Physics and Astronomy: Recent submissions
Now showing items 341-360 of 533
-
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 ... -
Detection of Cross-Correlation between Gravitational Lensing and γ Rays
(American Physical Society, 2020)In recent years, many γ -ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of ... -
Cosmological baryon transfer in the SIMBA simulations
(Oxford University Press, 2019)We present a framework for characterizing the large-scale movement of baryons relative to dark matter in cosmological simulations, requiring only the initial conditions and final state of the simulation. This is performed ... -
Non-Gaussianity constraints using future radio continuum surveys and the multitracer technique
(Oxford University Press, 2019)Tighter constraints on measurements of primordial non-Gaussianity (PNG) will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum – the standard method of measuring the local ... -
The frequency of very young galaxies in the local Universe – II. The view from SDSS spectra
(Oxford University Press, 2019)Only a handful of galaxies in the local Universe appear to be very young. We estimate the fraction of very young galaxies (VYGs), defined as those with more than half their stellar masses formed within the last Gyr. We fit ... -
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 ... -
Testing galaxy formation simulations with damped Lyman-α abundance and metallicity evolution
(Oxford University Press, 2020)We examine the properties of damped Lyman-α absorbers (DLAs) emerging from a single set of cosmological initial conditions in two state-of-the-art cosmological hydrodynamic simulations: SIMBA and TECHNICOLOR DAWN. The ... -
A null test to probe the scale dependence of the growth of structure as a test of general relativity
(Oxford University Press, 2019)The main science driver for the coming generation of cosmological surveys is understanding dark energy that relies on testing general relativity on the largest scales. Once we move beyond the simplest explanation for dark ... -
The impact of the connectivity of the cosmic web on the physical properties of galaxies at its nodes
(Oxford University Press, 2019)We investigate the impact of the number of filaments connected to the nodes of the cosmic web on the physical properties of their galaxies using the Sloan Digital Sky Survey. We compare these measurements to the cosmological ... -
Developing a unified pipeline for large-scale structure data analysis with angular power spectra – II. A case study for magnification bias and radio continuum surveys
(Oxford University Press, 2019)Following on our purpose of developing a unified pipeline for large-scale structure data analysis with angular power spectra, we now include the weak lensing effect of magnification bias on galaxy clustering in a publicly ... -
Cosmic evolution of star-forming galaxies to z 1.8 in the faint low-frequency radio source population
(Oxford University Press, 2019)We study the properties of star-forming galaxies selected at 610 MHz with the GMRT in a survey covering ∼1.86 deg2 down to a noise of ∼7.1 μJy beam−1. These were identified by combining multiple classification diagnostics: ... -
Classifying galaxies according to their H I content
(Oxford University Press, 2020)We use machine learning to classify galaxies according to their H I content, based on both their optical photometry and environmental properties. The data used for our analyses are the outputs in the range z = 0–1 from ... -
The impact of wind scalings on stellar growth and the baryon cycle in cosmological simulations
(Oxford University Press, 2020)Many phenomenologically successful cosmological simulations employ kinetic winds to model galactic outflows. Yet systematic studies of how variations in kinetic wind scalings might alter observable galaxy properties are ... -
Significance levels of common frequencies extracted from multiple data sets
(Oxford University Press, 2020)Large monitoring campaigns, particularly those using multiple filters, have produced replicated time series of observations for literally millions of stars. The search for periodicities in such replicated data can be ... -
Constraining the reionization history using deep learning from 21-cm tomography with the Square Kilometre Array
(Oxford University Press, 2020)Upcoming 21-cm surveys with the SKA1-LOW telescope will enable imaging of the neutral hydrogen distribution on cosmological scales in the early Universe. These surveys are expected to generate huge imaging data sets that ... -
The rest-frame UV luminosity function at z 4: A significant contribution of AGNs to the bright end of the galaxy population
(Oxford University Press, 2020)We measure the rest-frame ultraviolet (UV) luminosity function (LF) at z ∼ 4 self-consistently over a wide range in absolute magnitude (−27 ≲ MUV ≲ −20). The LF is measured with 46 904 sources selected using a photometric ... -
A spectroscopic analysis of the eclipsing nova-like EC 21178−5417 – discovery of spiral density structures
(Oxford University Press, 2020)We present phase-resolved optical spectroscopy of the eclipsing nova-like cataclysmic variable EC 21178−5417 obtained between 2002 and 2013. The average spectrum of EC 21178−5417 shows broad double-peaked emission lines ... -
Evidence for cosmic acceleration with next-generation surveys: A model-independent approach
(Oxford University Press, 2020)We quantify the evidence for cosmic acceleration using simulations of H(z) measurements from SKA- and Euclid-like surveys. We perform a non-parametric reconstruction of the Hubble parameters and its derivative to obtain ... -
Improved upper limits on the 21 cm signal power spectrum of neutral hydrogen at z ≈ 9.1 from LOFAR
(Oxford University Press, 2020)A new upper limit on the 21 cm signal power spectrum at a redshift of z ≈ 9.1 is presented, based on 141 h of data obtained with the Low-Frequency Array (LOFAR). The analysis includes significant improvements in spectrally ... -
A lack of evolution in the very bright end of the galaxy luminosity function from z 8 to 10
(Oxford University Press, 2020)ABSTRACT We utilize deep near-infrared survey data from the UltraVISTA fourth data release (DR4) and the VIDEO survey, in combination with overlapping optical and Spitzer data, to search for bright star-forming galaxies ...