Physics and Astronomy: Recent submissions
Now showing items 481-500 of 533
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SN Ia host galaxy properties from Sloan Digital Sky Survey-II spectroscopy
(Oxford University Press, 2013)We study the stellar populations of Type Ia supernova (SN Ia) host galaxies using Sloan Digital Sky Survey (SDSS)-II spectroscopy. The main focus is on the relationships of SN Ia properties with stellar velocity dispersion ... -
Stacked reverberation mapping
(Oxford University Press, 2013)Over the past 20 years reverberation mapping has proved one of the most successful techniques for studying the local (<1 pc) environment of supermassive black holes that drive active galactic nuclei. Key successes of ... -
Testing gravity using large-scale redshift-space distortions
(Oxford University Press, 2013)We use luminous red galaxies from the Sloan Digital Sky Survey (SDSS) II to test the cosmological structure growth in two alternatives to the standard cold dark matter ( CDM)+general relativity (GR) cosmological model. ... -
Shell-model studies of the astrophysical rp reaction 29P(p, y)30 S
(American Physical Society, 2013)We present results for levels in 30S (the mirror nucleus of 30Si) that are used for the 29P(p,γ ) rp reaction rate calculations. The resonance energies used in the reaction rate calculations are based on recent ... -
Testing homegeneity with Galaxy Star formation histories
(IOP Publishing, 2013)Observationally confirming spatial homogeneity on sufficiently large cosmological scales is of importance to test one of the underpinning assumptions of cosmology, and is also imperative for correctly interpreting dark ... -
The complex physics of dusty star-forming galaxies at high redshifts as revealed by Herschel and Spitzer
(IOP Publishing, 2013)We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared ... -
The COS-Halos survey: Rationale, design and a census of circumgalactic neutral hydrogen
(IOP Publishing, 2013)We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15–0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble ... -
The cosmic evolution of the IMF under the Jeans conjecture with implications for massive galaxies
(Oxford University Press, 2013)We examine the cosmic evolution of a stellar initial mass function (IMF) in galaxies that varies with the Jeans mass in the interstellar medium, paying particular attention to the K-band stellar mass-to-light ratio (M/LK) ... -
The Edinburgh-Cape Blue Object Survey - III. Zone 2; galactic latitudes -30? > b > -40?
(Oxford University Press, 2013)The Edinburgh–Cape Blue Object Survey seeks to identify point sources with an ultraviolet excess. Results for zone 2 of the survey are presented here, covering that part of the South Galactic Cap between 30◦ and 40◦ from ... -
The faint source population at 15.7 GHz - I. The radio properties
(Oxford University Press, 2013)We have studied a sample of 296 faint (>0.5 mJy) radio sources selected from an area of the Tenth Cambridge (10C) survey at 15.7 GHz in the Lockman Hole. By matching this catalogue to several lower frequency surveys (e.g. ... -
The high-ion content and kinematics of low-redshift lyman limit systems
(The American Astronomical Society, 2013)We study the high-ion content and kinematics of the circumgalactic medium around low-redshift galaxies using a sample of 23 Lyman limit systems (LLSs) at 0.08 < z < 0.93 observed with the Cosmic Origins Spectrograph on ... -
The host haloes of O I absorbers in the reionization epoch
(Oxford University Press, 2013)We use a radiation hydrodynamic simulation of the hydrogen reionization epoch to study OI absorbers at z ∼ 6. The intergalactic medium (IGM) is reionized before it is enriched; hence, OI absorption originates within dark ... -
Mind the gap: Science and engineering education at the secondary–tertiary interface
(Academy of Science of South Africa, 2013)In the South African higher education sector, there is increasing concern about the poor retention and throughput rates of undergraduate students. There is also concern that the participation rates in higher education, ... -
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 ... -
The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again
(EDP Sciences, 2013)CONTEXT: R Coronae Borealis stars( RCBs) are rare, hydrogen-deficient, carbon rich super giant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found ... -
Using a disciplinary discourse lens to explore how representations afford meaning making in a typical wave physics course
(Springer Verlag, 2013)We carried out a case study in a wave physics course at a Swedish university in order to investigate the relations between the representations used in the lessons and the experience of meaning making in interview–discussions. ... -
The preferentially magnified active nucleus in IRAS F10214+4724 - III. VLBI observations of the radio core
(Oxford University Press, 2013)We report 1.7GHz very long baseline interferometry (VLBI) observations of IRAS F10214+4724, a lensed z = 2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with ... -
The Q/U imaging experiment instrument
(The American Astronomical Society, 2013)The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the cosmic microwave background, targeting the imprint of inflationary gravitational waves at large angular scales(∼1◦). Between 2008 October and ... -
The roles of star formation and AGN activity of IRS sources in the HerMES fields
(Oxford University Press, 2013)In this work we explore the impact of the presence of an active galactic nucleus (AGN) on the mid- and far-infrared (IR) properties of galaxies as well as the effects of simultaneous AGN and starburst activity in these ... -
The slow flow model of dust eflux in local star-forming galaxies
(Oxford University Press, 2013)We develop a dust efflux model of radiation pressure acting on dust grains which successfully reproduces the relation between stellar mass, dust opacity and star forma- tion rate observed in local star-forming galaxies. ...