1306.6496 (L. Old et al.)

Brighter galaxy bias: underestimating the velocity dispersions of galaxy clusters    [PDF]

L. Old, M. E. Gray, F. R. Pearce

We study the systematic bias introduced when selecting the spectroscopic redshifts of brighter cluster galaxies to estimate the velocity dispersion of galaxy clusters from both simulated and observational galaxy catalogues. We select clusters with Ngal > 50 at five low redshift snapshots from a semi-analytic model galaxy catalogue, and from a catalogue of SDSS DR8 groups and clusters across the redshift range 0.021View original: http://arxiv.org/abs/1306.6496