Barred Galaxies in the Abell 901/2 Supercluster with Stages
Marinova, Irina; Jogee, Shardha; Heiderman, Amanda;Barazza, Fabio D.; Gray, Meghan E.; Barden, Marco;Wolf, Christian; Peng, Chien Y.; Bacon, David;Balogh, Michael; Bell, Eric F.; Böhm, Asmus;Caldwell, John A. R.; Häußler, Boris;Heymans, Catherine; Jahnke, Knud; van Kampen, Eelco;Lane, Kyle; McIntosh, Daniel H.; Meisenheimer, Klaus;Sánchez, Sebastian F.; Somerville, Rachel;Taylor, Andy; Wisotzki, Lutz; Zheng, Xianzhong. Barred Galaxies in the Abell 901/2 Supercluster with Stages. The Astrophysical Journal. 2009, Vol. Volume 698, Issue 2, pp. 1639-1658 (2009)., p. -2009.
We present a study of bar and host disk evolution in a dense cluster
environment, based on a sample of ~800 bright (M <SUB>V</SUB> <=
–18) galaxies in the Abell 901/2 supercluster at z~ 0.165. We use
Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) F606W
imaging from the STAGES survey, and data from Spitzer, XMM-Newton, and
COMBO-17. We identify and characterize bars through ellipse-fitting, and
other morphological features through visual classification. We find the
following results. (1) To define the optical fraction of barred disk
galaxies, we explore three commonly used methods for selecting disk
galaxies. We find 625, 485, and 353 disk galaxies, respectively, via
visual classification, a single component Sérsic cut (n <=
2.5), and a blue-cloud cut. In cluster environments, the latter two
methods suffer from serious limitations, and miss 31% and 51%,
respectively, of visually identified disks, particularly the many red,
bulge-dominated disk galaxies in clusters. (2) For moderately inclined
disks, the three methods of disk selection, however, yield a similar
global optical bar fraction (f <SUB>bar-opt</SUB>) of 34%<SUP>+10%</SUP>
<SUB>–3%</SUB> (115/340), 31%<SUP>+10%</SUP> <SUB>–3%</SUB>
(58/189), and 30%<SUP>+10%</SUP> <SUB>–3%</SUB> (72/241),
respectively. (3) We explore f <SUB>bar-opt</SUB> as a function of host
galaxy properties and find that it rises in brighter galaxies and those
which appear to have no significant bulge component. Within a given
absolute magnitude bin, f <SUB>bar-opt</SUB> is higher in visually
selected disk galaxies that have no bulge as opposed to those with
bulges. Conversely, for a given visual morphological class, f
<SUB>bar-opt</SUB> rises at higher luminosities. Both results are
similar to trends found in the field. (4) For bright early-types, as
well as faint late-type systems with no evident bulge, the optical bar
fraction in the Abell 901/2 clusters is comparable within a factor of
1.1-1.4 to that of field galaxies at lower redshifts (z < 0.04). (5)
Between the core and the virial radius of the cluster (R~ 0.25-1.2 Mpc)
at intermediate environmental densities (log(Σ<SUB>10</SUB>) ~
1.7-2.3), the optical bar fraction does not appear to depend strongly on
the local environment density tracers (κ, Σ<SUB>10</SUB>,
and intracluster medium (ICM) density), and varies at most by a factor
of ~1.3. Inside the cluster core, we are limited by number statistics,
projection effects, and different trends from different indicators, but
overall f <SUB>bar-opt</SUB> does not show evidence for a variation
larger than a factor of 1.5. We discuss the implications of our results
for the evolution of bars and disks in dense environments.
We present a study of bar and host disk evolution in a dense cluster
environment, based on a sample of ~800 bright (M <SUB>V</SUB> <=
–18) galaxies in the Abell 901/2 supercluster at z~ 0.165. We use
Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) F606W
imaging from the STAGES survey, and data from Spitzer, XMM-Newton, and
COMBO-17. We identify and characterize bars through ellipse-fitting, and
other morphological features through visual classification. We find the
following results. (1) To define the optical fraction of barred disk
galaxies, we explore three commonly used methods for selecting disk
galaxies. We find 625, 485, and 353 disk galaxies, respectively, via
visual classification, a single component Sérsic cut (n <=
2.5), and a blue-cloud cut. In cluster environments, the latter two
methods suffer from serious limitations, and miss 31% and 51%,
respectively, of visually identified disks, particularly the many red,
bulge-dominated disk galaxies in clusters. (2) For moderately inclined
disks, the three methods of disk selection, however, yield a similar
global optical bar fraction (f <SUB>bar-opt</SUB>) of 34%<SUP>+10%</SUP>
<SUB>–3%</SUB> (115/340), 31%<SUP>+10%</SUP> <SUB>–3%</SUB>
(58/189), and 30%<SUP>+10%</SUP> <SUB>–3%</SUB> (72/241),
respectively. (3) We explore f <SUB>bar-opt</SUB> as a function of host
galaxy properties and find that it rises in brighter galaxies and those
which appear to have no significant bulge component. Within a given
absolute magnitude bin, f <SUB>bar-opt</SUB> is higher in visually
selected disk galaxies that have no bulge as opposed to those with
bulges. Conversely, for a given visual morphological class, f
<SUB>bar-opt</SUB> rises at higher luminosities. Both results are
similar to trends found in the field. (4) For bright early-types, as
well as faint late-type systems with no evident bulge, the optical bar
fraction in the Abell 901/2 clusters is comparable within a factor of
1.1-1.4 to that of field galaxies at lower redshifts (z < 0.04). (5)
Between the core and the virial radius of the cluster (R~ 0.25-1.2 Mpc)
at intermediate environmental densities (log(Σ<SUB>10</SUB>) ~
1.7-2.3), the optical bar fraction does not appear to depend strongly on
the local environment density tracers (κ, Σ<SUB>10</SUB>,
and intracluster medium (ICM) density), and varies at most by a factor
of ~1.3. Inside the cluster core, we are limited by number statistics,
projection effects, and different trends from different indicators, but
overall f <SUB>bar-opt</SUB> does not show evidence for a variation
larger than a factor of 1.5. We discuss the implications of our results
for the evolution of bars and disks in dense environments.