A5051879629- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Scientific Research and Discoveries
- Distributed and Parallel Computing Systems
- Parallel Computing and Optimization Techniques
- Computational Physics and Python Applications
- Advanced Data Storage Technologies
- Astrophysical Phenomena and Observations
- Molecular Spectroscopy and Structure
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Atmospheric Ozone and Climate
- Bee Products Chemical Analysis
- Computer Graphics and Visualization Techniques
- Transportation Planning and Optimization
- Topological and Geometric Data Analysis
- Plant Water Relations and Carbon Dynamics
- Algorithms and Data Compression
- Plant pathogens and resistance mechanisms
- Physics and Engineering Research Articles
- Vehicle emissions and performance
- Gamma-ray bursts and supernovae
University of Geneva
2020-2024
Institute of Astronomy
2024
KU Leuven
2024
University of Exeter
2019-2022
Global Social Observatory
2022
RIKEN Center for Computational Science
2015-2021
Leiden University
2010-2016
University of Groningen
2013-2014
University of Amsterdam
2010-2013
We investigate the alignment of haloes with filaments cosmic web using an unprecedently large sample dark matter taken from P-Millennium $\Lambda$CDM cosmological N-body simulation. use state-of-the-art NEXUS morphological formalism which, due to its multiscale nature, simultaneously identifies structures at all scales. find strong and highly significant alignments, both major axis their peculiar velocity tending orient along filament. However, spin - filament displays a more complex trend...
The large-scale structure of the universe is comprised virialized blob-like clusters, linear filaments, sheet-like walls and huge near empty three-dimensional voids. Characterizing large scale essential to our understanding formation evolution galaxies. density range voids are relatively well separated, when compared which span a larger range. filamentary network thus forms an intricate part cosmic web. In this paper, we describe Felix, topology based framework for visual exploration...
We present the results of "Cosmogrid" cosmological N-body simulation suites based on concordance LCDM model. The Cosmogrid was performed in a 30Mpc box with 2048^3 particles. mass each particle is 1.28x10^5 Msun, which sufficient to resolve ultra-faint dwarfs. found that halo function shows good agreement Sheth & Tormen fitting down ~10^7 Msun. have analyzed spherically averaged density profiles three most massive halos are galaxy group size and contain at least 170 million slopes these...
The mode of star formation that results in the globular clusters and young massive is difficult to constrain through observations. We present models cluster using T ORCH framework, which uses Astrophysical MUltipurpose Software Environment (AMUSE) couple distinct multi-physics codes handle formation, stellar evolution dynamics, radiative transfer, magnetohydrodynamics. upgraded by implementing N-body code P ETAR , thereby enabling forming from 10 6 M ⊙ clouds with ≥10 5 individual stars....
We present a method to couple N -body star cluster simulations cosmological tidal field, using the Astrophysical Multipurpose Software Environment.We apply this clusters embedded in CosmoGrid dark matter-only ΛCDM simulation.Our are born at z = 10 (corresponding an age of Universe about 500 Myr) by selecting matter particle and initializing with 32,000 stars on its location.We then follow dynamical evolution within environment.We compare two Milky-Way size haloes different accretion...
We present simulations of the dynamical evolution young embedded star clusters. Our initial conditions are directly derived from X-ray, infrared, and radio observations local systems, our models evolve both gas stars simultaneously. regions begin with clustered extended distributions stars, a distribution which can include filamentary structure in addition to surrounding stellar subclusters. find that become spherical, monolithic, smooth quite quickly, is dominated by gravitational...
We study the formation and evolution of filamentary configurations dark matter haloes in voids. Our investigation uses high-resolution Λ cold simulation CosmoGrid to look for void systems resembling VGS_31 elongated system three interacting galaxies that was recently discovered by Void Galaxy Survey inside a large Sloan Digital Sky galaxy redshift survey. H i data revealed these be embedded common envelope, possibly intravoid filament. In we similar mass, size environment. find total eight...
Context. J1407 (1SWASP J140747.93-394542.6 in full) is a young star the Scorpius-Centaurus OB association that underwent series of complex eclipses over 56 days 2007. To explain these, it was hypothesised secondary substellar companion, J1407b, has giant ring system filling large fraction Hill sphere, causing eclipses. Observations have not successfully detected but do rule out circular orbits for companion around primary star.
ABSTRACT Young massive clusters (YMCs) are the most intense regions of star formation in galaxies. Formulating a model for YMC while at same time meeting constraints from observations is, however, highly challenging. We show that forming YMCs requires clouds with densities ≳ 100 cm−3 to collide high velocities (≳ 20 km s−1). present first simulations which, starting moderate cloud ∼100 cm−3, able convert large amount mass into stars over period around 1 Myr, produce dense similar those...
We present Ekster, a new method for simulating star clusters from birth in live galaxy simulation that combines the smoothed-particle hydrodynamics (SPH) Phantom with $N$-body PeTar. With it becomes possible to simulate individual stars only moderately high resolution gas, allowing us study whole sections of rather than be restricted clouds. use this and cluster formation spiral arms, investigating massive GMCs arm regions lower mass clouds, two models different potentials. After selecting...
We present a novel way of modeling common envelope evolution in binary and few-body systems. consider the inspiral as driven by drag force with power-law dependence relative distance velocity. The orbital motion is resolved either direct $N$-body integration or solving set differential equations for elements derived using perturbation theory. Our formalism can model eccentricity during inspiral, it gives results consistent smoothed particles hydrodynamical simulations. apply our to events...
