Date: Fri, 26 Jan 2007 11:12:31 +0100
From: Manfred Georg Kitzbichler <mgk@mpadmx-2.mpa-garching.mpg.de>
To: Angela Iovino <angela.iovino@brera.inaf.it>
Subject: Groups

Dear Angela,
thank you for your feedback on the cones.

You wrote:
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            thanks again for your info on the millennium mocks...
I have made a few plots of comparison with the DEEP2 data that you may want to have a look at. It seems that in your simulations there are very few groups/clusters in the high z range with respect to the Gerke et al. 2005 paper.
I would be interested in getting your comments on this point ....
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Actually we have not made any such test yet ourselves and it another  interesting aspect of our model that indicates where things are not yet  treated in sufficient detail. There has been some indication already for  some time that for deep (faint) samples the clustering doesn't come out  right and I would assume that the apparent underabundance of high redshift  groups is pointing in the same direction - ie that we are missing  satellite galaxies at intermediate and high redshifts. In this context I would have a suggestion/question for you. We have some indication that increasing the luminosity of satellites, ie Type 1 and 2  galaxies artificially improves the correlation functions to be more in agreement with observations. Could you thus check whether artificially brightening Type 1 and 2 galaxies as follows would help your results:
I'_AB=I_AB-redshift/2
This means that depending on redshift we make satellites moderately  brighter, amounting to half a magnitude at z=1.

I would be interested whether that improves your findings.

All the best,

    Manfred
 
back to  deep2 vs MS comparison page