A5003311827- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Critical Theory and Philosophy
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Political Economy and Marxism
- American Constitutional Law and Politics
- Political Philosophy and Ethics
- Contemporary Literature and Criticism
- Philosophy, Ethics, and Existentialism
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Astronomical Observations and Instrumentation
- Political and Economic history of UK and US
- Postmodernism in Literature and Education
- Crime, Deviance, and Social Control
- Coaching Methods and Impact
- Neutrino Physics Research
- Crime and Detective Fiction Studies
- Religion and Society Interactions
Queen's University Belfast
2016-2025
Swinburne University of Technology Sarawak Campus
2024
Queens University
2024
Northumbria University
2010-2023
Heidelberg Institute for Theoretical Studies
2011-2023
GSI Helmholtz Centre for Heavy Ion Research
2023
Technical University of Darmstadt
2023
RIKEN
2023
Pioneer (Japan)
2023
Heidelberg University
2018-2023
We present results for a suite of 14 three-dimensional, high-resolution hydrodynamical simulations delayed-detonation models Type Ia supernova (SN Ia) explosions. This model comprises the first set three-dimensional SN with detailed isotopic yield information. As such, it may serve as data base Chandrasekhar-mass nucleosynthetic yields and deriving synthetic observables such spectra light curves. employ physically motivated, stochastic based on turbulent velocity fluctuations fuel density to...
One of the most important questions regarding progenitor systems Type Ia supernovae (SNe Ia) is whether mergers two white dwarfs can lead to explosions that reproduce observations normal events. Here we present a fully three-dimensional simulation violent merger carbon-oxygen with masses $0.9 \mathrm{M_\odot}$ and $1.1 combining very high resolution exact initial conditions. A well-tested combination codes used study system. We start dynamical inspiral phase follow subsequent thermonuclear...
The explosion of sub-Chandrasekhar mass white dwarfs via the double detonation scenario is a potential explanation for type Ia supernovae. In this scenario, surface in helium layer initiates underlying carbon/oxygen core leading to an explosion. For given mass, lower bound has been determined on shell required dynamical burning during flash, which necessary prerequisite detonation. range and corresponding minimum masses, we investigate whether assumed capable triggering subsequent even...
Explosions of sub-Chandrasekhar-mass white dwarfs are one alternative to the standard Chandrasekhar-mass model Type Ia supernovae. They interesting since binary systems with primary should be common and this scenario would suggest a simple physical parameter which determines explosion brightness, namely mass exploding dwarf. Here we perform one-dimensional hydrodynamical simulations, associated post-processing nucleosynthesis multi-wavelength radiation transport calculations for pure...
We investigate whether pure deflagration models of Chandrasekhar-mass carbon–oxygen white dwarf stars can account for one or more subclass the observed population Type Ia supernova (SN Ia) explosions. compute a set 3D full-star hydrodynamic explosion models, in which strength is parametrized using multispot ignition approach. For each model, we calculate detailed nucleosynthesis yields post-processing step with 384 nuclide nuclear network. also synthetic observables our Monte Carlo radiative...
The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. We describe the data reduction strategy and products which are publicly available through ESO archive Data Release 1 (SSDR1). PESSTO uses New Technology Telescope with EFOSC2 SOFI to provide optical NIR spectroscopy imaging. target supernovae transients brighter than 20.5mag for classification. Science targets then selected follow-up based on...
We present the ATLAS discovery and initial analysis of first 18 days unusual transient event, ATLAS18qqn/AT2018cow. It is characterized by a high peak luminosity ($\sim$1.7 $\times$ 10$^{44}$ erg s$^{-1}$), rapidly evolving light curves ($>$5 mag rise to in $\sim$3.5 days), hot blackbody spectra, peaking at $\sim$27000 K that are relatively featureless unchanging over two weeks. The bolometric curve cannot be powered radioactive decay under realistic assumptions. detection high-energy...
Abridged. In the double detonation scenario for Type Ia supernovae (SNe Ia) a initiates in shell of He-rich material accreted from companion star by sub-Chandrasekhar-mass White Dwarf (WD). This drives shock front into carbon-oxygen (C/O) WD that triggers secondary core. The core results complete disruption WD. Earlier studies concluded this has difficulties accounting observed properties SNe since explosion ejecta are surrounded products explosive He burning shell. Recently, it was proposed...
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations used constrain explosion scenarios. We base our discussion on three-dimensional simulations a delayed detonation Chandrasekhar-mass white dwarf violent merger two dwarfs-realizations models appropriate most...