In the first few Myr massive stars dynamically interact, produce runaways and affect initial binary population. Observing interpreting dynamics of young clusters is key to our understanding star formation process predicting outcome stellar evolution. We have studied NGC6611 in Eagle Nebula (M16), a cluster hosting 19 O stars. used Gaia EDR3 data determine membership, age, kinematics including runaways. The membership analysis yields 137 members located at mean distance 1706 $\pm$ 7 pc....
Even though tens of directly imaged companions have been discovered in the past decades, number confirmed multiplanet systems is still small. Dynamical analysis these imposes important constraints on formation mechanisms wide-orbit companions. As part Young Suns Exoplanet Survey (YSES) we report detection a second planetary-mass companion around 17 Myr-old, solar-type star TYC 8998-760-1 that located Lower Centaurus Crux subgroup Scorpius-Centaurus association. The has projected physical...
Abstract We study the evolution of populations binary stars within massive cluster-forming regions. simulate formation young star clusters giant molecular clouds with masses ranging from 2 × 10 4 to 3.2 5 M ⊙ . use T orch , which couples stellar dynamics, magnetohydrodynamics, and formation, evolution, feedback through A muse framework. find that fraction decreases during cluster at all cloud masses. The binaries’ orbital properties also change, stronger quicker changes in denser, more...
We present MPWide, a platform independent communication library for performing message passing between computers. Our allows coupling of several local MPI applications through long distance network and is specifically optimized such communications. The implementation deliberately kept light-weight, the can be installed used without administrative privileges. only requirements are C++ compiler at least one open port to wide area on each site. In this paper we library, describe user interface,...
ABSTRACT Modelling star formation and resolving individual stars in numerical simulations of molecular clouds galaxies is highly challenging. Simulations on very small scales can be sufficiently well resolved to consistently follow the stars, whilst larger sinks that have masses sufficient fully sample IMF converted into realistic stellar populations. However, as yet, these methods do not work for intermediate scale resolutions whereby are more massive compared but IMF. In this paper, we...
Stars strongly impact their environment, and shape structures on all scales throughout the universe, in a process known as ``feedback''. Due to complexity of both stellar evolution physics larger astrophysical structures, there remain many unanswered questions about how feedback operates, what we can learn stars by studying imprint wider universe. In this white paper, summarize discussions from Lorentz Center meeting `Bringing Stellar Evolution Feedback Together' April 2022, identify key...
ABSTRACT Observations of clusters suffer from issues such as completeness, projection effects, resolving individual stars, and extinction. As such, how accurate measurements conclusions are likely to be? Here, we take cluster simulations (Westerlund2- Orion-type), synthetically observe them obtain luminosities, accounting for extinction, the inherent limits Gaia, then place within real Gaia DR3 catalogue. We attempt rediscover at distances between 500 4300 pc. show spatial kinematic criteria...
We present MPWide, a light weight communication library which allows efficient message passing over distributed network. MPWide has been designed to connect application running on (super)computing resources, and maximize the performance wide area networks for those without administrative privileges. It can be used provide message-passing between application, move files, make very fast connections in client-server environments. already applied enable cosmological simulations across up four...
Understanding the formation and evolution of high mass star clusters requires comparisons between theoretical observational data to be made. Unfortunately, while full phase space simulated regions is available, often only partial 2D spatial kinematic available for observed regions. This raises question as whether cluster parameters determined from alone are reliable representative real impact line-of-sight orientation. In this paper we derive a formed cloud-cloud collision with 6D space,...
We present results from our cosmological N-body simulation which consisted of 2048x2048x2048 particles and ran distributed across three supercomputers throughout Europe. The run, was performed as the concluding phase Gravitational Billion Body Problem DEISA project, integrated a 30 Mpc box dark matter using an optimized Tree/Particle Mesh integrator. up to day (z=0), obtained efficiency about 0.93 over 2048 cores compared single supercomputer run. In addition, we share experiences on...
We study the evolution of populations binary stars within massive cluster-forming regions. simulate formation young star clusters giant molecular clouds with masses ranging from 2 x 10$^{4}$ to 3.2 10$^{5}$ M$_{\odot}$. use Torch, which couples stellar dynamics, magnetohydrodynamics, and formation, evolution, feedback through AMUSE framework. find that fraction decreases during cluster at all cloud masses. The binaries' orbital properties also change, stronger quicker changes in denser, more...
We study the formation and evolution of cosmic web, using high-resolution CosmoGrid \$\Lambda\$CDM simulation. In particular, we investigate large-scale structure around void halo groups, compare this to observations VGS-31 galaxy group, which consists three interacting galaxies inside a large void. The such haloes shows great deal tenuous structure, with most systems being embedded in intra-void filaments walls. use Nexus+ algorithm detect walls CosmoGrid, find them be present detectable at...
Observations of clusters suffer from issues such as completeness, projection effects, resolving individual stars and extinction. As such, how accurate are measurements conclusions likely to be? Here, we take cluster simulations (Westerlund2- Orion- type), synthetically observe them obtain luminosities, accounting for extinction the inherent limits Gaia, then place within real Gaia DR3 catalogue. We attempt rediscover at distances between 500pc 4300pc. show spatial kinematic criteria which...