Browsing Research Articles (Physics) by Title
Now showing items 159-178 of 510
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Feature guided training and rotational standardization for the morphological classification of radio galaxies
(Oxford University Press, 2023)State-of-the-art radio observatories produce large amounts of data which can be used to study the properties of radio galaxies. However, with this rapid increase in data volume, it has become unrealistic to manually process ... -
Figure rotation of dark haloes in cold dark matter simulations
(Oxford University Press, 2007)We investigate the figure rotation of dark matter haloes identified in cold dark matter (CDM) simulations.We find that when strict criteria are used to select suitable haloes for study, five of the 222 haloes identified ... -
Finding universal relations in Subhalo properties with artificial intelligence
(The Astrophysical Journal, 2022)We use a generic formalism designed to search for relations in high-dimensional spaces to determine if the total mass of a subhalo can be predicted from other internal properties such as velocity dispersion, radius, or ... -
Fine structure of the isovector giant dipole resonance in 142-150Nd and 152Sm
(American Physical Society, 2020)Background: Inelastic proton scattering at energies of a few hundred MeV and very-forward scattering angles including 0 ∘ has been established as a tool for the study of electric-dipole strength distributions in nuclei. ... -
First ground-based observations of sprites over southern Africa
(Academy of Science of South Africa, 2018)Sprites are the optical signatures of electrical discharges in the mesosphere triggered by large lightning strikes associated with thunderstorms. Since their discovery in the late 1980s, sprites have been observed ... -
First HETDEX Spectroscopic Determinations of Lyα and UV Luminosity Functions at z=2–3: Bridging a Gap between Faint AGNs and Bright Galaxies
(The Astrophysical Journal, 2021)We present Lyα and ultraviolet (UV)-continuum luminosity functions (LFs) of galaxies and active galactic nuclei (AGNs) at z = 2.0–3.5 determined by the untargeted optical spectroscopic survey of the Hobby–Eberly Telescope ... -
First observation of the coexistence of multiple chiral doublet bands and pseudospin doublet bands in the A ≈ 80 mass region
(Elsevier, 2022)Two nearly degenerate positive-parity bands with the π g2 9/2 ⊗ ν g−1 9/2 configuration and three nearly degenerate negative-parity bands with the π g9/2(p3/2, f5/2) ⊗ ν g−1 9/2 configuration have been identified in ... -
First Observations of E-Region Near Range Echoes Partially Modulated by F-Region Traveling Ionospheric Disturbances Observed by the Same SuperDARN HF Radar
(Journal of Geophysical Research: Space Physics, 2022)We present the first observations from SuperDARN HF radar data of E-region Near Range Echoes (NREs) whose amplitudes are partially modulated by Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) propagating in the ... -
First Observations of E‐Region Near Range Echoes Partially Modulated by F‐Region Traveling Ionospheric Disturbances Observed by the Same SuperDARN HF Radar
(American Geophysical Union, 2022)We present the first observations from SuperDARN HF radar data of E‐region Near Range Echoes (NREs) whose amplitudes are partially modulated by Medium‐Scale Traveling Ionospheric Disturbances (MSTIDs) propagating in the ... -
First-principles investigation of W[sbnd]V and W[sbnd]Mo alloys as potential plasma facing materials (PFMs) for nuclear application
(Elsevier, 2021)Density-functional theory (DFT) based first-principles calculations were used to investigate the crystal structure, binding energy, phase stability and elastic properties of body-centered cubic (BCC) W-based binary solid ... -
A flexible method for estimating luminosity functions via Kernel Density Estimation
(IOP Publishing, 2020)We propose a flexible method for estimating luminosity functions (LFs) based on kernel density estimation (KDE), the most popular nonparametric density estimation approach developed in modern statistics, to overcome ... -
The fore ground transfer function for H I intensity mapping signal reconstruction: MeerKLASS and precision cosmology applications
(Oxford University Press, 2023)Blind cleaning methods are currently the preferred strategy for handling foreground contamination in single-dish H I intensity mapping surv e ys. Despite the increasing sophistication of blind techniques, some signal loss ... -
Foreground contamination in Lyα intensity mapping during the epoch of reoinization
(IOP Science, 2014)The intensity mapping of Lyα emission during the epoch of reionization will be contaminated by foreground emission lines from lower redshifts. We calculate the mean intensity and the power spectrum of Lyα emission at z ... -
Foreground modelling via Gaussian process regression: an application to HERA data
(Oxford University Press, 2020)The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on the different spectral properties of the ... -
Forming the Moon from terrestrial silicate-rich material
(Elsevier, 2013)Recent high-precision measurements of the isotopic composition of lunar rocks demonstrate that the bulk silicate Earth and the Moon show an unexpectedly high degree of similarity. This is inconsistent with one of the ... -
A framework for assessing the performance of pulsar search pipelines
(Oxford Unviersity Press, 2016)In this paper, we present a framework for assessing the effect of non-stationary Gaussian noise and radio frequency interference (RFI) on the signal to noise ratio, the number of false positives detected per true positive ... -
The frequency of very young galaxies in the local Universe – II. The view from SDSS spectra
(Oxford University Press, 2019)Only a handful of galaxies in the local Universe appear to be very young. We estimate the fraction of very young galaxies (VYGs), defined as those with more than half their stellar masses formed within the last Gyr. We fit ... -
A full treatment of peculiar velocities on the reionization light cone
(Oxford Academic, 2019)Accurate simulations of the 21-cm signal from the Epoch of Reionization require the generation of maps at specific frequencies given the values of astrophysical and cosmological parameters. The peculiar velocities of the ... -
Full-sky bispectrum in redshift space for 21cm intensity maps
(IOP Publishing, 2020)We compute the tree-level bispectrum of 21cm intensity mapping after reionisation. We work in directly observable angular and redshift space, focusing on equal-redshift correlations and thin redshift bins, for which the ... -
Fundamental physics with the square kilometre array
(Cambridge University Press, 2020)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 ...