===========================================================================
COSMOS CFHT Data                                                Version 2.0
===========================================================================

The Cosmic Evolution Survey (COSMOS) is an HST Treasury Project to survey
a 2 square degree equatorial field, centered on RA=10:00:28.6 and
DEC=+02:12:21.0, using the ACS camera. The project also incorporates major
commitments from other observatories around the world, including the VLA
radio telescope, ESO's VLT in Chile, ESA's XMM X-ray satellite, and the
Japanese 8-meter Subaru telescope in Hawaii.

These data represent one epoch of imaging on CFHT in i* band. These data
are NOT psf homogenized.  The filter transmission profile is included in
the file CFHT_filter_i.txt.

If you use these data in your work, please cite it as follows as follows:
McCracken, H.J., Capak, P., Salvato, M., et al. 2010, ApJ, 708, 202

The i* band data were used to define the COSMOS astrometric system.  The 
absolute astrometry of these data are tied to the VLA observations of the 
COSMOS field (Schinnerer et. al. 2004).  The astrometry of all other 
optical and IR data, including the HST images, are tied to this image.  
If datasets cover regions outside of this image, the Sloan Digital Sky 
Survey (SDSS) astrometry, corrected to the absolute COSMOS VLA frame, 
is used.

The key characteristics of these data are:

Telescope:		Canada-France-Hawaii 3.6m Telescope
Instrument:		MegaPrime
Effective Wavelength:	768.4nm
Filter Width:		138.0nm
Flux unit:		nJy
Zero Point		31.4
Area:			~4 sq degrees
Resolution:		0.15"/pix
Seeing:			0.94"
PSF Homogenized:	NO

The data products available here include the following at each of
144 tiled positions:
    
    1) an image in units of nJy
    2) a map of the image RMS in units of nJy

A tile diagram is included with the data.

These data were reduced by Henry J. McCracken (hjmcc@iap.fr) and the
TERAPIX team (terapix@iap.fr) using the ELIXIR and TERAPIX pipelines.
SWarp v.2.15 and Terapix software from 2004-12-16 were used for the
reduction.

Information on Elixir can be found at:                 
               
    http://www.cfht.hawaii.edu/Instruments/Elixir/                        

Information on Terapix can be found at:

    http://terapix.iap.fr/                                                

These data were prepared for release by:

Peter Capak (capak@astro.caltech.edu)         
Patrick Shopbell (pls@astro.caltech.edu)

Further information may be obtained from the COSMOS web page:

    http://cosmos.astro.caltech.edu/

===========================================================================
April 27, 2006