EXOVIG USAGE exovig -i instrume -x xpixel -y ypixel DESCRIPTION The script returns the vignetting correction factor appropriate for a given X and Y position in the EXOSAT CMA1 and CMA2 detectors. The X and Y pixel position should be entered as the unbinned image coordinates which range between -1024 and 1023 pixel. The correction factor is read from the vignetting map, which is rebinned by a factor of 16 from the original detector size. The vignetting map was part of the original calibration files included in the FOT data. The output vignetting factor is the value corresponding to the rebinned X and Y input position. Its value is > 1 for off-axis position and about 1 for on-axis and it is therefore a multiplicative factor for the observed count rate. The vignetting map is identical for the CMA1 and CMA2 detector but the pixel optical axis position is different in the CMA1 and CMA2 detectors. FLAGS -h - Prints this help file the following flags require arguments -i - instrument [input value CMA1 or CMA2] -x - X pixel [input value ranges -1024 1023] -y - Y pixel [input value ranges -1024 1023] EXAMPLES Calculate the CMA1 vignetting correction for pixel position X=-300 and Y=400 > exovig -i CMA1 -x -300 -y 400