TY - JOUR
T1 - The accretion histories of brightest cluster galaxies from their stellar population gradients
AU - Oliva-Altamirano, Paola
AU - Brough, Sarah
AU - Jimmy,
AU - Tran, Kim Vy
AU - Couch, Warrick J.
AU - McDermid, Richard M.
AU - Lidman, Chris
AU - von der Linden, Anja
AU - Sharp, Rob
N1 - Publisher Copyright:
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2015/3/21
Y1 - 2015/3/21
N2 - We analyse the spatially resolved stellar populations of nine local (z < 0.1) Brightest Cluster Galaxies (BCGs) observed with VIMOS in Integral Field Unit mode. Our sample is composed of seven slow-rotating and two 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 ± 3.8 Gyr). We also analyse the close massive companion galaxies of two of the BCGs. These galaxies have similar stellar populations to their respective BCGs.
AB - We analyse the spatially resolved stellar populations of nine local (z < 0.1) Brightest Cluster Galaxies (BCGs) observed with VIMOS in Integral Field Unit mode. Our sample is composed of seven slow-rotating and two 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 ± 3.8 Gyr). We also analyse the close massive companion galaxies of two of the BCGs. These galaxies have similar stellar populations to their respective BCGs.
KW - Galaxies: clusters: general
KW - Galaxies: elliptical and lenticular, cD- galaxies: evolution
KW - Galaxies: kinematics and dynamics
KW - Galaxies: stellar content
KW - Galaxies: structure
UR - http://www.scopus.com/inward/record.url?scp=84930020174&partnerID=8YFLogxK
U2 - 10.1093/mnras/stv475
DO - 10.1093/mnras/stv475
M3 - Article
SN - 0035-8711
VL - 449
SP - 3347
EP - 3359
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -