WALLABY Pilot Survey and ASymba: Comparing H i Detection Asymmetries to the SIMBA Simulation

Perron-Cormier, Mathieu; Deg, Nathan; Spekkens, Kristine; Richardson, Mark L. A.; Glowacki, Marcin; Oman, Kyle A.; Verheijen, Marc A. W.; Hank, Nadine A. N.; Blyth, Sarah; Dénes, Helga; Rhee, Jonghwan; Elagali, Ahmed; Shen, Austin Xiaofan; Raja, Wasim; Lee-Waddell, Karen; Cortese, Luca; Catinella, Barbara; Westmeier, Tobias

doi:10.3847/1538-3881/ada567

WALLABY Pilot Survey and ASymba: Comparing H i Detection Asymmetries to the SIMBA Simulation

Perron-Cormier, Mathieu; Deg, Nathan; Spekkens, Kristine; Richardson, Mark L. A.; Glowacki, Marcin; Oman, Kyle A.; Verheijen, Marc A. W.; Hank, Nadine A. N.; Blyth, Sarah; Dénes, Helga; Rhee, Jonghwan; Elagali, Ahmed; Shen, Austin Xiaofan; Raja, Wasim; Lee-Waddell, Karen; Cortese, Luca; Catinella, Barbara; Westmeier, Tobias

Authors

Mathieu Perron-Cormier

Nathan Deg

Kristine Spekkens

Mark L. A. Richardson

Marcin Glowacki

Dr Kyle Oman kyle.a.oman@durham.ac.uk
Associate Professor - Royal Society Dorothy Hodgkin Fellow

Marc A. W. Verheijen

Nadine A. N. Hank

Sarah Blyth

Helga Dénes

Jonghwan Rhee

Ahmed Elagali

Austin Xiaofan Shen

Wasim Raja

Karen Lee-Waddell

Luca Cortese

Barbara Catinella

Tobias Westmeier

Abstract

An avenue for understanding cosmological galaxy formation is to compare morphometric parameters in observations and simulations of galaxy assembly. In this second paper of the ASymba: Asymmetries of H i in SIMBA Galaxies series, we measure atomic gas (H i) asymmetries in spatially resolved detections from the untargeted Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) survey, and compare them to realizations of WALLABY-like mock samples from the SIMBA cosmological simulations. We develop a Scanline Tracing method to create mock galaxy H i data cubes that minimizes shot noise along the spectral dimension, compared to particle-based methods, and thus minimizes spurious asymmetry contributions. We compute 1D and 3D asymmetries for spatially resolved WALLABY Pilot Survey detections, and we find that the highest 3D asymmetries (A3D ≳ 0.5) stem from interacting systems or detections with strong bridges or tails. We then construct a series of WALLABY-like mock realizations drawn from the SIMBA 50 Mpc simulation volume and compare their asymmetry distributions. We find that the incidence of high A3D detections is higher in WALLABY than in the SIMBA mocks, but that difference is not statistically significant (p-value = 0.05). The statistical power of quantitative comparisons of asymmetries such as the one presented here will improve as the WALLABY survey progresses and as simulation volumes and resolutions increase.

Citation

Perron-Cormier, M., Deg, N., Spekkens, K., Richardson, M. L. A., Glowacki, M., Oman, K. A., Verheijen, M. A. W., Hank, N. A. N., Blyth, S., Dénes, H., Rhee, J., Elagali, A., Shen, A. X., Raja, W., Lee-Waddell, K., Cortese, L., Catinella, B., & Westmeier, T. (2025). WALLABY Pilot Survey and ASymba: Comparing H i Detection Asymmetries to the SIMBA Simulation. Astronomical Journal, 169(2), Article 114. https://doi.org/10.3847/1538-3881/ada567

Journal Article Type	Article
Acceptance Date	Dec 27, 2024
Online Publication Date	Feb 3, 2025
Publication Date	Feb 3, 2025
Deposit Date	Feb 13, 2025
Publicly Available Date	Feb 13, 2025
Journal	The Astronomical Journal
Print ISSN	0004-6256
Electronic ISSN	1538-3881
Publisher	IOP Publishing
Peer Reviewed	Peer Reviewed
Volume	169
Issue	2
Article Number	114
DOI	https://doi.org/10.3847/1538-3881/ada567
Keywords	Hydrodynamical simulations, Galaxy structure, H I line emission
Public URL	https://durham-repository.worktribe.com/output/3474818