Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17

Details Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17 Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17

2008-05-22

arxiv.org/abs/0805.3459v2

Astronomy and Astrophysics

Astrophysics

30 pages, 13 figures, accepted by MNRAS, major changes: improved redshift distributions of samples, now comoving number densit

Scientific paper

This paper studies the relative spatial distribution of red-sequence and blue-cloud galaxies, and their relation to the dark matter distribution in the COMBO-17 survey as function of scale down to z~1. We measure the 2nd-order auto- and cross-correlation functions of galaxy clustering and express the relative biasing by using aperture statistics. Also estimated is the relation between the galaxies and the dark matter distribution exploiting galaxy-galaxy lensing (GGL). All observables are further interpreted in terms of a halo model. To fully explain the galaxy clustering cross-correlation function with a halo model, we need to introduce a new parameter,R, that describes the statistical relation between numbers of red and blue galaxies within the same halo. We find that red and blue galaxies are clearly differently clustered, a significant evolution of the relative clustering with redshift was not found. There is evidence for a scale-dependence of relative biasing. The relative clustering, the GGL and, with some tension, the galaxy numbers can be explained consistently within a halo model. For the cross-correlation function one requires a HOD variance that becomes Poisson even for relatively small occupancy numbers. For our sample, this rules out with high confidence a "Poisson satellite" scenario as found in semi-analytical models. Red galaxies have to be concentrated towards the halo centre, either by a central red galaxy or by a concentration parameter above that for dark matter.The value of R depends on the presence or absence of central galaxies: If no central galaxies or only red central galaxies are allowed, R is consistent with zero, whereas a positive correlation $R=+0.5\pm0.2$ is needed if both blue and red galaxies can have central galaxies.[ABRIDGED]

Affiliated with

Also associated with

No associations

Rating

Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17 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 Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-511024