Publications of the Astronomical Society of Australia最新文献

{"title":"The Southern-sky MWA Rapid Two-metre (SMART) pulsar survey—II. Survey status, pulsar census, and first pulsar discoveries – ADDENDUM","authors":"N. Bhat, N. A. Swainston, S. McSweeney, M. Xue, B. W. Meyers, S. Kudale, S. Dai, S. Tremblay, W. van Straten, R. Shannon, K. R. Smith, M. Sokolowski, S. Ord, G. Sleap, A. Williams, P. Hancock, R. Lange, J. Tocknell, M. Johnston-Hollitt, D. Kaplan, S. Tingay, M. Walker","doi":"10.1017/pasa.2023.30","DOIUrl":"https://doi.org/10.1017/pasa.2023.30","url":null,"abstract":"","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90899204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Rapid ASKAP Continuum Survey III: Spectra and Polarisation In Cutouts of Extragalactic Sources (SPICE-RACS) first data release","authors":"A. Thomson, D. McConnell, E. Lenc, T. Galvin, L. Rudnick, G. Heald, C. Hale, S. Duchesne, C. Anderson, E. Carretti, C. Federrath, B. Gaensler, L. Harvey-Smith, M. Haverkorn, A. Hotan, Y. Ma, T. Murphy, N. M. McClure-Griffith, V. Moss, S. O’Sullivan, W. Raja, A. Seta, Cameron Van Eck, J. West, M. Whiting, M. Wieringa","doi":"10.1017/pasa.2023.38","DOIUrl":"https://doi.org/10.1017/pasa.2023.38","url":null,"abstract":"Abstract The Australian SKA Pathfinder (ASKAP) radio telescope has carried out a survey of the entire Southern Sky at 887.5 MHz. The wide area, high angular resolution, and broad bandwidth provided by the low-band Rapid ASKAP Continuum Survey (RACS-low) allow the production of a next-generation rotation measure (RM) grid across the entire Southern Sky. Here we introduce this project as Spectral and Polarisation in Cutouts of Extragalactic sources from RACS (SPICE-RACS). In our first data release, we image 30 RACS-low fields in Stokes I, Q, U at 25 \u0000$^{primeprime}$\u0000 angular resolution, across 744–1032 MHz with 1 MHz spectral resolution. Using a bespoke, highly parallelised, software pipeline we are able to rapidly process wide-area spectro-polarimetric ASKAP observations. Notably, we use ‘postage stamp’ cutouts to assess the polarisation properties of 105912 radio components detected in total intensity. We find that our Stokes Q and U images have an rms noise of \u0000$sim$\u0000 80 \u0000$unicode{x03BC}$\u0000 Jy PSF \u0000$^{-1}$\u0000 , and our correction for instrumental polarisation leakage allows us to characterise components with \u0000$gtrsim$\u0000 1% polarisation fraction over most of the field of view. We produce a broadband polarised radio component catalogue that contains 5818 RM measurements over an area of \u0000$sim$\u0000 1300 deg \u0000$^{2}$\u0000 with an average error in RM of \u0000$1.6^{+1.1}_{-1.0}$\u0000 rad m \u0000$^{-2}$\u0000 , and an average linear polarisation fraction \u0000$3.4^{+3.0}_{-1.6}$\u0000 %. We determine this subset of components using the conditions that the polarised signal-to-noise ratio is \u0000$>$\u0000 8, the polarisation fraction is above our estimated polarised leakage, and the Stokes I spectrum has a reliable model. Our catalogue provides an areal density of \u0000$4pm2$\u0000 RMs deg \u0000$^{-2}$\u0000 ; an increase of \u0000$sim$\u0000 4 times over the previous state-of-the-art (Taylor, Stil, Sunstrum 2009, ApJ, 702, 1230). Meaning that, having used just 3% of the RACS-low sky area, we have produced the 3rd largest RM catalogue to date. This catalogue has broad applications for studying astrophysical magnetic fields; notably revealing remarkable structure in the Galactic RM sky. We will explore this Galactic structure in a follow-up paper. We will also apply the techniques described here to produce an all-Southern-sky RM catalogue from RACS observations. Finally, we make our catalogue, spectra, images, and processing pipeline publicly available.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79965556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring photometric redshifts for high-redshift radio source surveys","authors":"K. Luken, R. Norris, X. R. Wang, L. Park, Ying Guo, M. Filipović","doi":"10.1017/pasa.2023.39","DOIUrl":"https://doi.org/10.1017/pasa.2023.39","url":null,"abstract":"Abstract With the advent of deep, all-sky radio surveys, the need for ancillary data to make the most of the new, high-quality radio data from surveys like the Evolutionary Map of the Universe (EMU), GaLactic and Extragalactic All-sky Murchison Widefield Array survey eXtended, Very Large Array Sky Survey, and LOFAR Two-metre Sky Survey is growing rapidly. Radio surveys produce significant numbers of Active Galactic Nuclei (AGNs) and have a significantly higher average redshift when compared with optical and infrared all-sky surveys. Thus, traditional methods of estimating redshift are challenged, with spectroscopic surveys not reaching the redshift depth of radio surveys, and AGNs making it difficult for template fitting methods to accurately model the source. Machine Learning (ML) methods have been used, but efforts have typically been directed towards optically selected samples, or samples at significantly lower redshift than expected from upcoming radio