On the H I Content of MaNGA Major Merger Pairs
Abstract
The role of H I content in galaxy interactions is still under debate. To study the H I content of galaxy pairs at different merging stages, we compile a sample of 66 major-merger galaxy pairs and 433 control galaxies from the Sloan Digital Sky Survey IV (SDSS-IV) MaNGA IFU survey. In this study, we adopt kinematic asymmetry as a new effective indicator to describe the merging stage of galaxy pairs. With archival data from the HI-MaNGA survey and new observations from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we investigate the differences in H I gas fraction (f H I), star formation rate (SFR), and H I star formation efficiency (SFEH I) between the pair and control samples. Our results suggest that the H I gas fraction of major-merger pairs on average is marginally decreased by ~15% relative to isolated galaxies, implying mild H I depletion during galaxy interactions. Compared to isolated galaxies, pre-passage paired galaxies have similar f H I, SFR, and SFEH I, while pairs during the pericentric passage have weakly decreased f H I (-0.10 ± 0.05 dex), significantly enhanced SFR (0.42 ± 0.11 dex), and SFEH I (0.48 ± 0.12 dex). When approaching the apocenter, paired galaxies show marginally decreased f H I (-0.05 ± 0.04 dex), comparable SFR (0.04 ± 0.06 dex), and SFEH I (0.08 ± 0.08 dex). We propose that the marginally detected H I depletion may originate from the gas consumption in fueling the enhanced H2 reservoir of galaxy pairs. In addition, new FAST observations also reveal a H I absorber (N H I ~ 4.7 × 1021 cm-2), which may suggest gas infalling and the triggering of active galactic nuclei activity.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2022
- DOI:
- 10.3847/1538-4357/ac78e6
- arXiv:
- arXiv:2206.06330
- Bibcode:
- 2022ApJ...934..114Y
- Keywords:
-
- Galaxy interactions;
- Galaxy pairs;
- Galaxy mergers;
- Interstellar atomic gas;
- Star formation;
- 600;
- 610;
- 608;
- 833;
- 1569;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 17 pages, 5 figures, accepted for publication in ApJ