The data are taken from the Luminous Red Galaxy sample of the Sloan Digital Sky Survey Data Release 4. From the SDSS spectra we compute the five indices Hbeta, Hgamma_F_, Dn(4000), [MgFe]', [Mg1Fe]'. These are matched indices from a synthetic library of spectra containing 31000 different star formation scenarios. From this we can infer probability distributions for a number of properties, such as age, metallicity, etc. The results are presented here as the 5th, 16th, 50th (median), 86th and 95th percentiles of the relevant distribution. The 4391 LRG properties presented here are chosen from the redshift range 0.15<z<0.4 and require all 5 of the above indices to have well-measured values (i.e. no contamination from skylines, bad pixels) Also given are a number of properties that come directly from the SDSS database, such as redshift, velocity dispersion etc. For the luminosity distance calculation (and subsequent mass estimates), we assume a FRW metric, with omega_m_=0.25, omega_lambda_=0.75 and H_0_=73km/s/Mpc.

Tom Barber, barber(at)hep.phy.cam.ac.uk