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We present WALLABY pilot data release 1, the first public release of HI pilot survey data from the Wide-field ASKAP L-band Legacy All-sky Blind Survey (WALLABY) on the Australian Square Kilometre Array Pathfinder. Phase 1 of the WALLABY pilot survey targeted three $60~{\rm deg}^2$ regions on the sky in the direction of the Hydra and Norma galaxy clusters and the NGC 4636 galaxy group, covering the redshift range of z < 0.08. The source catalogue, images and spectra of nearly 600 extragalactic HI detections and kinematic models for 109 spatially resolved galaxies are available. As the pilot survey targeted regions containing nearby group and cluster environments, the median redshift of the sample of z ~ 0.014 is relatively low compared to the full WALLABY survey. The median galaxy HI mass is $2.3 \times 10^{9}~M_{\odot}$. The target noise level of 1.6 mJy per $30''$ beam and 18.5 kHz channel translates into a $5\sigma$ HI mass sensitivity for point sources of about $5.2 \times 10^{8} \, (D_{\rm L} / \mathrm{100~Mpc})^{2} \, M_{\odot}$ across 50 spectral channels (~200 km/s) and a $5\sigma$ HI column density sensitivity of about $8.6 \times 10^{19} \, (1 + z)^{4}~\mathrm{cm}^{-2}$ across 5 channels (~20 km/s) for emission filling the $30''$ beam. As expected for a pilot survey, several technical issues and artefacts are still affecting the data quality. Most notably, there are systematic flux errors of up to several 10% caused by uncertainties about the exact size and shape of each of the primary beams as well as the presence of sidelobes due to the finite deconvolution threshold. In addition, artefacts such as residual continuum emission and bandpass ripples have affected some of the data. The pilot survey has been highly successful in uncovering such technical problems, most of which are expected to be addressed and rectified before the start of the full WALLABY survey., Comment: 24 pages, 13 figures, 5 tables, accepted for publication in PASA

We use high-resolution ASKAP observations of galaxies in the Eridanus supergroup to study their HI, angular momentum and star formation properties, as part of the WALLABY pre-pilot survey efforts. The Eridanus supergroup is composed of three sub-groups in the process of merging to form a cluster. The main focus of this study is the Eridanus (or NGC 1395) sub-group. The baryonic specific angular momentum - baryonic mass ($j_{\mathrm{b}} - M_{\mathrm{b}}$) relation for the Eridanus galaxies is observed to be an unbroken power law of the form $j_{\mathrm{b}} \propto M_{\mathrm{b}}^{0.57 \pm 0.05}$, with a scatter of $\sim 0.10 \pm 0.01$ dex, consistent with previous works. We examine the relation between the atomic gas fraction, $f_{\mathrm{atm}}$, and the integrated atomic disc stability parameter $q$ (the $f_{\mathrm{atm}} - q$ relation), and find that the Eridanus galaxies deviate significantly from the relation owing to environmental processes such as tidal interactions and ram-pressure affecting their HI gas. We find that a majority of the Eridanus galaxies are HI deficient compared to normal star-forming galaxies in the field. We also find that the star formation among the Eridanus galaxies may be suppressed owing to their environment, thus hinting at significant levels of pre-processing within the Eridanus sub-group, even before the galaxies have entered a cluster-like environment., 19 pages, 19 figures, accepted for publication in MNRAS

We combine observations from ALMA, ATCA, MUSE, andHerschel to study gas-to-dust ratios in 15 Fornax cluster galaxies detected in the FIR/sub-mm by Herschel and observed by ALMA as part of the ALMA Fornax Cluster Survey (AlFoCS). The sample spans a stellar mass range of 8.3 $\leq$ log (M$_*$ / M$_\odot$) $\leq$ 11.16, and a variety of morphological types. We use gas-phase metallicities derived from MUSE observations (from the Fornax3D survey) to study these ratios as a function of metallicity, and to study dust-to-metal ratios, in a sub-sample of nine galaxies. We find that gas-to-dust ratios in Fornax galaxies are systematically lower than those in field galaxies at fixed stellar mass/metallicity. This implies that a relatively large fraction of the metals in these Fornax systems is locked up in dust, which is possibly due to altered chemical evolution as a result of the dense environment. The low ratios are not only driven by HI deficiencies, but H$_2$-to-dust ratios are also significantly decreased. This is different in the Virgo cluster, where low gas-to-dust ratios inside the virial radius are driven by low HI-to-dust ratios, while H$_2$-to-dust ratios are increased. Resolved observations of NGC1436 show a radial increase in H$_2$-to-dust ratio, and show that low ratios are present throughout the disc. We propose various explanations for the low H$_2$-to-dust ratios in the Fornax cluster, including the more efficient stripping of H$_2$ compared to dust, more efficient enrichment of dust in the star formation process, and altered ISM physics in the cluster environment., Accepted for publication in MNRAS. 21 pages, 12 figures, and 3 tables

Sensitive (noise $\sim 16\,\mu$\Jyb), high-resolution ($\sim 10''$) MeerKAT observations of Fornax A show that its giant lobes have a double-shell morphology, where dense filaments are embedded in a diffuse and extended cocoon, while the central radio jets are confined within the host galaxy. The spectral radio properties of the lobes and jets of Fornax A reveal that its nuclear activity is rapidly flickering. Multiple episodes of nuclear activity must have formed the radio lobes, for which the last stopped $12$ Myr ago. More recently ($\sim 3$ Myr ago), a less powerful and short ($\lesssim 1$ Myr) phase of nuclear activity generated the central jets. The distribution and kinematics of the neutral and molecular gas in the centre give insights on the interaction between the recurrent nuclear activity and the surrounding interstellar medium., Comment: 5 pages, 3 figures; proceedings of IAU Symposium No. 359, 2020 -- Galaxy Evolution and Feedback Across Different Environments

We present results from our analysis of the Hydra I cluster observed in neutral atomic hydrogen (H I) as part of the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). These WALLABY observations cover a 60-square-degree field of view with uniform sensitivity and a spatial resolution of 30 arcsec. We use these wide-field observations to investigate the effect of galaxy environment on H I gas removal and star formation quenching by comparing the properties of cluster, infall, and field galaxies extending up to ∼5R200 from the cluster centre. We find a sharp decrease in the H I-detected fraction of infalling galaxies at a projected distance of ∼1.5R200 from the cluster centre from ∼85 per cent to ∼35 per cent⁠. We see evidence for the environment removing gas from the outskirts of H I-detected cluster and infall galaxies through the decrease in the H I to r-band optical disc diameter ratio. These galaxies lie on the star-forming main sequence, indicating that gas removal is not yet affecting the inner star-forming discs and is limited to the galaxy outskirts. Although we do not detect galaxies undergoing galaxy-wide quenching, we do observe a reduction in recent star formation in the outer disc of cluster galaxies, which is likely due to the smaller gas reservoirs present beyond the optical radius in these galaxies. Stacking of H I non-detections with H I masses below MHI≲108.4M⊙ will be required to probe the H I of galaxies undergoing quenching at distances ≳60 Mpc with WALLABY. © 2021 The Author(s)., This research was conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. The Australian SKA Pathfinder is part of the Australia Telescope National Facility which is managed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory (MRO), and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji as the traditional owners of the Observatory site. We also thank the MRO site staff. This paper includes archived data obtained through the CSIRO ASKAP Science Data Archive, CASDA (http://data.csiro.au). LC acknowledges support from the Australian Research Council Discovery Project and Future Fellowship funding schemes (DP210100337, FT180100066). DO is a recipient of an Australian Research Council Future Fellowship (FT190100083) funded by the Australian Government. JR acknowledges support from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant ‘The structure and evolution of galaxies and their central regions’ with reference PID2019-105602GB-I00/10.13039/501100011033. LVM acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the ‘Center of Excellence Severo Ochoa’ awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), from the grant RTI2018-096228-B-C31 (Ministry of Science, Innovation and Universities/State Agency for Research/European Regional Development Funds, European Union), from the grant RED2018-102587-T (Spanish Ministry of Science, Innovation and Universities/State Agency for Research), and grant IAA4SKA (Ref. P18-RT-3082) from the Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades de la Junta de Andalucia and the European Regional Development Fund from the European Union. AB acknowledges support from the Centre National d’Etudes Spatiales (CNES), France. ARHS acknowledges receipt of the Jim Buckee Fellowship at ICRAR-UWA. SHO acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT: MSIT) (No. NRF-2020R1A2C1008706). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 679627; project name FORNAX). This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. This publication makes use of data products from the Wide-field Infrared Survey Explorer (WISE), which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This work is based in part on observations made with the Galaxy Evolution Explorer (GALEX). GALEX is a NASA Small Explorer, whose mission was developed in cooperation with the Centre National d’Etudes Spatiales (CNES) of France and the Korean Ministry of Science and Technology. GALEX is operated for NASA by the California Institute of Technology under NASA contract NAS5-98034.

