Browsing Research Articles (Physics) by Title
Now showing items 174-193 of 497
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Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospects
(EDP Sciences, 2017)CONTEXT: The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are ... -
The Galactic halo pulsar population
(Oxford University Press, 2018)Most population studies of pulsars have hitherto focused on the disc of the Galaxy, the Galactic centre, globular clusters, and nearby galaxies. It is expected that pulsars, by virtue of their natal kicks, are also to ... -
Galaxy And Mass Assembly (GAMA): Defining passive galaxy samples and searching for the UV upturn
(Oxford University Press, 2019)We use data from the GAMA and GALEX surveys to demonstrate that the UV upturn, an unexpected excess of ultraviolet flux from a hot stellar component, seen in the spectra of many early-type galaxies, arises from processes ... -
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 ... -
Galaxy and Mass Assembly (GAMA): Mid-infrared properties as tracers of galaxy environment
(EDP Sciences, 2023)We investigate how different mid-infrared (mid-IR) properties of galaxies are correlated with the environment in which the galaxies are located. For this purpose, we first study the dependence of galaxy clustering on the ... -
Galaxy And Mass Assembly (GAMA): Resolving the role of environment in galaxy evolution
(Oxford University Press, 2013)We present observations of 18 galaxies from the Galaxy And Mass Assembly (GAMA) survey made with the SPIRAL optical integral field unit (IFU) on the Anglo- Australian Telescope. The galaxies are selected to ... -
Galaxy And Mass Assembly (GAMA): spectroscopic analysis
(Oxford University Press, 2013)The Galaxy And Mass Assembly (GAMA) survey is a multiwavelength photometric and spectroscopic survey, using the AAOmega spectrograph on the Anglo-Australian Telescope to obtain spectra for up to _ 300 000 galaxies over ... -
Galaxy and mass assembly: evolution of the Hα luminosity function and star formation rate density up to z < 0.35
(OUP, 2013)Measurements of the low-z Hα luminosity function, Φ, have a large dispersion in the local number density of sources (∼0.5–1 Mpc−3 dex−1), and correspondingly in the star formation rate density (SFRD). The possible causes ... -
Galaxy cold gas contents in modern cosmological hydrodynamic simulations
(Oxford University Press, 2020-07-03)We present a comparison of galaxy atomic and molecular gas properties in three recent cosmological hydrodynamic simulations, namely SIMBA, EAGLE, and IllustrisTNG, versus observations from z ∼ 0 to 2. These simulations ... -
Galaxy correlations and the BAO in a void universe: structure formation as a test of the Copernican Principle
(IOP Science, 2013)A suggested solution to the dark energy problem is the void model, where accelerated expansion is replaced by Hubble-scale inhomogeneity. In these models, density perturbations grow on a radially inhomogeneous background. ... -
Galaxy–galaxy lensing in the voice deep survey
(EDP Sciences, 2022)The multi-band photometry of the VOICE imaging data, overlapping with 4.9 deg2 of the Chandra Deep Field South (CDFS) area, enables both shape measurement and photometric redshift estimation to be the two essential ... -
Gama/H-Atlas: The dust opacity-stellar mass surface density relation for spiral galaxies
(IOP Science, 2013)We report the discovery of a well-defined correlation between B-band face-on central optical depth due to dust and the stellar mass surface density of nearby spiral galaxies. This relation was derived from a sample of ... -
Gaussian process regression for foreground removal in hi intensity mapping experiments
(Oxford University Press, 2022)We apply for the first time Gaussian Process Regression (GPR) as a foreground removal technique in the context of single-dish, low redshift H I intensity mapping, and present an open-source PYTHON toolkit for doing so. We ... -
Global analysis of the COVID-19 pandemic using simple epidemiological models
(Elsevier, 2021)Several analytical models have been developed in this work to describe the evolution of fatalities arising from coronavirus COVID-19 worldwide. The Death or ‘D’ model is a simplified version of the well-known SIR ... -
The global magneto-ionic medium survey: polarimetry of the southern Sky from 300 to 480 MHz
(Ithaca: Cornell University Library, 2021)The Galactic interstellar medium hosts a significant magnetic field, which can be probed through the synchrotron emission produced from its interaction with relativistic electrons. Linearly polarized synchrotron emission ... -
Global simulations of multi-frequency hf signal absorption for direct observation of middle atmosphere temperature and composition
(Wiley, 2023)This paper presents the first numerical study on a new concept for the direct measurement of D-region absorption in the high-frequency (HF) band. Numerical simulations based on the Appleton-Hartree and Garrett equations ... -
Grain structure orientational change in Ti6Al4V alloys induced by sea water quenching and novel stress relief annealing process
(Materials Chemistry and Physics, 2023)We report on the microstructures and properties of Ti6Al4V alloys, which were achieved upon quenching in sea water medium with potential high cooling rate. The Ti6Al4V alloys were quenched at 1000 and 1100 ◦C, respectively. ... -
Gravitational signal propagation in the double pulsar studied with the MeerKAT telescope
(Hans Publishers, 2022)The double pulsar PSR J0737−3039A/B has offered a wealth of gravitational experiments in the strong-field regime, all of which general relativity has passed with flying colours. In particular, among current gravity ... -
Gravitational wave mergers as tracers of large scale structures
(IOP Publishing Ltd, 2021)Clustering measurements of Gravitational Wave (GW) mergers in Luminosity Distance Space can be used in the future as a powerful tool for Cosmology. We consider tomographic measurements of the Angular Power Spectrum of ... -
Ground-based Ku-band microwave observations of ozone in the polar middle atmosphere
(Copernicus Publications, 2021)Ground-based observations of 11.072 GHz atmospheric ozone (O3) emission have been made using the NyÅlesund Ozone in the Mesosphere Instrument (NAOMI) at the UK Arctic Research Station (latitude 78 550000 N, longitude 11 ...
