Massive Galaxy Mergers Have Distinctive Global H i Profiles

• Main Authors: Ho, L.C (Author), Shangguan, J. (Author), Wang, J. (Author), Yu, N. (Author), Zuo, P. (Author)
• Format: Article
• Language: English
• Published: IOP Publishing Ltd 2022
• Online Access: View Fulltext in Publisher

 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. © 2022. The Author(s). Published by the American Astronomical Society.