This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited., We present the Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) Pilot Phase I HI kinematic models. This first data release consists of HI observations of three fields in the direction of the Hydra and Norma clusters, and the NGC 4636 galaxy group. In this paper, we describe how we generate and publicly release flat-disk tilted-ring kinematic models for 109/592 unique HI detections in these fields. The modelling method adopted here—which we call the WALLABY Kinematic Analysis Proto-Pipeline (WKAPP) and for which the corresponding scripts are also publicly available—consists of combining results from the homogeneous application of the FAT and 3DBAROLO algorithms to the subset of 209 detections with sufficient resolution and S/N in order to generate optimised model parameters and uncertainties. The 109 models presented here tend to be gas rich detections resolved by at least 3–4 synthesised beams across their major axes, but there is no obvious environmental bias in the modelling. The data release described here is the first step towards the derivation of similar products for thousands of spatially resolved WALLABY detections via a dedicated kinematic pipeline. Such a large publicly available and homogeneously analysed dataset will be a powerful legacy product that that will enable a wide range of scientific studies. © The Author(s), 2022. Published by Cambridge University Press on behalf of the Astronomical Society of Australia., The Australian SKA Pathfinder is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji as the traditional owners of the Observatory site. WALLABY acknowledges technical support from the Australian SKA Regional Centre (AusSRC) and Astronomy Data And Computing Services (ADACS). This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency. This paper includes archived data obtained through the CSIRO ASKAP Science Data Archive, CASDA (http://data.csiro.au). This paper uses resources from the Canadian Initiative for Radio Astronomy Data Analysis (CIRADA), which is funded by a grant from the Canada Foundation for Innovation 2017 Innovation Fund (Project 35999) and by the Provinces of Ontario, British Columbia, Alberta, Manitoba and Quebec, in collaboration with the National Research Council of Canada, the US National Radio Astronomy Observatory and Australia’s Commonwealth Scientific and Industrial Research Organisation. Part of this research was conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. AB acknowledges support from the Centre National d’Etudes Spatiales (CNES), France. EDT was supported by the US National Science Foundation under grant 1616177. JMvdH acknowledges support from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement nr. 291531 (HIStoryNU). KS acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). LVM acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the ‘Center of Excellence Severo Ochoa’ awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), from grant RTI2018-096228-B-C31 (MCIU/AEI/FEDER,UE), from the grant IAA4SKA (Ref. R18-RT-3082) from the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia and the European Regional Development Fund from the European Union. PK is partially supported by the BMBF project 05A17PC2 for D-MeerKAT. SHOH acknowledges a support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT: MSIT) (No. NRF-2020R1A2C1008706). TS acknowledges support by Fundação para a Ciência e a Tecnologia (FCT) through national funds (UID/FIS/04434/2013), FCT/MCTES through national funds (PIDDAC) by this grant UID/FIS/04434/2019 and by FEDER through COMPETE2020 (POCI-01-0145-FEDER-007672). TS also acknowledges the support by the fellowship SFRH/BPD/103385/2014 funded by the FCT (Portugal) and POPH/FSE (EC). TS additionally acknowledges support from DL 57/2016/CP1364/CT0009 from The Centro de Astrofísica da Universidade do Porto. This research uses Astropy,Footnotei a community-developed core Python package for Astronomy (Astropy Collaboration et al. Reference Astropy Collaboration2013; Astropy Collaboration et al. Reference Astropy Collaboration2018). It also uses the Numpy (Harris et al. Reference Harris2020), SciPy (Virtanen et al. Reference Virtanen2020), PANDAS (Reback et al. Reference Reback2020), and MatPlotLib (Hunter Reference Hunter2007) libraries.

Full list of authors: Wong, O.; Stevens, A. R. H.; For, B. -Q.; Westmeier, T.; Dixon, M.; Oh, S. -H.; Józsa, G. I. G.; Reynolds, T. N.; Lee-Waddell, K.; Román, J.; Verdes-Montenegro, L.; Courtois, H. M.; Pomarède, D.; Murugeshan, C.; Whiting, M.; Bekki, K.; Bigiel, F.; Bosma, A.; Catinella, B.; Dénes, H.; Elagali, A.; Holwerda, B. W.; Kamphuis, P.; Kilborn, V. A.; Kleiner, D.; Koribalski, B. S.; Lelli, F.; Madrid, J. P.; McQuinn, K. B. W.; Popping, A.; Rhee, J.; Roychowdhury, S.; Scott, T. C.; Sengupta, C.; Spekkens, K.; Staveley-Smith, L.; Wakker, B. P., We present the Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pre-pilot observations of two 'dark' H i sources (with H i masses of a few times 108 {M}_\odot and no known stellar counterpart) that reside within 363 kpc of NGC 1395, the most massive early-type galaxy in the Eridanus group of galaxies. We investigate whether these 'dark' H i sources have resulted from past tidal interactions or whether they are an extreme class of low surface brightness galaxies. Our results suggest that both scenarios are possible, and not mutually exclusive. The two 'dark' H i sources are compact, reside in relative isolation, and are more than 159 kpc away from their nearest H i-rich galaxy neighbour. Regardless of origin, the H i sizes and masses of both 'dark' H i sources are consistent with the H i size-mass relationship that is found in nearby low-mass galaxies, supporting the possibility that these H i sources are an extreme class of low surface brightness galaxies. We identified three analogues of candidate primordial 'dark' H i galaxies within the TNG100 cosmological, hydrodynamic simulation. All three model analogues are dark matter dominated, have assembled most of their mass 12-13 Gyr ago, and have not experienced much evolution until cluster infall 1-2 Gyr ago. Our WALLABY pre-pilot science results suggest that the upcoming large-area H i surveys will have a significant impact on our understanding of low surface brightness galaxies and the physical processes that shape them. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., Parts of this research was supported by the Australian Research Council Centre of Excellence for All-sky Astrophysics in 3 Dimensions (ASTRO 3D) through project number CE170100013. SHO acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT: MSIT) (No. NRF-2020R1A2C1008706). LVM and JR acknowledges financial support from the grants AYA2015-65973-C3-1-R and RTI2018-096228-B-C31 (MINECO/FEDER, UE), as well as from the State Agency for Research of the Spanish MCIU through the ‘Center of Excellence Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). JR acknowledges support from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant ‘The structure and evolution of galaxies and their central regions’ with reference PID2019-105602GB-I00/10.13039/501100011033. FB acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 - Research and Innovation Framework Programme (grant agreement No.726384/Empire). AB acknowledges support from the Centre National d’Etudes Spatiales (CNES), France. PK is partially supported by the BMBF project 05A17PC2 for D-MeerKAT. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020 and UIDP/04434/2020. TCS acknowledges support from FCT through national funds in the form of a work contract with the reference DL 57/2016/CP1364/CT0009. The Australian SKA Pathfinder is part of the Australia Telescope National Facility which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory, and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund.

