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	IRAC detected UBVRIzJHK + 3.6,4.5,5.8,8.0 micron catalog
		of the Extended Chandra Deep Field South


			version 3.0
		  	11/11/2010
	
								MD 
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COLUMN DESCRIPTIONS:

This catalogue is constructed following the standard MUSYC catalogues.
Columns are as follows:

id				Detection number
ra, dec			Celestial coordinates
x_pos, y_pos		Pixel position on the MUSYC-BVR astrometric grid
field		      	      	Field id number (E-CDFS = 8)

i_colf, i_colfe		'Color aperture' flux in band i, with associated error
j_totf, j_totfe        	'total' flux in band j, with associated error

iw				Normalised exposure time in band i (see note 5 below)

Flag_blended		Blended flag, see below (note 7)
Flag_star			Stellar flag: 0=galaxy, 1=star
Flag_qual			Quality flag, see below (note 8)

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NOTES ON CATALOGUE PARAMETERS:

1.  All fluxes are normalized to an AB magnitude zeropoint of 25.0,
       i.e. MAG_X_AB = -2.5 * log_10( FLUX_X ) + 25.0 .

2.  'Colour  aperture'  fluxes (i.e.   X_colf)  are  measured in  4.0"
    diameter  apertures. The IRAC images have not yet been PSF 
    matched. All images have been convolved with a Gaussian to the frame 
    with the largest FWHM, which is the 8.0 micron image.
    Sources that fall outside the area covered by a specific band X, 
    have their fluxes and photometric errors set to -99.
    NB. irac1 = 3.6 um
    	irac2 = 4.5 um
	irac3 = 5.8 um
	irac4 = 8.0 um


3a. The  'colour aperture'  errors  (i.e. X_colfe)  are determined  by
    placing  a large number of  apertures on  empty regions  of each
    image, and  thus account  for pixel--pixel correlations  introduced by
    dithering,  astrometric correction. 

    Errors have been weighted by means of the exposure map following:

           err_xy = err_m * sqrt(exp_m / exp_xy)

    where: 
    - err_xy is the error at position (x,y) = X_colfe
    - err_m is the measured error
    - exp_m is the effective exposure time of the area used to measure 
      the error (per pixel)
    - exp_xy is the exposure time of the source at position (x,y)

3b. The IRAC bands consist of combined deep CDFS-S (GOODS) data and 
    shallower SIMPLE data. Due to the difference in exposure time and 
    reduction method of both areas, errors for the CDFS GOODS and E-CDFS 
    SIMPLE data have been determined separately and scaled to GOODS-CDFS 
    and E-CDFS exposure times, respectively.

4.  Total fluxes are determined for all IRAC bands and MUSYC K-band using
    SExtractor's AUTO(APER) measurement. The fluxes in AUTO(APER) are 
    multiplied by a certain factor that was derived from the growhtcurves 
    of stars for each band.
    Total fluxes for the rest of the MUSYC bands can be derived as follows:

         X_totf = X_colf * K_totf / K_colf


5a. Relative weights (i.e. Xw)  give the value of the weight/exposure
    map, normalized  to the upper 5 percentiles of the exposure time.

5b. Using the highest percentiles exposure time as normalization value, 
    for IRAC data, the E-CDFS gets relatively low weights (see 3b). We 
    therefore have normalized the IRAC weights to the maximum exposure
    time of the SIMPLE mosaic without GOODS. 
    Weights of GOODS sources will, therefore, generally be > 1. 
    (GOODS sources can be identified using the FLAG_QUAL entry, see note 6)

5c. No exposure map is available for the z and H band.

6.  Sizes are given in arcsec; the pixel scale is 0.534 arcsec/pix.

7.  FLAG_BLENDED is bitwise encoded and contains the SExtractor deblending 
    flag, which indicates whether a source suffers from blending (bit = 1) 
    or whether it has a close neighbor (bit = 2). When a source's neighbour lies 
    within its aperture diameter and when the flux of the neighbour is brighter 
    than its own, FLAG_BLENDED is set to 4). 

8.  FLAG_QUAL can be used to identify contaminated/special areas and is 
    bitwise encoded.
    flag:   indicates:
    1  	    source in GOODS field
    2	    source in contaminated area (e.g. stellar trail)
    4	    source outside MUSYC field
    8 	    source corrected for muxbleed

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DESCRIPTION OF THE DATA:

The MUSYC E-CDFS dataset is a conglomeration of existing public and
original  observations, kindly made available to us by Edward Taylor. 
The E-CDFS IRAC data is based on the V1.0 release of the mosaics.
For more information on the images and the reduction, see the documentation
on the official release page:

http://data.spitzer.caltech.edu/popular/simple/20070601_enhanced/

SExtracor is used in double mode on a combined image of IRAC's deepest 
bands, 3.6 and 4.5 um.