RVSAO 2.0 - A Radial Velocity Package for IRAF

RVSAO 2.0 is the latest release of a package for calculating apparent radial velocities of celestial objects from observed spectral shifts. There are two main tasks in the package, XCSAO and EMSAO. XCSAO cross-correlates the Fourier transform of an object's spectrum against the transforms of a set of template spectra with known spectral shifts to obtain a velocity and error. EMSAO finds emission lines in a spectrum and computes the observed centers, getting individual shifts and errors for each line as well as a single velocity combining all of the lines. Three tasks which are new in this release are SUMSPEC, which combines spectra after shifting them all to a specified redshift, LINESPEC, which creates a spectrum at a specified redshift from a list of rest wavelengths, and BCVCORR, which computes the correction needed to translate the observed radial velocity to one relative to the solar system barycenter. Full documentation of this software, including numerous examples of its use, is on-line at http://tdc-www.harvard.edu/iraf/rvsao/