S-COSMOS is a deep infrared imaging survey carried out with the Spitzer Space Telescope. The survey covers the entire 2 square degrees of the Cosmic Evolution Survey (COSMOS) field. The S-COSMOS and COSMOS projects are closely coupled; therefore, their data are served as one large COSMOS Archive using IRSA's general search service, Atlas. S-COSMOS is part of the Spitzer Legacy Program. The data products released are part of the Spitzer General Observer Cycle 2 (GO2) program, including predominantly IRAC products (images and catalog). MIPS data include shallow images/catalogs covering the entire COSMOS field. There are also deep MIPS images covering only a test field of 0.16 sq. degrees for the upcoming GO3 program. The GO3 products will become public in September 2008.

Gator serves the S-COSMOS IRAC 4-channel Photometry Catalog June 2007
(56 columns [51 delivered + 5 IRSA-created], 345,512 data rows).

Please refer to the IRAC data delivery README file for general information on S-COSMOS catalogs and images.

Please read the following notes on the catalog (from README file); column descriptions are listed below.

Notes on the catalog.
(1) The catalog includes photometry in the 4 IRAC channels for all those sources 
     that have a measured flux in IRAC Channel 1 above 1 uJy [micro-Jansky].
     In the catalog, this flux is listed in column #16, "flux_c1_1".
(2) The first 15 columns are standard outputs (Astrometric and geometric  
     parameters) of SExstractor (http://terapix.iap.fr/IMG/pdf/sextractor.pdf)
(3) The following corrections (flux_catalog/correction) should be applied to each
     channel/aperture, in order to obtain the total flux:

         1.4''   1.9''   2.9''   4.1''  

 ch1    0.610   0.765   0.900   0.950
 ch2    0.590   0.740   0.900   0.940
 ch3    0.490   0.625   0.840   0.940
 ch4    0.450   0.580   0.730   0.910

(4) For very faint sources (roughly 4% of the catalog), measured fluxes  
    in the larger apertures will be reported with a negative number or  
    have lower fluxes than those measured in the smaller apertures.  
    These are objects lying near much brighter objects that compromise  
    measurement of the background. Despite the poorer flux measures,  
    these sources have been retained in the catalog since their infrared  
    detections are nonetheless real. For accurate photometry we advise  
    that flux_c#_2 be used whenever it is larger than flux_c#_3 and  
    flux_c#_4 (where #=1,2,3,4 is the IRAC channel number).

(5) Objects close to bright stars or close to the border of the images,
    do not have reliable  measured flux.  Values in flag columns #24 (fl_c1), 
    #33 (fl_c2), #42 (fl_c3) and #51 (fl_c4) indicate whether a source is close
    to a bright star (1 and 2) or not (0). All sources with flag=0 in all the
    4 channels are reliable.   

 (6) Flux errors are computed by SExtractor using an uncertainty map and 
     setting the MAP_WEIGHT parameter. The weighting is performed for 1 sigma 
     errors. [Uncertainty maps are created per IRAC channel as part of 
     generating the image mosaics, using MOPEX.]
     
 (7) To go from flux in uJy to AB magnitude, please use:
 
	 -2.5 log(flux) + 23.9
	 
     To go from flux in uJy to Vega magnitude, use:
     
	 -2.5 log (flux) + 23.9 + K
	 
     where K depends on the channel:	
     
          ch 1:   K = -2.788
          ch 2:   K = -3.255
          ch 3:   K = -3.743
          ch 4:   K = -4.372

1 The object has neighbours, bright and close enough to 
  significantly bias the MAG AUTO photometry or bad 
  pixels (more than 10% of the integrated area affected),

2 The object was originally blended with another one,

4 At least one pixel of the object is saturated (or very close to),

8 The object is truncated (too close to an image boundary),

16 Object's aperture data are incomplete or corrupted,

32 Object's isophotal data are incomplete or corrupted

64 A memory overflow occurred during deblending,

128 A memory overflow occurred during extraction.