surveys. This work compiles and homogenises a radio-selected dataset from both the northern hemisphere (making use of Sloan Digital Sky Survey optical photometry) and southern hemisphere (making use of Dark Energy Survey optical photometry). We then test commonly used ML algorithms such as k-Nearest Neighbours (kNN), Random Forest, ANNz, and GPz on this monolithic radio-selected sample. We show that kNN has the lowest percentage of catastrophic outliers, providing the best match for the majority of science cases in the EMU survey. We note that the wider redshift range of the combined dataset used allows for estimation of sources up to \u0000$z = 3$\u0000 before random scatter begins to dominate. When binning the data into redshift bins and treating the problem as a classification problem, we are able to correctly identify \u0000$approx$\u0000 76% of the highest redshift sources—sources at redshift \u0000$z > 2.51$\u0000 —as being in either the highest bin ( \u0000$z > 2.51$\u0000 ) or second highest ( \u0000$z = 2.25$\u0000 ).","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87288434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survey-scale discovery-based research processes: Evaluating a bespoke visualisation environment for astronomical survey data","authors":"C. Fluke, D. Vohl, V. Kilborn, C. Murugeshan","doi":"10.1017/pasa.2023.37","DOIUrl":"https://doi.org/10.1017/pasa.2023.37","url":null,"abstract":"Abstract Next-generation astronomical surveys naturally pose challenges for human-centred visualisation and analysis workflows that currently rely on the use of standard desktop display environments. While a significant fraction of the data preparation and analysis will be taken care of by automated pipelines, crucial steps of knowledge discovery can still only be achieved through various level of human interpretation. As the number of sources in a survey grows, there is need to both modify and simplify repetitive visualisation processes that need to be completed for each source. As tasks such as per-source quality control, candidate rejection, and morphological classification all share a single instruction, multiple data (SIMD) work pattern, they are amenable to a parallel solution. Selecting extragalactic neutral hydrogen (Hi) surveys as a representative example, we use system performance benchmarking and the visual data and reasoning methodology from the field of information visualisation to evaluate a bespoke comparative visualisation environment: the encube visual analytics framework deployed on the 83 Megapixel Swinburne Discovery Wall. Through benchmarking using spectral cube data from existing Hi surveys, we are able to perform interactive comparative visualisation via texture-based volume rendering of 180 three-dimensional (3D) data cubes at a time. The time to load a configuration of spectral cubes scale linearly with the number of voxels, with independent samples of 180 cubes (8.4 Gigavoxels or 34 Gigabytes) each loading in under 5 min. We show that parallel comparative inspection is a productive and time-saving technique which can reduce the time taken to complete SIMD-style visual tasks currently performed at the desktop by at least two orders of magnitude, potentially rendering some labour-intensive desktop-based workflows obsolete.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82965670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic detection of cataclysmic variables from SDSS images","authors":"Junfeng Huang, Meixia Qu, Bin Jiang, Yanxia Zhang","doi":"10.1017/pasa.2023.34","DOIUrl":"https://doi.org/10.1017/pasa.2023.34","url":null,"abstract":"Abstract Investigating rare and new objects have always been an important direction in astronomy. Cataclysmic variables (CVs) are ideal and natural celestial bodies for studying the accretion process of semi-detached binaries with accretion processes. However, the sample size of CVs must increase because a lager gap exists between the observational and the theoretical expanding CVs. Astronomy has entered the big data era and can provide massive images containing CV candidates. CVs as a type of faint celestial objects, are highly challenging to be identified directly from images using automatic manners. Deep learning has rapidly developed in intelligent image processing and has been widely applied in some astronomical fields with excellent detection results. YOLOX, as the latest YOLO framework, is advantageous in detecting small and dark targets. This work proposes an improved YOLOX-based framework according to the characteristics of CVs and Sloan Digital Sky Survey (SDSS) photometric images to train and verify the model to realise CV detection. We use the Convolutional Block Attention Module to increase the number of output features with the feature extraction network and adjust the feature fusion network to obtain fused features. Accordingly, the loss function is modified. Experimental results demonstrate that the improved model produces satisfactory results, with average accuracy (mean average Precision at 0.5) of 92.0%, Precision of 92.9%, Recall of 94.3%, and \u0000$F1-score$\u0000 of 93.6% on the test set. The proposed method can efficiently achieve the identification of CVs in test samples and search for CV candidates in unlabeled images. The image data vastly outnumber the spectra in the SDSS-released data. With supplementary follow-up observations or spectra, the proposed model can help astronomers in seeking and detecting CVs in a new manner to ensure that a more extensive CV catalog can be built. The proposed model may also be applied to the detection of other kinds of celestial objects.