Physics and Astronomy: Recent submissions
Now showing items 161-180 of 533
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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 ... -
A comparison of multi-phase magnetic field tracers in a high-galactic latitude region of the filamentary interstellar medium
(IOP Publishing, 2022)Understanding how the Galactic magnetic field threads the multiphase interstellar medium (ISM) remains a considerable challenge, as different magnetic field tracers probe dissimilar phases and field components. We search for ... -
Consequences of using a smooth cosmic distance in a lumpy Universe. I.
(American Physical Society, 2022)How do we appropriately fit a model based on an idealised Friedmann-Lemaˆıtre Robertson-Walker spacetime to observations made from a single location in a lumpy Universe? We address this question for surveys that measure ... -
Inferring halo masses with graph neural networks
(Institute of Physics, 2022)Understanding the halo–galaxy connection is fundamental in order to improve our knowledge on the nature and properties of dark matter. In this work, we build a model that infers the mass of a halo given the positions, ... -
The CAMELS multifield data set: Learning the universe’s fundamental parameters with artificial intelligence
(IOP, 2022)We present the Cosmology and Astrophysics with Machine Learning Simulations (CAMELS) Multifield Data set (CMD), a collection of hundreds of thousands of 2D maps and 3D grids containing many different properties of cosmic ... -
The Impact of Observing Strategy on Cosmological Constraints with LSST
(2022)The generation-defining Vera C. Rubin Observatory will make state-of-the-art measurements of both the static and transient universe through its Legacy Survey for Space and Time (LSST). With such capabilities, it is immensely ... -
Trapum discovery of 13 new pulsars in ngc 1851 using meerkat
(Hans Publishers, 2022)We report the discovery of 13 new pulsars in the globular cluster NGC 1851 by the TRAPUM Large Survey Project using the MeerKAT radio telescope. The discoveries consist of six isolated millisecond pulsars (MSPs) and seven ... -
Pulsar scintillation studies with LOFAR I. The census
(Hans Publishers, 2022)Interstellar scintillation (ISS) of pulsar emission can be used both as a probe of the ionized interstellar medium (IISM) and cause corruptions in pulsar timing experiments. Of particular interest are so-called scintillation ...