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Revista mexicana de astronomía y astrofísica

Print version ISSN 0185-1101


RODRIGUEZ-PUEBLA, A.; AVILA-REESE, V.; FIRMANI, C.  and  COLIN, P.. On The Stellar And Baryonic Mass Fractions Of Central Blue And Red Galaxies. Rev. mex. astron. astrofis [online]. 2011, vol.47, n.2, pp. 235-253. ISSN 0185-1101.

Using the abundance matching technique, we infer the local stellar and baryonic mass-halo mass ( Ms- Mh and Mb - Mh) relations separately for central blue and red galaxies (BGs and RGs). The observational inputs are the SDSS central BG and RG stellar mass functions and the measured gas mass-Ms relations. For halos associated to central BGs, the distinct ACDM halo mass function is used and set up to exclude: (i) the observed group/cluster mass function and (ii) halos with a central major merger at resdshifts z ≤ 0.8. For central RGs, the complement of this 5 mass function to the total one is used. At Mh > 1011.5 ΜΘ, the Ms of RGs tend to be higher than those of BGs for a given Mh, the difference not being larger than 1.7. At Mh < 1011.5 ΜΘ, this trend is inverted. For BGs (RGs): (a) the maximum value of fs = Ms / Mh is 0.021+0.016 -0.009(0.034 +0.026 -0.015)and it is attained at log(MhΘ) = 12.0 (= 11.9); (b) fs ∞ Mh ( fs ∞ Mh3) at the low-mass end while at the high-mass end, fs ∞ Mh-0.4 (fs ∞ Mh-06). The baryon mass fractions, fb = Mb / Mh, of BGs and RGs reach maximum values of fb = 0.028 +0.018 -0.011 y fb = 0.034 +0.025 -0.014., respectively. At Mh < 1011.3 ΜΘ, the dependence of fb on Mh is much steeper for RGs than for BGs. We discuss the differences found in the fs - Mh and fb - Mh relations between BGs and RGs in the light of semi-empirical galaxy evolution inferences.

Keywords : dark matter; galaxies [luminosity function]; galaxies [mass function].

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