Resumo

RODRIGUEZ-PUEBLA, A.; AVILA-REESE, V.; FIRMANI, C.  e  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 ( M_s- M_h and M_b - M_h) 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-M_s 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 M_h > 10^11.5 Μ_Θ, the M_s of RGs tend to be higher than those of BGs for a given M_h, the difference not being larger than 1.7. At M_h < 10^11.5 Μ_Θ, this trend is inverted. For BGs (RGs): (a) the maximum value of f_s = M_s / M_h is 0.021+0.016 -0.009(0.034 +0.026 -0.015)and it is attained at log(M_h/Μ_Θ) = 12.0 (= 11.9); (b) f_s ∞ M_h ( f_s ∞ M_h³) at the low-mass end while at the high-mass end, f_s ∞ M_h^-0.4 (f_s ∞ M_h^-06). The baryon mass fractions, f_b = M_b / M_h, of BGs and RGs reach maximum values of f_b = 0.028 +0.018 -0.011 y f_b = 0.034 +0.025 -0.014., respectively. At M_h < 10^11.3 Μ_Θ, the dependence of f_b on M_h is much steeper for RGs than for BGs. We discuss the differences found in the f_s - M_h and f_b - M_h relations between BGs and RGs in the light of semi-empirical galaxy evolution inferences.

Palavras-chave : dark matter; galaxies [luminosity function]; galaxies [mass function].

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