
显示样式: 排序: IF: - GO 导出
-
Remnant radio galaxies discovered in a multi-frequency survey Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-02-09 Benjamin Quici; Natasha Hurley-Walker; Nicholas Seymour; Ross J. Turner; Stanislav S. Shabala; Minh Huynh; H. Andernach; Anna D. Kapińska; Jordan D. Collier; Melanie Johnston-Hollitt; Sarah V. White; Isabella Prandoni; Timothy J. Galvin; Thomas Franzen; C. H. Ishwara-Chandra; Sabine Bellstedt; Steven J. Tingay; Bryan M. Gaensler; Andrew O’Brien; Johnathan Rogers; Kate Chow; Simon Driver; Aaron Robotham
The remnant phase of a radio galaxy begins when the jets launched from an active galactic nucleus are switched off. To study the fraction of radio galaxies in a remnant phase, we take advantage of a $8.31$ deg$^2$ subregion of the GAMA 23 field which comprises of surveys covering the frequency range 0.1–9 GHz. We present a sample of 104 radio galaxies compiled from observations conducted by the Murchison
-
The one-way speed of light and the Milne universe Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-02-08 Geraint F. Lewis; Luke A. Barnes
In Einstein’s special theory of relativity, all observers measure the speed of light, c, to be the same. However, this refers to the round-trip speed, where a clock at the origin times the outward and return trip of light reflecting off a distant mirror. Measuring the one-way speed of light is fraught with issues of clock synchronisation, and, as long as the average speed of light remains c, the speeds
-
Spectroscopic flat-fields can be used for precision CCD gain and noise tests Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-25 J. Gordon Robertson
One of the basic parameters of a charge coupled device (CCD) camera is its gain, that is, the number of detected electrons per output Analogue to Digital Unit (ADU). This is normally determined by finding the statistical variances from a series of flat-field exposures with nearly constant levels over substantial areas, and making use of the fact that photon (Poisson) noise has variance equal to the
-
High cadence optical transient searches using drift scan imaging II: Event rate upper limits on optical transients of duration <21 ms and magnitude <6.6 Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-18 Steven Tingay; Wynand Joubert
We have realised a simple prototype system to perform searches for short timescale optical transients, utilising the novel drift scan imaging technique described by Tingay (2020). We used two coordinated and aligned cameras, with an overlap field of view of approximately 3.7 deg$^2$, to capture over $34\,000 \times 5$ second images during approximately 24 h of observing. The system is sensitive to
-
Comparison of Gaia and Hipparcos parallaxes of close visual binary stars and the impact on determinations of their masses Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-18 Mashhoor Ahmad Al-Wardat; Abdallah M. Hussein; Hamid M. Al-Naimiy; Martin A. Barstow
Precise measurement of the fundamental parameters of stellar systems, including mass and radius, depends critically on how well the stellar distances are known. Astrometry from space provides parallax measurements of unprecented accuracy, from which distances can be derived, initially from the Hipparcos mission, with a further refinement of that analysis provided by van Leeuwen in 2007. The publication
-
Unexpected circular radio objects at high Galactic latitude Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-18 Ray P. Norris; Huib T. Intema; Anna D. Kapińska; Bärbel S. Koribalski; Emil Lenc; L. Rudnick; Rami Z. E. Alsaberi; Craig Anderson; G. E. Anderson; E. Crawford; Roland Crocker; Jayanne English; Miroslav D. Filipović; Tim J. Galvin; Andrew M. Hopkins; Natasha Hurley-Walker; Susumu Inoue; Kieran Luken; Peter J. Macgregor; Pero Manojlović; Josh Marvil; Andrew N. O’Brien; Laurence Park; Wasim Raja; Devika
We have found a class of circular radio objects in the Evolutionary Map of the Universe Pilot Survey, using the Australian Square Kilometre Array Pathfinder telescope. The objects appear in radio images as circular edge-brightened discs, about one arcmin diameter, that are unlike other objects previously reported in the literature. We explore several possible mechanisms that might cause these objects
-
Processing GOTO data with the Rubin Observatory LSST Science Pipelines I: Production of coadded frames Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-18 J. R. Mullaney; L. Makrygianni; V. Dhillon; S. Littlefair; K. Ackley; M. Dyer; J. Lyman; K. Ulaczyk; R. Cutter; Y.-L. Mong; D. Steeghs; D. K. Galloway; P. O’Brien; G. Ramsay; S. Poshyachinda; R. Kotak; L. Nuttall; E. Pallé; D. Pollacco; E. Thrane; S. Aukkaravittayapun; S. Awiphan; R. Breton; U. Burhanudin; P. Chote; A. Chrimes; E. Daw; C. Duffy; R. Eyles-Ferris; B. Gompertz; T. Heikkilä; P. Irawati;
The past few decades have seen the burgeoning of wide-field, high-cadence surveys, the most formidable of which will be the Legacy Survey of Space and Time (LSST) to be conducted by the Vera C. Rubin Observatory. So new is the field of systematic time-domain survey astronomy; however, that major scientific insights will continue to be obtained using smaller, more flexible systems than the LSST. One