We present a progress report of a study of FR I and FR II radio galaxies. Several new morphological features in the radio emission are now revealed using the high (μJy) sensitivity reached in the range 550–1712 MHz, more than a factor of three, at the high (∼4″−7″) angular resolution with the upgraded Giant Metrewave Radio Telescope (uGMRT) and MeerKAT. Therefore, the aim of this study is to understand if we need to revise our current classification scheme for classical radio galaxies. In order to address our goals, we have carefully constructed a sample of 14 (6 FR I, 6 FR II and 2 FR 0) radio galaxies. The uGMRT and MeerKAT images of our four target sources revealed a wealth of morphological details, e.g., filamentary structure in the emission from the lobes, misalignments, radio emission beyond the hot-spots in three sources, etc., see Fanaroff et al. (2021). Here, we present preliminary results for two more radio galaxies from our sample using uGMRT, in the light of the local environment. Finally, we are awaiting uGMRT and MeerKAT observations of remaining sample sources. Our results show that for the radio galaxies in this study, the morphological classification scheme for the classical FR I/FR II radio galaxies still holds, even with the improved imaging capabilities of the uGMRT and MeerKAT. Furthermore, we need to be cautious when using automated procedures for classification schemes, e.g., in surveys (with poorer sensitivities and angular resolutions) because of the rich morphological details that are shown in our uGMRT and MeerKAT images.

We present a multi-wavelength study of the gaseous medium surrounding the nearby active galactic nucleus (AGN) Fornax A. Using MeerKAT, ALMA and MUSE observations we reveal a complex distribution of the atomic (HI), molecular (CO), and ionised gas in its centre and along the radio jets. By studying the multi-scale kinematics of the multi-phase gas, we reveal the presence of concurrent AGN feeding and feedback phenomena. Several clouds and an extended 3 kpc filament -- perpendicular to the radio jets and the inner disk ($r\lesssim 4.5$ kpc) -- show highly-turbulent kinematics, which likely induces nonlinear condensation and subsequent Chaotic Cold Accretion (CCA) onto the AGN. In the wake of the radio jets and in an external ($r\gtrsim 4.5$ kpc) ring, we identify an entrained massive ($\sim$ $10^7$ M$_\odot$) multi-phase outflow ($v_{\rm OUT}\sim 2000$ km s$^{-1}$). The rapid flickering of the nuclear activity of Fornax A ($\sim$ 3 Myr) and the gas experiencing turbulent condensation raining onto the AGN provide quantitative evidence that a recurrent, tight feeding and feedback cycle may be self-regulating the activity of Fornax A, in agreement with CCA simulations. To date, this is one of the most in-depth probes of such a mechanism, paving the way to apply these precise diagnostics to a larger sample of nearby AGN hosts and their multi-phase ISM., 22 pages, 20 figures, accepted for publication on Astronomy & Astrophysics

Full list of authors: Namumba, B.; Koribalski, B. S.; Józsa, G. I. G.; Lee-Waddell, K.; Jones, M. G.; Carignan, C.; Verdes-Montenegro, L.; Ianjamasimanana, R.; de Blok, W. J. G.; Cluver, M.; Garrido, J.; Sánchez-Expósito, S.; Ramaila, A. J. T.; Thorat, K.; Andati, L. A. L.; Hugo, B. V.; Kleiner, D.; Kamphuis, P.; Serra, P.; Smirnov, O. M.; Maccagni, F. M.; Makhathini, S.; Molnár, D. Cs.; Perkins, S.; Ramatsoku, M.; White, S. V.; Loi, F., We report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (H I) around the core triplet galaxies in the nearby NGC 7232 galaxy group with MeerKAT. With a physical resolution of ∼1 kpc, we detect a complex web of low-surface-brightness H I emission down to a 4σ column density level of ∼1 × 1019 cm−2 (over 44 km s−1). The newly discovered H I streams extend over ∼20 arcmin corresponding to 140 kpc in projection. This is approximately three times the H I extent of the galaxy triplet (52 kpc). The H I debris has an H I mass of ∼6.6 × 109 M⊙, more than 50 per cent of the total H I mass of the triplet. Within the galaxy triplet, NGC 7233 and NGC 7232 have lost a significant amount of H I while NGC 7232B appears to have an excess of H I. The H I deficiency in NGC 7232 and NGC 7233 indicates that galaxy–galaxy interaction in the group concentrates on this galaxy pair while the other disc galaxies have visited them over time. In comparison to the AMIGA sample of isolated galaxies, we find that with regards to its total H I mass the NGC 7232/3 galaxy triplet is not H I-deficient. Despite the many interactions associated to the triplet galaxies, no H I seems to have been lost from the group (yet). © 2021 The Author(s)., The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. BN’s research is supported by the South African Radio Astronomy Observatory (SARAO). We acknowledge the Inter-University Institute for Data Intensive Astronomy (IDIA) for supporting us with the data intensive cloud for data processing. IDIA is a South African university partnership involving the University of Cape Town, the University of Pretoria, and the University of the Western Cape. BN acknowledges financial support from the CSIC Program of Scientific Cooperation for Development i-COOP+2019. The research of OS is supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation. PK is partially supported by the BMBF project 05A17PC2 for D-MeerKAT. LVM, MGJ, and BN acknowledge financial support from the State Agency for Research of the Spanish MCIU through the ‘Center of Excellence Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). BN acknowledges the discussion with the AMIGA team at IAA regarding data reduction and analysis. LVM, MJ, SSE, and JG acknowledge as well support from the grants AYA2015-65973-C3-1-R (MINECO/FEDER, UE) and RTI2018-096228-B-C31 (MCIU/AEI/FEDER,UE). MGJ fellowship was supported by a Juan de la Cierva formación fellowship. The work of WJGdB has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 882793/MeerGas). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 679627; project name FORNAX). MEC is a recipient of an Australian Research Council Future Fellowship (project No. FT170100273) funded by the Australian Government.

