A5033660138- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Magnetic confinement fusion research
- Radio Astronomy Observations and Technology
- Plant Water Relations and Carbon Dynamics
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Geophysics and Sensor Technology
- Dark Matter and Cosmic Phenomena
- earthquake and tectonic studies
- Data Mining Algorithms and Applications
- Advanced Database Systems and Queries
- Radiology practices and education
- Seismic Waves and Analysis
- Space Satellite Systems and Control
- Photonic and Optical Devices
- Astronomical Observations and Instrumentation
- Inertial Sensor and Navigation
- CCD and CMOS Imaging Sensors
European Gravitational Observatory
2022-2024
ARC Centre of Excellence for All-sky Astrophysics
2018-2022
International Centre for Radio Astronomy Research
2018-2022
The University of Western Australia
2018-2022
ASTRO-3D
2019-2022
University of Sussex
2014-2016
We present VELOCIraptor, a massively parallel galaxy/(sub)halo finder that is also capable of robustly identifying tidally disrupted objects and separate stellar halos from galaxies. The code written in c++11, use the MPI OpenMP API's for parallelisation, includes python tools to read/manipulate data products produced. demonstrate power VELOCIraptor (sub)halo finder, showing how it can identify subhalos deep within host have negligible density contrasts their parent halo. find subhalo...
The Dark Energy Survey (DES) is a next generation optical survey aimed at understanding the accelerating expansion of universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform 5000 sq-degree wide field 30 supernova surveys, DES Collaboration built Camera (DECam), 3 square-degree, 570-Megapixel CCD camera that was installed prime focus Blanco 4-meter telescope Cerro Tololo Inter-American...
We present the Synthetic UniveRses For Surveys (surfs) simulations, a set of N-body/Hydro simulations concordance Λ Cold Dark Matter (ΛCDM) cosmology. These use Planck cosmology, contain up to 10 billion particles, and sample scales halo masses down 1 kpc 108 M⊙. identify track haloes from z = 24 today using state-of-the-art 6D finder merger tree builder. demonstrate that certain properties trees are numerically converged for composed ≳100 particles. Haloes smoothly grow in mass, Vmax, with...
Using the EAGLE suite of simulations, we demonstrate that both cold gas stripping {\it and} starvation inflow play an important role in quenching satellite galaxies across a range stellar and halo masses, $M_{\star}$ $M_{200}$. By quantifying balance between inflows, outflows, star formation rates, show even at $z=2$, only $\approx30\%$ are able to maintain equilibrium or grow their reservoir cool - compared $\approx50\%$ central this redshift. We find number orbits completed by is very good...
Satellite galaxies are commonly used as tracers to measure the line-of-sight (LOS)velocity dispersion (σLOS) of dark matter halo associated with their central galaxy, and thereby estimate halo's mass. Recent observational estimates Local Group, including Milky Way M31, suggest σ ∼50 km s−1, which is surprisingly low when compared theoretical expectation ∼100 s−1 for systems Does this pose a problem Lambda cold (ΛCDM)? We explore tension using SURFS suite N-body simulations, containing over...
We investigate the evolutionary connection between local IR-bright galaxies ($\log L_{\rm IR}\ge 11.4\,L_\odot$) and quasars. use high angular resolution ($\sim$ 0.3-0.4 arcsec $\sim$ few hundred parsecs) $8-13\,\mu$m ground-based spectroscopy to disentangle AGN mid-IR properties from those of star formation. The comparison nuclear $11.3\,\mu$m PAH feature emission that measured with Spitzer/IRS indicates formation is extended over a kpc in galaxies. contribution total IR luminosity lower...
Abstract We present T ree F rog , a massively parallel halo merger tree builder that is capable comparing different catalogues and producing trees. The code written in c++11, use the MPI OpenMP API’s for parallelisation, includes python tools to read/manipulate data products produced. correlates binding energy sorted particle ID lists between catalogues, determining optimal descendant/progenitor matches using multiple snapshots, merit function maximises number of shared particles...
Linking the properties of galaxies to assembly history their dark matter haloes is a central aim galaxy evolution theory. This paper introduces dimensionless parameter $s\in[0,1]$, "tree entropy", parametrise geometry halo's entire mass hierarchy, building on generalisation Shannon's information entropy. By construction, minimum entropy ($s=0$) corresponds smoothly assembled without any mergers. In contrast, highest ($s=1$) represents grown purely by equal-mass binary Using simulated merger...
Abstract Merger trees harvested from cosmological N -body simulations encode the assembly histories of dark matter halos over cosmic time and are a fundamental component semi-analytical models galaxy formation. The ability to compare tools used construct merger trees, namely halo finders tree building algorithms, in an unbiased systematic manner is critical assess quality trees. In this paper, we present dendrogram, novel method visualise which provides comprehensive characterisation halo’s...
Hierarchical models of structure formation predict that dark matter halo assembly histories are characterised by episodic mergers and interactions with other haloes. An accurate description this process will provide insights into the dynamical evolution haloes galaxies reside in them. Using large cosmological N-body simulations, we characterise orbits to study between substructure their hosts, how different evolutionary map classes orbits. We use two new software tools - WhereWolf, which...
Resolving faint galaxies in large volumes is critical for accurate cosmic reionisation simulations. While less demanding than hydrodynamical simulations, semi-analytic models still require very N-body simulations order to resolve the atomic cooling limit across whole history within box sizes $\gtrsim 100 \, h^{-1} {\rm Mpc}$. To facilitate this, we extend mass resolution of using a Monte Carlo algorithm. We also propose method evolve positions halos, which can be an input models. illustrate,...
Multi-messenger astrophysics provides valuable insights into the properties of physical Universe. These arise from complementary information carried by photons, gravitational waves, neutrinos and cosmic rays about individual sources source populations. When a wave (GW) candidate is identified Ligo, Virgo Kagra (LVK) observatory network, an alert sent to astronomers in order search for electromagnetic or neutrino counterparts. The current LVK framework generation consists Gravitational-Wave...
Using the EAGLE suite of simulations, we demonstrate that both cold gas stripping {\it and} starvation inflow play an important role in quenching satellite galaxies across a range stellar and halo masses, $M_{\star}$ $M_{200}$. By quantifying balance between inflows, outflows, star formation rates, show even at $z=2$, only $\approx30\%$ are able to maintain equilibrium or grow their reservoir cool - compared $\approx50\%$ central this redshift. We find number orbits completed by is very good...
Predicting the merger timescale ($\tau_{\rm merge}$) of merging dark matter halos, based on their orbital parameters and structural properties hosts, is a fundamental problem in gravitational dynamics that has important consequences for our understanding cosmological structure formation galaxy formation. Previous models predicting $\tau_{\rm merge}$ have shown varying degrees success when compared to results $N$-body simulations. We build this previous work propose new model draws insights...