Stellar mass as a galaxy cluster mass proxy: application to the Dark Energy Survey redMaPPer clusters

• Published in: Monthly notices of the Royal Astronomical Society Vol. 493; no. 4; pp. 4591 - 4606
• Main Authors: Palmese, A, Annis, J, Burgad, J, Farahi, A, Soares-Santos, M, Welch, B, da Silva Pereira, M, Lin, H, Bhargava, S, Hollowood, D L, Wilkinson, R, Giles, P, Jeltema, T, Romer, A K, Evrard, A E, Hilton, M, Vergara Cervantes, C, Bermeo, A, Mayers, J, DeRose, J, Gruen, D, Hartley, W G, Lahav, O, Leistedt, B, McClintock, T, Rozo, E, Rykoff, E S, Varga, T N, Wechsler, R H, Zhang, Y, Avila, S, Brooks, D, Buckley-Geer, E, Burke, D L, Carnero Rosell, A, Carrasco Kind, M, Carretero, J, Castander, F J, Collins, C, da Costa, L N, Desai, S, De Vicente, J, Diehl, H T, Dietrich, J P, Doel, P, Flaugher, B, Fosalba, P, Frieman, J, García-Bellido, J, Gerdes, D W, Gruendl, R A, Gschwend, J, Gutierrez, G, Honscheid, K, James, D J, Krause, E, Kuehn, K, Kuropatkin, N, Liddle, A, Lima, M, Maia, M A G, Mann, R G, Marshall, J L, Menanteau, F, Miquel, R, Ogando, R L C, Plazas, A A, Roodman, A, Rooney, P, Sahlen, M, Sanchez, E, Scarpine, V, Schubnell, M, Serrano, S, Sevilla-Noarbe, I, Sobreira, F, Stott, J, Suchyta, E, Swanson, M E C, Tarle, G, Thomas, D, Tucker, D L, Viana, P T P, Vikram, V, Walker, A R
• Format: Journal Article
• Language: English
• Published: United Kingdom Oxford University Press 01-04-2020; Royal Astronomical Society
• Subjects: ASTRONOMY AND ASTROPHYSICS; cosmology; galaxies: clusters; galaxies: evolution; galaxies: haloes; surveys; surveys; galaxies: clusters: general; cosmology: observations; galaxies: evolution; galaxies: haloes
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/staa526

Abstract
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 $\sigma _{{\rm ln} T_\mathrm{ X}|\mu _\star }= 0.266^{+0.019}_{-0.020}$ 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 $\sigma _{{\rm ln} M|\mu _\star }= 0.26^{+ 0.15}_{- 0.10}$. 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.