filaments, mergers

Quintero provoked a nice discussion of filaments in group meeting. Evidently filaments do exist; the questions are as follows: (1) Are the galaxies in filaments different from other galaxies not in filaments but that live in the same local mass density environments? (2) Can we understand the evolution of clusters as the infall (and simultaneous evolution) of galaxies along the filaments? Not sure if we will pursue these questions, but there clearly are first steps we could take.

Masjedi showed me brand-new results on the rate of mergers of LRGs (that's luminous red galaxies) with smaller galaxies, as a function of color and magnitude of the smaller galaxy. Of course he really measures the cross-correlation functions, but we can use those to (severely) limit the merger rate. This project will give us the mass spectrum of mergers (or constrain it) and, we hope, limit the total mass accretion rate.