Physical Sciences and Mathematics | Open Access Articles

Wallaby Pre-Pilot Survey: Ultra-Diffuse Galaxies In The Eridanus Supergroup, B-Q For, K. Spekkens, L. Stavely-Smith, K. Bekki, A. Karunakaran, B. Catinella, Bärbel S. Koribalski, K. Lee-Waddell, Juan P. Madrid, C. Murugeshan

Physics and Astronomy Faculty Publications and Presentations

We present a pilot study of the atomic neutral hydrogen gas (H I) content of ultra-diffuse galaxy (UDG) candidates. In this paper, we use the pre-pilot Eridanus field data from the Widefield ASKAP L-band Legacy All-sky Blind Survey to search for H I in UDG candidates found in the Systematically Measuring Ultra-diffuse Galaxies survey (SMUDGes). We narrow down to 78 SMUDGes UDG candidates within the maximum radial extents of the Eridanus subgroups for this study. Most SMUDGes UDGs candidates in this study have effective radii smaller than 1.5 kpc and thus fail to meet the defining size threshold. We …

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Wallaby Pre-Pilot Survey: Radio Continuum Properties Of The Eridanus Supergroup, J. A. Grundy, O. I. Wong, K. Lee-Waddell, N. Seymour, B. -Q. For, C. Murugeshan, B. S. Koribalski, Juan P. Madrid, J. Rhee, T. Westmeier

Physics and Astronomy Faculty Publications and Presentations

We present the highest resolution and sensitivity ∼ 1.4 GHz continuum observations of the Eridanus supergroup obtained as a part of the Widefield Australian Square Kilometer Array Pathfinder (ASKAP) L-band Legacy All-sky Blind surveY (WALLABY) pre-pilot observations using the ASKAP. We detect 9461 sources at 1.37 GHz down to a flux density limit of ∼ 0.1 mJy at 6.1′′×7.9′′ resolution with a median root mean square of 0.05 mJy beam −1 . We find that the flux scale is accurate to within 5 % (compared to NVSS at 1.4 GHz). We then determine the global properties of eight Eridanus supergroup …

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Wallaby Pilot Survey: H I Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S. Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We examine the H I gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the H I properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform H I profile decomposition of the sample galaxies using a tool, BAYGAUD, which allows us to deblend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct H I superprofiles of the sample galaxies via …

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Galaxy And Mass Assembly (Gama): Extended Intragroup Light In A Group At Z = 0.2 From Deep Hyper Suprime-Cam Images, Cristina Martínez-Lombilla, Sarah Brough, Mireia Montes, Roberto Baena-Gallé, Mohammad Akhlaghi, Raúl Infante-Sainz, Simon P. Driver, Benne W. Holwerda, Kevin A. Pimbblet, Aaron S G Robotham

Faculty Scholarship

We present a pilot study to assess the potential of Hyper Suprime-Cam Public Data Release 2 (HSC-PDR2) images for the analysis of extended faint structures within groups of galaxies. We examine the intragroup light (IGL) of the group 400138 (M_dyn = 1.3 ± 0.5 × 1013 M_⊙, z ∼ 0.2) from the Galaxy And Mass Assembly (GAMA) survey using Hyper Suprime-Cam Subaru Strategic Program Public Data Release 2 (HSC-SSP PDR2) images in g, r, and i bands. We present the most extended IGL measurement to date, reaching down to μglim=30.76" role="presentation" style="box-sizing: border-box; margin: 0px; …

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Wallaby Pilot Survey: Hi Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Minsu Kim, Hye-Jin Park, Shinna Kim, Bigiel Frank, Helga Denes, Bi-Qing For, Peter Kamphuis, Se-Heon Oh, Benne Holwerda, Kristen Mcquinn, Juan Madrid, Ahmed Elagali, Gerhardt R. Meurer, Kristine Spekkens, Lister Staveley-Smith, Barbara Catinella, Nathan Deg, Karen Lee-Waddell, Jing Wang, Lourdes Verdes-Montenegro, Ivy Wong, Jonghwan Rhee

