Open AccessThe dwarf galaxy population in Abell 2218
Author(s) -
Pracy Michael B.,
De Propris Roberto,
Driver Simon P.,
Couch Warrick J.,
Nulsen Paul E. J.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.08008.x
Subject(s) - physics , astrophysics , dwarf galaxy , astronomy , galaxy , interacting galaxy , population , luminosity function , type cd galaxy , galaxy cluster , brightest cluster galaxy , dwarf spheroidal galaxy , abell 2744 , lenticular galaxy , luminosity , demography , sociology
We present results from a deep photometric study of the rich galaxy cluster Abell 2218 ( z = 0.18) based on archival Hubble Space Telescope WFPC2 F606W images. These have been used to derive the luminosity function to extremely faint limits ( M F606W ≈−13.2 mag, μ 0 ≈ 24.7 mag arcsec −2 ) over a wide field of view (1.3 h −2 Mpc 2 ) . We find the faint‐end slope of the luminosity function to vary with environment within the cluster, going from α=−1.23 ± 0.13 within the projected central core of the cluster (100 < r < 300 h −1 kpc) to α=−1.49 ± 0.06 outside this radius (300 < r < 750 h −1 kpc) . We infer that the core is ‘dwarf depleted’, and further quantify this by studying the ratio of ‘dwarf’ to ‘giant’ galaxies and its dependency as a function of clustercentric radius and local galaxy density. We find that this ratio varies strongly with both quantities, and that the dwarf galaxy population in A2218 has a more extended distribution than the giant galaxy population.