-
SPT-CL J2032–5627: A new Southern double relic cluster observed with ASKAP Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2021-01-18 S. W. Duchesne; M. Johnston-Hollitt; I. Bartalucci; T. Hodgson; G. W. Pratt
We present a radio and X-ray analysis of the galaxy cluster SPT-CL J2032–5627. Investigation of public data from the Australian Square Kilometre Array Pathfinder (ASKAP) at 943 MHz shows two previously undetected radio relics at either side of the cluster. For both relic sources, we utilise archival Australia Telescope Compact Array (ATCA) data at 5.5 GHz in conjunction with the new ASKAP data to determine
-
Arcminute-scale studies of the interstellar gas towards HESS J1804−216: Still an unidentified TeV γ-ray source Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-23 Kirsty Feijen; Gavin Rowell; Sabrina Einecke; Catherine Braiding; Michael G. Burton; Nigel Maxted; Fabien Voisin; Graeme F. Wong
The Galactic TeV ${\gamma}$ -ray source ${\mathrm{HESS\,J}1804{-}216}$ is currently an unidentified source. In an attempt to unveil its origin, we present here the most detailed study of interstellar gas using data from the Mopra Southern Galactic Plane CO Survey, 7- and 12-mm wavelength Mopra surveys and Southern Galactic Plane Survey of HI. Several components of atomic and molecular gas are found
-
Resolving VLBI correlator ambiguity in the time delay model improves precision of geodetic measurements Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-01 O. Titov; A. Melnikov; Y. Lopez
The modern Very Long Baseline Interferometry (VLBI) relativistic delay model, as documented in the IERS Conventions, refers to the time epoch when the signal passes one of two stations of an interferometer baseline (selected arbitrarily from the pair of stations and called the ‘reference station’ or ‘station 1’). This model consists of the previous correlation procedure used before the year 2002. However
-
The capability of the Australian Square Kilometre Array Pathfinder to detect prompt radio bursts from neutron star mergers Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-02 Ziteng Wang; Tara Murphy; David L. Kaplan; Keith W. Bannister; Dougal Dobie
We discuss observational strategies to detect prompt bursts associated with gravitational wave (GW) events using the Australian Square Kilometre Array Pathfinder (ASKAP). Many theoretical models of binary neutron stars mergers predict that bright, prompt radio emission would accompany the merger. The detection of such prompt emission would greatly improve our knowledge of the physical conditions, environment
-
A low-frequency blind survey of the low Earth orbit environment using non-coherent passive radar with the Murchison widefield array Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-09 S. Prabu; P. Hancock; X. Zhang; S. J. Tingay
We have extended our previous work to use the Murchison widefield array (MWA) as a non-coherent passive radar system in the FM frequency band, using terrestrial FM transmitters to illuminate objects in low Earth orbit (LEO) and the MWA as the sensitive receiving element for the radar return. We have implemented a blind detection algorithm that searches for these reflected signals in difference images
-
Galaxy spin direction distribution in HST and SDSS show similar large-scale asymmetry Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-09 Lior Shamir
Several recent observations using large data sets of galaxies showed non-random distribution of the spin directions of spiral galaxies, even when the galaxies are too far from each other to have gravitational interaction. Here, a data set of $\sim8.7\cdot10^3$ spiral galaxies imaged by Hubble Space Telescope (HST) is used to test and profile a possible asymmetry between galaxy spin directions. The
-
A hundred new eclipsing binary system candidates studied in a near-infrared window in the VVV survey Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-10 L. V. Gramajo; T. Palma; D. Minniti; R. K. Saito; J. J. Clariá; R. Kammers; F. Surot
We present the first results obtained from an extensive study of eclipsing binary (EB) system candidates recently detected in the VISTA Variables in the Vía Láctea (VVV) near-infrared (NIR) Survey. We analyse the VVV tile d040 in the southern part of the Galactic disc wherein the interstellar reddening is comparatively low, which makes it possible to detect hundreds of new EB candidates. We present
-
First search for low-frequency CH with a Square Kilometre Array precursor telescope Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-12-15 Chenoa D. Tremblay; J. A. Green; Stacy L. Mader; Chris J. Phillips; Matthew Whiting
The diatomic free radical methylidyne (CH) is an important tracer of the interstellar medium, and the study of it was critical to our earliest understanding of star formation. Although it is detectable across the electromagnetic spectrum, observations at radio frequencies allow for a study of the kinematics of the diffuse and dense gas in regions of new star formation. There is only two published (single-dish)