Faculty Scholarship

We examine the H I gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the H I properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform H I profile decomposition of the sample galaxies using a tool, BAYGAUD which allows us to de-blend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct H I super-profiles of the sample galaxies via …

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Wallaby Pre-Pilot Survey: H I Content Of The Eridanus Supergroup, B. Q. For, J. Wang, Tobias Westmeier, O. I. Wong, C. Murugeshan, L. Staveley-Smith, H. M. Courtois, D. Pomarede, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We present observations of the Eridanus supergroup obtained with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the pre-pilot survey for the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). The total number of detected H I sources is 55, of which 12 are background galaxies not associated with the Eridanus supergroup. Two massive H I clouds are identified and large H I debris fields are seen in the NGC 1359 interacting galaxy pair, and the face-on spiral galaxy NGC 1385. We describe the data products from the source finding algorithm and present the basic parameters. The …

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Galaxy And Mass Assembly: Group And Field Galaxy Morphologies In The Star-Formation Rate - Stellar Mass Plane, W. J. Pearson, L. Wang, S. Brough, Benne Holwerda, A. M. Hopkins, J. Loveday

Faculty Scholarship

Aims. We study the environment in which a galaxy lies (i.e. field or group) and its connection with the morphology of the galaxy. This is done by examining the distribution of parametric and non-parametric statistics across the star-formation rate (SFR) - stellar mass (M?) plane and studying how these distributions change with the environment in the local universe (z < 0.15). Methods. We determine the concentration (C), Gini, M20, asymmetry, Gini-M20 bulge statistic (GMB), 50% light radius (r50), total Sérsic index, and bulge Sérsic index (nBulge) for galaxies from the Galaxy and Mass Assembly (GAMA) survey using optical images from the Kilo Degree Survey. We determine the galaxy environment using the GAMA group catalogue and split the galaxies into field or group galaxies. The group galaxies are further divided by the group halo mass (Mh) - 11 ≤ log(Mh /M*) < 12, 12 ≤ log(Mh /M*) < 13, and 13 ≤ log(Mh /M*) < 14 - and into central and satellite galaxies. The galaxies in each of these samples are then placed onto the SFR-M? plane, and each parameter is used as a third dimension. We fit the resulting distributions for each parameter in each sample using two two-dimensional Gaussian distributions: one for star-forming galaxies and one for quiescent galaxies. The coefficients of these Gaussian fits are then compared between environments. Results. Using C and r50, we find that galaxies typically become larger as the group mass increases. This change is greater for larger galaxies. There is no indication that galaxies are typically more or less clumpy as the environment changes. Using GMB and nBulge , we see that the star-forming galaxies do not become more bulge or disk dominated as the group mass changes. Asymmetry does not appear to be greatly influenced by environment.

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Galaxy And Mass Assembly: Luminosity And Stellar Mass Functions In Gama Groups, J. A. Vazquez-Mata, J. Loveday, S. D. Riggs, I. K. Baldry, L. J.M. Davies, A. S.G. Robotham, Benne W. Holwerda, M. J.I. Brown, M. E. Cluver, L. Wang, M. Alpaslan, J. Bland-Hawthorn, S. Brough, S. P. Driver, A. M. Hopkins, E. N. Taylor, A. H. Wright

Faculty Scholarship

How do galaxy properties (such as stellar mass, luminosity, star formation rate, and morphology) and their evolution depend on the mass of their host dark matter halo? Using the Galaxy and Mass Assembly group catalogue, we address this question by exploring the dependence on host halo mass of the luminosity function (LF) and stellar mass function (SMF) for grouped galaxies subdivided by colour, morphology, and central/satellite. We find that spheroidal galaxies in particular dominate the bright and massive ends of the LF and SMF, respectively. More massive haloes host more massive and more luminous central galaxies. The satellites LF and …

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Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, Lister Staveley-Smith, Tobias Westmeier, M. Whiting, S. -H. Oh, Baerbel Koribalski, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We present an HI 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 HI sources that are not presented in previous optical catalogues. 23 out of 40 sources have new redshifts derived from the new HI data. This study is the largest …

