CUSTOMSM

Some spectrographs do not have Gaussian line-spread functions, and so the programs BSMOOTH2, BFLXSM2 and SMOOTH2 will not give satisfactory results. In some cases, there is no substitute for writing your own smoothing program incorporating the measured linespread function of your spectrograph, especially if the function is asymmetrical. However, if you need a linespread function that has more ``wing'' than a Gaussian, you might find CUSTOMSM useful. This program convolves the synthetic spectrum with a hybrid linespread function made from a weighted mean of a Gaussian and a Lorentzian profile. The Lorentzian profile has much broader wings & a narrower core than a Gaussian. In addition to inputing the information required with SMOOTH2, CUSTOMSM needs a ``line-shape parameter'' which runs from $0 \rightarrow 1$. When that parameter is 0, the linespread function is a pure Gaussian; when it is 1 it is a pure Lorentzian. Experimentation is required to get the best fit. CUSTOMSM, like SMOOTH2, is only for ascii spectra. It can be used in both the prompt mode and the command-line mode. Use the command-line mode format:

customsm input output input_spacing resolution output_spacing line_shape