A5025672621- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Nuclear physics research studies
- Astrophysics and Star Formation Studies
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- High-pressure geophysics and materials
- Particle Detector Development and Performance
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- Nuclear Physics and Applications
- Adaptive optics and wavefront sensing
- Astronomical and nuclear sciences
- Geological and Geophysical Studies
- Nuclear reactor physics and engineering
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Mitochondrial Function and Pathology
- Atomic and Molecular Physics
- earthquake and tectonic studies
UNSW Sydney
2017-2024
Australian Defence Force Academy
2017-2024
University of Canberra
2020-2024
UNSW Canberra
2020-2024
ACT Government
2016-2023
CTA Observatory
2021
Canberra (United Kingdom)
2020-2021
Australian National University
2015-2020
Mount Stromlo Observatory
2011-2019
ARC Centre of Excellence for All-sky Astrophysics
2014-2018
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...
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...
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...
During the course of an ongoing CCD monitoring program to investigate low-level light variations in subdwarf B (sdB) stars, we have serendipitously discovered a new class low-amplitude, multimode sdB pulsators with periods order hour. These are more than factor 10 longer those previously known (EC 14026 stars), implying that they due gravity modes rather pressure modes. The period found only among cooler where surprisingly common. iron opacity instability drives short-period EC stars is...
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...
Context: Manganese is predominantly synthesised in Type Ia supernova (SN Ia) explosions. Owing to the entropy dependence of Mn yield explosive thermonuclear burning, SNe involving near Chandrasekhar-mass white dwarfs (WDs) are predicted produce Fe ratios significantly exceeding those SN explosions sub-Chandrasekhar mass primary WDs. Of all current explosion models, only models near-Chandrasekhar WDs [Mn/Fe] > 0.0. Aims: Using specific yields for competing scenarios, we aim constrain relative...
SN 2014J in M82 is the closest detected Type Ia supernova (SN Ia) at least 28 years and perhaps 410 years. Despite its small distance of 3.3 Mpc, surprisingly faint, peaking V = 10.6 mag, assuming a typical luminosity, we infer an observed visual extinction A_V 2.0 +/- 0.1 mag. But this picture, with R_V 1.6 0.2, too simple to account for all observations. We combine 10 epochs (spanning month) HST/STIS ultraviolet through near-infrared spectroscopy HST/WFC3, KAIT, FanCam photometry from...
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...
In the classical picture, electron-capture supernovae and accretion-induced collapse of oxygen-neon white dwarfs (ONeWDs) undergo an oxygen deflagration phase before gravitational produces a neutron star (NS). These types core events are postulated to explain several astronomical phenomena. this work, is simulated for first time using multidimensional hydrodynamics, with aim gaining new insight into explosive deaths $8-10~M_\odot$ stars ONeWDs that accrete material from binary companion...
We develop and calibrate a realistic model flame for hydrodynamic simulations of deflagrations in white dwarf (Type Ia) supernovae. Our builds on the advection-diffusion-reaction Khokhlov includes electron screening Coulomb corrections to equation state self-consistent way. this flame—its energetics timescales energy release neutronization—with self-heating reaction network calculations that include both these effects up-to-date weak interactions. The burned material evolves postflame due...
In a companion paper, Seitenzahl et al. have presented set of three-dimensional delayed detonation models for thermonuclear explosions near-Chandrasekhar-mass white dwarfs (WDs). Here, we present multidimensional radiative transfer simulations that provide synthetic light curves and spectra those models. The model sequence explores both changes in the strength deflagration phase (which is controlled by ignition configuration our models) WD central density. agreement with previous studies,...
Some explosion models for Type Ia supernovae (SN Ia), such as the gravitationally confined detonation (GCD) or double sub-Chandrasekhar (DDSC) models, rely on spontaneous initiation of a in degenerate C/O material white dwarf. The length scales pertinent to are notoriously unresolved multi-dimensional stellar simulations, prompting use results 1D simulations at higher resolution, ones performed this work, guidelines deciding whether not conditions reached dimensional full star successfully...
We revisit the evidence for contribution of long-lived radioactive nuclides 44Ti, 55Fe, 56Co, 57Co, and 60Co to UVOIR light curve SN 1987A. show that V-band luminosity constitutes a roughly constant fraction bolometric between 900 1900 days, we obtain an approximate out 4334 days by scaling late time data factor where no is available. Considering five most relevant decay chains starting at 55Co, 56Ni, 57Ni, 60Co, perform least squares fit constructed composite curve. For nickel isotopes,...
The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay $^{56}$Ni to $^{56}$Co at early times, and $^{56}$Fe from ~60 days after explosion. We examine evolution [Co III] 5892 A emission complex during nebular phase for SNe with multiple spectra show that line flux follows square mass as a function time. This result indicates both efficient local energy deposition positrons produced in decay, long-term stability ionization state nebula. compile 77 25 SN literature...
In the version of single-degenerate scenario Type Ia supernovae (SNe Ia) studied here, a carbon–oxygen white dwarf explodes close to Chandrasekhar limit after accreting material from non-degenerate helium (He) companion star. present study, we employ Stellar GADGET code perform three-dimensional hydrodynamical simulations interaction SN ejecta with He star taking into account its orbital motion and spin. It is found that only 2%–5% initial mass stripped off outer layers stars due supernova...
We investigate evolutionary pathways leading to neutron star formation through the collapse of oxygen-neon white dwarf (ONe WD) stars in interacting binaries. consider (1) non-dynamical mass transfer where an ONe WD approaches Chandrasekhar accretion-induced (AIC) and (2) dynamical timescale merger-induced (MIC) between another WD. present rates, delay times, progenitor properties for two different treatments common envelope evolution. show that AIC are formed via many channels most dominant...
iPTF14atg, a subluminous peculiar Type Ia supernova (SN Ia) similar to SN 2002es, is the first for which strong UV flash was observed in early-time light curves. This has been interpreted as evidence single-degenerate (SD) progenitor system, where such signal expected from interactions between ejecta and non-degenerate companion star. Here, we compare synthetic observables of multidimensional state-of-the-art explosion models different scenarios curves spectra iPTF14atg. From our models,...
We present optical and near-infrared photometric spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. 2013ej is a hydrogen-rich supernova, classified as Type IIL due its relatively fast decline following initial peak. It has high peak luminosity (absolute magnitude MV = −17.6) but small 56Ni production ∼0.023 M⊙. Its photospheric evolution similar other II SNe, with shallow absorption Hα profile typical for IIL. During transition radioactive decay tail...