Abstract
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 〈lnλ|M500〉 ∝ BλlnM500 + Cλln E(z) and use SPT-SZ cluster masses and RM richnesses λ to constrain the parameters. We find Bλ = 1.14-0.18+0.21 and Cλ = 0.73-0.75+0.77. The associated scatter in mass at fixed richness is σlnM|λ = 0.18-0.05+0.08 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 RMselected 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 subdominant population characterized by larger offsets. We also cross-match the RMcatalogue 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 ∈ [4, 4.5].
Original language | English (US) |
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Pages (from-to) | 2305-2319 |
Number of pages | 15 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 454 |
Issue number | 3 |
DOIs | |
State | Published - Dec 11 2015 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Catalogues
- Cosmology: miscellaneous
- Galaxies: abundances
- Galaxies: clusters: general
- Galaxies: haloes
- Galaxies: statistics
- Large-scale structure of Universe
- Methods: data analysis