Full list of authors: Wang, Jing; Staveley-Smith, Lister; Westmeier, Tobias; Catinella, Barbara; Shao, Li; Reynolds, T. N.; For, Bi-Qing; Lee, Bumhyun; Liang, Ze-zhong; Wang, Shun; Elagali, A.; Dénes, H.; Kleiner, D.; Koribalski, Bärbel S.; Lee-Waddell, K.; Oh, S. -H.; Rhee, J.; Serra, P.; Spekkens, K.; Wong, O. I.; Bekki, K.; Bigiel, F.; Courtois, H. M.; Hess, Kelley M.; Holwerda, B. W.; McQuinn, Kristen B. W.; Pandey-Pommier, M.; van der Hulst, J. M.; Verdes-Montenegro, Lourdes., This study uses H i image data from the Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) pilot survey with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope, covering the Hydra cluster out to 2.5r 200. We present the projected phase-space distribution of H i-detected galaxies in Hydra, and identify that nearly two-thirds of the galaxies within 1.25r200 may be in the early stages of ram pressure stripping. More than half of these may be only weakly stripped, with the ratio of strippable H i (i.e., where the galactic restoring force is lower than the ram pressure in the disk) mass fraction (over total H i mass) distributed uniformly below 90%. Consequently, the H i mass is expected to decrease by only a few 0.1 dex after the currently strippable portion of H i in these systems has been stripped. A more detailed look at the subset of galaxies that are spatially resolved by WALLABY observations shows that, while it typically takes less than 200 Myr for ram pressure stripping to remove the currently strippable portion of H i, it may take more than 600 Myr to significantly change the total H i mass. Our results provide new clues to understanding the different rates of H i depletion and star formation quenching in cluster galaxies. © 2021. The American Astronomical Society. All rights reserved., J.W. acknowledges support from the National Science Foundation of China (12073002, 11721303). Parts of this research were supported by High-performance Computing Platform of Peking University. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 679627; project name FORNAX). F.B. acknowledges funding from the ERC under the European Union's Horizon 2020 research and innovation program (grant agreement No.726384/Empire). L.V.M. acknowledges financial support from grants AYA2015-65973-C3-1-R and RTI2018-096228-B-C31 (MINECO/FEDER, UE), as well as from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). S.H.O. acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT: MSIT) (No. NRF-2020R1A2C1008706). The Australian SKA Pathfinder is part of the Australia Telescope National Facility, which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory sites. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation.

We have undertaken a systematic study of FRI and FRII radio galaxies with the upgraded Giant Metrewave Radio Telescope (uGMRT) and MeerKAT. The main goal is to explore whether the unprecedented few $\mu$Jy sensitivity reached in the range 550-1712 MHz at the resolution of $\sim4^{\prime\prime}-7^{\prime\prime}$ reveals new features in the radio emission which might need us to revise our current classification scheme for classical radio galaxies. In this paper we present the results for the first set of four radio galaxies, i.e. 4C 12.02, 4C 12.03, CGCG 044-046 and CGCG 021-063. The sources have been selected from the 4C sample with well-defined criteria, and have been imaged with the uGMRT in the range 550-850 MHz (band 4) and with the MeerKAT in the range 856-1712 MHz (L-band). Full resolution images are presented for all sources in the sample, together with MeerKAT in-band spectral images. Additionally, the uGMRT-MeerKAT spectral image and MeerKAT L-band polarisation structure are provided for CGCG 044-046. Our images contain a wealth of morphological details, such as filamentary structure in the emission from the lobes, radio emission beyond the hot-spots in three sources, and misalignments. We briefly discuss the overall properties of CGCG 044-046 in the light of the local environment as well, and show possible restarted activity in 4C 12.03 which needs to be confirmed. We conclude that at least for the sources presented here, the classical FRI/FRII morphological classification still holds with the current improved imaging capabilities, but the richness in details also suggests caution in the systematic morphological classification carried out with automatic procedures in surveys with poorer sensitivity and angular resolution., Comment: 16 pages, 8 figures, and 3 tables; accepted for publication in MNRAS

We present the first interferometric blind HI survey of the Fornax galaxy cluster, which covers an area of 15 deg2 out to the cluster virial radius. The survey has a spatial and velocity resolution of 67″ × 95″(∼6 × 9 kpc at the Fornax cluster distance of 20 Mpc) and 6.6 km s−1 and a 3σ sensitivity of NHI ∼ 2 × 1019 cm−2 and MHI ∼ 2 × 107 M⊙, respectively. We detect 16 galaxies out of roughly 200 spectroscopically confirmed Fornax cluster members. The detections cover about three orders of magnitude in HI mass, from 8 × 106 to 1.5 × 1010 M⊙. They avoid the central, virialised region of the cluster both on the sky and in projected phase-space, showing that they are recent arrivals and that, in Fornax, HI is lost within a crossing time, ∼2 Gyr. Half of these galaxies exhibit a disturbed HI morphology, including several cases of asymmetries, tails, offsets between HI and optical centres, and a case of a truncated HI disc. This suggests that these recent arrivals have been interacting with other galaxies, the large-scale potential or the intergalactic medium, within or on their way to Fornax. As a whole, our Fornax HI detections are HI-poorer and form stars at a lower rate than non-cluster galaxies in the same M⋆ range. This is particularly evident at M⋆ ≲ 109 M⊙, indicating that low mass galaxies are more strongly affected throughout their infall towards the cluster. The MHI/M⋆ ratio of Fornax galaxies is comparable to that in the Virgo cluster. At fixed M⋆, our HI detections follow the non-cluster relation between MHI and the star formation rate, and we argue that this implies that thus far they have lost their HI on a timescale ≳1−2 Gyr. Deeper inside the cluster HI removal is likely to proceed faster, as confirmed by a population of HI-undetected but H2-detected star-forming galaxies. Overall, based on ALMA data, we find a large scatter in H2-to-HI mass ratio, with several galaxies showing an unusually high ratio that is probably caused by faster HI removal. Finally, we identify an HI-rich subgroup of possible interacting galaxies dominated by NGC 1365, where pre-processing is likely to have taken place.

We present MeerKAT neutral hydrogen (HI) observations of the Fornax A group, that is likely falling into the Fornax cluster for the first time. Our HI image is sensitive to 1.4 x 10$^{19}$ cm$^{-2}$ over 44.1 km s$^{-1}$, where we detect HI in 10 galaxies and a total of 1.12 x 10$^{9}$ Msol of HI in the intra-group medium (IGM). We search for signs of pre-processing in the 12 group galaxies with confirmed optical redshifts that reside within our HI image. There are 9 galaxies that show evidence of pre-processing and we classify the pre-processing status of each galaxy, according to their HI morphology and gas (atomic and molecular) scaling relations. Galaxies yet to experience pre-processing have extended HI disks, a high HI content with a H$_2$-to-HI ratio an order of magnitude lower than the median for their stellar mass. Galaxies currently being pre-processed display HI tails, truncated HI disks with typical gas ratios. Galaxies in the advanced stages of pre-processing are HI deficient. If there is any HI, they have lost their outer HI disk and efficiently converted their HI to H$_2$, resulting in H$_2$-to-HI ratios an order of magnitude higher than the median for their stellar mass. The central, massive galaxy in our group underwent a 10:1 merger 2 Gyr ago, and ejected 6.6 - 11.2 x 10$^{8}$ Msol of HI that we detect as clouds and streams in the IGM, some forming coherent structures up to 220 kpc in length. We also detect giant (100 kpc) ionised hydrogen (H$\alpha$) filaments in the IGM, likely from cool gas being removed (and ionised) from an infalling satellite. The H$\alpha$ filaments are situated within the hot halo of NGC 1316 and some regions contain HI. We speculate that the H$\alpha$ and multiphase gas is supported by magnetic pressure (possibly assisted by the AGN), such that the hot gas can condense and form HI that survives in the hot halo for cosmological timescales., Comment: 18 pages, 9 figured. Accepted for publication in Astronomy and Astrophysics (A&A)

In this paper we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers 31 square degrees at 800 MHz. As a two-dimensional array of 36x12m antennas, with baselines ranging from 22m to 6km, ASKAP also has excellent snapshot imaging capability and 10 arcsecond resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 MHz and 1800 MHz and is expected to facilitate great advances in our understanding of galaxy formation, cosmology and radio transients while opening new parameter space for discovery of the unknown., 38 pages, 24 figures, accepted for publication in PASA

