Research Articles (Physics): Recent submissions
Now showing items 381-400 of 520
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The optically selected 1.4-GHz quasar luminosity function below 1 mJy
(Oxford University Press, 2020)We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test ... -
The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design
(The Astronomical Society of the Pacific, 2020)The Very Large Array Sky Survey (VLASS) is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2 5), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear ... -
An ALMA survey of the SCUBA-2 CLS UDS field: Physical properties of 707 sub-millimetre galaxies
(Oxford University Press, 2020)We analyse the physical properties of a large, homogeneously selected sample of ALMA-located sub-millimetre galaxies (SMGs). This survey, AS2UDS, identified 707 SMGs across the ∼1 deg2 field, including ∼17 per cent, which ... -
Properties of CVSO 30 from TESS measurements: probably a binary T Tauri star with complex light curves and no obvious planets
(Oxford University Press, 2020)‘Transiting Exoplanet Survey Satellite’ (TESS) photometry of CVSO 30 spanned 21.8 d, with a single large gap of 1.1 d. This allows alias-free determination of the two periodicities in the data. It is confirmed that both ... -
Photometric properties of reionization-epoch galaxies in the SIMBA simulations
(Oxford University Press, 2020)We study the photometric properties and sizes of the reionization-epoch galaxies in high-resolution SIMBA cosmological hydrodynamical simulations with box sizes of [25,50]h−1Mpc. Assuming various attenuation laws, we ... -
SCUBA-2 overdensities associated with candidate protoclusters selected from Planck data
(Oxford University Press, 2020)We measure the 850-μm source densities of 46 candidate protoclusters selected from the Planck high-z catalogue (PHz) and the Planck Catalogue of Compact Sources (PCCS) that were followed up with Herschel-SPIRE and SCUBA-2. ... -
The impact of quenching on galaxy profiles in the SIMBA simulation
(Oxford University Press, 2020)We study specific star formation rate (sSFR) and gas profiles of star-forming (SF) and green valley (GV) galaxies in the SIMBA cosmological hydrodynamic simulation. SF galaxy half-light radii (Rhalf) at z = 0 and their ... -
Constraining the astrophysics and cosmology from 21 cm tomography using deep learning with the SKA
(Oxford University Press, 2020)Future Square Kilometre Array (SKA) surveys are expected to generate huge data sets of 21 cm maps on cosmological scales from the Epoch of Reionization. We assess the viability of exploiting machine learning techniques, ... -
The e-MERGE Survey (e-MERLIN Galaxy Evolution Survey): Overview and survey description
(Oxford University Press, 2020)We present an overview and description of the e-MERGE Survey (e-MERLIN Galaxy Evolution Survey) Data Release 1 (DR1), a large program of high-resolution 1.5-GHz radio observations of the GOODS-N field comprising ∼140 h of ... -
The VANDELS survey: a strong correlation between Ly α equivalent width and stellar metallicity at 3 ≤ z ≤ 5
(Oxford University Press, 2020)We present the results of a new study investigating the relationship between observed Ly α equivalent width (Wλ(Ly α)) and the metallicity of the ionizing stellar population ( Z⋆) for a sample of 768 star-forming galaxies ... -
The optical polarization of the blazar PKS 2155–304 during an optical flare in 2010
(Oxford University Press, 2020)An analysis is presented of the optical polarimetric and multicolour photometric (BVRJ) behaviour of the blazar PKS 2155–304 during an outburst in 2010. This flare develops over roughly 117 d, with a flux doubling time τ ... -
The three hundred project: The stellar and gas profiles
(Oxford University Press, 2020)Using the catalogues of galaxy clusters from The Three Hundred project, modelled with both hydrodynamic simulations (GADGET-X and GADGET-MUSIC), and semi-analytical models (SAMs), we study the scatter and self-similarity ... -
Prospects for cosmic magnification measurements using H I intensity mapping
(Oxford University Press, 2020)We investigate the prospects of measuring the cosmic magnification effect by cross-correlating neutral hydrogen intensity mapping (H I IM) maps with background optical galaxies. We forecast the signal-to-noise ratio for ... -
The relation between the diffuse X-ray luminosity and the radio power of the central AGN in galaxy groups
(Oxford University Press, 2020)Our understanding of how active galactic nucleus feedback operates in galaxy clusters has improved in recent years owing to large efforts in multiwavelength observations and hydrodynamical simulations. However, it is much ... -
A wide-area GMRT 610-MHz survey of ELAIS N1 field
(Oxford University Press, 2020)In this paper, we present a wide-area 610-MHz survey of the ELAIS N1 field with the GMRT, covering an area of 12.8 deg2 at a resolution of 6 arcsec and with an rms noise of ∼40 μJy beam−1. This is equivalent to ∼20 μJy ... -
The baryonic Tully–Fisher relation in the SIMBA simulation
(Oxford University Press, 2020)We investigate the Baryonic Tully–Fisher relation (BTFR) in the (100h−1Mpc)3SIMBA hydrodynamical galaxy formation simulation together with a higher resolution (25h−1Mpc)3SIMBA run, for over 10 000 disc-dominated, H I-rich ... -
Unsupervised machine learning for transient discovery in deeper, wider, faster light curves
(Oxford University Press, 2020)Identification of anomalous light curves within time-domain surveys is often challenging. In addition, with the growing number of wide-field surveys and the volume of data produced exceeding astronomers’ ability for manual ... -
The evolution of the low-frequency radio AGN population to z 1.5 in the ELAIS N1 field
(Oxford University Press, 2021)We study the cosmic evolution of radio sources out to z ≃ 1.5 using a GMRT 610 MHz survey covering ∼1.86 deg2 of the ELAIS N1 field with a minimum/median rms noise 7.1/19.5 μJy beam−1 and an angular resolution of 6 arcsec. ... -
A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances
(The Journal of Space Weather and Space Climate, 2020)This paper presents the results from one of the first observations of ionospheric scintillation taken using the Low-Frequency Array (LOFAR). The observation was of the strong natural radio source Cassiopeia A, taken ... -
Recursion relations for gravitational lensing
(Springer Nature, 2019)The weak gravitational lensing formalism can be extended to the strong lensing regime by integrating a nonlinear version of the geodesic deviation equation. The resulting ‘roulette’ expansion generalises the notion of ...