TY - JOUR
T1 - WALLABY pilot survey : the potential polar ring galaxies NGC 4632 and NGC 6156
AU - Deg, N.
AU - Palleske, R.
AU - Spekkens, K.
AU - Wang, J.
AU - Jarrett, T.
AU - English, J.
AU - Lin, X.
AU - Yeung, J.
AU - Mould, J.R.
AU - Catinella, B.
AU - Denes, H.
AU - Elagali, A.
AU - For, B.-Q.
AU - Kamphuis, P.
AU - Koribalski, B.S.
AU - Lee-Waddell, K.
AU - Murugeshan, C.
AU - Oh, S.
AU - Rhee, J.
AU - Serra, P.
AU - Westmeier, T.
AU - Wong, O.I.
AU - Bekki, K.
AU - Bosma, A.
AU - Carignan, C.
AU - Holwerda, B.W.
AU - Yu, N.
N1 - Publisher Copyright:
© 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2023/11/1
Y1 - 2023/11/1
N2 - We report on the discovery of two potential polar ring galaxies (PRGs) in the WALLABY Pilot Data Release 1 (PDR1). These untargeted detections, cross-matched to NGC 4632 and NGC 6156, are some of the first galaxies where the H i observations show two distinct components. We used the iDaVIE virtual reality software to separate the anomalous gas from the galactic gas and found that the anomalous gas comprises ?50 per cent of the total H i content of both systems. We have generated plausible 3D kinematic models for each galaxy, assuming that the rings are circular and inclined at 90° to the galaxy bodies. These models show that the data are consistent with PRGs but do not definitively prove that the galaxies are PRGs. By projecting these models at different combinations of main disc inclinations, ring orientations, and angular resolutions in mock data cubes, we have further investigated the detectability of similar PRGs in WALLABY. Assuming that these galaxies are indeed PRGs, the detectability fraction, combined with the size distribution of WALLABY PDR1 galaxies, implies an incidence rate of ?1-3 per cent. If this rate holds true, the WALLABY survey will detect hundreds of new polar ring galaxies.
AB - We report on the discovery of two potential polar ring galaxies (PRGs) in the WALLABY Pilot Data Release 1 (PDR1). These untargeted detections, cross-matched to NGC 4632 and NGC 6156, are some of the first galaxies where the H i observations show two distinct components. We used the iDaVIE virtual reality software to separate the anomalous gas from the galactic gas and found that the anomalous gas comprises ?50 per cent of the total H i content of both systems. We have generated plausible 3D kinematic models for each galaxy, assuming that the rings are circular and inclined at 90° to the galaxy bodies. These models show that the data are consistent with PRGs but do not definitively prove that the galaxies are PRGs. By projecting these models at different combinations of main disc inclinations, ring orientations, and angular resolutions in mock data cubes, we have further investigated the detectability of similar PRGs in WALLABY. Assuming that these galaxies are indeed PRGs, the detectability fraction, combined with the size distribution of WALLABY PDR1 galaxies, implies an incidence rate of ?1-3 per cent. If this rate holds true, the WALLABY survey will detect hundreds of new polar ring galaxies.
KW - radio lines: galaxies
KW - galaxies: peculiar
UR - https://hdl.handle.net/1959.7/uws:73043
UR - http://www.scopus.com/inward/record.url?scp=85173247174&partnerID=8YFLogxK
U2 - 10.1093/mnras/stad2312
DO - 10.1093/mnras/stad2312
M3 - Article
SN - 0035-8711
VL - 525
SP - 4663
EP - 4684
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -