Description of the dataset
The current release comprises WIRCAM JHK images on the D1-CFHTLS legacy survey fields processed using the TERAPIX/WIRCAM pipeline developed by P. Hudelot. A detailed description of the data processing steps involved will appear in a forthcoming paper (Bielby et al., in preparation). This release concerns only images taken the D1 field; other fields will be released in the coming months.
The WIRDS-D1 stacks are first being made available to all registered CFHTLS users. From the 1st of March 2010 all WIRDS data will become public world-wide.
Data access point
All images and catalogues are distributed by the CADC at this location->http://www1.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/cfht/WIRDST0001.html].
Data summary release table
The following table describes what data is being made available in this release. For a full explanation of terms used please refer to the explanatory table .
|Field name||Filter||Seeing||50% Point-source completeness||Exposure time (s)||Area (deg^2)||Number counts|
|D1||J (qualityFITS)||0.80"||24.90 (plot)||12105||0.5984||J-band counts|
|D1||H (qualityFITS)||0.68"||24.85 (plot)||13600||0.5984||H-band counts|
|D1||Ks (qualityFITS)||0.73"||24.80 (plot)||15700||0.5984||Ks-band counts|
Description of the stacked images
All images have been stacked using SWarp
All images have a the same tangent point and pixel scale (0.186''/pixel) as the CFHTLS-D1 images
All images have a zero point of 30.00 AB. AB Magnitude of sources: -2.5 *log10(flux) + 30.0.
Description of distributed catalogues
Several different kinds of catalogues are provided with this release:
Single band catalogues. These catalogues are generated by running sextractor on each input image and weight map. There are three catalogues for J, H and K images.
Optically-selected matched aperture chisquared catalogues. These catalogues were constructed by using SExtractor in "dual-image mode" using the optical gri-chisquared image as a detection image. The optical images used were the CFHTLS-T05 D1 85% seeing images. There are eight catalogues in total for the u,g,r,i,z,J,H and K images; in these catalogues the SAME object ID refers to the SAME object.
Infrared-selected matched aperture catalogues. These catalogues were constructed by using SExtractor in "dual-image mode" using the Near-infrared Ks image as a detection image. There are eight catalogues in total for the u,g,r,i,z,J,H and K images; in these catalogues the SAME object ID refers to the SAME object. As before, the optical images used were the CFHTLS-T05 D1 85% seeing images.
Merged catalogues. These catalogues contain a subset of columns from the above catalogues. "Total" (Kron) magnitudes are reported for objects in the detection band; 2" aperture magnitudes are reported in all other bands.
A three-colour JHK image of the D1-WIRDS field can be found here.
A polygonal mask file indicating the boundaries of the D1 field can be found here, in units of D1-megacam pixels.
Acknowledging WIRDS data
If you use these data or catalogues in a paper you must include the following text, as well as referring to the WIRDS data paper, Bielby et al (in preparation):
Based on observations obtained with WIRCam, a joint project of CFHT,Taiwan, Korea, Canada, France, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX, the WIRDS (WIRcam Deep Survey) consortium, and the Canadian Astronomy Data Centre. This research was supported by a grant from the Agence Nationale de la Recherche ANR-07-BLAN-0228