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, , 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 = 1013.8 Mo; 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.
Original language | English (US) |
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Article number | 98 |
Journal | Astrophysical Journal |
Volume | 816 |
Issue number | 2 |
DOIs | |
State | Published - Jan 10 2016 |
Externally published | Yes |
Keywords
- galaxies: clusters: general
- galaxies: evolution
- galaxies: groups: general
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science