2022ApJ...929...15Z

The global 21 cm H I emission-line profile of a galaxy encodes valuable information on the spatial distribution and kinematics of the neutral atomic gas. Galaxy interactions significantly influence the H I disk and imprint observable features on the integrated H I line profile. In this work, we study the neutral atomic gas properties of galaxy mergers selected from the Great Observatories All-sky LIRG Survey. The H I spectra come from new observations with the Five-hundred-meter Aperture Spherical Telescope and from a collection of archival data. We quantify the H I profile of the mergers with a newly developed method that uses the curve of growth of the line profile. Using a control sample of non-merger galaxies carefully selected to match the stellar mass of the merger sample, we show that mergers have a larger proportion of single-peaked H I profiles, as well as a greater tendency for the H I central velocity to deviate from the systemic optical velocity of the galaxy. By contrast, the H I profiles of mergers are not significantly more asymmetric than those of non-mergers.