-
The Rapid ASKAP Continuum Survey I: Design and first results Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-11-30 D. McConnell; C. L. Hale; E. Lenc; J. K. Banfield; George Heald; A. W. Hotan; James K. Leung; Vanessa A. Moss; Tara Murphy; Andrew O’Brien; Joshua Pritchard; Wasim Raja; Elaine M. Sadler; Adam Stewart; Alec J. M. Thomson; M. Whiting; James R. Allison; S. W. Amy; C. Anderson; Lewis Ball; Keith W. Bannister; Martin Bell; Douglas C.-J. Bock; Russ Bolton; J. D. Bunton; A. P. Chippendale; J. D. Collier;
The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band
-
Recreating the OSIRIS-REx slingshot manoeuvre from a network of ground-based sensors Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-11-27 Trent Jansen-Sturgeon; Benjamin A. D. Hartig; Gregory J. Madsen; Philip A. Bland; Eleanor K. Sansom; Hadrien A. R. Devillepoix; Robert M. Howie; Martin Cupák; Martin C. Towner; Morgan A. Cox; Nicole D. Nevill; Zacchary N. P. Hoskins; Geoffrey P. Bonning; Josh Calcino; Jake T. Clark; Bryce M. Henson; Andrew Langendam; Samuel J. Matthews; Terence P. McClafferty; Jennifer T. Mitchell; Craig J. O’Neill;
Optical tracking systems typically trade off between astrometric precision and field of view. In this work, we showcase a networked approach to optical tracking using very wide field-of-view imagers that have relatively low astrometric precision on the scheduled OSIRIS-REx slingshot manoeuvre around Earth on 22 Sep 2017. As part of a trajectory designed to get OSIRIS-REx to NEO 101955 Bennu, this flyby
-
Neutron Star Extreme Matter Observatory: A kilohertz-band gravitational-wave detector in the global network Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-11-05 K. Ackley; V. B. Adya; P. Agrawal; P. Altin; G. Ashton; M. Bailes; E. Baltinas; A. Barbuio; D. Beniwal; C. Blair; D. Blair; G. N. Bolingbroke; V. Bossilkov; S. Shachar Boublil; D. D. Brown; B. J. Burridge; J. Calderon Bustillo; J. Cameron; H. Tuong Cao; J. B. Carlin; S. Chang; P. Charlton; C. Chatterjee; D. Chattopadhyay; X. Chen; J. Chi; J. Chow; Q. Chu; A. Ciobanu; T. Clarke; P. Clearwater; J. Cooke;
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide
-
The impact of tandem redundant/sky-based calibration in MWA Phase II data analysis Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-11-04 Zheng Zhang; Jonathan C. Pober; Wenyang Li; Bryna J. Hazelton; Miguel F. Morales; Cathryn M. Trott; Christopher H. Jordan; Ronniy C. Joseph; Adam Beardsley; Nichole Barry; Ruby Byrne; Steven J. Tingay; Aman Chokshi; Kenji Hasegawa; Daniel C. Jacobs; Adam Lanman; Jack L. B. Line; Christene Lynch; Benjamin McKinley; Daniel A. Mitchell; Steven Murray; Bart Pindor; Mahsa Rahimi; Keitaro Takahashi; Randall
Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array’s (MWA) Phase II compact configuration offers us opportunities for both redundant calibration and sky-based calibration algorithms; using the two in tandem is a potential approach to mitigate calibration errors caused by inaccurate sky models. The MWA Epoch of Reionization (EoR) experiment
-
Absolute $V$ -band magnitudes and mass-to-light ratios of Galactic globular clusters Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-11-04 H. Baumgardt; A. Sollima; M. Hilker
We have used Hubble Space Telescope and ground-based photometry to determine total V-band magnitudes and mass-to-light ratios of more than 150 Galactic globular clusters. We do this by summing up the magnitudes of their individual member stars, using colour-magnitude information, Gaia DR2 proper motions, and radial velocities to distinguish cluster stars from background stars. Our new magnitudes confirm
-
The stellar rotation–activity relation for a sample of SuperWASP and ASAS-SN field stars Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-10-14 Heidi B. Thiemann; Andrew J. Norton; Ulrich C. Kolb
It is well established that late-type main-sequence (MS) stars display a relationship between X-ray activity and the Rossby number, Ro, the ratio of rotation period to the convective turnover time. This manifests itself as a saturated regime (where X-ray activity is constant) and an unsaturated regime (where X-ray activity anti-correlates with Rossby number). However, this relationship breaks down
-
Dynamically formed black hole binaries: In-cluster versus ejected mergers Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-10-13 O. Anagnostou; M. Trenti; A. Melatos
The growing number of black hole binary (BHB) mergers detected by the Laser Interferometer Gravitational-Wave Observatory have the potential to enable an unprecedented characterisation of the physical processes and astrophysical conditions that govern the formation of compact binaries. In this paper, we focus on investigating the dynamical formation of BHBs in dense star clusters through a state-of-the-art
-
