Browsing Faculty of Natural Sciences by Subject "Astrophysics"
Now showing items 1-20 of 45
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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 ... -
Breaking baryon-cosmology degeneracy with the electron density power spectrum
(IOP Publishing, 2022)Uncertain feedback processes in galaxies affect the distribution of matter, currently limiting the power of weak lensing surveys. If we can identify cosmological statistics that are robust against these uncertainties, or ... -
The bright extragalactic ALMA redshift survey (BEARS) – II. Millimetre photometry of gravitational lens candidates
(Oxford University Press, 2023)We present 101- and 151-GHz ALMA continuum images for 85 fields selected from Herschel observations that have 500-μm flux densities >80 mJy and 250–500-μm colours consistent with z > 2, most of which are expected to be ... -
The circumgalactic medium from the camels simulations: Forecasting constraints on feedback processes from future Sunyaev–Zeldovich observations
(IOP Publishing, 2022)It is important to understand the cycle of baryons through the circumgalactic medium (CGM) in the context of galaxy formation and evolution. In this study, we forecast constraints on the feedback processes heating the ... -
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 ... -
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 ... -
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 ... -
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 ... -
Cosmological constraints from the power spectrum and bispectrum of 21cm intensity maps
(IOP Publishing, 2022)The 21cm emission of neutral hydrogen is a potential probe of the matter distribution in the Universe after reionisation. Cosmological surveys of this line intensity will be conducted in the coming years by the SKAO and ... -
Coulomb excitation of 102 Ru with 12 C and 16 O
(American Physical Society, 2022)The Coulomb excitation of 102Ru was performed with beams of 12C and 16O ions. The beam particles scattered at forward angles were momentum analyzed with a magnetic spectrograph. The resolution achieved enabled the ... -
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 ... -
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 ... -
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 ... -
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 ... -
HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift
(American Astronomical Society, 2013)The cosmic infrared background (CIB), discovered in Far Infrared Absolute Spectrophotometer (FIRAS) data from the Cosmic Background Explorer (COBE; Puget et al. 1996; Fixsen et al. 1998), originates from thermal ... -
Herschel-ATLAS: A binary HyLIRG pinpointing a cluster of starbursting protoellipticals
(American Astronomical Society, 2013)Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across ... -
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 ... -
High-precision half-life determination of 14O via direct β counting
(Springer, 2022)The half-life of the superallowed Fermi β+ emitter 14O was determined to high precision via a direct β counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, T1/2( 14O) ...