Physics and Astronomy: Recent submissions
Now showing items 41-60 of 520
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On the time delay between ultra-relativistic particles
(Elsevier, 2016)The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through ... -
Simulating a full-sky high resolution Galactic synchrotron spectral index map using neural networks
(Monthly Notices of the Royal Astronomical Society, 2023)We present a model for the full-sky diffuse Galactic synchrotron spectral index with an appropriate level of spatial structure for a resolution of 56 arcmin (to match the resolution of the Haslam 408 MHz data). Observational ... -
Disentangling non-gaussianity, bias, and general relativistic effects in the galaxy distribution
(American Physical Society, 2012)Local non-Gaussianity, parametrized by f NL , introduces a scale-dependent bias that is strongest at large scales, precisely where general relativistic (GR) effects also become significant. With future data, it should ... -
Wide-angle effects in multi-tracer power spectra with Doppler corrections
(IOP Publishing, 2023). We examine the computation of wide-angle corrections to the galaxy power spectrum including redshift-space distortions and relativistic Doppler corrections, and also including multiple tracers with differing clustering, ... -
Mining mini-halos with MeerKAT I. Calibration and imaging
(Oxford University Press, 2023)Radio mini-halos are clouds of diffuse, low-surface brightness synchrotron emission that surround the Brightest Cluster Galaxy (BCG) in massive cool-core galaxy clusters. In this paper, we use third generation calibration ... -
Feature guided training and rotational standardization for the morphological classification of radio galaxies
(Oxford University Press, 2023)State-of-the-art radio observatories produce large amounts of data which can be used to study the properties of radio galaxies. However, with this rapid increase in data volume, it has become unrealistic to manually process ... -
Clustering of HI galaxies in the HI parkes all sky survey and arecibo legacy fast alfa survey
(Oxford University Press, 2011)We investigate the clustering of H I-selected galaxies in the Arecibo Legacy Fast ALFA Survey (ALFALFA) and compare results with those obtained for the H I Parkes All Sky Survey (HIPASS). Measurements of the angular ... -
Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
(Institute for Ionics, 2023)Surveys of the matter distribution contain ‘fossil’ information on possible non-Gaussianity that is generated in the primordial universe. This primordial signal survives only on the largest scales where cosmic variance ... -
Constraining primordial non-gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
(SpringerOpen, 2023)Surveys of the matter distribution contain ‘fossil’ information on possible non-Gaussianity that is generated in the primordialUniverse. This primordial signal survives only on the largest scales where cosmic variance ... -
Mightee-h i: Possible interactions with the galaxy NGC 895
(Oxford University Press, 2023)The transformation and evolution of a galaxy is strongly influenced by interactions with its environment. Neutral hydrogen (H i) is an excellent way to trace these interactions. Here, we present H i observations of the ... -
Impact of Rubin Observatory Cadence Choices on Supernovae Photometric Classification
(The Astrophysical Journal Supplement Series, 2023)The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will discover an unprecedented number of supernovae (SNe), making spectroscopic classification for all the events infeasible. LSST will thus rely on ... -
Height determination of a blue discharge observed by asim/mmia on the international space station
(Wiley, 2023)We analyze simultaneous photometric observations of thundercloud discharges from the Modular Multispectral Imaging Array of the Atmosphere-Space Interactions Monitor (ASIM) on board the International Space Station with ... -
Multifilter time-series observations of eleven blue short-period atlas variable stars
(IOP Publishing, 2023)Eleven periodic variable stars were observed photometrically through two to four filters from the set UBVRCIC. Phase-folded data for each star cover full cycles of variation. Spectral energy distributions, based on ... -
Efficient long-range active galactic nuclei (agns) feedback affects the low-redshift lyα forest
(American Astronomical Society, 2023)Active galactic nuclei (AGNs) feedback models are generally calibrated to reproduce galaxy observables such as the stellar mass function and the bimodality in galaxy colors. We use variations of the AGN feedback implementations ... -
Solar irradiance spectra from the compact SOLSTICE (CSOL) experiment: instrument design, FUV calibration, measurements, and comparison of the 2018 rocket flight
(Solar Physics, 2023)The Compact SOLSTICE, a compact far and mid ultraviolet (FUV and MUV) spectrograph, flew on a sounding rocket on 18 June 2018 to validate and potentially calibrate the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) ... -
Solar irradiance spectra from the compact SOLSTICE (CSOL) experiment: Instrument design, FUV calibration, measurements, and comparison of the 2018 rocket flight
(Springer, 2023)The Compact SOLSTICE, a compact far and mid ultraviolet (FUV and MUV) spectrograph, flew on a sounding rocket on 18 June 2018 to validate and potentially calibrate the SOLar STellar Irradiance Comparison Experiment ... -
Solid state dewetting of a metal –semiconductor bi-layers deposited onto c-Si substrate
(Springer, 2023)A bi-layers stack consisting of a semiconductor thin film of a varied thickness and a very thin Pd layer (SiC/Pd/c-Si).was deposited onto c-Si by e-beam evaporation at room temperature. The multi-layers structure was ... -
Impact of Rubin observatory cadence choices on supernovae photometric classification
(American Astronomical Society, 2023)The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will discover an unprecedented number of supernovae (SNe), making spectroscopic classification for all the events infeasible. LSST will thus rely on ... -
PSRJ1910–5959A: A rare gravitational laboratory for testing white dwarf models
(EDP Sciences, 2023)Context. PSR J1910-5959A is a binary millisecond pulsar in a 0.837 day circular orbit around a helium white dwarf (HeWD) companion. The position of this pulsar is 6.3 arcmin (∼74 core radii) away from the optical centre ... -
Quijote-png: Quasi-maximum likelihood estimation of primordial non-gaussianity in the nonlinear dark matter density field
(American Astronomical Society, 2022)Future large-scale structure surveys are expected to improve current bounds on primordial non-Gaussianity (PNG), with a significant impact on our understanding of early universe physics. The level of such improvements ...