A5080665198- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- CCD and CMOS Imaging Sensors
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Relativity and Gravitational Theory
- Ecosystem dynamics and resilience
- Advanced Vision and Imaging
- Impact of Light on Environment and Health
- Advanced Fluorescence Microscopy Techniques
- Remote Sensing in Agriculture
- Chaos control and synchronization
- Statistical and numerical algorithms
- Astrophysics and Star Formation Studies
- Biomimetic flight and propulsion mechanisms
The University of Queensland
2020-2024
Australian National University
2019-2020
ARC Centre of Excellence for All-sky Astrophysics
2016
University of Cape Town
2014-2016
The University of Western Australia
2016
International Centre for Radio Astronomy Research
2016
University of Central Thailand
2014
We present constraints on cosmological parameters from the Pantheon+ analysis of 1701 light curves 1550 distinct Type Ia supernovae (SNe Ia) ranging in redshift $z=0.001$ to 2.26. This work features an increased sample size, span, and improved treatment systematic uncertainties comparison original Pantheon results a factor two improvement constraining power. For Flat$\Lambda$CDM model, we find $\Omega_M=0.334\pm0.018$ SNe alone. Flat$w_0$CDM measure $w_0=-0.90\pm0.14$ alone, H$_0=73.5\pm1.1$...
In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift sample. This includes 248682 galaxy spectra, and, in combination with earlier surveys, results 330542 redshifts across five sky regions covering ~250deg^2. The density, is the highest over such a sustained area, has exceptionally high completeness (95 per cent to r_KIDS=19.65mag), and well suited for study of mergers, groups, low (z<0.25) population. DR4 32 value-added tables or...
With Cosmicflows-4, distances are compiled for 55,877 galaxies gathered into 38,065 groups. Eight methodologies employed, with the largest numbers coming from correlations between photometric and kinematic properties of spiral (TF) elliptical (FP). Supernovae that arise degenerate progenitors (type Ia Sne) an important overlapping component. Smaller contributions come distance estimates surface brightness fluctuations luminosities expansion rates core collapse supernovae (SNII). Cepheid...
Abstract The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect DESI spectra approximately 2500 bright galaxies, 3500 luminous red (LRGs), 10,000 emission-line (ELGs) obtain robust redshift identifications. We then utilize inspected information characterize performance operation. Based on visual inspection (VI) catalogs, our...
Abstract We propose an effective model to describe the bias induced on cosmological observables by Laniakea, gravitational supercluster hosting Milky Way, which was defined using peculiar velocity data from Cosmicflows-4 (CF4). The structure is well described ellipsoidal shape exhibiting triaxial expansion, reasonably approximated a constant expansion rate along principal axes. Our best fits suggest that ellipsoid, after subtracting background contracts two smaller axes and expands longest...
Abstract The Dark Energy Spectroscopic Instrument (DESI) collaboration measured a tight relation between the Hubble constant ( H 0 ) and distance to Coma cluster using fundamental plane (FP) of deepest, most homogeneous sample early-type galaxies. To determine , we measure by several independent routes, each with its own geometric reference. We precise from 13 Type Ia supernovae (SNe Ia) in mean standardized brightness <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Measurement of peculiar velocities by combining redshifts and distance indicators is a powerful way to measure the growth rate cosmic structure test theories gravity at low redshift. Here we constrain comparing observed Fundamental Plane for 15894 galaxies from 6dF Galaxy Survey (6dFGS) Sloan Digital Sky (SDSS) with predicted densities 2M$++$ redshift survey. We velocity scale parameter $\beta \equiv {\Omega_m^\gamma}/b = 0.372^{+0.034}_{-0.050}$ $0.314^{+0.031}_{-0.047}$ 6dFGS SDSS...
