This is the astro-ph blog of the Theoretical Modelling of Cosmic Structures group (TMoX) at the Max-Planck-Institute for Extraterrestrial Physics. We are an independent Max-Planck Research Group focusing on the various aspects in the formation and evolution of galaxies. Part of our focus is on the formation and evolution of early-type galaxies, super-massive black holes, the formation of the first structures in the universe and the enrichment history of the Universe. We are theoreticians using analytic modelling as well as numerical simulations in our work.

The CosmologyCake blog is dedicated to the discussion of research papers and current developments. We will regularly post interesting papers and comment on them. Feel free to leave your comments as well. We encourage authors of discussed papers to post replies if they wish to. Our aim is to provide a platform to discuss recent astro-ph papers within a wider audience. Please feel free to send papers you would like to be discussed to us at

20 January 2012

Which galaxy property is the best indicator of its host dark matter halo properties?

This paper (link) discusses an interesting new observational trend: It is found that the clustering of massive galaxies depends more strongly on the central velocity dispersion (s) than on stellar mass (m). This fact is emphasized by measuring w_p for subsamples of a given s (or m) at various bins in m (or s). The authors claim that this observational evidence supports the idea that the halo mass is more tightly related to s, than to m. In addition, the paper includes results that show the clustering dependence on surface density, color, and dynamical mass estimates.

1 comment:

  1. I wonder about the role that assembly bias may play in interpreting these results. Is it possible that dispersion is correlated with any property known from simulations to cause bias (e.g. formation time, halo spin, halo shape, etc.) ?