003; Alonso et al. 2004; Nikolic, Cullen & Alexander 2004; Woods, Geller & Barton 2006; Woods & Geller 2007; Ellison et al. 2008, 2010; Patton…”
The Environmental Dependence of Galaxy Properties in the Local Universe: Dependences on Luminosity, Local Density, and System Richness (2004, background): “Actually, galaxies in close pairs show enhanced star formation rates over those of isolated galaxies, and probably they are currently in the process of interaction (Patton et al. 1997; Barton, Geller, & Kenyon 2000; Lambas et al. 2003).”