2010/01/31 by Ricardo Demarco, Gillian Wilson, Adam Muzzin +6 · 78 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy groups and clusters #Open cluster #Sample (material) #Type-cD galaxy #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/711/2/1185
published in The Astrophysical Journal 711(2), 1185-1197 (IOP Publishing) · Accepted for publication in the Astrophysical Journal. 18 pages, 11 figures
arxiv created 2010/01/31 · openalex publication_date 2010/02/22 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z '-passband imaging survey of the 50 deg 2 Spitzer SWIRE Legacy fields, designed with the primary aim of creating the first large, homogeneously selected sample of massive clusters at z > 1. SpARCS uses an infrared adaptation of the two-filter cluster red-sequence technique. In this paper, we report Keck/LRIS spectroscopic confirmation of two new exceptionally rich galaxy clusters, SpARCS J161315+564930 at z = 0.871 ± 0.002, with 14 high-confidence members and a rest-frame velocity dispersion of σ v = 1230 ± 320 km s −1 , and SpARCS J161641+554513 at z = 1.161 ± 0.003, with seven high-confidence members (including one active galactic nucleus) and a rest-frame velocity dispersion of σ v = 950 ± 330 km s −1 . We also report confirmation of a third new system, SpARCS J161037+552417 at z = 1.210 ± 0.002, with seven high-confidence members and a rest-frame velocity dispersion of σ v = 410 ± 300 km s −1 . These three new spectroscopically confirmed clusters further demonstrate the efficiency and effectiveness of two-filter imaging for detecting bona fide galaxy clusters at high redshift. We conclude by demonstrating that prospects are good for the current generation of surveys aiming to estimate cluster redshifts and masses at z ≳ 1 directly from optical-infrared imaging.