The estimation of γ-ray Doppler factor for Fermi/LAT-detected blazars Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-10-12 Zhiyuan Pei; Junhui Fan; Jianghe Yang; Denis Bastieri
Blazars are a subclass of active galactic nuclei with extreme observation properties, which is caused by the beaming effect, expressed by a Doppler factor ( $\delta$ ), in a relativistic jet. Doppler factor is an important parameter in the blazars paradigm to indicate all of the observation properties, and many methods were proposed to estimate its value. In this paper, we present a method following
-
ASKAP reveals giant radio halos in two merging SPT galaxy clusters Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-10-08 Amanda G. Wilber; Melanie Johnston-Hollitt; Stefan W. Duchesne; Cyril Tasse; Hiroki Akamatsu; Huib Intema; Torrance Hodgson
Early science observations from the Australian Square Kilometre Array Pathfinder (ASKAP) have revealed clear signals of diffuse radio emission associated with two clusters detected by the South Pole Telescope via their Sunyaev Zel’dovich signal: SPT CLJ0553-3342 (MACS J0553.4-3342) and SPT CLJ0638-5358 (Abell S0592) are both high-mass lensing clusters that have undergone major mergers. To create science-fidelity
-
w-Stacking w-projection hybrid algorithm for wide-field interferometric imaging: implementation details and improvements Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-10-08 Luke Pratley; Melanie Johnston-Hollitt; Jason D. McEwen
We present a detailed discussion of the implementation strategies for a recently developed w-stacking w-projection hybrid algorithm used to reconstruct wide-field interferometric images. In particular, we discuss the methodology used to deploy the algorithm efficiently on a supercomputer via use of a Message Passing Interface (MPI) k-means clustering technique to achieve efficient construction and
-
Common envelope episodes that lead to double neutron star formation Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-09-23 Alejandro Vigna-Gómez; Morgan MacLeod; Coenraad J. Neijssel; Floor S. Broekgaarden; Stephen Justham; George Howitt; Selma E. de Mink; Serena Vinciguerra; Ilya Mandel
Close double neutron stars (DNSs) have been observed as Galactic radio pulsars, while their mergers have been detected as gamma-ray bursts and gravitational wave sources. They are believed to have experienced at least one common envelope episode (CEE) during their evolution prior to DNS formation. In the last decades, there have been numerous efforts to understand the details of the common envelope
-
A survey of spatially and temporally resolved radio frequency interference in the FM band at the Murchison Radio-astronomy Observatory Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-09-22 S. J. Tingay; M. Sokolowski; R. Wayth; D. Ung
We present the first survey of radio frequency interference (RFI) at the future site of the low frequency Square Kilometre Array (SKA), the Murchison Radio-astronomy Observatory (MRO), that both temporally and spatially resolves the RFI. The survey is conducted in a 1 MHz frequency range within the FM band, designed to encompass the closest and strongest FM transmitters to the MRO (located in Geraldton
-
Murchison Widefield Array detection of steep-spectrum, diffuse, non-thermal radio emission within Abell 1127 Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-09-11 S. W. Duchesne; M. Johnston-Hollitt; Z. Zhu; R. B. Wayth; J. L. B. Line
Diffuse, non-thermal emission in galaxy clusters is increasingly being detected in low-frequency radio surveys and images. We present a new diffuse, steep-spectrum, non-thermal radio source within the cluster Abell 1127 found in survey data from the Murchison Widefield Array (MWA). We perform follow-up observations with the ‘extended’ configuration MWA Phase II with improved resolution to better resolve
-
A SETI survey of the Vela region using the Murchison Widefield Array: Orders of magnitude expansion in search space Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-09-07 C. D. Tremblay; S. J. Tingay
Following the results of our previous low-frequency searches for extraterrestrial intelligence (SETI) using the Murchison Widefield Array (MWA), directed towards the Galactic Centre and the Orion Molecular Cloud (Galactic Anticentre), we report a new large-scale survey towards the Vela region with the lowest upper limits thus far obtained with the MWA. Using the MWA in the frequency range 98–128 MHz
-
An introduction to Bayesian inference in gravitational-wave astronomy: parameter estimation, model selection, and hierarchical models—Corrigendum Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-09-02 Eric Thrane; Colm Talbot
This is an introduction to Bayesian inference with a focus on hierarchical models and hyper-parameters. We write primarily for an audience of Bayesian novices, but we hope to provide useful insights for seasoned veterans as well. Examples are drawn from gravitational-wave astronomy, though we endeavour for the presentation to be understandable to a broader audience. We begin with a review of the fundamentals:
-
