Magnitude and color errors have been determined in observations of several rich galaxy clusters having external “truth” observations. Specific requirement is that galaxy deblended magnitude errors at i < 22 for 99% of the sample be <0.1 mag.

Testing this goal will require comparison to multi-band HST imaging, ideally for a few rich clusters. There is one X-ray detected cluster at RA=34.394583, Dec=-5.2241389 with z=0.645 which is in the CANDELS UDS field. This cluster falls within the nominal Spectroscopic Training Field for SV. Three SPT clusters in the Maximum Visibility field will have two band ACS data (F606W and F814W), but these will not be public until spring of 2013.

Possible additional cluster fields include: the CLASH clusters A209 (RA=01:31, Dec=-13:36, z=0.206), A383 (RA=02:48, Dec=-03:31, z=0.187), MACSJ0329 (RA=03:29, Dec=-02:11, z=0.450), MACSJ0416 (RA=04:16, Dec=-24:04, z=0.420) and the Bullet Cluster (RA=06:59, Dec=-55:57, z=0.296).


  • Full depth imaging of HST observed clusters (ideally more than one) taken at a range of seeing conditions with SExtractor runs on the detection images.
  • "Truth" tables derived from the available HST data