A Simple Code for Rotational Broadening of Broad Wavelength Range High-Dispersion Spectra

In high dispersion spectra of rotating bodies such as stars and planets, the rotation contributes significantly to, and sometimes dominates, the line broadening. We present a simple method for rotationally broadening large wavelength ranges of high-dispersion spectra. The broadening is rapid and scales linearly with the length of the spectrum array. For large wavelength ranges, the method is much faster than the popular convolution-based broadening. We provide the code implementation of this method in a publicly accessible repository.