G.A. Mamon, F. Combes, C. Deffayet and B. Fort (eds)
EAS Publications Series, 20 (2006) 131-134
Mass-to-light ratios of ellipticals in ΛCDM
INAF-Observatory of Capodimonte, Naples, Italy
2 Planetary Nebula Spectrograph team: see http://www.astro.rug.nl/~pns/pns_team.html#coll
We use the mass-to-light gradients in early-type galaxies to infer the global dark matter fraction, fd = Md/M*, for these systems. We discuss implications about the total star formation efficiency in dark-matter halos and show that the the trend of fd with mass produces virial mass-to-light ratios which are consistent semi-analitical models. Preliminary kurtosis analysis of the quasi-constant M/L galaxies in Romanowsky et al. seems at odd with Dekel et al. simulations.
© EAS, EDP Sciences, 2006