MWA tied-array processing III: Microsecond time resolution via a polyphase synthesis filter Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-08-24 S. J. McSweeney; S. M. Ord; D. Kaur; N. D. R. Bhat; B. W. Meyers; S. E. Tremblay; J. Jones; B. Crosse; K. R. Smith
A new high time resolution observing mode for the Murchison Widefield Array (MWA) is described, enabling full polarimetric observations with up to $30.72\,$ MHz of bandwidth and a time resolution of ${\sim}$ $0.8\,\upmu$ s. This mode makes use of a polyphase synthesis filter to ‘undo’ the polyphase analysis filter stage of the standard MWA’s Voltage Capture System observing mode. Sources of potential
-
Low(er) frequency follow-up of 28 candidate, large-scale synchrotron sources Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-08-20 Torrance Hodgson; Melanie Johnston-Hollitt; Benjamin McKinley; Tessa Vernstrom; Valentina Vacca
We follow up on a report by Vacca et al. (2018) of 28 candidate large-scale diffuse synchrotron sources in an 8° × 8° area of the sky (centred at RA 5h0m0s; Dec 5°48ʹ00ʹʹ). These sources were originally observed at 1.4 GHz using a combination of the single-dish Sardinia Radio Telescope and archival NRAO VLA Sky Survey data. They are in an area with nine massive galaxy clusters at $z \approx 0.1$ and
-
Can an infinitely long object fit in an expanding universe? Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-08-20 Aaron Glanville; Tamara M. Davis
Does space stretch its contents as the universe expands? Usually, we say the answer is no—the stretching of space is not like the stretching of a rubber sheet that might drag things with it. In this paper, we explore a potential counterexample—namely, we show that it is impossible to make an arbitrarily long object in an expanding universe, because it is impossible to hold the distant end of the object
-
Investigation on the mass transferring near-contact binary TT Cet Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-08-18 Xiao-Man Tian; Lin-Feng Chang
First multi-colour complete light curves and low-resolution spectra of short-period eclipsing binary TT Cet are presented. The stellar atmospheric parameters of the primary star were derived through spectra fitting as: $T_{eff}=7\,091\pm124\,{\text{K}}$ , $\log g = 4.15\pm0.33\,{\text{cm}}/\text{s}^2$ , and $[Fe/H]=-0.23\pm0.04\,\text{dex}$ . The light curves were analysed using the Wilson–Devinney
-
The POlarised GLEAM Survey (POGS) II: Results from an all-sky rotation measure synthesis survey at long wavelengths Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-07-17 C. J. Riseley; T. J. Galvin; C. Sobey; T. Vernstrom; S. V. White; X. Zhang; B. M. Gaensler; G. Heald; C. S. Anderson; T. M. O. Franzen; P. J. Hancock; N. Hurley-Walker; E. Lenc; C. L. Van Eck
The low-frequency linearly polarised radio source population is largely unexplored. However, a renaissance in low-frequency polarimetry has been enabled by pathfinder and precursor instruments for the Square Kilometre Array. In this second paper from the POlarised GaLactic and Extragalactic All-Sky MWA Survey-the POlarised GLEAM Survey, or POGS-we present the results from our all-sky MWA Phase I Faraday
-
The GLEAMing of the first supermassive black holes Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-07-16 Guillaume Drouart; Nick Seymour; Tim J. Galvin; Jose Afonso; Joseph R. Callingham; Carlos De Breuck; Melanie Johnston-Hollitt; Anna D. Kapińska; Matthew D. Lehnert; Joël Vernet
We present the results of a new selection technique to identify powerful ( $L_{\rm 500\,MHz} \gt 10^{27}\,\text{WHz}^{-1}$ ) radio galaxies towards the end of the Epoch of Reionisation. Our method is based on the selection of bright radio sources showing radio spectral curvature at the lowest frequency ( ${\sim}100\,\text{MHz}$ ) combined with the traditional faintness in K-band for high-redshift galaxies
-
Modelling and peeling extended sources with shapelets: A Fornax A case study Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-07-16 J. L. B. Line; D. A. Mitchell; B. Pindor; J. L. Riding; B. McKinley; R. L. Webster; C. M. Trott; N. Hurley-Walker; A. R. Offringa
To make a power spectrum (PS) detection of the 21-cm signal from the Epoch of Reionisation (EoR), one must avoid/subtract bright foreground sources. Sources such as Fornax A present a modelling challenge due to spatial structures spanning from arc seconds up to a degree. We compare modelling with multi-scale (MS) CLEAN components to ‘shapelets’, an alternative set of basis functions. We introduce a
-
The MeerKAT telescope as a pulsar facility: System verification and early science results from MeerTime Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-07-15 M. Bailes; A. Jameson; F. Abbate; E. D. Barr; N. D. R. Bhat; L. Bondonneau; M. Burgay; S. J. Buchner; F. Camilo; D. J. Champion; I. Cognard; P. B. Demorest; P. C. C. Freire; T. Gautam; M. Geyer; J.-M. Griessmeier; L. Guillemot; H. Hu; F. Jankowski; S. Johnston; A. Karastergiou; R. Karuppusamy; D. Kaur; M. J. Keith; M. Kramer; J. van Leeuwen; M. E. Lower; Y. Maan; M. A. McLaughlin; B. W. Meyers; S.
