Physics and Astronomy: Recent submissions
Now showing items 121-140 of 520
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Cold-pressing and vacuum arc melting of γ-tial based alloys
(ScienceDirect, 2019)eta (β) solidifying γ-TiAl intermetallic alloys of nominal composition Ti-48Al, Ti-48Al-2Nb, Ti-48Al-2Nb-0.7Cr alloys have been cold pressed and vacuum arc melted. The Al loss was due to compaction method used prior to the ... -
Comparing galaxy clustering in horizon-agn simulated light-cone mocks and video observations
(Oxford academic, 2019)Hydrodynamical cosmological simulations have recently made great advances in reproducing galaxy mass assembly over cosmic time – as often quantified from the comparison of their predicted stellar mass functions to observed ... -
Mergers, starbursts, and quenching in the SIMBA simulation
(Oxford Academic, 2019)We use the SIMBAcosmological galaxy formation simulation to investigate the relationship between major mergers (4:1), starbursts, and galaxy quenching. Mergers are identified via sudden jumps in stellar mass M∗ well above ... -
Comparing galaxy clustering in horizon-agn simulated light-cone mocks and video observations
(Oxford University Press, 2019-04-12)Hydrodynamical cosmological simulations have recently made great advances in reproducing galaxy mass assembly over cosmic time – as often quantified from the comparison of their predicted stellar mass functions to observed ... -
Astronomy for Development – A story from South Africa
(UWC, 2021)In this article we describe the recent history of astronomy in South Africa from the perspective of development. We describe how all major astronomy initiatives have carried a component of development with them, be it ... -
Inclusive education and research through African Network of Women in Astronomy and STEM for GIRLS in Ethiopia initiatives
(UWC, 2021)The African Network of Women in Astronomy and STEM for GIRLS in Ethiopia initiatives have been established with aim to strengthen the participation of girls and women in astronomy and science in Africa and Ethiopia. We ... -
Effect of the annealing atmosphere on the layer interdiffusion in Pd/Ti/Pd multilayer stacks deposited on pure Ti and Ti-alloy substrates
(University of the Western Cape, 2019)Pd(50 nm)/Ti(25 nm)/Pd(50 nm) multilayer stack has been deposited on Ti and Ti6Al4V substrates; we have studied the intermixing of layers upon annealing at the hydrogenation temperature of 550 °C, under vacuum, H/Ar gas ... -
Energy-momentum tensor and helicity for gauge fields coupled to a pseudoscalar inflaton
(University of the Western Cape, 2019)We study the energy-momentum tensor and helicity of gauge fields coupled through $g \phi F \tilde{F}/4$ to a pseudo-scalar field $\phi$ driving inflation. Under the assumption of a constant time derivative of the background ... -
Rotational structures in 196Hg
(University of the Western Cape, 2019)High spin states in 196 Hg were populated in the 198 Pt (α,6n) reaction at 65 MeV and γ −γ coincidence measurements were performed using the AFRODITE array at iThemba LABS. The level scheme was extended and new rotational ... -
On the primordial origin of the smoothing excess in the Planck temperature power spectrum in light of LSS data
(IOP Publishing, 2022)The Planck DR3 measurements of the temperature and polarization anisotropies power spectra of the cosmic microwave background (CMB) show an excess of smoothing of the acoustic peaks with respect to ΛCDM, often quantified ... -
Cosmological constraints on post-Newtonian parameters in effectively massless scalar-tensor theories of gravity
(2019)We study the cosmological constraints on the variation of Newton’s constant and on post-Newtonian parameters for simple models of the scalar-tensor theory of gravity beyond the extended Jordan-BransDicke theory. We restrict ... -
Imprints of temperature fluctuations on the z ∼ 5 Lyman-α forest: a view from radiation-hydrodynamic simulations of reionization
(Oxford academic, 2019)Reionization leads to large spatial fluctuations in the intergalactic temperature that can persist well after its completion. We study the imprints of such fluctuations on the z ∼ 5 Ly α forest flux power spectrum using ... -
IQ-Collaboratory 1.1: The Star-forming Sequence of Simulated Central Galaxies
(The astrophysical journal, 2019)A tightly correlated star formation rate (SFR)–stellar mass relation of star-forming galaxies, or star-forming sequence (SFS), is a key feature in galaxy property-space that is predicted by modern galaxy formation models. ... -
Asteroseismology of Massive Stars with the TESS Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr
(The Astrophysical journal letter, 2019)We report an analysis of the first known β Cep pulsator observed by the Transiting Exoplanet Survey Satellite (TESS) mission, the runaway star PHL 346 = HN Aqr. The star, previously known as a singly periodic pulsator, has ... -
Multi-instrument observations of large-scale atmospheric gravity waves/traveling ionospheric disturbances associated with enhanced auroral activity over Svalbard
(Elsevier, 2019-09-03)This study reports on observations of large-scale atmospheric gravity waves/traveling ionospheric disturbances (AGWs/TIDs) using Global Positioning System (GPS) total electron content (TEC) and Fabry–Perot Interferometer’s ... -
Preface Metamorphism and Orogenic belts—response from micro- to macro-scale
(Springerlink, 2019)The geological toolbox for the analysis of orogenic processes has seen substantial additions over the recent decades. Major advances have been made in the ability to simulate geological conditions and processes by computer ... -
Surveys with small optical telescopes
(Oxford academic, 2019)odern astrophysics owes its existence to small-telescope surveys dating back to the 18th century, for example Flamsteed (1725). In the 19th century, Argelander’s survey based on visual observations with small telescopes and ... -
Semi-analytic forecasts for jwst – ii. Physical properties and scaling relations for galaxies at z = 4–10
(Oxford academic, 2019)The long anticipated James Webb Space Telescope (JWST) will be able to directly detect large samples of galaxies at very high redshift. Using the well-established, computationally efficient Santa Cruz semi-analytic model, ... -
Probing primordial features with the primary CMB
(Elsevier, 2019)We propose to study the imprint of features in the primordial power spectrum with the primary CMB after the subtraction of the reconstructed ISW signal from the observed CMB temperature angular power spectrum. We consider ... -
Hierarchiral 4-tetranitro copper(II)phthalocyanine based metal organic framework hybrid composite with improved electrocatalytic efficiency towards hydrogen evolution reaction
(Elsivier, 2019)A novel hybrid-hybrid nanocomposite based on 4-tetranitro copper(II)phthalocyanine (TNCuPc) grown on metal organic frameworks (MOF) as a noble metal-free catalyst for hydrogen evolution reaction (HER) was developed by a ...