Abstract Separating the components of redshift due to expansion and peculiar motion in nearby universe ( z < 0.1) is critical for using Type Ia Supernovae (SNe Ia) measure Hubble constant H 0 ) equation-of-state parameter dark energy w ). Here, we study two dominant “motions” contributing velocities: large-scale, coherent-flow (CF) motions small-scale gravitationally associated galaxies deemed be a galaxy group. We use set 584 low- SNe from Pantheon+ sample, evaluate efficacy corrections...
Abstract We examine the redshifts of a comprehensive set published Type Ia supernovae, and provide combined, improved catalogue with updated redshifts. improve on original catalogues by using most up-to-date heliocentric redshift data available; ensuring all have uncertainty estimates; exact formulae to convert into Cosmic Microwave Background (CMB) frame; utilising an peculiar velocity model that calculates local motions in redshift-space more realistically accounts for external bulk flow...
ABSTRACT We present a new catalogue of distances and peculiar velocities (PVs) 34 059 early-type galaxies derived from fundamental plane (FP) measurements using data the Sloan Digital Sky Survey (SDSS). This $7016\, \mathrm{deg}^{2}$ homogeneous sample comprises largest set PVs produced to date extends reach PV surveys up redshift limit z = 0.1. Our SDSS-based FP distance have mean uncertainty 23 per cent. Alongside data, we produce an ensemble 2048 mock galaxy catalogues that reproduce...
We present WALLABY pilot data release 1, the first public of HI survey from Wide-field ASKAP L-band Legacy All-sky Blind Survey (WALLABY) on Australian Square Kilometre Array Pathfinder. Phase 1 targeted three $60~{\rm deg}^2$ regions sky in direction Hydra and Norma galaxy clusters NGC 4636 group, covering redshift range z < 0.08. The source catalogue, images spectra nearly 600 extragalactic detections kinematic models for 109 spatially resolved galaxies are available. As containing nearby...
We describe the target selection and characteristics of DESI Peculiar Velocity Survey, largest survey peculiar velocities (PVs) using both fundamental plane (FP) Tully-Fisher (TF) relationship planned to date. detail how we identify suitable early-type galaxies (ETGs) for FP late-type (LTGs) TF relation photometric data provided by Legacy Imaging Survey DR9. Subsequently, provide targets 373 533 ETGs 118 637 LTGs within 5-year footprint. validate these selections existing morphological...
ABSTRACT Peculiar velocities are an important probe of the mass distribution in Universe and growth rate structure, directly measuring effects gravity on largest scales providing a test for theories gravity. Comparing peculiar predicted from density field mapped by galaxy redshift survey with measured using distance estimator such as Tully–Fisher relation yields factor large-scale structure. We present method forward modelling sample magnitudes velocity widths that simultaneously determines...
Abstract At the low-redshift end ( z < 0.05) of Hubble diagram with Type Ia Supernovae (SNe Ia), contribution to residual scatter from peculiar velocities (PVs) is similar size that due limitations standardization SN light curves. A way improve redshift measurement host galaxy utilize average group, effectively averaging over small-scale/intracluster PVs. One limiting factor fraction galaxies in groups, previously found be 30% using (relatively incomplete) magnitude-limited catalogs....
Abstract The cosmological principle asserting the large-scale uniformity of Universe is a testable assumption standard model. We explore constraints on anisotropic expansion provided by measuring directional variation in Hubble constant, H 0 , derived from differential zeropoint measurements Tully-Fisher distance estimator. fit various models for using dataset all-sky Cosmicflows-4 catalog. best-fit dipole has an amplitude 0.063 ± 0.016 mag direction ( ℓ b ) = (142 30°,52 10°). If this were...
ABSTRACT We propose an improved comprehensive method for determining the Hubble constant ($H_0$) using Tully–Fisher relation. By fitting a peculiar velocity model in conjunction with relation, all available data can be used to derive self-consistent parameters. In comparison previous approaches, our offers several improvements: it readily generalized different forms of relation and its intrinsic scatter; uses predict distances more accurately; account selection effects; entire set fit...
