Issues in joint SZ and optical cluster finding

Abstract

We apply simple optical and SZ (Sunyaev-Zel'dovich) cluster finders to mock galaxy catalogues and SZ flux maps created from dark matter haloes in a (1 h-1 Gpc)3 dark matter simulation, at redshifts 0.5 and 0.9. At each redshift, the two catalogues are then combined to assess how well they can improve each other, and compared to several variants of catalogues made using SZ flux and galaxy information simultaneously. We use several different criteria to compare the catalogues, and illustrate some of the tradeoffs which arise in tuning the galaxy cluster finders with respect to these criteria. We detail many of the resulting improvements and issues which arise in comparing and combining these two types of data sets. © 2009 RAS.