Images:
Each image covers approximated 1 square degree and measures
roughly 20000x20000 pixels.
All the images for each field are registered with each other:
a pixel of one image in one band covers exactly the same bit of sky as
the equivalent pixel in another image.
All the images
have a photometric zero-point of 30.000. That is to say:
Mag = -2.5 *log10 (counts) + 30
in AB magnitudes.
The naming convention is:
D1U.2008B.fits
^ ^ ^
| | |______ Version: this is the 2008B release.
| |________ Band
|__________ Field
Weight maps:
These are inverse variance weight maps.
They have names like:
D1U.2008B.weight.fits
Multiband photometric catalogues:
These catalogues (one per deep field) give photometry in all 5 filters
through matched apertures. The detection and aperture determination is
done in the I band. That is to say, the catalogues are I-selected.
The photometric catalogues are all in ASCII format:
The photometric catalogues were generated as described here. The magnitudes are all in AB
magnitudes, measured in Kron-style apertures (SExtractor's
MAG_AUTO). No corrections have been made for galactic
extinction. A magnitude of 99 indicates no measurable flux. The
column HLR is the half light radius (in
arcseconds) of the object. A value of 99 means that the half light
radius could not be measured.
The multiband photometric catalogues have names like
D1.2008B.cat
Single-band Photometric Catalogues:
These catalogues contain the photometry and a few image shape
paramters determined for each filter individually for each of the deep
fields. The columns are labelled and described in each of the ASCII
format files: These photometric catalogues were generated by running
SExtractor in normal mode on the relevant images as described here. Most of the columns are
fairly self explanatory.
MAG_APER is the aperture magnitude measured through 3 arcsecond
diameter radius.
FLUX_RADIUS is the half-light radius.
They have names like:
D1U.2008B.cat
|