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 Zhang,A Bermeo-Hernandez,M A G Maia,N Kuropatkin,L N Da Costa,D L Burke,K Honscheid,A Carnero Rosell,V Scarpine,Paul Martini,H Wilcox,E Suchyta,M E C Swanson,A A Plazas,R Perfecto,E Bertin,H T Diehl,A K Romer,F B Abdalla,A Roodman,E Buckley-Geer,B Flaugher,M Makler,P Doel,A E Evrard,T Jeltema,D Gruen,D Brooks,P Fosalba,V Vikram,M Banerji,R A Gruendl,J L Marshall,M Soares-Santos,B Hoyle,R C Nichol,E S Rykoff,F J Castander,D Capozzi,O Lahav,R Miquel,J Frieman,F Sobreira,M Schubnell,A Bauer ,David Bacon ,Nicola Mehrtens ,Martin Sahlén ,T M C Abbott ,J J Mohr ,D L Tucker ,E Sánchez ,Casey Papovich ,I Sevilla-Noarbe ,Scott T Kay ,A Benoît-Levy ,C E Cunha ,E Fernández ,Ritanjan Das ,P T P Viana ,D W Gerdes ,K Kuêhn ,Timothy A Mckay ,Matthew Hilton ,John P Stott ,J J Thaler ,G Tarlé ,M Šako ,Chris Collins ,Christopher J Miller ,D J James ,Robert Mann ,D L Hollowood ,Philip Rooney ,R L C Ogando ,E Gaztañaga ,Andrew R Liddle ,Rory Smith ,S Desai,A Fausti Neto,T F Eifler,C Hennig,J Song

doi:10.3847/0004-637x/816/2/98

Abstract

ABSTRACT Using the science verification data of the Dark Energy Survey 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 z ~ 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 an analysis of a redshift-dependent BCG-cluster mass relation, m &ast; &prop; M 200 1.5 × 10 14 M &CircleDot; 0.24 &PlusMinus; 0.08 ( 1 + z ) − 0.19 &PlusMinus; 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 M 200,z = 1013.8 M ⊙; at z = 1.0: m *,BCG appears to have grown by 0.13 ± 0.11 dex, in tension at the ∼2.5σ significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates.

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