N. Menci et al. 2005 ApJ 632 49 doi:10.1086/432788
N. Menci1, A. Fontana1, E. Giallongo1 and S. Salimbeni1
Show affiliationsWe show how the observed bimodality in the color distribution of galaxies can be explained in the framework of the hierarchical clustering picture in terms of the interplay between the properties of the merging histories and the feedback/star formation processes in the progenitors of local galaxies. Using a semianalytic model of hierarchical galaxy formation, we compute the color distributions of galaxies with different luminosities and compare them with the observations. Our fiducial model matches the fundamental properties of the observed distributions, namely: (1) the distribution of objects brighter than Mr
-18 is clearly bimodal, with a fraction of red objects increasing with luminosity; (2) for objects brighter than Mr
-21, the color distribution is dominated by red objects with color u - r ≈ 2.2-2.4; (3) the spread on the distribution of the red population is smaller than that of the blue population; (4) the fraction of red galaxies is larger in denser environments, even for low-luminosity objects; and (5) the bimodality in the distribution persists up to z ≈ 1.5. We discuss the role of the different physical processes included in the model in producing the above results.
cosmology: theory; galaxies: evolution; galaxies: formation; galaxies: high-redshift
Issue 1 (2005 October 10)
Received 2005 February 4, accepted for publication 2005 June 15
N. Menci et al. 2005 ApJ 632 49
A. I. MacFadyen et al. 2001 ApJ 550 410
P M Glover 2009 Phys. Med. Biol. 54 R99
P. D. Shankland et al. 2006 ApJ 653 700
Steven R. Cranmer 2009 ApJ 706 824
V I Fal'ko et al 1991 J. Phys.: Condens. Matter 3 5079
Sanghee Cho et al 2008 Phys. Med. Biol. 53 2809
Jason M. Kirk et al. 2009 ApJS 185 198
U Jeleń et al 2005 Phys. Med. Biol. 50 1747
Paula Szkody et al. 1999 ApJ 521 362