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Galaxy And Mass Assembly (Gama): Environmental Quenching Of Centrals And Satellites In Groups, L. J.M. Davies, A. S.G. Robotham, C. Del P. Lagos, S. P. Driver, A. R.H. Stevens, Y. M. Bahé, M. Alpaslan, M. N. Bremer, M. J.I. Brown, S. Brough, J. Bland-Hawthorn, L. Cortese, P. Elahi, M. W. Grootes, Benne W. Holwerda, A. D. Ludlow, S. Mcgee, M. Owers, S. Phillipps

Faculty Scholarship

Recently a number of studies have found a similarity between the passive fraction of central and satellite galaxies when controlled for both stellar and halo mass. These results suggest that the quenching processes that affect galaxies are largely agnostic to central/satellite status, which contradicts the traditional picture of increased satellite quenching via environmental processes such as stripping, strangulation, and starvation. Here we explore this further using the Galaxy And Mass Assembly (GAMA) survey, which extends to ~2 dex lower in stellar mass than SDSS, is more complete for closely separated galaxies (≳395 per cent compared to ≳370 per cent), and …

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Deep Extragalactic Visible Legacy Survey (Devils): Motivation, Design, And Target Catalogue, L. J.M. Davies, A. S.G. Robotham, S. P. Driver, C. P. Lagos, L. Cortese, E. Mannering, C. Foster, C. Lidman, A. Hashemizadeh, S. Koushan, S. O'Toole, I. K. Baldry, M. Bilicki, J. Bland-Hawthorn, M. N. Bremer, M. J.I. Brown, J. J. Bryant, B. Catinella, S. M. Croom, M. W. Grootes, Benne W. Holwerda, M. J. Jarvis, N. Maddox, M. Meyer, A. J. Moffett, S. Phillipps, E. N. Taylor, R. A. Windhorst, C. Wolf

Faculty Scholarship

The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a large spectroscopic campaign at the Anglo-Australian Telescope (AAT) aimed at bridging the near and distant Universe by producing the highest completeness survey of galaxies and groups at intermediate redshifts (0.3 < z < 1.0). Our sample consists of ~60 000 galaxies to Y < 21.2mag, over ~6 deg2 in threewell-studied deep extragalactic fields (Cosmic Origins Survey field, COSMOS; Extended Chandra Deep Field South, ECDFS; and the X-ray Multi-Mirror Mission Large-Scale Structure region, XMM-LSS - all Large Synoptic Survey Telescope deep-drill fields). This paper presents the broad experimental design of DEVILS. Our target sample has been selected from deep Visible and Infrared Survey Telescope for Astronomy (VISTA) Y-band imaging (VISTA Deep Extragalactic Observations, VIDEO and UltraVISTA), with photometry measured by PROFOUND. Photometric star/galaxy separation is done on the basis of near-infrared colours and has been validated by visual inspection. To maximize our observing efficiency for faint targets, we employ a redshift feedback strategy, which continually updates our target lists, feeding back the results from the previous night's observations. We also present an overview of the initial spectroscopic observations undertaken in late 2017 and early 2018.

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Galaxy And Mass Assembly (Gama): The Environmental Dependence Of The Galaxy Main Sequence, L. Wang, P. Norberg, S. Brough, M. J.I. Brown, E. Da Cunha, L. J. Davies, S. P. Driver, Benne W. Holwerda, A. M. Hopkins, M. A. Lara-Lopez, J. Liske, J. Loveday, M. W. Grootes, C. C. Popescu, A. H. Wright

Faculty Scholarship

Aims: We aim to investigate if the environment (characterised by the host dark matter halo mass) plays any role in shaping the galaxy star formation main sequence (MS). Methods: The Galaxy and Mass Assembly project (GAMA) combines a spectroscopic survey with photometric information in 21 bands from the far-ultraviolet (FUV) to the far-infrared (FIR). Stellar masses and dust-corrected star-formation rates (SFR) are derived from spectral energy distribution (SED) modelling using MAGPHYS. We use the GAMA galaxy group catalogue to examine the variation of the fraction of star-forming galaxies (SFG) and properties of the MS with respect to the environment. Results: …

