EDP Sciences
Free access
Volume 430, Number 3, February II 2005
Page(s) 827 - 842
Section Cosmology (including clusters of galaxies)
DOI http://dx.doi.org/10.1051/0004-6361:20041450

A&A 430, 827-842 (2005)
DOI: 10.1051/0004-6361:20041450

Time evolution of the stochastic linear bias of interacting galaxies on linear scales

P. Simon

Institut für Astrophysik und Extraterrestrische Forschung, Auf dem Hügel 71, 53121 Bonn, Germany
    e-mail: psimon@astro.uni-bonn.de

(Received 10 June 2004 / Accepted 1 October 2004)

We extend the time dependent bias model of Tegmark & Peebles (1998) to predict the large-scale evolution of the stochastic linear bias of different galaxy populations with respect to both the dark matter and each other. The resulting model equations contain a general expression, coined the "interaction term", accounting for the destruction or production of galaxies. This term may be used to model couplings between different populations that lead to an increase or decrease of the number of a galaxies belonging to a population, e.g. passive evolution or merging processes. This is explored in detail using a toy model. In particular, it is shown that the presence of such a coupling may change the evolution of the bias parameter compared to an interaction-free evolution. We argue that the observation of the evolution of the large-scale bias and galaxy number density with wide-field surveys may be used to infer fundamental interaction parameters between galaxy populations, possibly giving an insight in their formation and evolution.

Key words: galaxies: statistics -- cosmology: theory -- cosmology: dark matter -- cosmology: large-scale structure of Universe -- Galaxy: fundamental parameters

© ESO 2005