WALLABY Pilot Survey: Star Formation Enhancement and Suppression in Gas-rich Galaxy Pairs

WALLABY Pilot Survey: Star Formation Enhancement and Suppression in Gas-rich Galaxy Pairs

Galaxy interactions can significantly affect the star formation in galaxies, but it remains a challenge to achieve a consensus on the star formation rate (SFR) enhancement in galaxy pairs. Here, we investigate the SFR enhancement of gas-rich galaxy pairs detected by the Widefield ASKAP L -band Legac...

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Main Authors: Qifeng Huang, Jing Wang, Xuchen Lin, Se-Heon Oh, Xinkai Chen, B. Catinella, N. Deg, H. Dénes, B. -Q. For, B. S. Koribalski, K. Lee-Waddell, J. Rhee, A. X. Shen, Li Shao, K. Spekkens, L. Staveley-Smith, T. Westmeier, O. I. Wong, A. Bosma
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
Subjects:
Galaxies
Galaxy evolution
Galaxy interactions
Interstellar atomic gas
Online Access:https://doi.org/10.3847/1538-4357/ad9579
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Summary:Galaxy interactions can significantly affect the star formation in galaxies, but it remains a challenge to achieve a consensus on the star formation rate (SFR) enhancement in galaxy pairs. Here, we investigate the SFR enhancement of gas-rich galaxy pairs detected by the Widefield ASKAP L -band Legacy All-sky Blind surveY. We construct a sample of 278 paired galaxies spanning a stellar mass ( M _* ) range from 10 ^7.6 to 10 ^11.2 M _⊙ . We obtain individual masses of atomic hydrogen (H i ) for these paired galaxies using a novel deblending algorithm for H i data cubes. Quantifying the interaction stages and strengths with parameters motivated by first-principles analysis, we find that, at fixed stellar and H i mass, the alteration in the SFR of galaxy pairs starts when their dark matter halos are encountered. For galaxies with a stellar mass lower than 10 ^9 M _⊙ , their SFRs show tentative suppression of 1.4 σ after the halo encounter, and then become enhanced when their H i disks overlap, regardless of mass ratios. In contrast, the SFRs of galaxies with M _* > 10 ^9 M _⊙ increase monotonically toward smaller projected distances and radial velocity offsets. When a close companion is present, a pronounced SFR enhancement is found for the most H i -poor high-mass galaxies in our sample. Collecting the observational evidence, we provide a coherent picture of the evolution of galaxy pairs and discuss how the tidal effects and hydrodynamic processes shape the SFR enhancement. Our results provide a coherent picture of gas-rich galaxy interactions and impose constraints on the underlying physical processes.
ISSN:1538-4357

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