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Galaxy And Mass Assembly (Gama): The Effect Of Galaxy Group Environment On Active Galactic Nuclei, Yjan A. Gordon, Kevin A. Pimbblet, Matt S. Owers, Joss Bland-Hawthorn, Sarah Brough, Michael J.I. Brown, Michelle E. Cluver, Scott M. Croom, Benne W. Holwerda, Jonathan Loveday, Smriti Mahajan, Lingyu Wang

Faculty Scholarship

In galaxy clusters, efficiently accreting active galactic nuclei (AGNs) are preferentially located in the infall regions of the cluster projected phase-space, and are rarely found in the cluster core. This has been attributed to both an increase in triggering opportunities for infalling galaxies, and a reduction of those mechanisms in the hot, virialized, cluster core. Exploiting the depth and completeness (98 per cent at r < 19.8mag) of the Galaxy And Mass Assembly survey (GAMA), we probe down the group halo mass function to assess whether AGNs are found in the same regions in groups as they are in clusters. We select 451 optical AGNs from 7498 galaxies with log10(M*/M⊙) > 9.9 in 695 groups with 11.53 ≤ log10(M200/M⊙) ≤ 14.56 at < 0.15. By analysing the projected phase-space positions of these galaxies, we demonstrate that when split both radially, and into physically derived infalling and core populations, AGN position within group projected phase-space is dependent on halo mass. For groups with log10(M200/M⊙) > 13.5,AGNs are preferentially found in the infalling galaxy populationwith 3.6s confidence. At lower halo masses, we observe no difference in AGN fraction between core …

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Full-Text Articles in Physical Sciences and Mathematics

Wallaby Pre-Pilot Survey: Ultra-Diffuse Galaxies In The Eridanus Supergroup, B-Q For, K. Spekkens, L. Stavely-Smith, K. Bekki, A. Karunakaran, B. Catinella, Bärbel S. Koribalski, K. Lee-Waddell, Juan P. Madrid, C. Murugeshan

Physics and Astronomy Faculty Publications and Presentations

Wallaby Pre-Pilot Survey: Radio Continuum Properties Of The Eridanus Supergroup, J. A. Grundy, O. I. Wong, K. Lee-Waddell, N. Seymour, B. -Q. For, C. Murugeshan, B. S. Koribalski, Juan P. Madrid, J. Rhee, T. Westmeier

Physics and Astronomy Faculty Publications and Presentations

Wallaby Pilot Survey: H I Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S. Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

Faculty Scholarship

Faculty Scholarship

Wallaby Pre-Pilot Survey: H I Content Of The Eridanus Supergroup, B. Q. For, J. Wang, Tobias Westmeier, O. I. Wong, C. Murugeshan, L. Staveley-Smith, H. M. Courtois, D. Pomarede, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

Galaxy And Mass Assembly: Group And Field Galaxy Morphologies In The Star-Formation Rate - Stellar Mass Plane, W. J. Pearson, L. Wang, S. Brough, Benne Holwerda, A. M. Hopkins, J. Loveday

Faculty Scholarship

Faculty Scholarship

Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, Lister Staveley-Smith, Tobias Westmeier, M. Whiting, S. -H. Oh, Baerbel Koribalski, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

Faculty Scholarship

Faculty Scholarship

Galaxy And Mass Assembly (Gama): The Environmental Dependence Of The Galaxy Main Sequence, L. Wang, P. Norberg, S. Brough, M. J.I. Brown, E. Da Cunha, L. J. Davies, S. P. Driver, Benne W. Holwerda, A. M. Hopkins, M. A. Lara-Lopez, J. Liske, J. Loveday, M. W. Grootes, C. C. Popescu, A. H. Wright

Faculty Scholarship

Faculty Scholarship