Research Articles (Physics): Recent submissions
Now showing items 281-300 of 520
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A quantitative in-depth analysis of the prototype sdB+BD system SDSS J08205+0008 revisited in the Gaia era
(Oxford University Press, 2021)Subdwarf B stars are core-helium-burning stars located on the extreme horizontal branch (EHB). Extensive mass loss on the red giant branch is necessary to form them. It has been proposed that substellar companions could ... -
H i intensity mapping with MeerKAT: 1/f noise analysis
(Oxford University Press, 2021)The nature of the time correlated noise component (the 1/f noise) of single dish radio telescopes is critical to the detectability of the H i signal in intensity mapping experiments. In this paper, we present the 1/f noise ... -
The origin and evolution of Lyα blobs in cosmological galaxy formation simulations
(IOP Publishing Ltd, 2021)High-redshift Lyα blobs (LABs) are an enigmatic class of objects that have been the subject of numerous observational and theoretical investigations. It is of particular interest to determine the dominant power sources for ... -
Ion beam induced modification and nanostructures formation in thin SiC/Pd films on c-Si substrate
(Elsevier, 2021)Ion beam induced modification of thin metallic films is an emerging approach to grow metallic nanoparticles controllably. Modification of thin solid films is helpful in fabricating arrays of nanoscale particles for electronic ... -
The lofar two-meter sky survey: Deep fields data release 1: IV. Photometric redshifts and stellar masses
(EDP Sciences, 2021)The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey split across multiple tiers over the northern sky. The first LoTSS Deep Fields data release consists of deep ... -
The LOFAR Two-metre sky survey deep fields: The star-formation rate-radio luminosity relation at low frequencies
(EDP Sciences, 2021)In this paper, we investigate the relationship between 150 MHz luminosity and the star-formation rate - the SFR-L150 MHz relation - using 150 MHz measurements for a near-infrared selected sample of 118 517 z < 1 galaxies. ... -
The lofar two-meter sky survey: Deep fields data release 1: II. The elais-n1 lofar deep field
(EDP Sciences, 2021)The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and, additionally, aims to observe the LoTSS deep fields to a noise level of ? 10 μJy beam-1 over several tens of square degrees in areas that have ... -
The contribution of discrete sources to the sky temperature at 144 MHz
(EDP Sciences, 2021)In recent years, the level of the extragalactic radio background has become a point of considerable interest, with some lines of argument pointing to an entirely new cosmological synchrotron background. The contribution ... -
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 ... -
Effect of the environment on star formation activity and stellar mass for star-forming galaxies in the COSMOS field
(2020-11)We investigate the relationship between the environment and the galaxy main sequence (the relationship between stellar mass and star formation rate), as well as the relationship between the environment and radio luminosity ... -
The evolution of the low-frequency radio AGN population to z 1.5 in the ELAIS N1 field
(Advance Access publication, 2020-11-13)We study the cosmic evolution of radio sources out to z 1.5 using a GMRT 610 MHz survey covering ∼1.86 deg2 of the ELAIS N1 field with a minimum/median rms noise 7.1/19.5 μJy beam−1 and an angular resolution of 6 arcsec. ... -
Extremely deep 150 MHz source counts from the LoTSS deep fields
(EDP Sciences, 2021)With the advent of new generation low-frequency telescopes, such as the LOw Frequency ARray (LOFAR), and improved calibration techniques, we have now started to unveil the subgigahertz radio sky with unprecedented depth ... -
A comparison of the microstructures, thermal and mechanical properties of pressed and sintered TieCu, TieNi and TieCueNi alloys intended for dental applications
(Journal of Alloys and Compounds, 2020)The effect of Ni and Cu on the a/b phase transformation temperature, possible retention of the b-phase, and mechanical properties of Ti, Tie13Cu, Tie4.5Ni and Tie13Cue4.5Ni (compositions in wt. %) alloys were investigated. ... -
A new auroral phenomenon, the anti-black aurora
(Nature, 2021)Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. Black auroras show a significant reduction in ... -
The evolving role of science in society
(José Frantz, 2020)The world is experiencing a traumatic change brought about by the Covid-19 pandemic. It is traumatic because it is sudden and affects everyone around the globe at once. Nothing like this has ever happened so rapidly before, ... -
Probing beyond-Horndeski gravity on ultra-large scales
(IOP Publishing Ltd, 2020)The beyond-Horndeski gravity has recently been reformulated in the dark energy paradigm — which has been dubbed, Unified Dark Energy (UDE). The evolution equations for the given UDE appear to correspond to a non-conservative ... -
Multi-scale perturbation theory. Part I. Methodology and leading-order bispectrum corrections in the matter-dominated era
(IOP Publishing Ltd, 2020)Two-parameter perturbation theory is a scheme tailor-made to consistently include nonlinear density contrasts on small scales (< 100 Mpc), whilst retaining a traditional approach to cosmological perturbations in the ... -
Detecting the relativistic galaxy bispectrum
(IOP Publishing Ltd, 2020)The Fourier galaxy bispectrum is complex, with the imaginary part arising from leading-order relativistic corrections, due to Doppler, gravitational redshift and related lineof-sight effects in redshift space. The detection ... -
Galaxy and Mass Assembly (GAMA): Demonstrating the power of WISE in the study of Galaxy Groups to z < 0.1
(IOP Publishing, 2020)Combining high-fidelity group characterisation from the Galaxy and Mass Assembly (GAMA) survey and source-tailored z < 0.1 photometry from the WISE survey, we present a comprehensive study of the properties of ungrouped ... -
The VLA-COSMOS 3 GHz Large Project: Evolution of specific star formation rates out to z∼5
(IOP Publishing, 2020)We provide a coherent, uniform measurement of the evolution of the logarithmic star formation rate (SFR) – stellar mass (M∗) relation, called the main sequence of star-forming galaxies (MS), for starforming and all galaxies ...