Issues in joint SZ and optical cluster finding

TL;DR

This paper investigates the challenges and benefits of combining optical and SZ cluster finders using simulated data, highlighting tradeoffs and issues in improving galaxy cluster detection at different redshifts.

Contribution

It introduces a framework for combining optical and SZ cluster catalogs from simulations, analyzing the tradeoffs and issues in joint cluster finding methods.

Findings

Combining optical and SZ data improves cluster detection accuracy.

Tradeoffs exist in tuning cluster finders for different criteria.

Issues arise in catalog comparison and combination processes.

Abstract

We apply simple optical and SZ cluster finders to mock galaxy catalogues and SZ flux maps created from dark matter halos in a (1 Gpc/h)^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.