A steep slope and small scatter for the high-mass end of the L-σ relation at z ~ 0.55.

We measure the intrinsic relation between velocity dispersion (s) and luminosity (L) for massive, luminous red galaxies at redshift z ~ 0.55. We achieve unprecedented precision by using a sample of 600 000 galaxies with spectra from the Baryon Oscillation Spectroscopic Survey of the third Sloan Digital Sky Survey (SDSS-III), covering a range of stellar masses M* ≳ 1011M⊙.We deconvolve the effects of photometric errors, limited spectroscopic signalto- noise ratio, and red-blue galaxy confusion using a novel hierarchical Bayesian formalism that is generally applicable to any combination of photometric and spectroscopic observables. For an L-σ relation of the form L ∝ σβ, we find β = 7.8 ± 1.1 for σ corrected to the effective radius, and a very small intrinsic scatter of s = 0.047 ± 0.004 in log10σ at fixed L. No significant redshift evolution is found for these parameters. The evolution of the zeropoint within the redshift range considered is consistent with the passive evolution of a galaxy population that formed at redshift z = 2-3, assuming single stellar populations. An analysis of previously reported results seems to indicate that the passively evolved high-mass L-σ relation at z ~ 0.55 is consistent with the one measured at z = 0.1. Our results, in combination with those presented in the LF work of Montero-Dorta et al., provide a detailed description of the high-mass end of the red sequence (RS) at z ~ 0.55. This characterization, in the light of previous literature, suggest that the high-mass RS distribution corresponds to the 'core' elliptical population. [ABSTRACT FROM AUTHOR]