Galaxy luminosities, stellar masses, sizes, velocity dispersions as a function of morphological type

摘要: We provide fits to the distribution of galaxy luminosity, size, velocity dispersion and stellar mass as a function concentration index Cr morphological type in Sloan Digital Sky Survey (SDSS). (Our size estimate, simple analogue SDSS cmodel magnitude, is new: it computed using combination seeing-corrected quantities data base, substantially better agreement with results from more detailed bulge/disc decompositions.) also quantify how estimates fraction ‘early’- or ‘late’-type galaxies depend on whether samples were cut colour, light profile shape, compare similar based morphology. Our show that ellipticals account for about 20 per cent r-band luminosity density, , 25 ρ*; including S0s Sas increases these numbers 33 40 cent, 50 60 respectively. The values ρ*, mean sizes, E, E+S0 E+S0+Sa are within 10 those Hyde & Bernardi, Cr≥ 2.86 2.6 samples, Summed over all types, we find ρ*∼ 3 × 108 M⊙ Mpc−3 at z∼ 0. This good expectations integrating star formation history. However, compared most previous work, an excess objects large masses, up factor ∼10 M*∼ 5 1011 M⊙. density further masses if assume different initial functions elliptical spiral galaxies, suggested by some recent chemical evolution models, dynamical function. We trend ellipticity decrease primarily because E/S0 ratio L. massive M*≥ 1011 M⊙, less concentrated not round expected one extrapolates lower L, they well fit pure deVaucouleur laws. suggests histories radial mergers. Finally, age–size relation flat fixed mass, but, Mdyn, sizes tend be younger. Hence, selected basis colour will yield scalings. Explaining this difference between E S0 new challenge models early-type formation.