2019/10/09 by L. E. Bleem, S. Bocquet, B. Stalder +135 · 1 voice
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.3847/1538-4365/ab6993
49 pages, 14 figures, 10 tables. Minor changes to match accepted version in ApJS
arxiv published 2019/10/09 · arxiv created 2019/12/13 · arxiv updated 2020/03/11
We describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect, and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete followup we have confirmed as clusters 244 of 266 candidates at a detection significance ξ≥ 5 and an additional 204 systems at 4<ξ<5. The confirmed sample has a median mass of M500c ∼ 4.4 × 1014 M_\odot h70-1, a median redshift of z=0.49, and we have identified 44 strong gravitational lenses in the sample thus far. Radio data are used to characterize contamination to the SZ signal; the median contamination for confirmed clusters is predicted to be ∼1% of the SZ signal at the ξ>4 threshold, and <4% of clusters have a predicted contamination >10% of their measured SZ flux. We associate SZ-selected clusters, from both SPT-ECS and the SPT-SZ survey, with clusters from the DES redMaPPer sample, and find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets. Adopting a fixed Planck-like cosmology, we measure the optical richness-to-SZ-mass (λ-M) relation and find it to be 28% shallower than that from a weak-lensing analysis of the DES data---a difference significant at the 4 σ level---with the relations intersecting at λ=60 . The SPT-ECS cluster sample will be particularly useful for studying the evolution of massive clusters and, in combination with DES lensing observations and the SPT-SZ cluster sample, will be an important component of future cosmological analyses.