-- README for the variability catalogs for CDFS sources (Paolillo et al. 2004)

The file 'var_param_0.5-7keV+RA_Dec.dat' contains the variability parameters of sources in the Giacconi et al. 2002 (ApJ, 139, 369) catalog calculated as explained in Paolillo et al. 2004 (Apj, 611, 93). Also available on request (e.g. in different files) are variability parameters in the 0.5-2 and 2-7 keV bands.

M.Paolillo - paolillo@na.infn.it
 
The meaning of each column is listed below:
N.			 	- X_ID from the Giacconi catalog   
RA      			- RA from the Giacconi catalog 
Dec     		 	- Dec from the Giacconi catalog
d.o.f.  		 	- Degrees of freedom: number-1 of acceptable observations used to construct the lightcurve. See paper for the criteria adopted to define the good observations among the 11 Chandra pointings. 
Excess var  		 	- Excess variance (see expression in paper) computed from the lightcurve
Excess var_err  	 	- Excess variance error
Max.exc.var  		 	- Maximum excess variance, i.e. excess variance of the observations which differs the most from the mean
Max.exc.var_err  	 	- Maximum excess variance error
Tot.Excess Var.  	 	- Excess variance x number of points in the lightcurve (used for quality tests)
Chisq.Prob.Simul.  	 	- Probability of a source of being variable according to a chi-square comparison with simulations
Chisq.Prob.Simul.Singlebin  	- As 'Chisq.Prob.Simul.' for the bin with the maximum excess variance 
R_Max-Min/<Rate>   		- Max. fractional variation of the source count rate (not used in the analysis because it doesen't take into account sistematic effects due to statistical errors)
t_max-t_min			- Time interval between minimum and maximum count rate (R_min and R_max) (not used in the analysis because it doesen't take into account sistematic effects due to statistical errors)
R_Diff/Delta_t  		- Count rate variation (R_Max-Min/<Rate>) / Time interval (t_max-t_min) (not used in the analysis because it doesen't take into account sistematic effects due to statistical errors)
Min.Timescale			- Shortest timescale on which variability is detected