Browsing Research Articles (Physics) by Title
Now showing items 421-440 of 497
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Sample variance, source clustering and their influence on the counts of faint radio sources
(Oxford University Press, 2013)The shape of the curves defined by the counts of radio sources per unit area as a function of their flux density was one of the earliest cosmological probes. Radio source counts continue to be an area of astrophysical ... -
Scalar-tensor theories of gravity, neutrino physics, and the H0 tension
(IOP Publishing, 2020)We use Planck 2018 data to constrain the simplest models of scalar-tensor theories characterized by a coupling to the Ricci scalar of the type F(σ)R with F(σ) = N2 pl + ξσ2 . We update our results with previous Planck ... -
SCUBA-2 observations of candidate starbursting protoclusters selected by Planck and Herschel-SPIRE
(Royal Astronomical Society, 2019)We present SCUBA-2 850 μm observations of 13 candidate starbursting protoclusters selected using Planck and Herschel data. The cumulative number counts of the 850 μm sources in 9 of 13 of these candidate protoclusters show ... -
SCUBA-2 overdensities associated with candidate protoclusters selected from Planck data
(Oxford University Press, 2020)We measure the 850-μm source densities of 46 candidate protoclusters selected from the Planck high-z catalogue (PHz) and the Planck Catalogue of Compact Sources (PCCS) that were followed up with Herschel-SPIRE and SCUBA-2. ... -
A search for variable subdwarf B stars in TESS Full Frame Images III. An update on variable targets in both ecliptic hemispheres – contamination analysis and new sdB pulsators
(Oxford University Press, 2023)We present an update on the variable star survey performed on the TESS 30 min Full Frame Image (FFI) data reported by our first two papers in this series. This update includes a contamination analysis in order to identify ... -
Self-catalytic growth of tin oxide nanowires by chemical vapor deposition process
(Hindawi, 2013)We report on the synthesis of tin oxide (SnO2) nanowires by a chemical vapor deposition (CVD) process. Commercially bought SnO nanopowders were vaporized at 1050∘C for 30 minutes with argon gas continuously passing through ... -
Semi-analytic forecasts for jwst – ii. Physical properties and scaling relations for galaxies at z = 4–10
(Oxford academic, 2019)The long anticipated James Webb Space Telescope (JWST) will be able to directly detect large samples of galaxies at very high redshift. Using the well-established, computationally efficient Santa Cruz semi-analytic model, ... -
Semi-analytic forecasts for JWST – IV. Implications for cosmic reionization and LyC escape fraction
(Oxford University Press, 2020-06-20)Galaxies forming in low-mass haloes are thought to be primarily responsible for reionizing the Universe during the first billion years after the big bang. Yet, these haloes are extremely inefficient at forming stars in ... -
Semi-analytic forecasts for Roman – the beginning of a new era of deep-wide galaxy surveys
(Oxford University Press, 2023)The Nancy Grace Roman Space Telescope, NASA’s next flagship observatory, will redefine deep-field galaxy survey with a field of view two orders of magnitude larger than Hubble and an angular resolution of matching quality. ... -
Shell-model studies of the astrophysical rp reaction 29P(p, y)30 S
(American Physical Society, 2013)We present results for levels in 30S (the mirror nucleus of 30Si) that are used for the 29P(p,γ ) rp reaction rate calculations. The resonance energies used in the reaction rate calculations are based on recent ... -
Short-period pulsating hot-subdwarf stars observed by TESS: I. Southern ecliptic hemisphere
(EDP Sciences, 2023)We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere ... -
Significance levels of common frequencies extracted from multiple data sets
(Oxford University Press, 2020)Large monitoring campaigns, particularly those using multiple filters, have produced replicated time series of observations for literally millions of stars. The search for periodicities in such replicated data can be ... -
SIMBA: the average properties of the circumgalactic medium of 2 ≤ z ≤ 3 quasars are determined primarily by stellar feedback
(Oxford University Press, 2020-10-05)We use the SIMBA cosmological hydrodynamic simulation suite to explore the impact of feedback on the circumgalactic medium (CGM) and intergalactic medium (IGM) around 2 ≤ z ≤ 3 quasars. We identify quasars in SIMBA as the ... -
Simulating a full-sky high resolution Galactic synchrotron spectral index map using neural networks
(Monthly Notices of the Royal Astronomical Society, 2023)We present a model for the full-sky diffuse Galactic synchrotron spectral index with an appropriate level of spatial structure for a resolution of 56 arcmin (to match the resolution of the Haslam 408 MHz data). Observational ... -
Simulations of primary beam effects on the cosmic bispectrum phase observed with the Hydrogen Epoch of Reionization Array
(Royal Astronomical Society, 2022)The 21 cm transition from neutral hydrogen promises to be the best observational probe of the epoch of reionization (EoR). The main difficulty in measuring the 21 cm signal is the presence of bright foregrounds that require ... -
SKAO HI intensity mapping: blind foreground subtraction challenge
(University of the Western Cape, 2022)Neutral Hydrogen Intensity Mapping (H I IM) surveys will be a powerful new probe of cosmology. However, strong astrophysical foregrounds contaminate the signal and their coupling with instrumental systematics further ... -
The slow flow model of dust eflux in local star-forming galaxies
(Oxford University Press, 2013)We develop a dust efflux model of radiation pressure acting on dust grains which successfully reproduces the relation between stellar mass, dust opacity and star forma- tion rate observed in local star-forming galaxies. ... -
SN Ia host galaxy properties from Sloan Digital Sky Survey-II spectroscopy
(Oxford University Press, 2013)We study the stellar populations of Type Ia supernova (SN Ia) host galaxies using Sloan Digital Sky Survey (SDSS)-II spectroscopy. The main focus is on the relationships of SN Ia properties with stellar velocity dispersion ... -
Solar irradiance spectra from the compact SOLSTICE (CSOL) experiment: instrument design, FUV calibration, measurements, and comparison of the 2018 rocket flight
(Solar Physics, 2023)The Compact SOLSTICE, a compact far and mid ultraviolet (FUV and MUV) spectrograph, flew on a sounding rocket on 18 June 2018 to validate and potentially calibrate the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) ... -
Solar irradiance spectra from the compact SOLSTICE (CSOL) experiment: Instrument design, FUV calibration, measurements, and comparison of the 2018 rocket flight
(Springer, 2023)The Compact SOLSTICE, a compact far and mid ultraviolet (FUV and MUV) spectrograph, flew on a sounding rocket on 18 June 2018 to validate and potentially calibrate the SOLar STellar Irradiance Comparison Experiment ...
