posted on 2024-07-26, 13:58authored byPaola Oliva Altamirano, S. Brough, Kim-Vy Jimmy, K.-V. Tran, Warrick CouchWarrick Couch, R. M. McDermid, C. Lidman, A. von der Linden, R. Sharp
We analyse the spatially-resolved stellar populations of 9 local (z<0.1) Brightest Cluster Galaxies (BCGs) observed with VIMOS in IFU mode. Our sample is composed of 7 slow-rotating and 2 fast-rotating BCGs. We do not find a connection between stellar kinematics and stellar populations in this small sample. The BCGs have shallow metallicity gradients (median Δ[Fe/H] =−0.11±0.1), high central metallicities (median [Fe/H][α/Fe]=0=0.13±0.07), and a wide range of central ages (from 5 to 15 Gyr). We propose that the reason for this is diverse evolutionary paths in BCGs. 67 per cent of the sample (6/9) show ∼7 Gyr old central ages, which reflects an active accretion history, and 33 per cent of the sample (3/9) have central ages older than 11 Gyr, which suggest no star formation since z=2. The BCGs show similar central stellar populations and stellar population gradients to early-type galaxies of similar mass (Mdyn>1011.3M⊙) from the ATLAS3D survey (median [Z/H] =0.04±0.07, Δ[Z/H] =−0.19±0.1). However, massive early-type galaxies from ATLAS3D have consistently old ages (median Age =12.0±3.8Gyr). We also analyse the close massive companion galaxies of two of the BCGs. These galaxies have similar stellar populations to their respective BCGs.