ESO 149-G003 is a close-by, isolated dwarf irregular galaxy. Previous observations with the ATCA indicated the presence of anomalous neutral hydrogen (HI) deviating from the kinematics of a regularly rotating disc. We conducted follow-up observations with the MeerKAT radio telescope during the 16-dish Early Science programme as well as with the MeerLICHT optical telescope. Our more sensitive radio observations confirm the presence of anomalous gas in ESO 149-G003, and further confirm the formerly tentative detection of an extraplanar HI component in the galaxy. Employing a simple tilted-ring model, in which the kinematics is determined with only four parameters but including morphological asymmetries, we reproduce the galaxy's morphology, which shows a high degree of asymmetry. By comparing our model with the observed HI, we find that in our model we cannot account for a significant (but not dominant) fraction of the gas. From the differences between our model and the observed data cube we estimate that at least 7%-8% of the HI in the galaxy exhibits anomalous kinematics, while we estimate a minimum mass fraction of less than 1% for the morphologically confirmed extraplanar component. We investigate a number of global scaling relations and find that, besides being gas-dominated with a neutral gas-to-stellar mass ratio of 1.7, the galaxy does not show any obvious global peculiarities. Given its isolation, as confirmed by optical observations, we conclude that the galaxy is likely currently acquiring neutral gas. It is either re-accreting gas expelled from the galaxy or accreting pristine intergalactic material., 16 pages, 14 figures, MNRAS, Accepted 2020 December 2, in original form 2019 September 18

We present results from neutral atomic hydrogen (HI) observations of Hydra I, the first cluster observed by the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) on the Australian Square Kilometre Array Pathfinder. For the first time we show that WALLABY can reach its final survey sensitivity. Leveraging the sensitivity, spatial resolution and wide field of view of WALLABY, we identify a galaxy, ESO 501-G075, that lies near the virial radius of Hydra I and displays an HI tail. ESO 501-G075 shows a similar level of morphological asymmetry as another cluster member, which lies near the cluster centre and shows signs of experiencing ram pressure. We investigate possible environmental processes that could be responsible for producing the observed disturbance in the HI morphology of ESO 501-G075. We rule out tidal interactions, as ESO 501-G075 has no nearby neighbours within $\sim0.34$Mpc. We use a simple model to determine that ram pressure can remove gas from the disc at radii $r\gtrsim25$kpc. We conclude that, as ESO 501-G075 has a typical HI mass compared to similar galaxies in the field and its morphology is compatible with a ram pressure scenario, ESO 501-G075 is likely recently infalling into the cluster and in the early stages of experiencing ram pressure., Comment: 14 pages, 11 figures, accepted for publication in MNRAS

We present the discovery of a single radio relic located at the edge of the galaxy cluster A2384, using the MeerKAT radio telescope. A2384 is a nearby ($z$ = 0.092), low mass, complex bimodal, merging galaxy cluster that displays a dense X-ray filament ($\sim$ 700 kpc in length) between A2384(N) (Northern cluster) and A2384(S) (Southern cluster). The origin of the radio relic is puzzling. By using the MeerKAT observation of A2384, we estimate that the physical size of the radio relic is 824 $\times$ 264 kpc$^{2}$ and that it is a steep spectrum source. The radio power of the relic is $P_{1.4\mathrm{GHz}}$ $\sim$ (3.87 $\pm$ 0.40) $\times$ 10$^{23}$ W Hz$^{-1}$. This radio relic could be the result of shock wave propagation during the passage of the low-mass A2384(S) cluster through the massive A2384(N) cluster, creating a trail appearing as a hot X-ray filament. In the previous GMRT 325 MHz observation we detected a peculiar FR I radio galaxy interacting with the hot X-ray filament of A2384, but the extended radio relic was not detected; it was confused with the southern lobe of the FR I galaxy. This newly detected radio relic is elongated and perpendicular to the merger axis, as seen in other relic clusters. In addition to the relic, we notice a candidate radio ridge in the hot X-ray filament. The physical size of the radio ridge source is $\sim$ 182 $\times$ 129 kpc$^{2}$. Detection of the diffuse radio sources in the X-ray filament is a rare phenomenon, and could be a new class of radio source found between the two merging clusters of A2384(N) and A2384(S)., 12 pages, 6 figures, accepted in MNRAS

We present HI observations of the jellyfish galaxy, JO201. This massive galaxy (M$_{\ast} = 3.5 \times 10^{10}$ M$_\odot$) is falling along the line-of-sight towards the centre of a rich cluster (M$_{200} \sim 1.6 \times 10^{15}$ M$_\odot$, $\sigma_{cl} \sim 982$ km/s) at a high velocity $\geq$3363 km/s. Its H$\alpha$ emission shows a $\sim$40 kpc tail confined closely to its stellar disc and a $\sim$100 kpc tail extending further out. We find HI emission coinciding only with the shorter clumpy H$\alpha$ tail. In total, we measure an HI mass of M$_{\rm HI} = 1.65 \times 10^{9}$ M$_\odot$, which is about 60% lower than expected based on its stellar mass and stellar surface density. We compared JO201 to another jellyfish in the GASP sample, JO206 (of similar mass but residing in a 10$\times$ less massive cluster), and find that they are similarly HI-deficient. Of the total HI mass in JO201, about 30% lies outside the galaxy disc in projection. This HI fraction is probably a lower limit since most of the HI is redshifted relative to the stellar disc and could be outside the disc. The global star formation rate (SFR) analysis of JO201 suggests that its observed SFR would be expected if it had 10$\times$ its current HI mass. The disc is the main contributor of the high star formation efficiency at a given HI gas density for both galaxies, but their tails also show higher star formation efficiencies compared to the outer regions of field galaxies. Generally, we find that JO201 and JO206 are similar based on their HI content, stellar mass and star formation rate. This finding is unexpected considering their different environments. A toy model comparing the ram pressure of the ICM versus the restoring forces of these galaxies suggests that the ram pressure strength exerted on them could be comparable if we consider their 3D orbital velocities and radial distances relative to the clusters., Comment: 9 pages, 8 figures, Accepted for publication in A&A

We present the study of the south-west group in the Fornax cluster centred on the brightest group galaxy (BGG) Fornax A, observed as part of the Fornax Deep Survey (FDS). This includes the analysis of the bright group members (mB < 16 mag) and the intra-group light (IGL). The main objective of this work is to investigate the assembly history of the Fornax A group and to compare its physical quantities as a function of the environment to that of the Fornax cluster core. For all galaxies, we extract the azimuthally averaged surface brightness profiles in three optical bands (g, r, i) by modelling the galaxy's isophotes. We derive their colour profiles and structural parameters in all respective bands. The long integration time and large covered area of the FDS allow us to also estimate the amount of IGL. The majority of galaxies in the Fornax A group are late-type galaxies (LTGs), spanning a range of stellar mass of $8 < log (M_* M_{\odot}) < 10.5$. Six out of nine LTGs show a Type III (up-bending) break in their light profiles, which is either suggestive of strangulation halting star-formation in their outskirts or their HI-richness causing enhanced star-formation in their outer-discs. The estimated luminosity of the IGL is $6 \pm 2 \times 10^{10} L_{\odot}$ in g-band, which corresponds to about 16% of the total light in the group. The Fornax A group appears to be in an early stage of assembly with respect to the cluster core. The environment of the Fornax A group is not as dense as that of the cluster core, with all galaxies except the BGG showing similar morphology, comparable colours and stellar masses, and Type III disc-breaks, without any clear trend of these properties with group-centric distances. The main contribution to the IGL is from the minor merging in the outskirts of the BGG NGC1316 and, probably, the disrupted dwarf galaxies close to the group centre., Published in A&A. Replaced version: corrected typos and title (series number X)