We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for the newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. MeerKAT is a high-gain ( ${\sim}2.8\,\mbox{K Jy}^{-1}$ ) low-system temperature ( ${\sim}18\,\mbox{K at }20\,\mbox{cm}$ ) radio array that currently operates at 580–1 670 MHz and can produce tied-array beams suitable
-
Megahertz emission of massive early-type stars in the Cygnus region Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-07-15 P. Benaglia; M. De Becker; C. H. Ishwara-Chandra; H. T. Intema; N. L. Isequilla
Massive, early-type stars have been detected as radio sources for many decades. Their thermal winds radiate free–free continuum and in binary systems hosting a colliding-wind region, non-thermal emission has also been detected. To date, the most abundant data have been collected from frequencies higher than 1 GHz. We present here the results obtained from observations at 325 and 610 MHz, carried out
-
Understanding galaxy formation and evolution through an all-sky submillimetre spectroscopic survey Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-29 Mattia Negrello; Matteo Bonato; Zhen-Yi Cai; Helmut Dannerbauer; Gianfranco De Zotti; Jacques Delabrouille; Douglas Scott
We illustrate the extraordinary discovery potential for extragalactic astrophysics of a far-infrared/submillimetre (far-IR/submm) all-sky spectroscopic survey with a 3-m-class space telescope. Spectroscopy provides a three-dimensional view of the Universe and allows us to take full advantage of the sensitivity of present-day instrumentation, close to fundamental limits, overcoming the spatial confusion
-
The bivariate gas–stellar mass distributions and the mass functions of early- and late-type galaxies at Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-19 Aldo Rodríguez-Puebla; A. R. Calette; Vladimir Avila-Reese; Vicente Rodriguez-Gomez; Marc Huertas-Company
We report the bivariate $\rm HI$ - and $\rm H_{2}$ -stellar mass distributions of local galaxies in addition of an inventory of galaxy mass functions, MFs, for $\rm HI$ , $\rm H_{2}$ , cold gas, and baryonic mass, separately into early- and late-type galaxies. The MFs are determined using the $\rm HI$ and $\rm H_{2}$ conditional distributions and the galaxy stellar mass function (GSMF). For the conditional
-
Calibration database for the Murchison Widefield Array All-Sky Virtual Observatory Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-11 Marcin Sokolowski; Christopher H. Jordan; Gregory Sleap; Andrew Williams; Randall Bruce Wayth; Mia Walker; David Pallot; Andre Offringa; Natasha Hurley-Walker; Thomas M. O. Franzen; Melanie Johnston-Hollitt; David L. Kaplan; David Kenney; Steven J. Tingay
We present a calibration component for the Murchison Widefield Array All-Sky Virtual Observatory (MWA ASVO) utilising a newly developed PostgreSQL database of calibration solutions. Since its inauguration in 2013, the MWA has recorded over 34 petabytes of data archived at the Pawsey Supercomputing Centre. According to the MWA Data Access policy, data become publicly available 18 months after collection
-
Self-similar structure of resistive ADAFs with outflow and large-scale magnetic field Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-11 S. M. Ghoreyshi
The observations and simulations have revealed that large-scale magnetic field and outflows can exist in the inner regions of an advection-dominated accretion disc where the resistive diffusion may also be important. In the present paper, the roles of large-scale magnetic field and outflows in the structure of resistive advection-dominated accretion discs are explored by assuming that the accretion
-
Bridging the ultraviolet and optical regions: Transformation equations between GALEX and UBV photometric systems Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-10 S. Bilir; N. Alan; S. Tunçel Güçtekin; M. Çelebi; T. Yontan; O. Plevne; S. Ak; T. Ak; S. Karaali
We derive transformation equations between GALEX and UBV colours by using the reliable data of 556 stars. We present two sets of equations: as a function of (only) luminosity class and as a function of both luminosity class and metallicity. The metallicities are provided from the literature, while the luminosity classes are determined by using the PARSEC mass tracks in this study. Small colour residuals
-
The Parkes Pulsar Timing Array project: second data release Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-05 Matthew Kerr; Daniel J. Reardon; George Hobbs; Ryan M. Shannon; Richard N. Manchester; Shi Dai; Christopher J. Russell; Songbo Zhang; Willem van Straten; Stefan Osłowski; Aditya Parthasarathy; Renee Spiewak; Matthew Bailes; N. D. Ramesh Bhat; Andrew D. Cameron; William A. Coles; James Dempsey; Xinping Deng; Boris Goncharov; Jane F. Kaczmarek; Michael J. Keith; Paul D. Lasky; Marcus E. Lower; Brett
We describe 14 yr of public data from the Parkes Pulsar Timing Array (PPTA), an ongoing project that is producing precise measurements of pulse times of arrival from 26 millisecond pulsars using the 64-m Parkes radio telescope with a cadence of approximately 3 weeks in three observing bands. A comprehensive description of the pulsar observing systems employed at the telescope since 2004 is provided
