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Title: Constraints on the richness-mass relation and the optical-SZE positional offset distribution for SZE-selected clusters

In this study, we cross-match galaxy cluster candidates selected via their Sunyaev–Zel'dovich effect (SZE) signatures in 129.1 deg2 of the South Pole Telescope 2500d SPT-SZ survey with optically identified clusters selected from the Dark Energy Survey science verification data. We identify 25 clusters between 0.1 ≲ z ≲ 0.8 in the union of the SPT-SZ and redMaPPer (RM) samples. RM is an optical cluster finding algorithm that also returns a richness estimate for each cluster. We model the richness λ-mass relation with the following function 500> ∝ Bλln M500 + Cλln E(z) and use SPT-SZ cluster masses and RM richnesses λ to constrain the parameters. We find Bλ=1.14+0.21–0.18 and Cλ=0.73+0.77–0.75. The associated scatter in mass at fixed richness is σlnM|λ = 0.18+0.08–0.05 at a characteristic richness λ = 70. We demonstrate that our model provides an adequate description of the matched sample, showing that the fraction of SPT-SZ-selected clusters with RM counterparts is consistent with expectations and that the fraction of RM-selected clusters with SPT-SZ counterparts is in mild tension with expectation. We model the optical-SZE cluster positional offset distribution with the sum of two Gaussians, showing that it is consistent with a dominant, centrally peaked population and a subdominantmore » population characterized by larger offsets. We also cross-match the RM catalogue with SPT-SZ candidates below the official catalogue threshold significance ξ = 4.5, using the RM catalogue to provide optical confirmation and redshifts for 15 additional clusters with ξ ε [4, 4.5].« less
  1. Ludwig-Maximilians-Univ., Muenchen (Germany); Excellence Cluster Universe, Garching (Germany). et al.
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0035-8711; arXiv eprint number arXiv:1506.07814
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 454; Journal Issue: 3; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS catalogues; methods: data analysis; galaxies: abundances; galaxies: clusters: general; galaxies: haloes; galaxies: statistics; cosmology: miscellaneous; large-scale structure of Universe