Satellite Luminosities in Galaxy Groups

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8 pages, 3 figures. Matches version accepted by MNRAS

Scientific paper

10.1111/j.1365-2966.2007.12504.x

Halo model interpretations of the luminosity dependence of galaxy clustering assume that there is a central galaxy in every sufficiently massive halo, and that this central galaxy is very different from all the others in the halo. The halo model decomposition makes the remarkable prediction that the mean luminosity of the non-central galaxies in a halo should be almost independent of halo mass: the predicted increase is about 20% while the halo mass increases by a factor of more than 20. In contrast, the luminosity of the central object is predicted to increase approximately linearly with halo mass at low to intermediate masses, and logarithmically at high masses. We show that this weak, almost non-existent mass-dependence of the satellites is in excellent agreement with the satellite population in group catalogs constructed by two different collaborations. This is remarkable, because the halo model prediction was made without ever identifying groups and clusters. The halo model also predicts that the number of satellites in a halo is drawn from a Poisson distribution with mean which depends on halo mass. This, combined with the weak dependence of satellite luminosity on halo mass, suggests that the Scott effect, such that the luminosities of very bright galaxies are merely the statistically extreme values of a general luminosity distribution, may better apply to the most luminous satellite galaxy in a halo than to BCGs. If galaxies are identified with halo substructure at the present time, then central galaxies should be about 4 times more massive than satellite galaxies of the same luminosity, whereas the differences between the stellar M/L ratios should be smaller. Therefore, a comparison of the weak lensing signal from central and satellite galaxies should provide useful constraints. [abridged]

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Satellite Luminosities in Galaxy Groups 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 Satellite Luminosities in Galaxy Groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Satellite Luminosities in Galaxy Groups will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-59405

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.