Stellar mass as a galaxy cluster mass proxy: application to the Dark Energy Survey redMaPPer clusters
Annis, J.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Doel, P.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Plazas, A. A.; Romer, A. K.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Walker, A. R.; DES Collaboration; Mann, R. G.; Zhang, Y.; Vergara Cervantes, C.; Hollowood, D. L.; Bhargava, S.; Palmese, A.; Jeltema, T.; Avila, S.; Buckley-Geer, E.; De Vicente, J.; Evrard, A. E.; Hartley, W. G.; Lahav, O.; Roodman, A.; Serrano, S.; Thomas, D.; Varga, T. N.; Giles, P.; Dietrich, J. P.; DeRose, J.; Krause, E.; Lin, H.; Vikram, V.; Wechsler, R. H.; Tucker, D. L.; Hilton, M.; Farahi, A.; McClintock, T.; Rooney, P.; Liddle, A.; Rozo, E.; Viana, P. T. P.; Collins, C.; Leistedt, B.; Wilkinson, R.; Sahlen, M.; Bermeo, A.; Mayers, J.; Stott, J.; Welch, B.; Burgad, J.; da Silva Pereira, M.
United States, United Kingdom, South Africa, Switzerland, Germany, Spain, Brazil, India, Australia, Portugal, Chile
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.