-
The GLEAM 4-Jy (G4Jy) Sample: II. Host galaxy identification for individual sources Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-01 Sarah V. White; Thomas M. O. Franzen; Chris J. Riseley; O. Ivy Wong; Anna D. Kapińska; Natasha Hurley-Walker; Joseph R. Callingham; Kshitij Thorat; Chen Wu; Paul Hancock; Richard W. Hunstead; Nick Seymour; Jesse Swan; Randall Wayth; John Morgan; Rajan Chhetri; Carole Jackson; Stuart Weston; Martin Bell; B. M. Gaensler; Melanie Johnston–Hollitt; André Offringa; Lister Staveley–Smith
The entire southern sky (Declination, $\delta< 30^{\circ}$ ) has been observed using the Murchison Widefield Array (MWA), which provides radio imaging of $\sim$ 2 arcmin resolution at low frequencies (72–231 MHz). This is the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey, and we have previously used a combination of visual inspection, cross-checks against the literature, and internal matching
-
The GLEAM 4-Jy (G4Jy) Sample: I. Definition and the catalogue Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-06-01 Sarah V. White; Thomas M. O Franzen; Chris J. Riseley; O. Ivy Wong; Anna D. Kapińska; Natasha Hurley-Walker; Joseph R. Callingham; Kshitij Thorat; Chen Wu; Paul Hancock; Richard W. Hunstead; Nick Seymour; Jesse Swan; Randall Wayth; John Morgan; Rajan Chhetri; Carole Jackson; Stuart Weston; Martin Bell; Bi-Qing For; B. M. Gaensler; Melanie Johnston-Hollitt; André Offringa; Lister Staveley-Smith
The Murchison Widefield Array (MWA) has observed the entire southern sky (Declination, $\delta< 30^{\circ}$ ) at low radio frequencies, over the range 72–231MHz. These observations constitute the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey, and we use the extragalactic catalogue (EGC) (Galactic latitude, $|b| >10^{\circ}$ ) to define the GLEAM 4-Jy (G4Jy) Sample. This is a complete sample
-
A linear formation-flying astronomical interferometer in low Earth orbit Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-05-29 Jonah T. Hansen; Michael J. Ireland
Space interferometry is the inevitable end point of high angular resolution astrophysics, and a key technology that can be leveraged to analyse exoplanet formation and atmospheres with exceptional detail. However, the anticipated cost of large missions, such as Darwin and TPF-I, and inadequate technology readiness levels have resulted in limited developments since the late 2000s. Here, we present a
-
SimSpin—Constructing mock IFS kinematic data cubes Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-05-11 Katherine E. Harborne; Chris Power; Aaron S. G. Robotham
We present SimSpin, a new, public, software framework for generating integral field spectroscopy (IFS) data cubes from N-body/hydrodynamical simulations of galaxies, which can be compared directly with observational datasets. SimSpin provides a consistent method for studying a galaxy’s stellar component. It can be used to explore how observationally inferred measurements of kinematics, such as the
-
An ultra-wide bandwidth (704 to 4 032 MHz) receiver for the Parkes radio telescope Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-04-08 George Hobbs; Richard N. Manchester; Alex Dunning; Andrew Jameson; Paul Roberts; Daniel George; J. A. Green; John Tuthill; Lawrence Toomey; Jane F. Kaczmarek; Stacy Mader; Malte Marquarding; Azeem Ahmed; Shaun W. Amy; Matthew Bailes; Ron Beresford; N. D. R. Bhat; Douglas C.-J. Bock; Michael Bourne; Mark Bowen; Michael Brothers; Andrew D. Cameron; Ettore Carretti; Nick Carter; Santy Castillo; Raji Chekkala;
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band ( ${\sim}60\%$ ), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific
-
High-cadence optical transient searches using drift scan imaging I: Proof of concept with a pre-prototype system Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-04-08 Steven Tingay
An imaging technique with sensitivity to short duration optical transients is described. The technique is based on the use of wide-field cameras operating in a drift scanning mode, whereby persistent objects produce trails on the sensor and short duration transients occupy localised groups of pixels. A benefit of the technique is that sensitivity to short duration signals is not accompanied by massive
-
The core-cusp problem revisited: ULDM vs. CDM Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-25 Emily Kendall; Richard Easther
The core-cusp problem is a widely cited motivation for the exploration of dark matter models beyond standard cold dark matter. One such alternative is ultralight dark matter (ULDM), extremely light scalar particles exhibiting wavelike properties on kiloparsec scales. Astrophysically realistic ULDM halos are expected to consist of inner solitonic cores embedded in NFW-like outer halos. The presence
-
PKS 2250–351: A giant radio galaxy in Abell 3936 Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-25 N. Seymour; M. Huynh; S. S. Shabala; J. Rogers; L. J. M. Davies; R. J. Turner; A. O’Brien; C. H. Ishwara-Chandra; J. E. Thorne; T. J. Galvin; T. Jarrett; H. Andernach; C. Anderson; J. Bunton; K. Chow; J. D. Collier; S. Driver; M. D. Filipovic; G. Gürkan; A. M. Hopkins; A. D. Kapińska; D. A. Leahy; J. Marvil; P. Manojlovic; R. P. Norris; C. Phillips; A. Robotham; L. Rudnick; V. Singh; S. V. White
