The Velocity Dispersion Function of Early-Type Galaxies


Sheth RK, Bernardi M, Schechter PL, Burles S, Eisenstein DJ, Finkbeiner DP, Frieman J, Lupton RH, Schlegel DJ, SubbaRao M, et al. The Velocity Dispersion Function of Early-Type Galaxies. The Astrophysical Journal. 2003;594 :225-231.

Date Published:

September 1, 200


The distribution of early-type galaxy velocity dispersions,φ(σ), is measured using a sample drawn from the Sloan DigitalSky Survey database. Its shape differs significantly from that obtainedby simply using the mean correlation between luminosity L and velocitydispersion σ to transform the luminosity function into a velocityfunction: ignoring the scatter around the mean σ-L relation is abad approximation. An estimate of the contribution from late-typegalaxies is also made, which suggests that φ(σ) is dominatedby early-type galaxies at velocities larger than ~200 km s-1.