IATE   20350
INSTITUTO DE ASTRONOMIA TEORICA Y EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
Galaxy properties in clusters: dependence on the environment and the cluster identification techniques
Autor/es:
COENDA, V.; MURIEL, H.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Año: 2009 vol. 504 p. 347 - 358
ISSN:
0004-6361
Resumen:
Aims: We investigate the dependence of several galaxy properties on the
environment and cluster identification techniques. Methods: We
select clusters of galaxies from two catalogues based on the SDSS: the
ROSAT-SDSS galaxy cluster survey, which is an X-ray selected cluster
sample and the MaxBCG catalogue, in which clusters are optically
selected. Based on a volume limited sample of galaxies drawn from the
spectroscopic DR5 SDSS, we constructed sub-samples of clusters of
galaxies with more than ten members. Scaling relations as well as
segregation of galaxy properties as a function of the normalized
clustocentric radii are analyzed. The properties of galaxies in clusters
are compared with those of field galaxies. Results: Galaxies in
X-ray and MaxBCG selected clusters show similar size-luminosity
relations. At equal luminosity, late type galaxies in the field have
sizes smaller than cluster galaxies of the same morphological type. The
Faber-Jackson relation for early-type galaxies in clusters is also the
same for X-ray selected and MaxBCG clusters. We found clear differences
between the dynamical properties of galaxies in clusters, the brightest
cluster galaxies (BCG_s) and field galaxies. Using several criteria to
classify galaxies into morphological types, we reproduce the well know
morphological segregation. The correlation is up to r/r200
1. For the whole range of clustocentric distances, X-ray
selected clusters present a higher fraction of early type galaxies than
MaxBCG clusters. We also found that bright galaxies preferentially
inhabit the cluster centers. Median sizes of galaxies, such as the
radius that encloses 50% of Petrosian flux r50, present a
behaviour that also depends on the cluster selection criteria. For
galaxies in X-ray selected clusters, median values of r50
decrease as r/r200 goes to zero, whereas the opposite is
observed for galaxies in the MaxBCG clusters. These different behaviours
are mainly due to early type galaxies. The results are discussed in
terms of the different processes that affect the evolution of galaxies
in different environments.
Appendix A is only available in electronic form at http://www.aanda.org