Document Type

Article

Publication Date

11-24-2022

Department

Physics and Astronomy

Abstract

We examine the H I gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the H I properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform H I profile decomposition of the sample galaxies using a tool, BAYGAUD which allows us to de-blend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct H I super-profiles of the sample galaxies via stacking of their line profiles after aligning the central velocities. We fit a double Gaussian model to the super-profiles and classify them as kinematically narrow and broad components with respect to their velocity dispersions. Additionally, we investigate the gravitational instability of H I gas disks of the sample galaxies using Toomre Q parameters and H I morphological disturbances. We investigate the effect of the cluster environment on the H I properties of galaxy pairs by dividing the cluster environment into three subcluster regions (i.e., outskirts, infalling and central regions). We find that the denser cluster environment (i.e., infalling and central regions) is likely to impact the H I gas properties of galaxies in a way of decreasing the amplitude of the kinematically narrow H I gas (⁠MnarrowHI" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">MHInarrowMnarrowHI/MtotalHI" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">MHItotalMtotalHI⁠), and increasing the Toomre Q values of the infalling and central galaxies. This tendency is likely to be more enhanced for galaxy pairs in the cluster environment.

Comments

© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society

Original Publication Information

Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Tobias Westmeier, O Ivy Wong, Gerhardt R Meurer, Peter Kamphuis., Barbara Catinella, Kristen B W McQuinn, Frank Bigiel, Benne W Holwerda, Jonghwan Rhee Karen Lee-Waddell, Nathan Deg, Lourdes Verdes-Montenegro, Bi-Qing For, Juan P Madrid, Helga Dénes, Ahmed Elagali, WALLABY Pilot Survey: H I gas kinematics of galaxy pairs in cluster environment, Monthly Notices of the Royal Astronomical Society, 2022;, stac3480, https://doi.org/10.1093/mnras/stac3480

DOI

10.1093/mnras/stac3480

ORCID

0000-0002-4884-6756

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