Authors: Koribalski, Bärbel S.; Staveley-Smith, L.; Westmeier, T.; Serra, P.; Spekkens, K.; Wong, O. I.; Lee-Waddell, K.; Lagos, C. D. P.; Obreschkow, D.; Ryan-Weber, E. V.; Zwaan, M.; Kilborn, V.; Bekiaris, G.; Bekki, K.; Bigiel, F.; Boselli, A.; Bosma, A.; Catinella, B.; Chauhan, G.; Cluver, M. E. Colless, M.; Courtois, H. M.; Crain, R. A.; de Blok, W. J. G.; Dénes, H.; Duffy, A. R.; Elagali, A.; Fluke, C. J.; For, B. -Q.; Heald, G.; Henning, P. A.; Hess, K. M.; Holwerda, B. W.; Howlett, C.; Jarrett, T.; Jones, D. H.; Jones, M. G.; Józsa, G. I. G.; Jurek, R.; Jütte, E.; Kamphuis, P.; Karachentsev, I.; Kerp, J.; Kleiner, D.; Kraan-Korteweg, R. C.; López-Sánchez, Á. R.; Madrid, J.; Meyer, M.; Mould, J.; Murugeshan, C.; Norris, R. P.; Oh, S. -H.; Oosterloo, T. A.; Popping, A.; Putman, M.; Reynolds, T. N.; Rhee, J.; Robotham, A. S. G.; Ryder, S.; Schröder, A. C.; Shao, Li; Stevens, A. R. H.; Taylor, E. N.; van der Hulst, J. M.; Verdes-Montenegro, L.; Wakker, B. P.; Wang, J.; Whiting, M.; Winkel, B.; Wolf, C., The Widefield ASKAP L-band Legacy All-sky Blind surveY (wallaby) is a next-generation survey of neutral hydrogen (H i) in the Local Universe. It uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 × 12 -m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radio-quiet zone in Western Australia. wallaby aims to survey three-quarters of the sky (− 90 < δ< + 30 ) to a redshift of z≲ 0.26 , and generate spectral line image cubes at ∼30 arcsec resolution and ∼1.6 mJy beam per 4 km s channel sensitivity. ASKAP’s instantaneous field of view at 1.4 GHz, delivered by the PAF’s 36 beams, is about 30 sq deg. At an integrated signal-to-noise ratio of five, wallaby is expected to detect around half a million galaxies with a mean redshift of z∼ 0.05 (∼200 Mpc). The scientific goals of wallaby include: (a) a census of gas-rich galaxies in the vicinity of the Local Group; (b) a study of the H i properties of galaxies, groups and clusters, in particular the influence of the environment on galaxy evolution; and (c) the refinement of cosmological parameters using the spatial and redshift distribution of low-bias gas-rich galaxies. For context we provide an overview of recent and planned large-scale H i surveys. Combined with existing and new multi-wavelength sky surveys, wallaby will enable an exciting new generation of panchromatic studies of the Local Universe. — First results from the wallaby pilot survey are revealed, with initial data products publicly available in the CSIRO ASKAP Science Data Archive (CASDA). © 2020, Springer Nature B.V., The Australian SKA Pathfinder (ASKAP) is part of the Australia Telescope National Facility (ATNF) which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy (NCRIS). ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory (MRO) and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji as the traditional owners of the Observatory site. FB and DK acknowledge funding from the European Union's Horizon 2020 research and innovation programme; grant agreement No 726384 (FB) and No 679627 (DK). MEC is a recipient of an Australian Research Council Future Fellowship (project number FT170100273) funded by the Australian Government. RKK acknowledges the South African Research Chairs Initiative of the Department of Science and Innovation. RKK and GIGJ acknowledge the South African National Research Foundation for their support. MGJ and LVM acknowledge support from the grants AYA2015-65973-C3-1-R (MINECO/FEDER, UE) and RTI2018-096228-B-C31 (MICIU/FEDER, EU), as well as from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-20170709). MGJ is supported by a Juan de la Cierva formacion fellowship (FJCI-2016-29685). PK is partially supported by the BMBF project 05A17PC2 for D-MeerKAT. DO is a recipient of an Australian Research Council Future Fellowship (FT190100083) funded by the Australian Government. KS acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). JMvdH acknowledges support from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement nr. 291531. Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013.

We present MeerKAT 1000 MHz and 1400 MHz observations of a bright radio galaxy in the southern hemisphere, ESO~137-006. The galaxy lies at the centre of the massive and merging Norma galaxy cluster. The MeerKAT continuum images (rms ~0.02 mJy/beam at ~10" resolution) reveal new features that have never been seen in a radio galaxy before: collimated synchrotron threads of yet unknown origin, which link the extended and bent radio lobes of ESO~137-006. The most prominent of these threads stretches in projection for about 80 kpc and is about 1 kpc in width. The radio spectrum of the threads is steep, with a spectral index of up to $\alpha\simeq 2$ between 1000 MHz and 1400 MHz., Comment: 5 pages, 4 figures, accepted for publication in A&A letters

We present an H i study of the galaxy group LGG 351 using Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) early science data observed with the Australian Square Kilometre Array Pathfinder (ASKAP). LGG 351 resides behind the M 83 group at a velocity range (cz) of ∼3500–4800 km s−1 within the rich Hydra-Centaurus overdensity region. We detect 40 sources with the discovery of a tidally interacting galaxy pair and two new H i sources that are not presented in previous optical catalogues. 23 out of 40 sources have new redshifts derived from the new H i data. This study is the largest WALLABY sub-sample to date and also allows us to further validate the performance of ASKAP and the data reduction pipeline askapsoft. Extended H i emission is seen in six galaxies indicating interaction within the group, although no H i debris is found. We also detect H i in a known ultra-faint dwarf galaxy (dw 1328−29), which demonstrates that it is not a satellite of the M 83 group as previously thought. In conjunction with multiwavelength data, we find that our galaxies follow the atomic gas fraction and baryonic Tully–Fisher scaling relations derived from the GALEX Arecibo SDSS Survey. In addition, majority of our galaxies fall within the star formation main sequence indicating inefficiency of gas removal processes in this loose galaxy group.

