Surface photometry of brightest cluster galaxies and intracluster stars in ΛCDM
Abstract
We simulate the phase-space distribution of stellar mass in nine massive Λ cold dark matter galaxy clusters by applying the semi-analytic particle tagging method of Cooper et al. to the Phoenix suite of high-resolution N-body simulations (M200 ≈ 7.5-33 × 1014 M⊙). The resulting surface brightness (SB) profiles of brightest cluster galaxies (BCGs) match well to observations. On average, stars formed in galaxies accreted by the BCG account for ≳90 per cent of its total mass (the remainder is formed in situ). In circular BCG-centred apertures, the superposition of multiple debris clouds (each ≳10 per cent of the total BCG mass) from different progenitors can result in an extensive outer diffuse component, qualitatively similar to a `cD envelope'. These clouds typically originate from tidal stripping at z ≲ 1 and comprise both streams and the extended envelopes of other massive galaxies in the cluster. Stars at very low SB contribute a significant fraction of the total cluster stellar mass budget: in the central 1 Mpc2 of a z ∼ 0.15 cluster imaged at SDSS-like resolution, our fiducial model predicts 80-95 per cent of stellar mass below a SB of μV ∼ 26.5 mag arcsec-2 is associated with accreted stars in the envelope of the BCG. The ratio of BCG stellar mass (including this diffuse component) to total cluster stellar mass is ∼30 per cent.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2015
- DOI:
- 10.1093/mnras/stv1042
- arXiv:
- arXiv:1407.5627
- Bibcode:
- 2015MNRAS.451.2703C
- Keywords:
-
- methods: numerical;
- galaxies: clusters: general;
- galaxies: elliptical and lenticular;
- cD;
- galaxies: haloes;
- galaxies: photometry;
- galaxies: structure;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted by MNRAS, conclusions and figures unchanged, minor revision to discussion