2002cx-like supernovae are a sub-class of sub-luminous Type Ia (SNe). Their light curves and spectra characterized by distinct features that indicate strong mixing the explosion ejecta. Pure turbulent deflagrations have been shown to produce such mixed Here, we present hydrodynamics, nucleosynthesis radiative-transfer calculations for 3D full-star deflagration Chandrasekhar-mass white dwarf. Our model is able reproduce characteristic observational SN 2005hk (a prototypical supernova), not...
A Monte Carlo code (artis) for modelling time-dependent three-dimensional spectral synthesis in chemically inhomogeneous models of Type Ia supernova ejecta is presented. Following the propagation γ-ray photons, emitted by radioactive decay nucleosynthesis products, energy deposited and radiative transfer problem solved self-consistently, enforcing constraint conservation comoving frame. Assuming a photoionization-dominated plasma, equations ionization equilibrium are together with thermal...
We assemble a sample of 24 hydrogen-poor super-luminous supernovae (SLSNe). Parameterizing the light curve shape through rise and decline timescales shows that two are highly correlated. Magnetar-powered models can reproduce correlation, with diversity in rates driven by diffusion timescale. Circumstellar interaction exhibit similar rise-decline relation, but only for narrow range densities, which may be problematic these models. find SLSNe approximately 3.5 magnitudes brighter have curves 3...
We present tardis – an open-source code for rapid spectral modelling of supernovae (SNe). Our goal is to develop a tool that sufficiently fast allow exploration the complex parameter spaces models SN ejecta. This can be used analyse growing number high-quality spectra being obtained by transient surveys. The uses Monte Carlo methods obtain self-consistent description plasma state and compute synthetic spectrum. It has modular design facilitate implementation range physical approximations...
We present theoretical delay times and rates of thermonuclear explosions that are thought to produce Type Ia supernovae, including the double-detonation sub-Chandrasekhar mass model, using population synthesis binary evolution code StarTrack. If detonations carbon-oxygen white dwarfs following a detonation in an accumulated layer helium on dwarf's surface ("double-detonation" models) able which characteristically similar those SNe Ia, then these may account for at least some substantial...
Thermonuclear explosions may arise in binaries which a CO white dwarf (WD) accretes He from companion. If the accretion rate allows sufficiently large mass of to accumulate prior ignition nuclear burning, surface layer detonate, giving rise an astrophysical transient. Detonation generates shock waves that propagate into underlying WD. This might directly ignite detonation at edge WD or compress core trigger near centre. either mechanism works, two detonations can release sufficient energy...
We present a sample of normal Type Ia supernovae (SNe Ia) from the Nearby Supernova Factory data set with spectrophotometry at sufficiently late phases to estimate ejected mass using bolometric light curve. measure 56Ni masses peak luminosity, then compare luminosity in 56Co-decay tail expected rate radioactive energy release ejecta given mass. infer Bayesian context semi-analytic model ejecta, incorporating constraints contemporary numerical models as priors on density structure and...
Accretion disk winds are thought to produce many of the characteristic features seen in spectra active galactic nuclei (AGN) and quasi-stellar objects (QSOs). These outflows also represent a natural form feedback between central supermassive black hole its host galaxy. The mechanism for driving this mass loss remains unknown, although radiation pressure mediated by spectral lines is leading candidate. Here, we calculate ionization state of, emergent for, hydrodynamic simulation line-driven...
We investigate the brightness distribution expected for thermonuclear explosions that might result from ignition of a detonation during violent merger white dwarf (WD) binaries. Violent WD mergers are subclass canonical double degenerate scenario where two carbon–oxygen (CO) WDs merge when larger fills its Roche lobe. Determining their is critical evaluating whether such an explosion model could be responsible significant fraction observed population Type Ia supernovae (SNe Ia). argue...
Stellar evolution models predict the existence of hybrid white dwarfs (WDs) with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born masses ~1.1 Msun, WDs in binary system may easily approach Chandrasekhar mass (MCh) accretion and give rise to thermonuclear explosion. Here, we investigate off-centre deflagration near-MCh WD under assumption that nuclear burning only occurs carbon-rich material. Performing hydrodynamics simulations explosion detailed nucleosynthesis...
The ejected mass distribution of Type Ia supernovae (SNe Ia) directly probes progenitor evolutionary history and explosion mechanisms, with implications for their use as cosmological probes.Although the Chandrasekhar is a natural scale white dwarfs SNe Ia, models allowing to explode at other masses have attracted much recent attention.Using an empirical relation between light-curve width, we derive M ej 56 Ni sample 337 redshifts z < 0.7 used in analyses.We hierarchical Bayesian inference...