We present MeerKAT observations of neutral hydrogen gas (HI) in the nearby merger remnant NGC 1316 (Fornax A), the brightest member of a galaxy group which is falling into the Fornax cluster. We find HI on a variety of scales, from the galaxy centre to its large-scale environment. For the first time we detect HI at large radii (70 - 150 kpc in projection), mostly distributed on two long tails associated with the galaxy. Gas in the tails dominates the HI mass of NGC 1316: 7e+8 Msun -- 14 times more than in previous observations. The total HI mass is comparable to the amount of neutral gas found inside the stellar body, mostly in molecular form. The HI tails are associated with faint optical tidal features thought to be the remnant of a galaxy merger occurred a few billion years ago. They demonstrate that the merger was gas-rich. During the merger, tidal forces pulled some gas and stars out to large radii, where we now detect them in the form of optical tails and, thanks to our new data, HI tails; while torques caused the remaining gas to flow towards the centre of the remnant, where it was converted into molecular gas and fuelled the starburst revealed by the galaxy's stellar populations. Several of the observed properties of NGC 1316 can be reproduced by a ~ 10:1 merger between a dominant, gas-poor early-type galaxy and a smaller, gas-rich spiral occurred 1 - 3 Gyr ago, likely followed by subsequent accretion of satellite galaxies., Astronomy & Astrophysics, accepted

We present a Wide-field ASKAP L-Band Legacy All-sky Blind surveY (WALLABY) study of the nearby ($v_{\rm sys}$ = 915 km s$^{-1}$) spiral galaxy IC 5201 using the Australian Square Kilometre Array Pathfinder (ASKAP). IC 5201 is a blue, barred spiral galaxy that follows the known scaling relations between stellar mass, SFR, HI mass and diameter. We create a four-beam mosaicked HI image cube, from 175 hours of observations made with a 12-antenna sub-array. The RMS noise level of the cube is 1.7 mJy beam$^{-1}$ per channel, equivalent to a column density of $N_{\rm HI}$ = 1.4 $\times$ 10$^{20}$ cm$^{-2}$ over 25 km s$^{-1}$. We report 9 extragalactic HI detections $-$ 5 new HI detections including the first velocity measurements for 2 galaxies. These sources are IC 5201, 3 dwarf satellite galaxies, 2 galaxies and a tidal feature belonging to the NGC 7232/3 triplet and 2 potential infalling galaxies to the triplet. There is evidence of a previous tidal interaction between IC 5201 and the irregular satellite AM 2220$-$460. A close fly-by is likely responsible for the asymmetric optical morphology of IC 5201 and warping its disc, resulting in the irregular morphology of AM 2220$-$460. We quantify the HI kinematics of IC 5201, presenting its rotation curve as well as showing that the warp starts at 14 kpc along the major axis, increasing as a function of radius with a maximum difference in position angle of 20$^\circ$. There is no evidence of stripped HI, triggered or quenched star formation in the system as measured using DECam optical and $GALEX$ UV photometry., Comment: 19 pages, 11 figures, accepted in MNRAS

We present new observations of Fornax A taken at 1 GHz with the MeerKAT telescope and at 6 GHz with the Sardinia Radio Telescope (SRT). The sensitive (noise ~16 micro-Jy beam$^{-1}$), high resolution ( < 10'') MeerKAT images show that the lobes of Fornax A have a double-shell morphology, where dense filaments are embedded in a diffuse and extended cocoon. We study the spectral properties of these components by combining the MeerKAT and SRT observations with archival data between 84 MHz and 217 GHz. For the first time, we show that multiple episodes of nuclear activity must have formed the extended radio lobes. The modelling of the radio spectrum suggests that the last episode of injection of relativistic particles into the lobes started ~ 24 Myr ago and stopped approximately 12 Myr ago. More recently (~ 3 Myr ago), a less powerful and short ( < 1 Myr) phase of nuclear activity generated the central jets. Currently, the core may be in a new active phase. It appears that Fornax A is rapidly flickering. The dense environment in which Fornax A lives has lead to a complex recent merger history for this galaxy, including mergers spanning a range of gas contents and mass ratios, as shown by the analysis of the galaxy's stellar- and cold-gas phases. This complex recent history may be the cause of the rapid, recurrent nuclear activity of Fornax A., Accepted for publication in Astronomy & Astrophysics

This paper reports on the atomic hydrogen gas (HI) observations of the spiral galaxy NGC 1566 using the newly commissioned Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. We measure an integrated HI flux density of $180.2$ Jy km s$^{-1}$ emanating from this galaxy, which translates to an HI mass of $1.94\times10^{10}$M$_\circ$ at an assumed distance of $21.3$ Mpc. Our observations show that NGC 1566 has an asymmetric and mildly warped HI disc. The HI-to-stellar mass fraction of NGC 1566 is $0.29$, which is high in comparison with galaxies that have the same stellar mass ($10^{10.8}$M$_\circ$). We also derive the rotation curve of this galaxy to a radius of $50$ kpc and fit different mass models to it. The NFW, Burkert and pseudo-isothermal dark matter halo profiles fit the observed rotation curve reasonably well and recover dark matter fractions of $0.62$, $0.58$ and $0.66$, respectively. Down to the column density sensitivity of our observations ($N_{HI} = 3.7\times10^{19}$ cm$^{-2}$), we detect no HI clouds connected to, or in the nearby vicinity of, the HI disc of NGC 1566 nor nearby interacting systems. We conclude that, based on a simple analytic model, ram pressure interactions with the IGM can affect the HI disc of NGC 1566 and is possibly the reason for the asymmetries seen in the HI morphology of NGC 1566., Comment: Accepted for publication in MNRAS

The ITER magnetic system includes 18 toroidal field (TF) coils constructed using a Nb3Sn cable-in-conduit superconductor. Each TF coil comprises a winding pack (WP) composed of seven double pancake (DP) modules stacked together, impregnated, and inserted into a stainless steel coil case. Ten TF coils are being produced in Europe, under the responsibility of Fusion for Energy (F4E) (the European Domestic Agency), whereas the remaining nine TF coils are being produced in Japan. F4E has implemented a procurement strategy aimed to minimize costs and risks by subdividing the procurement into three main packages, each foreseeing first an R&D and a qualification phase. One procurement package is related to the construction of 72 radial plates (RP), another to the fabrication of the ten WPs, and a third to the cold test and coil-case insertion of ten WPs. All industrial contracts have now been signed and are running. The situation as of September 2015 is as follows: 2 RP prototypes and 32 production RPs (enough for four TF coils) have been successfully (enough for four TF coils) produced and delivered to the winding pack supplier. A full-size superconducting DP prototype has been successfully fabricated and subjected to a thermal cycle at 80 K. So far, 33 DPs have been wound, 27 DPs have been heat treated, and 26 DPs have been successfully transferred into the RP grooves. The cover plate welding has been successfully completed on 18 DPs. Regarding the insertion contract, an alternative way to insert the WP inside the coil case has been devised, and the corresponding transfer tooling is being procured. The qualification for the most important manufacturing processes is underway.

This paper reflects the status of the manufacturing of 70 radial plates (RPs) for the EU ITER TF Coils. About 3700 t of stainless steel 316 LN have been forged and 240 t of cover plate (CP) raw material bars have been procured for the procurement of the RPs. Each RP is composed of six forged segments welded using local vacuum EB Welding technology for 35 RPs and narrow-gap TIG for the other 35 RPs. All RP plates are finally machined to final dimensions (9 m $\times$ 14 m) and tolerances using large portal milling machines. The groove length, planarity, and D-shape form tolerances are the most challenging required tolerances: ±30 ppm for the groove length and 1 mm for both planarity and D-shape form. The main challenges faced and results achieved so far are presented and improvements with respect to the prototype phase are described.

