Thursday, 24 January 2008

Large Scale Structures at High Redshift in the GOODS Field

Castellano et al., (conference proc.)

These authors identify overdense regions up to z~2.5 in GOODS-S using photometric redshifts. The most interesting feature is a proto-cluster at z~1.6. This figure shows the distribution of rest-frame color, mass, and M_B for candidate members of this proto-cluster (open histograms) and for field galaxies at similar redshift (filled histograms).

The candidate cluster galaxies tend to be brighter and more massive. There is also a prominent red sequence (and I suspect that the effect of interlopers is to contribute to the blue cloud, so the red sequence is probably even more prominent than is immediately apparent). These characteristics have been seen before at high-z, but this is a nice illustration and it is neat that they are able to do this kind of thing using photometric redshifts.

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