A5038967616- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Astrophysics and Star Formation Studies
- Computational Physics and Python Applications
- Remote Sensing in Agriculture
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Black Holes and Theoretical Physics
- Superconducting and THz Device Technology
- Pulsars and Gravitational Waves Research
- Relativity and Gravitational Theory
- Plant Water Relations and Carbon Dynamics
- Scientific Research and Discoveries
- Quantum Chromodynamics and Particle Interactions
- Impact of Light on Environment and Health
Leiden University
2011-2025
Royal Observatory
2019
University of Edinburgh
2019
University of California, Berkeley
2015-2018
Lawrence Berkeley National Laboratory
2015-2018
Max Planck Institute for Astrophysics
2011-2016
Max Planck Society
2015
Upcoming weak lensing surveys, such as LSST, EUCLID, and WFIRST, aim to measure the matter power spectrum with unprecedented accuracy.In order fully exploit these observations, models are needed that, given a set of cosmological parameters, can predict non-linear at level 1% or better for scales corresponding comoving wave numbers 0.1 k 10 h Mpc -1 .We have employed large suite simulations from OWLS project investigate effects various baryonic processes on spectrum.In addition, we examined...
Observational cosmology in the next decade will rely on probes of distribution matter redshift range between $0<z<3$ to elucidate nature dark and energy. In this range, galaxy formation is known have a significant impact observables such as two-point correlations shapes positions, altering their amplitude scale dependence beyond expected statistical uncertainty upcoming experiments at separations under 10 Mpc. Successful extraction information regime thus requires, very least, unbiased...
ABSTRACT We introduce the Virgo Consortium’s FLAMINGO suite of hydrodynamical simulations for cosmology and galaxy cluster physics. To ensure are sufficiently realistic studies large-scale structure, subgrid prescriptions stellar AGN feedback calibrated to observed low-redshift mass function gas fractions. The calibration is performed using machine learning, separately each FLAMINGO’s three resolutions. This approach enables specification model by observables which they calibrated. accounts...
ABSTRACT Numerical simulations have become one of the key tools used by theorists in all fields astrophysics and cosmology. The development modern that target largest existing computing systems exploit state-of-the-art numerical methods algorithms is thus crucial. In this paper, we introduce fully open-source highly-parallel, versatile, modular coupled hydrodynamics, gravity, cosmology, galaxy-formation code Swift. software package exploits hybrid shared- distributed-memory task-based...
We use matter power spectra from cosmological hydrodynamic simulations to quantify the effect of baryon physics on weak gravitational lensing shear signal. The consider a number processes, such as radiative cooling, star formation, supernovae and feedback active galactic nuclei (AGN). Van Daalen et al. used same show that physics, in particular strong is required solve overcooling problem, modifies spectrum scales relevant for studies. As result, dark can lead significant biases inferred...
We use cosmological hydrodynamical simulations to investigate how the inclusion of physical processes relevant galaxy formation (star formation, metal-line cooling, stellar winds, supernovae and feedback from Active Galactic Nuclei, AGN) change properties haloes, over four orders magnitude in mass. find that gas expulsion associated dark matter (DM) expansion induced by supernova-driven winds are important for haloes with masses M200 < 10^13 Msun, lowering their up 20% relative a DM-only...
Upcoming weak lensing surveys require a detailed theoretical understanding of the matter power spectrum in order to derive accurate and precise cosmological parameter values. While galaxy formation is known play an important role, its effects are currently unknown. We present set 92 spectra from OWLS, cosmo-OWLS BAHAMAS simulation suites, including different $\Lambda$CDM cosmologies, neutrino masses, subgrid prescriptions AGN feedback strengths. conduct investigation dependence relative...
We report the alignment and shape of dark matter, stellar, hot gas distributions in EAGLE cosmo-OWLS simulations. The combination these state-of-the-art hydro-cosmological simulations enables us to span four orders magnitude halo mass ($11 < log_{10}(M_{200}/ [h^{-1}M_\odot]) 15$), a wide radial range ($-2.3 log_{10}(r/[h^{-1}Mpc ]) 1.3$) redshifts $0 z 1$. parameters stellar follow qualitatively similar trends: they become more aspherical (and triaxial) with increasing mass, radius...
To fully take advantage of the data provided by large-scale structure surveys, we need to quantify potential impact baryonic effects, such as feedback from active galactic nuclei (AGN) and star formation, on cosmological observables. In simulations, processes originate scales that remain unresolved. Therefore, they be sourced via subgrid models contain free parameters. We use machine learning calibrate AGN stellar for FLAMINGO (Fullhydro Large-scale simulations with All-sky Mapping...
Abstract Large-scale structure surveys have reported measurements of the density matter, Ωm, and amplitude clustering, σ8, that are in tension with values inferred from observations cosmic microwave background. While this may be a sign new physics slows growth at late times, strong astrophysical feedback processes could also responsible. In work, we argue not independent cosmology their coupling naturally leads to stronger baryonic cosmological models suppressed formation or when combined...
The observed clustering of galaxies and the cross-correlation mass provide important constraints on both cosmology models galaxy formation. Even though dissipation feedback processes associated with formation are thought to affect distribution matter, essentially all used predict data based collisionless simulations. Here, we use large hydrodynamical simulations investigate how affects autocorrelation functions subhaloes, as well their matter. We show that changes due inclusion baryons not...
