Galaxies in X-ray Selected Clusters and Groups in Dark Energy Survey Data I: Stellar Mass Growth of Bright Central Galaxies Since z~1.2

Y.-Y. Zhang, C. J. Miller, T. A. McKay, P. J. Rooney, A. E. Evrard, A. K. Romer, R. Perfecto, J. Song, S. Desai, J. J. Mohr, H. Wilcox, A. Bermeo, T. E. Jeltema, D. L. Hollowood, D. Bacon, D. Capozzi, C. A. Collins, R. Das, D. Gerdes, C. Hennig, M. Hilton, B. Hoyle, S. T. Kay, A. R. Liddle, R. G. Mann, N. Mehrtens, R. C. Nichol, C. Papovich, M. Soares-Santos, J. P. Stott, P. T. P. Viana, T. M. C. Abbott, F. B. Abdalla, M. Banerji, A.H. Bauer, A. Benoit-Levy, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, F. J. Castander, H. T. Diehl, P. Doel, C. E. Cunha, T. F. Eifler, A. Fausti Neto, E. Fernandez, B. Flaugher, P. Fosalba, J. A. Frieman, E. Gaztanaga, D. Gruen, R. A. Gruendl, K. Honscheid, D. J. James, K. Kuehn, N. Kuropatkin, O. Lahav, M. A. G. Maia, M. Makler, J. L. Marshall, P. Martini, R. Miquel, R. L. C. Ogando, A. A. Plazas Malagón, A. Roodman, E. S. Rykoff, M. Sako, E. Sanchez, V. Scarpine, M. Schubnell, I. Sevilla, R. C. Smith, F. Sobreira, E. Suchyta, M. E. C. Swanson, G. Tarle, J. Thaler, D. L. Tucker, V. Vikram,

Abstract
Using the science verification data of the Dark Energy Survey (DES) for a new sample of 106 X-Ray selected clusters and groups, we study the stellar mass growth of Bright Central Galaxies (BCGs) since redshift 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into analysis of a redshift-dependent BCG-cluster mass relation, m∗∝(M2001.5×1014M⊙)0.24±0.08(1+z)−0.19±0.34, and compare the observed relation to the model prediction. We estimate the average growth rate since z=1.0 for BCGs hosted by clusters of M200,z=1013.8M⊙, at z=1.0: m∗,BCG appears to have grown by 0.13±0.11 dex, in tension at ∼2.5σ significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the buildup of extended intra-cluster light after z=1.0 may alleviate this tension in BCG growth rates.

Acta Astronautica
December 2015