A5081336322- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Blind Source Separation Techniques
- Advanced Vision and Imaging
- Archaeological Research and Protection
- Radio Astronomy Observations and Technology
- Gaussian Processes and Bayesian Inference
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- CCD and CMOS Imaging Sensors
- demographic modeling and climate adaptation
- Advanced Computational Techniques and Applications
- Plant Diversity and Evolution
- Archaeology and ancient environmental studies
- Adaptive optics and wavefront sensing
- Statistics Education and Methodologies
- Spectroscopy and Chemometric Analyses
- Mathematics and Applications
- History and Theory of Mathematics
- Astrophysical Phenomena and Observations
- Remote Sensing in Agriculture
- Cultural Heritage Management and Preservation
- Cosmology and Gravitation Theories
University College London
2018-2023
Utrecht University
2021-2023
NSW Environment and Heritage
2014
United States Department of Agriculture
1942
ABSTRACT Intrinsic alignments (IAs) of galaxies are an important contaminant for cosmic shear studies, but the modelling is complicated by dependence signal on source galaxy sample. In this paper, we use halo model formalism to capture diversity and examine its implications Stage-III Stage-IV surveys. We account different IA signatures at large small scales, as well contributions from central/satellite red/blue galaxies, realistic mocks characteristics populations a function redshift. inform...
We present a bright galaxy sample with accurate and precise photometric redshifts (photo-zs), selected using $ugriZYJHK_\mathrm{s}$ photometry from the Kilo-Degree Survey (KiDS) Data Release 4 (DR4). The highly pure complete dataset is flux-limited at $r<20$ mag, covers $\sim1000$ deg$^2$, contains about 1 million galaxies after artifact masking. exploit overlap Galaxy And Mass Assembly (GAMA) spectroscopy as calibration to determine photo-zs supervised machine learning neural network...
We directly constrain the non-linear alignment (NLA) model of intrinsic galaxy alignments, analysing most representative and complete flux-limited sample spectroscopic galaxies available for cosmic shear surveys. measure projected position-intrinsic correlations clustering signal using high-resolution imaging from Kilo Degree Survey (KiDS) overlapping with GAMA survey, data Sloan Digital Sky Survey. Separating samples by colour, we make no significant detection blue constraining NLA...
We constrain the luminosity and redshift dependence of intrinsic alignment (IA) a nearly volume-limited sample luminous red galaxies selected from fourth public data release Kilo-Degree Survey (KiDS-1000). To measure shapes galaxies, we used two complementary algorithms, finding consistent IA measurements for overlapping galaxy sample. The global significance detection across our independent samples, with favoured method shape estimation, is $\sim10.7\sigma$. find no significant signal in...
The outer regions of galaxies are more susceptible to the tidal interactions that lead intrinsic alignments galaxies. resulting alignment signal may therefore depend on passband if colours vary spatially. To quantify this, we measured shapes with spectroscopic redshifts from GAMA survey using deep gri imaging data KiloDegree Survey. performance moment-based shape measurement algorithm DEIMOS was assessed dedicated image simulations, which showed ellipticities could be determined an accuracy...
We present the first measurements of projected clustering and intrinsic alignments (IA) galaxies observed by Physics Accelerating Universe Survey (PAUS). With photometry in 40 narrow optical passbands ($450\rm{nm}-850\rm{nm}$), quality photometric redshift estimation is $\sigma_{z} \sim 0.01(1 + z)$ for $19\,\rm{deg}^{2}$ Canada-France-Hawaii Telescope Legacy (CFHTLS) W3 field, allowing us to measure 3D IA flux-limited, faint ($i < 22.5$) out $z\sim0.8$. To two-point statistics, we...
We present a new method for the mitigation of observational systematic effects in angular galaxy clustering through use corrective random catalogues. Real and synthetic data from Kilo Degree Survey’s (KiDS) 4th Data Release (KiDS-1000) Full-sky Lognormal Astro-fields Simulation Kit package, respectively, are used to train self-organising maps learn multivariate relationships between observed number density up six systematic-tracer variables, including seeing, Galactic dust extinction,...
We present a sample of luminous red sequence galaxies as the basis for study large-scale structure in fourth data release Kilo-Degree Survey. The selected are defined by template, form data-driven model colour-magnitude relation conditioned on redshift. In this work, template was built using broad-band optical+near infrared photometry KiDS-VIKING and overlapping spectroscopic sets. selection process involved estimating redshifts, assessing purity underlying redshift distributions bins. After...
Recent works have shown that weak lensing magnification must be included in upcoming large-scale structure analyses, such as for the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), to avoid biasing cosmological results. In this work we investigate whether including has a positive impact on precision constraints, well being necessary bias. We forecast using an LSST mock catalog halo model calculate galaxy power spectra. find little effect parameter constraints clustering...
We present a sample of luminous red-sequence galaxies to study the large-scale structure in fourth data release Kilo-Degree Survey. The selected are defined by template, form data-driven model colour-magnitude relation conditioned on redshift. In this work, template is built using broad-band optical+near infrared photometry KiDS-VIKING and overlapping spectroscopic sets. selection process involves estimating redshifts, assessing purity sample, underlying redshift distributions bins. After...
Cosmological constraints from key probes of the Euclid imaging survey rely critically on accurate determination true redshift distributions, $n(z)$, tomographic bins. We determine whether mean redshift, $$, ten bins can be calibrated to target uncertainties $σ()<0.002\,(1+z)$ via cross-correlation, with spectroscopic samples akin those Baryon Oscillation Spectroscopic Survey (BOSS), Dark Energy Instrument (DESI), and Euclid's NISP survey. construct mock galaxy Flagship simulation measure...
ABSTRACT Residuals between measured galactic radii and those predicted by the Fundamental Plane (FP) are possible tracers of weak lensing magnification. However, observations have shown these to be systematically correlated with large-scale structure. We use Horizon-AGN hydrodynamical cosmological simulation analyse intrinsic size correlations (ISCs) for both elliptical (early-type) spiral (late-type) galaxies at $z$ = 0.06. fit separate FPs each sample, finding similarly distributed radius...
We explore the enhanced self-calibration of photometric galaxy redshift distributions, $n(z)$, through combination up to six two-point functions. Our $\rm 3\times2pt$ configuration is comprised shear, spectroscopic clustering, and spectroscopic-photometric galaxy-galaxy lensing (GGL). further include cross-clustering; GGL; auto-clustering, using shear sample as density tracer. perform simulated likelihood forecasts cosmological nuisance parameter constraints for Stage-III- Stage-IV-like...