First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS

Details First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS

2011-12-12

arxiv.org/abs/1112.2691v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

final version accepted by ApJL, see http://z-fourge.strw.leidenuniv.nl for more details

Scientific paper

We report the first results from the Z-FOURGE survey: the discovery of a candidate galaxy cluster at z = 2.2 consisting of two compact overdensities with red galaxies detected at >20{\sigma} above the mean surface density. The discovery was made possible by a new deep (Ks < 24.8 AB 5{\sigma}) Magellan/FourStar near-IR imaging survey with 5 custom medium-bandwidth filters. The filters pinpoint the location of the Balmer/4000\AA\ break in evolved stellar populations at 1.5 < z < 3.5, yielding significantly more accurate photometric redshifts than possible with broadband imaging alone. The overdensities are within 1' of each other in the COSMOS field and appear to be embedded in a larger structure that contains at least one additional overdensity (\sim10{\sigma}). Considering the global properties of the overdensities, the z = 2.2 system appears to be the most distant example of a galaxy cluster with a population of red galaxies. A comparison to a large {\Lambda}CDM simulation suggests that the system may consist of merging subclusters, with properties in between those of z > 2 protoclusters with more diffuse distributions of blue galaxies and the lower-redshift galaxy clusters with prominent red sequences. The structure is completely absent in public optical catalogs in COSMOS and only weakly visible in a shallower near-IR survey. The discovery showcases the potential of deep near-IR surveys with medium-band filters to advance the understanding of environment and galaxy evolution at z > 1.5.

Affiliated with

Also associated with

No associations

Rating

First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS 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 First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First Results from Z-FOURGE: Discovery of a Candidate Cluster at z = 2.2 in COSMOS will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-484773