Browsing Research Articles (Physics) by Title
Now showing items 16-35 of 510
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An∼600 pc View of the Strongly Lensed, Massive Main-sequence Galaxy J0901: A Baryon-dominated, Thick Turbulent Rotating Disk with a Clumpy Cold Gas Ring at z=2.259
(Institute of Physics, 2023)We present a high-resolution kinematic study of the massive main-sequence star-forming galaxy (SFG) SDSS J090122.37+181432.3 (J0901) at z = 2.259, using ∼0 36 Atacama Large Millimeter/submillimeter Array CO(3–2) and ∼0 ... -
An∼600 pc view of the strongly lensed, massive main-sequence galaxy j0901: A baryon-dominated, thick turbulent rotating disk with a clumpy cold gas ring at z=2.259
(American Astronomical Society, 2023)We present a high-resolution kinematic study of the massive main-sequence star-forming galaxy (SFG) SDSS J090122.37+181432.3 (J0901) at z = 2.259, using ∼0 36 Atacama Large Millimeter/submillimeter Array CO(3–2) and ∼0 ... -
Artist: Fast radiative transfer for large-scale simulations of the epoch of reionization
(Oxford University Press, 2019)We introduce the ‘Asymmetric Radiative Transfer In Shells Technique’ (ARTIST), a new method for photon propagation on large scales that explicitly conserves photons, propagates photons at the speed of light, approximately ... -
An askap survey for hi absorption towards dust-obscured quasars
(Oxford Academic, 2019)Obscuration of quasars by accreted gas and dust, or dusty intervening galaxies, can cause active galactic nuclei (AGN) to be missed in optically selected surveys. Radio observations can overcome this dust bias. In particular, ... -
Assessing accessibility and availability of portable water supply in selected communities of Lepelle-Nkumpi local municipality, Limpopo province of South Africa
(elsevier, 2022)In this study, we assessed the accessibility and availability of portable water supply in selected communities of the Lepelle-Nkumpi Local Municipality. A systematic random sampling method was used to select 49 households ... -
Assessing non-linear models for galaxy clustering – II. Model validation and forecasts for Stage IV surveys
(Oxford University Press, 2020)Accurate modelling of non-linear scales in galaxy clustering will be crucial for data analysis of Stage IV galaxy surveys. A selection of competing non-linear models must be made based on validation studies. We provide a ... -
Asteroseismology of Massive Stars with the TESS Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr
(The Astrophysical journal letter, 2019)We report an analysis of the first known β Cep pulsator observed by the Transiting Exoplanet Survey Satellite (TESS) mission, the runaway star PHL 346 = HN Aqr. The star, previously known as a singly periodic pulsator, has ... -
Astronomy for Development – A story from South Africa
(UWC, 2021)In this article we describe the recent history of astronomy in South Africa from the perspective of development. We describe how all major astronomy initiatives have carried a component of development with them, be it ... -
Augmenting machine learning photometric redshifts with Gaussian mixture models
(Oxford University Press, 2020-09-11)Wide-area imaging surveys are one of the key ways of advancing our understanding of cosmology, galaxy formation physics, and the large-scale structure of the Universe in the coming years. These surveys typically require ... -
Automated detection of antenna malfunctions in large-n interferometers: A case study with the hydrogen epoch of reionization array
(2022)We present a framework for identifying and flagging malfunctioning antennas in large radio interferometers. We outline two distinct categories of metrics designed to detect outliers along known failure modes of large ... -
The baryonic Tully–Fisher relation in the SIMBA simulation
(Oxford University Press, 2020)We investigate the Baryonic Tully–Fisher relation (BTFR) in the (100h−1Mpc)3SIMBA hydrodynamical galaxy formation simulation together with a higher resolution (25h−1Mpc)3SIMBA run, for over 10 000 disc-dominated, H I-rich ... -
Beta decay along the n=z line and its relevance in rp-process and x-ray bursts
(EDP Sciences, 2023)Nucleosynthesis in Type I X-ray bursts (XRB) proceeds eventually through the rp-process near the proton drip-line. Several N=Z nuclei act as waiting points in the reaction network chain. Astrophysical calculations of XRB ... -
Big data research infrastructure collaboration toward the SKA (BRICSKA)
(Academia Brasileira de Ciencias, 2021)Astronomy is entering an era of mega-data that will render conventional research methods as well as data and visual analytics tools ineffective. The Square Kilometre Array (SKA) drives one of the most significant big ... -
Bio-synthesised black α-Cr2O3 nanoparticles; experimental analysis and density function theory calculations
(Elsevier, 2021)A selective single phase black α-Cr2O3 nanoparticles was bio-synthesised via simple straight-forward green synthesis approach. The process involves extraction of phytochemicals contained in peels of sweet potatoes. Extraction ... -
Black hole - galaxy correlations without self-regulation
(American Astronomical Society, 2013)Recent models of black hole growth in a cosmological context have forwarded a paradigm in which the growth is self-regulated by feedback from the black hole itself. Here we use cosmological zoom simulations of galaxy formation ... -
Boundless baryons: how diffuse gas contributes to anisotropic tSZ signal around simulated three hundred clusters
(Oxford University Press, 2023)Upcoming advances in galaxy surveys and cosmic microwave background data will enable measurements of the anisotropic distribution of diffuse gas in filaments and superclusters at redshift z = 1 and beyond, observed through ... -
Breaking baryon-cosmology degeneracy with the electron density power spectrum
(IOP Publishing, 2022)Uncertain feedback processes in galaxies affect the distribution of matter, currently limiting the power of weak lensing surveys. If we can identify cosmological statistics that are robust against these uncertainties, or ... -
The bright extragalactic ALMA redshift survey (BEARS) – II. Millimetre photometry of gravitational lens candidates
(Oxford University Press, 2023)We present 101- and 151-GHz ALMA continuum images for 85 fields selected from Herschel observations that have 500-μm flux densities >80 mJy and 250–500-μm colours consistent with z > 2, most of which are expected to be ... -
Bringing together knowledge and capabilities: a case study of engineering graduates
(Springer Verlag, 2016)In contemporary times there is a renewed focus on the purposes of university education in science or engineering, especially inemerging economycontexts like South Africa where the massification of higher education is in ... -
Broad-band radio polarimetry of disc galaxies and AGN with KAT-7
(Oxford University Press, 2020-10-24)We report broad-band (1.2–1.9 GHz) radio continuum observations at arcminute resolutions of two nearby disc galaxies, NGC 1808 and NGC 1097, and four active galactic nuclei (AGN)-powered radio sources: PKS B1934−638, PKS ...