The SPTPoL extended cluster survey

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 follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ ≥ 5 and an additional 204 systems at 4 4 threshold, and 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 we 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-SZ mass (l - 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 4σ 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

The Future Landscape of High-Redshift Galaxy Cluster Science

Large scale structure and cosmolog

Een huis en zijn bewoners

Geschiedenis van perceel Breestraat 2

De Kattenkampen te Amersfoort

De herkomst van de naam van dit buurtj

Een stadsgezicht van J. van Groenestein

Gezicht op Amersfoort in de 19de eeu

Uit het manuscript van Ds. J.F. Asma

Bezoek van Ds. Joan Frederik Asma (1802-1884) o.a. aan Utrecht op 3 september 183

Bezoek aan "Nimmerdor" in 1875

Bezoek van Ds. Joan Frederik Asma (1802-1884) op 13 juli 1875 aan het landhuis Nimmerdor te Leusde

Amersfoort of Rhenen?

N.a.v. schilderijen van Hercules Segher