HST/ACS Coma Cluster Treasury Survey - Data Release 1
Mapping of Astro-WISE and MAST release conventions.
Data formats and headers
The MAST archive contains Multi Extension Fits files of the HST/ACS Coma Legacy Survey. They contain a primary header plus 3 extensions:
- Science image with a header
- Weight image with a header
- Context image with a header
See
this section of the ACS data handbook for details.
In Astro-WISE the data are split as follows:
- Science image with a header that is a merge of the science image header and primary header plus additional keywords that are added by the Astro-WISE system
- Weight image with a header that is a merg of the weight image header and primary header plus additional keywords that are added by the Astro-WISE system
The header keyword DATE is the only keyword with a different value in the MAST archive and Astro-WISE system. In Astro-WISE it gives the date of observation whereas in the MAST archive is gives a date related to processing. Note that the header keywords specific for Multi Extension Fits are not retained in the Astro-WISE header for obvious reasons.
Extension 3 is not stored in Astro-WISE.
Filenames
Mapping between the MAST and Astro-WISE filenames can be determined via the FITS header keyword FILENAME which contains the filename of the corresponding file in the MAST archive.
Filenames in Astro-WISE start with information about creator, filter, instrument, detector and type of data and end with a hash code to make the filename unique. The creator in this case is the person who ingested (i.e., imported) the data into the Astro-WISE environment.