We present a detailed analysis of the radio galaxy PKS $2250{-}351$ , a giant of 1.2 Mpc projected size, its host galaxy, and its environment. We use radio data from the Murchison Widefield Array, the upgraded Giant Metre-wavelength Radio Telescope, the Australian Square Kilometre Array Pathfinder, and the Australia Telescope Compact Array to model the jet power and age. Optical and IR data come from
-
The development of non-coherent passive radar techniques for space situational awareness with the Murchison Widefield Array Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-23 Steve Prabu; Paul J. Hancock; Xiang Zhang; Steven J. Tingay
The number of active and non active satellites in Earth orbit has dramatically increased in recent decades, requiring the development of novel surveillance techniques to monitor and track them. In this paper, we build upon previous non-coherent passive radar space surveillance demonstrations undertaken using the Murchison Widefield Array (MWA). We develop the concept of the Dynamic Signal to Noise
-
A survey of extended matter around chromospherically active binary systems Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-23 Osman Karakuş; Fehmi Ekmekçi
We present an analysis of colour excess (CE) observations for 13 chromospherically active binary systems, together with 27 inactive reference stars of similar spectral types and luminosity classes of the components of these 13 binaries. We used the observations which were made by Johnson-Cousins ${BVR}_{c}\mathrm{I}_{c}$ , 2MASS, and WISE photometric systems. Our new photometric ${BVR}_{c}\mathrm{I}_{c}$
-
Science with the Murchison Widefield Array: Phase I results and Phase II opportunities – Corrigendum Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-23 A. P. Beardsley; M. Johnston-Hollitt; C. M. Trott; J. C. Pober; J. Morgan; D. Oberoi; D. L. Kaplan; C. R. Lynch; G. E. Anderson; P. I. McCauley; S. Croft; C. W. James; O. I. Wong; C. D. Tremblay; R. P. Norris; I. H. Cairns; C. J. Lonsdale; P. J. Hancock; B. M. Gaensler; N. D. R. Bhat; W. Li; N. Hurley-Walker; J. R. Callingham; N. Seymour; S. Yoshiura; R. C. Joseph; K. Takahashi; M. Sokolowski; J. C
The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore
-
Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: Technical specifications and performance forecasts Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-03-06 Square Kilometre Array Cosmology Science Working Group:; David J. Bacon; Richard A. Battye; Philip Bull; Stefano Camera; Pedro G. Ferreira; Ian Harrison; David Parkinson; Alkistis Pourtsidou; Mário G. Santos; Laura Wolz; Filipe Abdalla; Yashar Akrami; David Alonso; Sambatra Andrianomena; Mario Ballardini; José Luis Bernal; Daniele Bertacca; Carlos A. P. Bengaly; Anna Bonaldi; Camille Bonvin; Michael
We present a detailed overview of the cosmological surveys that we aim to carry out with Phase 1 of the Square Kilometre Array (SKA1) and the science that they will enable. We highlight three main surveys: a medium-deep continuum weak lensing and low-redshift spectroscopic HI galaxy survey over 5 000 deg2; a wide and deep continuum galaxy and HI intensity mapping (IM) survey over 20 000 deg2 from $z
-
Evolution of mobile phases in cometary interiors Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-02-24 Christopher M. Fellows; Trevor C. Brown; Andrew Cooper; Marco Parigi
Beginning with loose aggregations of dust particles coated with heterogeneous ices under vacuum at Kuiper Belt temperatures, moving to Jupiter/Saturn distances and eventually to low-perihelion orbit, we consider the likely development of the gaseous phase within a cometary nucleus over the course of its lifetime. From the perspective of physical chemistry, we consider limits on the spatial and temporal
-
Fundamental physics with the Square Kilometre Array Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-01-27 A. Weltman; P. Bull; S. Camera; K. Kelley; H. Padmanabhan; J. Pritchard; A. Raccanelli; S. Riemer-Sørensen; L. Shao; S. Andrianomena; E. Athanassoula; D. Bacon; R. Barkana; G. Bertone; C. Bœhm; C. Bonvin; A. Bosma; M. Brüggen; C. Burigana; F. Calore; J. A. R. Cembranos; C. Clarkson; R. M. T. Connors; Á. de la Cruz-Dombriz; P. K. S. Dunsby; J. Fonseca; N. Fornengo; D. Gaggero; I. Harrison; J. Larena;
The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope. The SKA will address many important topics in astronomy, ranging from planet formation to distant galaxies. However, in this work, we consider the perspective of the SKA as
-
Investigation of the coronal heating through phase relation of solar activity indexes Publ. Astron. Soc. Aust. (IF 5.067) Pub Date : 2020-01-24 K. J. Li; J. C. Xu; Z. Q. Yin; J. L. Xie; W. Feng
The coronal heating problem is a long-standing perplexing issue. In this study, 13 solar activity indexes are used to investigate their phase relation with the sunspot number (SSN). Only three of them are found to statistically significantly lag the SSN (large-scale magnetic activity) by about one solar rotation period; the three indexes are total solar irradiance (TSI), the modified coronal index