We analyze the clustering properties of ultraviolet-selected galaxies by using GALEX-SDSS data at z < 0.6 and CFHTLS deep u′ imaging at z ∼ 1. These data sets provide a unique basis at z ≤ 1 which can be directly compared with high-redshift samples built with similar selection criteria. We discuss the dependence of the correlation function parameters (r0, and δ) on the ultraviolet luminosity, as well as the linear bias evolution. We find that the bias parameter shows a gradual decline from high (b8 ≳ 2) to low redshift (b8 ≃ 0.79 -0.08+0.1). When accounting for the fraction of the star formation activity enclosed in the different samples, our results suggest that the bulk of star formation migrated from high-mass dark matter halos at z > 2 (1012 M⊙ ≤ Mmin ≤ 1013 M⊙, located in high-density regions) to less massive halos at low redshift (Mmin ≤ 1012 M⊙, located in low-density regions). This result extends the "downsizing" picture (shift of the star formation activity from high stellar mass systems at high z to low stellar mass at low z) to the dark matter distribution.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science