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STAGES is a multiwavelength project designed to probe physical drivers of galaxy evolution across a wide range of environments and luminosity.  The complex Abell 901(a,b)/902 multi-cluster system at z=0.16 has been the subject of extensive multiwavelength observations ranging from the X-ray to radio, including an 80-orbit ACS/HST mosaic covering the full 0.5x0.5 degree span of the supercluster (one orbit per tile). 

Our survey goals include simultaneously linking galaxy morphology with other observables such as age, star-formation rate, nuclear activity, and stellar mass.  In addition, with the unique multiwavelength dataset and new high resolution mass maps from gravitational lensing, we are able to
disentangle the large-scale structure of the supercluster.  By examining all aspects of environment we aim to determine the relative importance of the dark matter halos, the local galaxy density, and the hot X-ray gas in driving galaxy transformation. 

For a complete description of the survey, please see:
STAGES: The A901/902 Galaxy Evolution Survey
M.E. Gray, C. Wolf, M. Barden + STAGES
MNRAS (accepted)

We acknowledge support from HST grant GO-10395.

Observations of the A901/902 supercluster field

Facility Data Primary Science goals
(PI: M. Gray)
80 tile mosiac, 1 orbit per tile
WFPC2 F450W (parallel)
NIC3 F110W, F160W (parallel)
(PIs: C. Wolf,
K.  Meisenheimer)
17-band optical imaging
12 medium-band filters
(PI: E. Bell)
MIR imaging 24 micron:  39 h
(PI: M. Gray)
spectroscopy of ~300 cluster galaxies
600V and 1200B gratings
(PI: M. Gray)
imaging and spectroscopy 90ks
(GALEX team)
ultraviolet imaging
nuv: 57.18 ks
fuv: 50.19 ks
(PI: K. Meisenheimer)
near-IR extension to COMBO-17
Y, J1, J2, H
(PI: M. Gray)
radio imaging
610 MHz:  6.5 h
1280 MHz: 6.5 h
constrained simulations
(PI: E. van Kampen)
N-body + hydrodynamic + semi-analytic simulations simulations of dark matter, gas and galaxies
download publicly available data. . .

Field Schematic

Multiwavelength coverage of the A901/2 field (from Gray et al. 2008; click for full-size):
STAGES field

ACS tiles superimposed on COMBO-17 image (click for full-size; tiles labelled in red are oriented at 180 degrees to the main mosaic):

Related Surveys

STAGES has close ties to two other surveys:

  • COMBO-17:  this 17-band optical survey has imaged three 0.5x0.5 degree fields, of which the A901/902 field is one.  The photometric redshift catalogue for one of the other fields -- the Chandra Deep Field South (CDFS) -- is available for download here.
  • GEMS:  this HST imaging survey has tiled the CDFS in two bands:  F606W (V)  and 850LP (z).  The reduced ACS data is archived and is publicly available at MAST.  As the CDFS field is also a COMBO-17 field but contains no significant large-scale structure, it provides a matched field comparison sample for our work in the A901/902 supercluster.  

Next:  download data. . .