The Dependence of the Galaxy Luminosity Function on Large-Scale Environment

Details The Dependence of the Galaxy Luminosity Function on Large-Scale Environment The Dependence of the Galaxy Luminosity Function on Large-Scale Environment

2003-10-06

arxiv.org/abs/astro-ph/0310147v2

Mon.Not.Roy.Astron.Soc. 349 (2004) 205

Astronomy and Astrophysics

Astrophysics

9 pages, 9 figures, published in MNRAS

Scientific paper

10.1111/j.1365-2966.2004.07485.x

A basic assumption in current halo occupation model is that the properties of a galaxy depend only on the mass of its dark matter halo. An important consequence of this is that the segregation of the galaxy population by large-scale environment is entirely due to the environmental dependence of the halo population. In this paper we use such a model to predict how the galaxy luminosity function depends on large-scale environment. The latter is represented by the density contrast (delta) averaged over a spherical volume of radius R=8Mpc/h. The model predicts that the Schechter function is a good approximation to the luminosity functions of galaxies brighter than ~10^9 h^{-2}L_sun (b_j-band) in virtually all environments. The characteristic luminosity, L^{\star}, increases moderately with \delta. The faint-end slope, \alpha, on the other hand, is quite independent of $\delta$. However, when splitting the galaxy population into early and late types, it is found that for late-types \alpha is virtually constant, whereas for early-types \alpha increases from ~-0.3 in underdense regions (\delta~-0.5) to ~-0.8 in highly overdense regions with \delta ~ 10. The luminosity function at L_{b_j}<10^9 h^{-2} L_sun is significantly steeper than the extrapolation of the Schechter function that fits the brighter galaxies. This steepening is more significant for early-types and in low-density environments. The model also predicts that the luminosity density and mass density are closely correlated. The relation between the two is monotonic but highly non-linear. This suggests that one can use the luminosity density, averaged over a large volume, to rank the mass density. This, in turn, allows the environmental effects predicted here to be tested by observations.

Affiliated with

Also associated with

No associations

Rating

The Dependence of the Galaxy Luminosity Function on Large-Scale Environment does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Dependence of the Galaxy Luminosity Function on Large-Scale Environment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Dependence of the Galaxy Luminosity Function on Large-Scale Environment will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-344311