WALLABY Pilot Survey: KNN identification of perturbed galaxies through H i morphometrics
Artikel i vetenskaplig tidskrift, 2025

Galaxy morphology in stellar light can be described by a series of "non-parametric"or "morphometric"parameters, such as concentrationasymmetry-smoothness, Gini, M20, and Sersic fit. These parameters can be applied to column density maps of atomic hydrogen (Hi). The Hi distribution is susceptible to perturbations by environmental effects, e.g. inter-galactic medium pressure and tidal interactions. Therefore, Hi morphology can potentially identify galaxies undergoing ram-pressure stripping or tidal interactions. We explore three fields in theWALLABY Pilot Hi survey and identify perturbed galaxies based on a k-nearest Neighbor (kNN) algorithm using an Hi morphometric feature space. For training, we used labeled galaxies in the combined NGC 4808 and NGC 4636 fields with six Hi morphometrics to train and test a kNN classifier. The kNN classification is proficient in classifying perturbed galaxies with all metrics -accuracy, precision and recall- at 70-80%. By using the kNN method to identify perturbed galaxies in the deployment field, the NGC 5044 mosaic, we find that in most regards, the scaling relations of perturbed and unperturbed galaxies have similar distribution in the scaling relations of stellar mass vs star formation rate and the Baryonic Tully-Fisher relation, but the Hi and stellar mass relation flatter than of the unperturbed galaxies. Our results for NGC 5044 provide a prediction for future studies on the fraction of galaxies undergoing interaction in this catalogue and to build a training sample to classify such galaxies in the fullWALLABY survey.

Galaxies galaxies: structure

Galaxies galaxies: ISM

galaxies: evolution

Galaxies galaxies: interactions

Galaxies

Författare

B. W. Holwerda

University of Louisville

H. Dénes

Yachay Tech

Jonghwan Rhee

University of Western Australia

Denis Leahy

University of Calgary

B. Koribalski

Western Sydney University

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

Niankun Yu

Chinese Academy of Sciences

Nathan Deg

Queen's University

T. Westmeier

University of Western Australia

Karen Lee-Wadde

Universidad Autonoma de Madrid (UAM)

Australian SKA Regional Centre (AusSRC)

Yago Ascasibar

Universidad Autonoma de Madrid (UAM)

Manasvee Saraf

University of Western Australia

ARC Centre of Excellence for All-sky Astrophysics

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

Xuchen Lin

Beijing University of Technology

B. Catinella

University of Western Australia

ARC Centre of Excellence for All-sky Astrophysics

Kelley Michelle Hess

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium

Publications Astronomical Society of Australia

1323-3580 (ISSN) 1448-6083 (eISSN)

Vol. In Press

Ämneskategorier (SSIF 2025)

Astronomi, astrofysik och kosmologi

DOI

10.1017/pasa.2025.5

Mer information

Senast uppdaterat

2025-02-10