Feedback from massive stars plays a critical role in the evolution of the Universe by driving powerful outflows from galaxies that enrich the intergalactic medium and regulate star formation. An important source of outflows may be the most numerous galaxies in the Universe: dwarf galaxies. With small gravitational potential wells, these galaxies easily lose their star-forming material in the presence of intense stellar feedback. Here, we show that the nearby dwarf galaxy, the Small Magellanic Cloud (SMC), has atomic hydrogen outflows extending at least 2 kiloparsecs (kpc) from the star-forming bar of the galaxy. The outflows are cold, $T, Published in Nature Astronomy, 29 October 2018, http://dx.doi.org/10.1038/s41550-018-0608-8

We present Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) early science results from the Australian Square Kilometre Array Pathfinder (ASKAP) observations of the NGC 7162 galaxy group. We use archival HIPASS and Australia Telescope Compact Array (ATCA) observations of this group to validate the new ASKAP data and the data reduction pipeline ASKAPsoft. We detect six galaxies in the neutral hydrogen (HI) 21-cm line, expanding the NGC 7162 group membership from four to seven galaxies. Two of the new detections are also the first HI detections of the dwarf galaxies, AM 2159-434 and GALEXASC J220338.65-431128.7, for which we have measured velocities of $cz=2558$ and $cz=2727$ km s$^{-1}$, respectively. We confirm that there is extended HI emission around NGC 7162 possibly due to past interactions in the group as indicated by the $40^{\circ}$ offset between the kinematic and morphological major axes for NGC 7162A, and its HI richness. Taking advantage of the increased resolution (factor of $\sim1.5$) of the ASKAP data over archival ATCA observations, we fit a tilted ring model and use envelope tracing to determine the galaxies' rotation curves. Using these we estimate the dynamical masses and find, as expected, high dark matter fractions of $f_{\mathrm{DM}}\sim0.81-0.95$ for all group members. The ASKAP data are publicly available., 20 pages, 11 figures, accepted for publication in MNRAS

Drug-induced liver injury can lead to changes of the biliary tree that resemble sclerosing cholangitis. These changes can be seen on magnetic resonance cholangiopancreatography. Idiosyncratic drug-induced liver injury (DILI) has a variable presentation including cholestatic liver injury,1 in which case magnetic resonance imaging (MRI) is often performed to exclude pancreaticobiliary causes of obstruction. Sclerosing cholangitis (SC)-like changes on imaging have been described anecdotally with DILI.2,3 A recent study of 25 consecutive, unselected DILI patients found that 10% had SC-like changes on magnetic resonance cholangiopancreatography (MRCP).4 The aim of the current study was to identify the clinical features of patients enrolled in the U.S. Drug Induced Liver Injury Network (DILIN) prospective study who had SC-like changes on MRCP.

Summary Drug-induced liver injury (DILI) is often caused by innate and adaptive host immune responses. Characterization of inflammatory infiltrates in the liver may improve understanding of the underlying pathogenesis of DILI. This study aimed to enumerate and characterize leucocytes infiltrating liver tissue from subjects with acute DILI (n = 32) versus non-DILI causes of acute liver injury (n = 25). Immunostains for CD11b/CD4 (Kupffer and T helper cells), CD3/CD20 (T and B cells) and CD8/CD56 [T cytotoxic and natural killer (NK) cells] were evaluated in biopsies from subjects with acute DILI, either immunoallergic (IAD) or autoimmune (AID) and idiopathic autoimmune (AIH) and viral hepatitis (VH) and correlated with clinical and pathological features. All biopsies showed numerous CD8+ T cells and macrophages. DILI cases had significantly fewer B lymphocytes than AIH and VH and significantly fewer NK cells than VH. Prominent plasma cells were unusual in IAD (three of 10 cases), but were associated strongly with AIH (eight of nine) and also observed in most with AID (six of nine). They were also found in five of 10 cases with VH. Liver biopsies from subjects with DILI were characterized by low counts of mature B cells and NK cells in portal triads in contrast to VH. NK cells were found only in cases of VH, whereas AIH and VH both showed higher counts of B cells than DILI. Plasma cells were associated most strongly with AIH and less so with AID, but were uncommon in IAD.

Fenofibrate is a commonly used hypolipidemic associated with rare instances of hepatotoxicity, and routine liver biochemistry monitoring is recommended. The aim of this study is to describe the presenting clinical features, liver histopathology, and outcomes of 7 cases of acute liver injury associated with fenofibrate. All cases of definite, very likely, and probable drug-induced liver injury (DILI) attributed to fenofibrate enrolled in the DILI Network study between 2004 and 2015 were reviewed. Among 1229 patients with confirmed DILI, 7 cases (0.6%) were attributed to fenofibrate. The median age was 43 (range 37–61) years, and latency to onset was short (5–8 weeks) in 4 patients but more prolonged (18–56 weeks) in the rest. Laboratory results at presentation showed hepatocellular, mixed, and cholestatic injury, but 6 cases presented with jaundice. No patient had undergone routine monitoring. Four patients required hospitalization and 2 in whom drug discontinuation was delayed had a severe outcome, 1 undergoing liver transplantation, and 1 developing chronic injury and death. Liver biopsy was available in 4 patients and showed diverse injury patterns. Genetic studies showed the presence of the rare HLA-A*33:01 in 3 patients (43 vs. 1% in control populations). The causality scores were highly likely in 5 and probable in 2. Liver injury after fenofibrate exposure occurs with variable latency, enzyme elevation, and histology. Although most cases are self-limited, severe injury and mortality can occur, particularly if drug withdrawal is delayed. Jaundice or abnormal laboratory tests during fenofibrate therapy should trigger prompt discontinuation.

We examine the HI-to-stellar mass ratio (HI fraction) for galaxies near filament backbones within the nearby Universe ($d, Comment: 20 pages, 13 figures. Accepted in MNRAS

Taipan is a multi-object spectroscopic galaxy survey starting in 2017 that will cover 2pi steradians over the southern sky, and obtain optical spectra for about two million galaxies out to z2000. The main scientific goals of Taipan are: (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H_0) to 1% precision, and the structure growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of mass and environment. The final survey, which will be completed within 5 years, will consist of a complete magnitude-limited sample (i, Published in PASA; 29 pages, 17 figures, 2 tables

In this paper, we will report on the manufacturing of 6 helium inlet mock-ups for the EU ITER TF coils, and on the results of the mock-up tests and other qualification activities carried out in the European industry on this subject.

To advance our knowledge on the rubbing behavior of Andean bears (Tremarctos ornatus), we assessed characteristics of their rub-trees in the Peruvian tropical dry forest, where water is a rare and critical resource. We registered characteristics of rubbed and unrubbed trees and shrubs along bear trails in an area of approximately 100 km2 surrounding 7 waterholes in the western Andes foothills of Peru during austral summer 2014–2015. Analysis of 94 trees selected for rubbing (hereafter, rub-trees) and 253 available unmarked trees within a 5-m radius of each rub-tree showed that bears selected trees to rub that were relatively small and close to waterholes. Bears seemed to avoid the most common tree species, palo santo (Bursera graveolens), for tree-rubbing. We suggest that waterholes are important habitat features for Andean bears in the Peruvian dry forest, and that these sites be incorporated into conservation and land use management.

The flux tensor motion flow algorithm is a versatile computer vision technique for robustly detecting moving objects in cluttered scenes [1]. The flux tensor represents the temporal variations of the optical flow field within the local 3D spatiotemporal volume [2]. In this paper we present a prototype software implementation of the flux tensor based on the GStreamer multimedia framework and leveraging the computational performance of NVIDIA CUDA to achieve realtime motion detection in ultra-high definition video streams (i.e. UHD 4K @ 60fps) on suitably equipped GPU systems. GStreamer is a pipeline-based software framework that links together a wide variety of media processing elements to complete complex workflows [3]. CUDA is a parallel computing platform and application programming interface (API) model created by NVIDIA [4]. We assert that the modular nature of the GStreamer framework a) represents the algorithm naturally and declaratively and b) allows easy incorporation of the algorithm into other video processing systems. Several GStreamer and CUDA concepts are explored, with an emphasis on those relevant to the flux tensor implementation. We further discuss tradeoff decisions made within the current implementation, and conclude with avenues of future work and improvements.