Physics and Astronomy: Recent submissions
Now showing items 141-160 of 520
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HELP: a catalogue of 170 million objects, selected at 0.36–4.5 μm, from 1270 deg2 of prime extragalactic fields
(Oxford University Press, 2019)We present an optical to near-infrared (NIR) selected astronomical catalogue covering 1270 deg2. This is the first attempt to systematically combine data from 23 of the premier extragalactic survey fields – the product of ... -
SCUBA-2 observations of candidate starbursting protoclusters selected by Planck and Herschel-SPIRE
(Royal Astronomical Society, 2019)We present SCUBA-2 850 μm observations of 13 candidate starbursting protoclusters selected using Planck and Herschel data. The cumulative number counts of the 850 μm sources in 9 of 13 of these candidate protoclusters show ... -
Evolution of the chemical composition of Sn thin films heated during x-ray photoelectron spectroscopy
(2019)High-vacuum XPS have been used to analyse the surface modification of a 3 nm-thick Sn thin film on Si (100) before and after annealing up to 450 °C. Increasing the XPS stage temperature led to a reduction in the amount of ... -
The WISE Extended Source Catalog (WXSC). I. The 100 Largest Galaxies
(University of the Western Cape, 2019)We present mid-infrared photometry and measured global properties of the 100 largest galaxies in the sky, including the well-studied Magellanic Clouds, Local Group galaxies M31 and M33, the Fornax and Virgo galaxy cluster ... -
Probabilistic learning for pulsar classification
(IOP Publishing, 2022)In this work, we explore the possibility of using probabilistic learning to identify pulsar candidates. We make use of Deep Gaussian Process (DGP) and Deep Kernel Learning (DKL). Trained on a balanced training set in ... -
Hiflow: Generating diverse hi maps and inferring cosmology while marginalizing over astrophysics using normalizing flows
(IOP Publishing, 2022)A wealth of cosmological and astrophysical information is expected from many ongoing and upcoming large-scale surveys. It is crucial to prepare for these surveys now and develop tools that can efficiently extract ... -
Patterns of primary beam non-redundancy in close-packed 21 cm array observations
(Oxford University Press, 2021)Radio interferometer arrays such as HERA consist of many close-packed dishes arranged in a regular pattern, giving rise to a large number of ‘redundant’ baselines with the same length and orientation. Since identical ... -
Gaussian process regression for foreground removal in hi intensity mapping experiments
(Oxford University Press, 2022)We apply for the first time Gaussian Process Regression (GPR) as a foreground removal technique in the context of single-dish, low redshift H I intensity mapping, and present an open-source PYTHON toolkit for doing so. We ... -
Identification of single spectral lines in large spectroscopic surveys using UMLAUT: an Unsupervised Machine Learning Algorithm based on Unbiased Topology
(The Astrophysical Journal Supplement Series, 2021)The identification of an emission line is unambiguous when multiple spectral features are clearly visible in the same spectrum.However, in many cases, only one line is detected, making it difficult to correctly determine ... -
Lenses In VoicE (LIVE): Searching for strong gravitational lenses in the VOICE@VST survey using Convolutional Neural Networks
(Monthly notices of the Royal Astronomical Society, 2021)We present a sample of 16 likely strong gravitational lenses identified in the VST Optical Imaging of the CDFS and ES1 fields (VOICE survey) using Convolutional Neural Networks (CNNs). We train two different CNNs on composite ... -
Constraining the neutrino mass using a multitracer combination of two galaxy surveys and cosmic microwave background lensing
(Oxford University Press, 2022)Measuring the total neutrino mass is one of the most exciting opportunities available with next-generation cosmological data sets. We study the possibility of detecting the total neutrino mass using large-scale clustering ... -
Antenna beam characterization for the global 21-cm experiment LEDA and its impact on signal model parameter reconstruction
(Oxford University Press, 2022)Cosmic dawn, the onset of star formation in the early universe, can in principle be studied via the 21-cm transition of neutral hydrogen, for which a sky-averaged absorption signal, redshifted to MHz frequencies, is predicted ... -
Dynamic Properties of a Sporadic Sodium Layer Revealed by Observations Over Zhongshan, Antarctica: A Case Study
(Journal of Geophysical Research: Space Physics, 2021)A sodium Doppler lidar system with three-directional measurements of sodium density, atmospheric wind field, and temperature was established at Zhongshan (69.4°S, 76.4°E), Antarctica. On November 14, 2019, a sporadic sodium ... -
First HETDEX Spectroscopic Determinations of Lyα and UV Luminosity Functions at z=2–3: Bridging a Gap between Faint AGNs and Bright Galaxies
(The Astrophysical Journal, 2021)We present Lyα and ultraviolet (UV)-continuum luminosity functions (LFs) of galaxies and active galactic nuclei (AGNs) at z = 2.0–3.5 determined by the untargeted optical spectroscopic survey of the Hobby–Eberly Telescope ... -
Development of a 127Xe calibration source for nEXO
(IOP Publishing, 2022)We study a possible calibration technique for the nEXO experiment using a 127Xe electron capture source. nEXO is a next-generation search for neutrinoless double beta decay (0νββ) that will use a 5-tonne, monolithic liquid ... -
A structure function analysis of vst-cosmos agn
(EDP Sciences, 2022)We present our sixth work in a series dedicated to variability studies of active galactic nuclei (AGN), based on the survey of the COSMOS field by the VLT Survey Telescope (VST). Its 54 r-band visits over 3.3 yr and ... -
Exomol line lists – xliv. Infrared and ultraviolet line list for silicon monoxide (28si16o)
(Oxford University Press, 2022)A new silicon monoxide ( 28Si16O) line list covering infrared, visible, and ultraviolet regions called SiOUVenIR is presented. This line list extends the infrared EBJT ExoMol line list by including vibronic transitions ... -
First observation of the coexistence of multiple chiral doublet bands and pseudospin doublet bands in the A ≈ 80 mass region
(Elsevier, 2022)Two nearly degenerate positive-parity bands with the π g2 9/2 ⊗ ν g−1 9/2 configuration and three nearly degenerate negative-parity bands with the π g9/2(p3/2, f5/2) ⊗ ν g−1 9/2 configuration have been identified in ... -
Ultralarge-scale approximations and galaxy clustering: Debiasing constraints on cosmological parameters
(Oxford University Press, 2022)Upcoming galaxy surveys will allow us to probe the growth of the cosmic large-scale structure with improved sensitivity compared to current missions, and will also map larger areas of the sky. This means that in addition ... -
Mightee-hi: Evolution of hi scaling relations of star-forming galaxies at z < 0.5*
(IOP Publishing, 2022)We present the first measurements of H I galaxy scaling relations from a blind survey at z > 0.15. We perform spectral stacking of 9023 spectra of star-forming galaxies undetected in H I at 0.23 < z < 0.49, extracted ...