"Per-Observation Detection Data Products"
In CSC 2.0, data products, e.g. light curves, are produced for every single detection of a source. This implies that if a given 2CXO source has been observed several times, we provide one light curve for each of those observations of the detected source. This is why in CSCView the light curves are identified with two numbers: the ObsID to which the detection corresponds and the region ID that identifies the detection within that observation. When a source is selected in the Results window in CSCView and the light curve data products are requested, all the light curves associated with that source will be displayed.
For example, the field corresponding to the source 2CXO J000024.6-575131 has only been observed once, in ObsID 9335, and in that observation the source corresponds to region 3. Therefore, the name of the light curve file is: acisf09335_000N021_r0003b_lc3.fits. But take, for example, source 2CXO J182030.7-161026. This source has been observed in 6 different ObsIDs, and therefore we have six light curve files for it:
acisf00972_002N021_r2164b_lc3.fits acisf06403_002N021_r2164b_lc3.fits acisf06420_002N021_r2164b_lc3.fits acisf06421_002N021_r2164b_lc3.fits acisf08460_002N021_r2164b_lc3.fits acisf08461_002N021_r2164b_lc3.fits