Processing:
The data were retreived from
The ESO website.
The data at this site are
detrended (flat-fielded and so on). Each image is roughly 4000x4000 pixels. There are 15
pointings in all, with partial overlaps, as shown by the figure
below. The images have also been calibrated photometrically. The
obsevations are in 3 filters: J,H Ks, roughly
equivalent to BVIZ).
In order to generate a complete catalog, all the images in each band
were combined using Emmanuel Bertin's SWarp program into one big
image. The resulting images have identical World Coordinate Systems
and are registered to each other with sub-pixel accuarcy. SExtractor
was run in double-image on the images to generate an I-band selected
catalog. The ACS data has also been SWarped on the same system. These
images, although still very deep, are undersampled.
The total area covered by the ISAAC data is:
Band | Area (sq. deg.) | Area (sq. min.) |
J | 0.0151 | 54.4 |
H | 0.0153 | 55.1 |
Ks | 0.0154 | 55.6 |
|