A5042425827- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Nuclear Physics and Applications
- Advanced Power Generation Technologies
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Galaxies: Formation, Evolution, Phenomena
- Radiative Heat Transfer Studies
- Global Energy Security and Policy
- Gas Dynamics and Kinetic Theory
- Mitochondrial Function and Pathology
- Solid-state spectroscopy and crystallography
- Cardiac Arrest and Resuscitation
- Vehicle emissions and performance
- Electric and Hybrid Vehicle Technologies
Heidelberg Institute for Theoretical Studies
2016-2025
Heidelberg University
2016-2023
GSI Helmholtz Centre for Heavy Ion Research
2023
Technical University of Darmstadt
2023
RIKEN
2023
Pioneer (Japan)
2023
Queen's University Belfast
2023
Robert Bosch (Germany)
2022
Robert Bosch (Taiwan)
2020
Stockholm University
2013-2017
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...
Double detonations in double white dwarf (WD) binaries undergoing unstable mass transfer have emerged recent years as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. One potential outcome this "dynamically driven double-degenerate double-detonation" (D^6) scenario is that companion WD survives explosion and flung away with a velocity equal to its > 1000 km/s pre-SN orbital velocity. We perform search for these hypervelocity runaway WDs using Gaia's second data...
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...
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...
We present 32 epochs of optical (3300-9700 \AA) spectrophotometric observations the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in galaxy M101, extending from -15 to +97 d with respect B-band maximum, obtained by Nearby Supernova Factory collaboration. is closest (\mu = 29.04) and brightest (Bmax 9.94 mag) observed since advent modern large scale programs for intensive periodic followup supernovae. Both synthetic light curve measurements spectral feature analysis...
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...
The progenitors of Type Ia Supernovae (SNe Ia) are still unknown, despite significant progress during the last years in theory and observations. Violent mergers two carbon--oxygen (CO) white dwarfs (WDs) one candidate suggested to be responsible for at least a fraction normal SNe Ia. Here, we simulate merger CO WDs using moving-mesh code that allows inclusion thin helium (He) shells (0.01\,\msun) on top WDs, an unprecedented numerical resolution. accretion He onto primary WD leads formation...
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...
Extended optical and near-IR observations reveal that SN 2009dc shares a number of similarities with normal Type Ia supernovae (SNe Ia), but is clearly overluminous, (pseudo-bolometric) peak luminosity log (L) = 43.47 (erg s−1). Its light curves decline slowly over half year after maximum [Δm15(B)true= 0.71], the early-time show secondary maxima, although minima between first second peaks are not very pronounced. The bluer bands exhibit an enhanced fading ∼200 d, which might be caused by...
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...
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...
Type-Ia supernovae result from binary systems that include a carbon-oxygen white dwarf, and these thermonuclear explosions typically produce 0.5 M_solar of radioactive 56Ni. The 56Ni is commonly believed to be buried deeply in the expanding supernova cloud. Surprisingly, SN2014J we detected lines at 158 812 keV decay (τ~8.8 days) earlier than expected several-week time scale, only ~20 days after explosion, with flux levels corresponding roughly 10% total amount Some mechanism must break...
The detection of GW170817 and the accompanying electromagnetic counterpart, AT2017gfo, have provided an important set observational constraints for theoretical models neutron star mergers, nucleosynthesis, radiative transfer kilonovae. We apply 3D Monte Carlo code ARTIS to produce synthetic light curves dynamical ejecta from a merger, which has been modelled with smooth-particle hydrodynamics (SPH) included neutrino interactions. Nucleosynthesis calculations provide energy released...