We present a deep near-infrared (NIR; J, H, and Ks bands) photometric catalogue of sources from the Parkes H i Zone Avoidance (HIZOA) survey, which forms basis for an investigation matter distribution in Avoidance. Observations were conducted between 2006 2013 using Infrared Survey Facility (IRSF), 1.4-m telescope situated at South African Astronomical Observatory site Sutherland. The images cover all 1108 HIZOA detections yield 915 galaxies. An additional 105 bright 2MASS galaxies southern...
The Dark Energy Spectroscopic Instrument (DESI) collaboration measured a tight relation between the Hubble constant ($H_0$) and distance to Coma cluster using fundamental plane (FP) of deepest, most homogeneous sample early-type galaxies. To determine $H_0$, we measure by several independent routes each with its own geometric reference. We precise from 12 Type Ia Supernovae (SNe Ia) in mean standardized brightness $m_B^0=15.712\pm0.041$ mag. Calibrating absolute magnitude SNe HST ladder...
Dust extinction and stellar confusion by the Milky Way reduce efficiency of detecting galaxies at low Galactic latitudes, creating so-called Zone Avoidance. This stands as a stumbling block in charting distribution cosmic flow fields, therewith our understanding local dynamics Universe (CMB dipole, convergence radius bulk flows). For instance, ZoA are generally excluded from whole-sky Tully-Fisher Surveys ($|b| \leq 5^\circ$) even if catalogued. We show here that fine-tuning near-infrared TF...
High-accuracy HI profiles and linewidths are presented for inclined ($(b/a)^o < 0.5$) spiral galaxies in the southern Zone of Avoidance (ZOA). These define a sample use determinations peculiar velocities using near-infrared Tully-Fisher (TF) relation. The is based on 394 HI-selected from Parkes survey (HIZOA). Follow-up narrow-band observations were obtained 2010 2015 290 galaxies, while further 104 sufficiently high signal-to-noise spectra available original HIZOA data. All reduced...
An H i mass function (HIMF) was derived for 751 galaxies selected from the deep Parkes survey across Zone of Avoidance (HIZOA). HIZOA contains both Great Attractor Wall and Local Void, two most extreme environments in local Universe, making sample eminently suitable to explore overall HIMF as well its dependence on environment. To avoid any selection bias because different distances these large-scale structures, we first used 2D stepwise maximum-likelihood method definition an average HIMF....
Peculiar velocities are an important probe of the mass distribution in Universe and growth rate structure, directly measuring effects gravity on largest scales providing a test for theories gravity. Comparing peculiar predicted from density field mapped by galaxy redshift survey with measured using distance estimator such as Tully-Fisher relation yields factor large-scale structure. We present method forward-modelling sample magnitudes velocity widths that simultaneously determines...
Measurements of cosmic flows enable us to test whether cosmological models can accurately describe the evolution density field in nearby Universe. In this paper, we measure low-order kinematic moments flow field, namely bulk and shear moments, using Cosmicflows-4 Tully-Fisher catalogue (CF4TF). To make accurate inferences with CF4TF sample, it is important realistic mock catalogues. We present sampling algorithm CF4TF. These realize survey geometry luminosity selection function, enabling...
ABSTRACT The WALLABY pilot survey has been conducted using the Australian SKA Pathfinder (ASKAP). integrated 21-cm H i line spectra are formed in a very different manner compared to usual single-dish Tully–Fisher measurements. It is thus extremely important ensure that slight differences (e.g. biases due missing flux) quantified and understood order maximise use of large amount data becoming available soon. This article based on four fields for which scientifically interesting by themselves....
In this paper, we present our calibrations of the TF relation in mid-infrared W1 ($3.4\mu$m) and W2 ($4.6\mu$m) bands, using large samples 848 galaxies 857 bands respectively. calibration performed a correction for cluster population incompleteness bias, morphological type correction. The was new, iterative bivariate fitting procedure. For these used total absolute magnitudes, HI linewidths $W_{F50}$ derived from global profiles as measure rotational velocities. We then two additional on...