The Cornell Digital HI Archive is a homogeneous compilation of HI spectral parameters extracted from global 21 cm line spectra for some 9000 galaxies in the local universe (heliocentric velocity -200 < V > 28,000 km/s) obtained with a variety of large single dish radio telescopes but reanalyzed using a single set of parameter extraction algorithms. The database contains a catalog of HI parameters (systemic velocities, integrated HI line fluxes and full widths), plots of the HI spectra, and the digital spectra themselves. The Cornell Digital HI Archive data is currently served by NED.
High frequency water maser and HI spectra are available through this web service. The water maser phenomena are found in active galactic nuclei (AGN) and have been surveyed with the NRAO Green Bank Telescope. HI spectra are measured mostly from galaxies in the local Universe.
