Browsing Research Articles (Physics) by Title
Now showing items 387-406 of 547
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Patterns of primary beam non-redundancy in close-packed 21 cm array observations
(Oxford University Press, 2021)Radio interferometer arrays such as HERA consist of many close-packed dishes arranged in a regular pattern, giving rise to a large number of ‘redundant’ baselines with the same length and orientation. Since identical ... -
The performance of photometric reverberation mapping at high redshift and the reliability of damped random walk models
(Oxford University Press, 2020-03)Accurate methods for reverberation mapping using photometry are highly sought after since they are inherently less resource intensive than spectroscopic techniques. However, the effectiveness of photometric reverberation ... -
Periodic low-frequency electric field structures in a magnetized non-thermal auroral plasma
(Elsevier, 2019)The theoretical explanation of electric field structures associated with density depletion in the Earth’s upper ionosphere is presented. Using the quasi-neutrality hypothesis, the effect of excess energetic electron ... -
Periodic variations in the O-C diagrams of five pulsation frequencies of the DB white dwarf EC 20058-5234
(American Physical Society, 2013)Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058−5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent ... -
Photometric properties of reionization-epoch galaxies in the SIMBA simulations
(Oxford University Press, 2020)We study the photometric properties and sizes of the reionization-epoch galaxies in high-resolution SIMBA cosmological hydrodynamical simulations with box sizes of [25,50]h−1Mpc. Assuming various attenuation laws, we ... -
Photon strength functions from (p,γ) reactions
(Journal of Physics: Conference Series, 2023)The 50Cr(p,γ)51Mn proton capture reaction has been used to study the photon strength functions by utilizing primary gamma ray transitions from the entry states to discrete states of known spins and parities. The reaction ... -
The physical nature of circumgalactic medium absorbers in SIMBA
(Oxford University Press, 2023)We study the nature of the low-redshift circumgalactic medium (CGM) in the SIMBA cosmological simulations as traced by ultraviolet absorption lines around galaxies in bins of stellar mass (M > 1010M) for star-forming, ... -
Physical properties of spectroscopically confirmed galaxies at Z ≥ 6. I. Basic characteristics of the rest-frame UV continuum and lyman-alpha emission
(American Astronomical Society, 2013)We present deep HST near-IR and Spitzer mid-IR observations of a large sample of spectroscopically- confirmed galaxies at z ≥ 6. The sample consists of 51 Ly-alpha emitters (LAEs) at z ≃ 5.7, 6.5, and 7.0, and 16 Lyman-break ... -
Physical properties of spectroscopically-confirmed galaxies at z >= 6. II. Morphology of the rest-frame UV continuum and Lyman-alpha emission
(IOP Science, 2013)We present a detailed structural and morphological study of a large sample of spectroscopicallyconfirmed galaxies at z ≥ 6, using deep HST near-IR broad-band images and Subaru optical narrowband images. The galaxy sample ... -
The physical properties of star-forming galaxies with strong [oiii]lines at z=3.25
(IOP Publishing, 2022)We present an analysis of physical properties of 34 [O III] emission-line galaxies (ELGs) at z = 3.254 ± 0.029 in the Extended Chandra Deep Field South (ECDFS). These ELGs are selected from deep narrow H2S(1) and broad Ks ... -
Pks 1830-211: oh and hi at z = 0.89 and the first meerkat uhf spectrum
(EDP Sciences, 2021)The Large Survey Project (LSP) "MeerKAT Absorption Line Survey"(MALS) is a blind H I 21 cm and OH 18 cm absorption line survey in the L- and UHF-bands, primarily designed to better determine the occurrence of atomic and ... -
Planck 2018 results IX. Constraints on primordial non-Gaussianity
(EDP Sciences, 2020)We analyse the Planck full-mission cosmic microwave background (CMB) temperature and E-mode polarization maps to obtain constraints on primordial non-Gaussianity (NG). We compare estimates obtained from separable ... -
Planck 2018 results VII. Isotropy and statistics of the CMB
(EDP Sciences, 2020)Analysis of the Planck 2018 data set indicates that the statistical properties of the cosmic microwave background (CMB) temperature anisotropies are in excellent agreement with previous studies using the 2013 and 2015 data ... -
Planck 2018 results VIII. Gravitational lensing
(EDP Sciences, 2020)We present measurements of the cosmic microwave background (CMB) lensing potential using the final Planck 2018 temperature and polarization data. Using polarization maps filtered to account for the noise anisotropy, we ... -
Planck 2018 results. XI. Polarized dust foregrounds
(EDP Sciences, 2020)The study of polarized dust emission has become entwined with the analysis of the cosmic microwave background (CMB) polarization in the quest for the curl-like B-mode polarization from primordial gravitational waves and ... -
Planck intermediate results. LVII. Joint Planck LFI and HFI data processing
(ESO, 2020)We present the NPIPE processing pipeline, which produces calibrated frequency maps in temperature and polarization from data from the Planck Low Frequency Instrument (LFI) and High Frequency Instrument (HFI) using ... -
Plausible explanation for the third COVID-19 wave in India and its implications
(KeAi Communications, 2023)Recently some of us used a random-walk Monte Carlo simulation approach to study the spread of COVID-19. The calculations were reasonably successful in describing secondary and tertiary waves of infection, in countries such ... -
Possible periodic activity in the repeating FRB 121102
(Oxford University Press, 2020)The discovery that at least some Fast Radio Bursts (FRBs) repeat has ruled out cataclysmic events as the progenitors of these particular bursts. FRB 121102 is the most well-studied repeating FRB but despite extensive ... -
Powder characteristics blending and microstructural analysis of a hot-pack rolled vacuum arc-melted gamma-tial-based sheet
(The Southern African Institute for Industrial Engineering, 2022)In the quest for cost-effective fabrication processes capable of producing sound γ-TiAl products, the microstructure and mechanical properties of a modified second-generation hot-rolled γ-TiAl-based alloy with nominal ... -
Practical galaxy morphology tools from deep supervised representation learning
(Oxford University Press, 2022)Astronomers have typically set out to solve supervised machine learning problems by creating their own representations from scratch. We show that deep learning models trained to answer every Galaxy Zoo DECaLS question ...
