Stellar mass as a galaxy cluster mass proxy [Elektronisk resurs] application to the Dark Energy Survey redMaPPer clusters

• We introduce a galaxy cluster mass observable, μ⋆, based on the stellar masses of cluster members, and we present results for the Dark Energy Survey (DES) Year 1 (Y1) observations. Stellar masses are computed using a Bayesian model averaging method, and are validated for DES data using simulations and COSMOS data. We show that μ⋆ works as a promising mass proxy by comparing our predictions to X-ray measurements. We measure the X-ray temperature–μ⋆ relation for a total of 129 clusters matched between the wide-field DES Y1 redMaPPer catalogue and Chandra and XMM archival observations, spanning the redshift range 0.1 < z < 0.7. For a scaling relation that is linear in logarithmic space, we find a slope of α = 0.488 ± 0.043 and a scatter in the X-ray temperature at fixed μ⋆ of σlnTX|μ⋆=0.266+0.019−0.020 for the joint sample. By using the halo mass scaling relations of the X-ray temperature from the Weighing the Giants program, we further derive the μ⋆-conditioned scatter in mass, finding σlnM|μ⋆=0.26+0.15−0.10⁠. These results are competitive with well-established cluster mass proxies used for cosmological analyses, showing that μ⋆ can be used as a reliable and physically motivated mass proxy to derive cosmological constraints. 

Ämnesord

Natural Sciences  (hsv)

Physical Sciences  (hsv)

Astronomy, Astrophysics and Cosmology  (hsv)

Naturvetenskap  (hsv)

Fysik  (hsv)

Astronomi, astrofysik och kosmologi  (hsv)

Genre

government publication  (marcgt)

Indexterm och SAB-rubrik

surveys

galaxies: clusters: general

galaxies: evolution

galaxies: haloes

cosmology: observations

Astrophysics - Cosmology and Nongalactic Astrophysics