Browsing Research Articles (Physics) by Title
Now showing items 311-330 of 510
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Multi-scale perturbation theory II: Solutions and leading-order bispectrum in the ΛcDM universe
(IOP Publishing, 2021)Two-parameter perturbation theory (2PPT) is a framework designed to include the relativistic gravitational effects of small-scale nonlinear structures on the large-scale properties of the Universe. In this paper we use ... -
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 ... -
Multi-wavelength properties of radio- and machine-learning-identified counterparts to submillimeter sources in s2cosmos
(The Astrophysical Journal, 2019)We identify multi-wavelength counterparts to 1147 submillimeter sources from the S2COSMOS SCUBA-2 survey of the COSMOS field by employing a recently developed radio+machine-learning method trained on a large sample of ... -
Multifilter observations of the complex periodic variations in eight pre-main sequence stars
(Royal Astronomical Society, 2023)Follow up time series photometry through various combinations of the BVRCIC filter set is presented for eight young stars. The complex periodic variability of seven of the stars was first discovered in TESS photometry, ... -
Multifilter time-series observations of eleven blue short-period atlas variable stars
(IOP Publishing, 2023)Eleven periodic variable stars were observed photometrically through two to four filters from the set UBVRCIC. Phase-folded data for each star cover full cycles of variation. Spectral energy distributions, based on ... -
Multimodality and new materialism in science learning: Exploring insights from an introductory physics lesson
(Unisa Press, 2021)Science disciplines are inherently multimodal, involving written and spoken language, bodily gestures, symbols, diagrams, sketches, simulation and mathematical formalism. Studies have shown that ... -
Multipole expansion for 21 cm intensity mapping power spectrum: forecasted cosmological parameters estimation for the ska observatory
(Oxford University Press, 2023)The measurement of the large-scale distribution of neutral hydrogen in the late Universe, obtained with radio telescopes through the hydrogen 21 cm line emission, has the potential to become a key cosmological probe in the ... -
Multipole expansion for H I intensity mapping experiments: simulations and modelling
(Oxford University Press, 2020)We present a framework and an open-source PYTHON toolkit to analyse the two-point statistics of 3D fluctuations in the context of H I intensity maps using the multipole expansion formalism. We include simulations of the ... -
Multipoles of the relativistic galaxy bispectrum
(IOP Publishing Ltd, 2020)Above the equality scale the galaxy bispectrum will be a key probe for measuring primordial non-Gaussianity which can help differentiate between different inflationary models and other theories of the early universe. On ... -
The neutral hydrogen content of galaxies in cosmological hydrodynamic simulations
(Oxford University Press, 2013)We examine the global HI properties of galaxies in quarter billion particle cosmological simulations using GADGET-2, focusing on howgalactic outflows impactHI content.We consider four outflow models, including a new one ... -
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 ... -
New constraints on primordial features from the galaxy two-point correlation function
(Physical Review, 2023)Features in the primordial power spectrum represent the imprinted signal in the density perturbations of the physics and evolution of the early Universe. A measurement of such signals will represents the need to go beyond ... -
New formulas for the (−2) moment of the photoabsorption cross section, σ−2
(American Physical Society, 2015)Two new formulas for the (−2) moment of the photoabsorption cross section, σ−2, have been determined, respectively, from the 1988 photoneutron evaluation of Dietrich and Berman and a mass-dependent symmetry energy ... -
A New Model For Including Galactic Winds in Simulations of Galaxy Formation II: Implementation of PhEW in Cosmological Simulations
(Monthly Notices of the Royal Astronomical Society, 2021)Although galactic winds play a critical role in regulating galaxy formation, hydrodynamic cosmological simulations do not resolve the scales that govern the interaction between winds and the ambient circumgalactic medium ... -
A new model for including galactic winds in simulations of galaxy formation – I. Introducing the Physically Evolved Winds (PhEW) model
(Oxford University Press, 2020-07-08)The propagation and evolution of cold galactic winds in galactic haloes is crucial to galaxy formation models. However, modelling of this process in hydrodynamic simulations of galaxy formation is oversimplified owing to ... -
A new sample of southern radio galaxies: Host-galaxy masses and star-formation rates
(Oxford University Press, 2019)In this study we define a new sample of distant powerful radio galaxies in order to study their host galaxy properties and provide targets for future observations of H I absorption with new radio telescopes and to understand ... -
A new technique to isolate kinematically anomalous gas in HI data cubes
(Oxford University Press, 2023)H I line observations of nearby galaxies often reveal the presence of extraplanar and/or kinematically anomalous gas that deviates from the general circular flow. In this work, we study the dependence of kinematically ... -
News from the EREBOS project
(De Gruyter Open, 2017)Planets and brown dwarfs in close orbits will interact with their host stars, as soon as the stars evolve to become red giants. However, the outcome of those interactions is still unclear. Recently, several brown dwarfs ... -
nIFTy galaxy cluster simulations – V. Investigation of the cluster infall region
(Oxford University Press, 2016)We examine the properties of the galaxies and dark matter haloes residing in the cluster infall region surrounding the simulated cold dark matter galaxy cluster studied by Elahi et al. at z = 0. The 1.1 × 1015 h−1M ... -
NIFTY galaxy cluster simulations – VI. The dynamical imprint of substructure on gaseous cluster outskirts
(Oxford University Press, 2019)Galaxy cluster outskirts mark the transition region from the mildly non-linear cosmic web to the highly non-linear, virialized, cluster interior. It is in this transition region that the intracluster medium (ICM) begins ...