We report results for the alignments of galaxies in EAGLE and cosmo-OWLS simulations as a function galaxy separation halo mass. The combination these hydro-cosmological enables us to span four orders magnitude mass ($10.7<log_{10}(M_{200}/[h^{-1}M_\odot])<15$) large range separations ($-1<log_{10}(r/[h^{-1}Mpc])< 2$). focus on two classes alignments: orientations with respect either directions to, or of, surrounding galaxies. find that strength alignment is strongly decreasing distance...
Numerical simulations have become one of the key tools used by theorists in all fields astrophysics and cosmology. The development modern that target largest existing computing systems exploit state-of-the-art numerical methods algorithms is thus crucial. In this paper, we introduce fully open-source highly-parallel, versatile, modular coupled hydrodynamics, gravity, cosmology, galaxy-formation code SWIFT. software package exploits hybrid shared- distributed-memory task-based parallelism,...
ABSTRACT A number of recent studies have found evidence for a tension between observations large-scale structure (LSS) and the predictions standard model cosmology with cosmological parameters fit to cosmic microwave background (CMB). The origin this ‘S8 tension’ remains unclear, but possibilities include new physics beyond model, unaccounted systematic errors in observational measurements and/or uncertainties role that baryons play. Here, we carefully examine latter possibility using...
We introduce the Virgo Consortium's FLAMINGO suite of hydrodynamical simulations for cosmology and galaxy cluster physics. To ensure are sufficiently realistic studies large-scale structure, subgrid prescriptions stellar AGN feedback calibrated to observed low-redshift mass function gas fractions. The calibration is performed using machine learning, separately three resolutions. This approach enables specification model by observables which they calibrated. accounts a number potential...
ABSTRACT The splashback radius, coinciding with the minimum in dark matter radial density gradient, is thought to be a universal definition of edge halo. Observational methods detect it have traced using weak gravitational lensing or galaxy number counts. Recent attempts also claimed detection similar feature Sunyaev–Zel’dovich (SZ) observations hot intracluster gas. Here, we use FLAMINGO simulations investigate whether an extremum gradient position radius predicted occur cluster gas...
ABSTRACT Weak gravitational lensing convergence peaks, the local maxima in weak maps, have been shown to contain valuable cosmological information complementary commonly used two-point statistics. To exploit full power of for cosmology, we must model baryonic feedback processes because these reshape matter distribution on non-linear and mildly scales. We study impact physics number density peaks using FLAMINGO hydrodynamical simulation suite. generate ray-traced full-sky maps mimicking...
Halo-based models have been successful in predicting the clustering of matter. However, validity postulate that is fully determined by matter inside haloes remains largely untested, and it not clear a priori whether non-virialized might contribute significantly to non-linear signal. Here, we investigate contribution power spectrum as function both scale halo mass combining set cosmological N-body simulations calculate contributions different spherical overdensity regions, Friends-of-Friends...
Large-scale structure surveys have reported measurements of the density matter, $\Omega_\mathrm{m}$, and amplitude clustering, $\sigma_8$, that are in tension with values inferred from observations cosmic microwave background. While this may be a sign new physics slows growth at late times, strong astrophysical feedback processes could also responsible. In work, we argue not independent cosmology their coupling naturally leads to stronger baryonic cosmological models suppressed formation or...
Abstract Energetic feedback processes associated with accreting supermassive black holes can expel gas from massive haloes and significantly alter various measures of clustering on ∼Mpc scales, potentially biasing the values cosmological parameters inferred analyses large-scale structure (LSS) if not modelled accurately. Here we use state-of-the-art FLAMINGO suite hydrodynamical simulations to gauge impact by comparing Planck + ACT stacking measurements kinetic Sunyaev-Zel’dovich (kSZ)...
ABSTRACT The clustering of matter, as measured by the matter power spectrum, informs us about cosmology, dark and baryonic effects on distribution in universe. Using cosmological hydrodynamical simulations from cosmo-OWLS BAHAMAS simulation projects, we investigate contribution haloes with various masses, to full well ratio between only (DMO) for a matched (between simulations) an unmatched set haloes. We find that presence AGN feedback suppresses all scales masses examined (1011.25 ≤ M500,...
ABSTRACT Galaxy clusters are important probes for both cosmology and galaxy formation physics. We test the cosmological, hydrodynamical FLAMINGO (Full-hydro large-scale structure simulations with all-sky mapping interpretation of next generation observations) by comparing to observations gaseous properties measured from X-ray observations. contains unprecedented numbers massive groups ($\gt 10^6$) 10^5$) includes variations in predict evolution cluster scaling relations as well radial...
Abstract The effect of baryon physics associated with galaxy formation onto the large-scale matter distribution Universe is a key uncertainty in theoretical modelling required for interpretation Stage IV cosmology surveys. We use Flamingo suite simulations to study response due total power spectrum. find that it only well converged simulation volumes excess 2003 Mpc3. report results varying feedback intensity, which either match X-ray inferred gas fractions clusters and z = 0 stellar mass...
We introduce methods which allow observed galaxy clustering to be used together with luminosity or stellar mass functions constrain the physics of formation. show how projected two-point correlation function galaxies in a large semi-analytic simulation can estimated better than ~10% using only very small subsample subhalo merger trees. This allows measured correlations as constraints Monte Carlo Markov Chain exploration astrophysical and cosmological parameter space. An important part our...
To fully take advantage of the data provided by large-scale structure surveys, we need to quantify potential impact baryonic effects, such as feedback from active galactic nuclei (AGN) and star formation, on cosmological observables. In simulations, processes originate scales that remain unresolved. Therefore, they be sourced via subgrid models contain free parameters. We use machine learning calibrate AGN stellar for FLAMINGO hydrodynamical simulations. Using Gaussian process emulators...