Using eagle simulations to study the effect of observational constraints on the determination of H i asymmetries in galaxies

Bilimogga, Pooja V; Oman, Kyle A; Verheijen, Marc AW; van der Hulst, Thijs

doi:10.1093/mnras/stac1213

Using eagle simulations to study the effect of observational constraints on the determination of H i asymmetries in galaxies

Bilimogga, Pooja V; Oman, Kyle A; Verheijen, Marc AW; van der Hulst, Thijs

Authors

Pooja V Bilimogga

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

Marc AW Verheijen

Thijs van der Hulst

Abstract

We investigate the effect of observational constraints such as signal-to-noise (S/N) ratio, resolution, and column density level on the H I morphological asymmetry (Amod) and the effect of noise on the H I global profile (Aflux) asymmetry indices. Using mock galaxies from the EAGLE simulations, we find an optimal combination of the observational constraints that are required for a robust measurement of the Amod value of a galaxy: a column density threshold of 5 × 1019 cm−2 or lower at a minimal S/N of 3 and a galaxy resolved with atleast 11 beams. We also use mock galaxies to investigate the effect of noise on the Aflux values and conclude that a global profile with S/N greater than 6 is required to achieve a robust measurement of asymmetry. We investigate the relation between Amod and Aflux indices and find them to be uncorrelated, which implies that Aflux values cannot be used to predict morphological asymmetries in galaxies.

Citation

Bilimogga, P. V., Oman, K. A., Verheijen, M. A., & van der Hulst, T. (2022). Using eagle simulations to study the effect of observational constraints on the determination of H i asymmetries in galaxies. Monthly Notices of the Royal Astronomical Society, 513(4), 5310-5327. https://doi.org/10.1093/mnras/stac1213

Journal Article Type	Article
Acceptance Date	Apr 27, 2022
Online Publication Date	May 3, 2022
Publication Date	2022-07
Deposit Date	Jul 14, 2022
Publicly Available Date	Jul 14, 2022
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	513
Issue	4
Pages	5310-5327
DOI	https://doi.org/10.1093/mnras/stac1213

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This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. ©: 2022 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.