especplot produces a plot in log-log space of the net source and background spectrum as measured by EPIC. The source spectrum is produced by evselect and the background spectrum can be produced either by evselect or evselect followed by backcorr. They are both supplied in FITS format, where the spectrum is in channel and counts.
The binning scheme is defined by the user or automatically set to a geometric binning scheme, such that it ensures that each data point of the binned spectrum is statistically significant. In the present version, the statistical criteria is more than 10 counts in each bin (with a minimum of 25 spectral bins)
In a PPS run, the device by default is postscript. Nevertheless, especplot allows the user, in an IAS run, to choose from several device types (e.g. XWINDOW, GIF) for the output.
The user can bin the data by channels using a constant rebinning (positive values of the parameter `binsize') or geometrically (negative values of the parameter `binsize'). Alternatively, the user can bin by a minimum number of counts per channel.