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86680271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Parkes Pulsar Timing Array third data release","authors":"A. Zic, D. Reardon, Agastya Kapur, G. Hobbs, R. Mandow, M. Curyło, R. Shannon, Jacob Askew, M. Bailes, N. D. R. Bhat, A. Cameron, Zu-Cheng Chen, Shi Dai, Valentina Di Marco, Yi Feng, M. Kerr, Atharva Kulkarni, M. Lower, Rui Luo, R. Manchester, M. T. Miles, R. Nathan, S. Osłowski, Axl F. Rogers, C. Russell, J. Sarkissian, Mohsen Shamohammadi, R. Spiewak, N. Thyagarajan, L. Toomey, Shuangqiang Wang, Lei Zhang, Songbo Zhang, Xingjiang Zhu","doi":"10.1017/pasa.2023.36","DOIUrl":"https://doi.org/10.1017/pasa.2023.36","url":null,"abstract":"Abstract We present the third data release from the Parkes Pulsar Timing Array (PPTA) project. The release contains observations of 32 pulsars obtained using the 64-m Parkes ‘Murriyang’ radio telescope. The data span is up to 18 yr with a typical cadence of 3 weeks. This data release is formed by combining an updated version of our second data release with \u0000$sim$\u0000 3 yr of more recent data primarily obtained using an ultra-wide-bandwidth receiver system that operates between 704 and 4032 MHz. We provide calibrated pulse profiles, flux density dynamic spectra, pulse times of arrival, and initial pulsar timing models. We describe methods for processing such wide-bandwidth observations and compare this data release with our previous release.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82941612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of radio emission from stars via proper-motion searches","authors":"L. Driessen, G. Heald, S. Duchesne, T. Murphy, E. Lenc, J. Leung, V. Moss","doi":"10.1017/pasa.2023.26","DOIUrl":"https://doi.org/10.1017/pasa.2023.26","url":null,"abstract":"Abstract We present a method for identifying radio stellar sources using their proper-motion. We demonstrate this method using the FIRST, VLASS, RACS-low and RACS-mid radio surveys, and astrometric information from Gaia Data Release 3. We find eight stellar radio sources using this method, two of which have not previously been identified in the literature as radio stars. We determine that this method probes distances of \u0000$sim$\u0000 90pc when we use FIRST and RACS-mid, and \u0000$sim$\u0000 250pc when we use FIRST and VLASS. We investigate the time baselines required by current and future radio sky surveys to detect the eight sources we found, with the SKA (6.7 GHz) requiring \u0000$<$\u0000 3 yr between observations to find all eight sources. We also identify nine previously known and 43 candidate variable radio stellar sources that are detected in FIRST (1.4 GHz) but are not detected in RACS-mid (1.37 GHz). This shows that many stellar radio sources are variable, and that surveys with multiple epochs can detect a more complete sample of stellar radio sources.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85525618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On more than two decades of Celestial Reference Frame VLBI observations in the deep south: IVS-CRDS (1995–2021)","authors":"S. Weston, A. D. Witt, H. Krásná, K. Bail, Sara Hardin, D. Gordon, F. Shu, A. Fey, M. Schartner, S. Basu, O. Titov, D. Behrend, C. Jacobs, W. Hankey, Federico Salguero, J. Reynolds, Le Bail Krásná H, CS Jacobs","doi":"10.1017/pasa.2023.33","DOIUrl":"https://doi.org/10.1017/pasa.2023.33","url":null,"abstract":"Abstract The International VLBI Service for Geodesy and Astrometry (IVS) regularly provides high-quality data to produce Earth Orientation Parameters (EOP), and for the maintenance and realisation of the International Terrestrial and Celestial Reference Frames, ITRF and ICRF. The first iteration of the celestial reference frame (CRF) at radio wavelengths, the ICRF1, was adopted by the International Astronomical Union (IAU) in 1997 to replace the FK5 optical frame. Soon after, the IVS began official operations and in 2009 there was a significant increase in data sufficient to warrant a second iteration of the CRF, ICRF2. The most recent ICRF3, was adopted by the IAU in 2018. However, due to the geographic distribution of observing stations being concentrated in the Northern hemisphere, CRFs are generally weaker in the South due to there being fewer Southern Hemisphere observations. To increase the Southern Hemisphere observations, and the density, precision of the sources, a series of deep South observing sessions was initiated in 1995. This initiative in 2004 became the IVS Celestial Reference Frame Deep South (IVS-CRDS) observing programme. This paper covers the evolution of the CRDS observing programme for the period 1995–2021, details the data products and results, and concludes with a summary of upcoming improvements to this ongoing project.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86211723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Rapid ASKAP Continuum Survey IV: continuum imaging at 1367.5 MHz and the first data release of RACS-mid","authors":"S. Duchesne, A. Thomson, J. Pritchard, E. Lenc, V. Moss, D. McConnell, M. Wieringa, M. Whiting, Z. Wang, Y. Wang, K. Rose, W. Raja, T. Murphy, J. Leung, M. Huynh, A. Hotan, T. Hodgson, G. Heald, SW Duchesne, Pritchard J Lenc E Thomson AJM","doi":"10.1017/pasa.2023.31","DOIUrl":"https://doi.org/10.1017/pasa.2023.31","url":null,"abstract":"Abstract The Australian SKA Pathfinder (ASKAP) is being used to undertake a campaign to rapidly survey the sky in three frequency bands across its operational spectral range. The first pass of the Rapid ASKAP Continuum Survey (RACS) at 887.5 MHz in the low band has already been completed, with images, visibility datasets, and catalogues made available to the wider astronomical community through the CSIRO ASKAP Science Data Archive (CASDA). This work presents details of the second observing pass in the mid band at 1367.5 MHz, RACS-mid, and associated data release comprising images and visibility datasets covering the whole sky south of \u0000$delta_{text{J2000}}=+49^circ$\u0000 . This data release incorporates selective peeling to reduce artefacts around bright sources, as well as accurately modelled primary beam responses. The Stokes I images reach a median noise of 198 \u0000$mu$\u0000 Jy PSF \u0000$^{-1}$\u0000 with a declination-dependent angular resolution of 8.1–47.5 arcsec that fills a niche in the existing ecosystem of large-area astronomical surveys. We also supply Stokes V images after application of a widefield leakage correction, with a median noise of 165 \u0000$mu$\u0000 Jy PSF \u0000$^{-1}$\u0000 . We find the residual leakage of Stokes I into V to be \u0000$lesssim 0.9$\u0000 – \u0000$2.4$\u0000 % over the survey. This initial RACS-mid data release will be complemented by a future release comprising catalogues of the survey region. As with other RACS data releases, data products from this release will be made available through CASDA.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76784886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WALLABY pilot survey: The diversity of HI structural parameters in nearby galaxies","authors":"T. Reynolds, B. Catinella, L. Cortese, N. Deg, H. Denes, A. Elagali, B. For, P. Kamphuis, D. Kleiner, B. Koribalski, K. Lee-Waddell, C. Murugeshan, W. Raja, J. Rhee, K. Spekkens, L. Staveley-Smith, J. M. van der Hulst, J. Wang, T. Westmeier, O. I. Wong, F. Bigiel, A. Bosma, B. Holwerda, D. Leahy, M. Meyer","doi":"10.1017/pasa.2023.28","DOIUrl":"https://doi.org/10.1017/pasa.2023.28","url":null,"abstract":"Abstract We investigate the diversity in the sizes and average surface densities of the neutral atomic hydrogen (H i) gas discs in \u0000$sim$\u0000 280 nearby galaxies detected by the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). We combine the uniformly observed, interferometric H i data from pilot observations of the Hydra cluster and NGC 4636 group fields with photometry measured from ultraviolet, optical, and near-infrared imaging surveys to investigate the interplay between stellar structure, star formation, and H i structural parameters. We quantify the H i structure by the size of the H i relative to the optical disc and the average H i surface density measured using effective and isodensity radii. For galaxies resolved by \u0000$>$\u0000 \u0000$1.3$\u0000 beams, we find that galaxies with higher stellar masses and stellar surface densities tend to have less extended H i discs and lower H i surface densities: the isodensity H i structural parameters show a weak negative dependence on stellar mass and stellar mass surface density. These trends strengthen when we limit our sample to galaxies resolved by \u0000$>$\u0000 2 beams. We find that galaxies with higher H i surface densities and more extended H i discs tend to be more star forming: the isodensity H i structural parameters have stronger correlations with star formation. Normalising the H i disc size by the optical effective radius (instead of the isophotal radius) produces positive correlations with stellar masses and stellar surface densities and removes the correlations with star formation. This is due to the effective and isodensity H i radii increasing with mass at similar rates while, in the optical, the effective radius increases slower than the isophotal radius. Our results are in qualitative agreement with previous studies and demonstrate that with WALLABY we can begin to bridge the gap between small galaxy samples with high spatial resolution H i data and large, statistical studies using spatially unresolved, single-dish data.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89620832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}