We explore, using a state-of-the-art simulation code in 3D and to late enough times to witness final observables, the dependence of core-collapse supernova explosions on the nuclear equation of state. Going beyond questions of explodability, we compare final explosion energies, nucleosynthetic yields, recoil kicks, and gravitational-wave and neutrino signatures using the SFHo and DD2 nuclear equations of state (EOS) for a 9-$M_{\odot}$/solar-metallicity progenitor star. The DD2 EOS is stiffer and has a lower effective nucleon mass. The result is a more extended protoneutron star (PNS) and lower central densities. As a consequence, the mean neutrino energies, final explosion energy, and recoil kick speed are lower. Moreover, the evolution of PNS convection differs between the two EOS models in significant ways. This translates in part into interestingly altered neutrino ``light" curves and noticeably altered gravitational-wave signal strengths and frequency characteristics that may be diagnostic. The faster exploding model (SFHo) yields slightly more neutron-rich ejecta and more species with atomic weights between 60 and 90 and a weak r-process. However, this is merely a preliminary study. The next step is a more comprehensive and multi-progenitor set of 3D supernova simulations for various EOSes to late times when the observables have asymptoted. Such a future investigation will have a direct bearing on the neutron star and black hole birth mass functions and the quest towards a fully quantitative theory of supernova observables.
The death of massive stars is shrouded in many mysteries. One of them is the mechanism that overturns the collapse of the degenerate iron core into an explosion, a process that determines the supernova explosion energy, properties of the surviving compact remnant, and the nucleosynthetic yields. The number of core-collapse supernova observations has been growing with an accelerating pace thanks to modern time-domain astronomical surveys and new tests of the explosion mechanism are becoming possible. We review predictions of parameterized supernova explosion models and compare them with explosi…
A model of a supernova explosion inside a dense extended hydrogenless envelope is proposed to explain the properties of the light curve for one of the superluminous supernovae PTF12dam. It is argued in the literature that the flux of this supernova rises too fast to be explained by the explosion model due to the instability associated with the electron-positron pair production (pair-instability supernova, PISNe), but it is well described by the models with energy input by a magnetar. We show that the PTF12dam-type supernovae can be explained without a magnetar in a model with a radiative shock…
Most existing criteria derived from progenitor properties of core-collapse supernovae are not very accurate in predicting explosion outcomes. We present a novel look at identifying the explosion outcome of core-collapse supernovae using a machine learning approach. Informed by a sample of 100 2D axisymmetric supernova simulations evolved with Fornax, we train and evaluate a random forest classifier as an explosion predictor. Furthermore, we examine physics-based feature sets including the compactness parameter, the Ertl condition, and a newly developed set that characterizes the silicon/oxygen…
By performing axisymmetric hydrodynamic simulations of core-collapse supernovae with spectral neutrino transport based on the isotropic diffusion source approximation scheme, we support the assumption that the neutrino-heating mechanism aided by the standing accretion shock instability and convection can initiate an explosion of a 13 $M_{\odot}$ star. Our results show that bipolar explosions are more likely to be associated with models which include rotation. We point out that models, which form a north-south symmetric bipolar explosion, can lead to larger explosion energies than for the corre…
We report on a method, PUSH, for triggering core-collapse supernova (CCSN) explosions of massive stars in spherical symmetry. This method provides a framework to study many important aspects of core collapse supernovae: the effects of the shock passage through the star, explosive supernova nucleosynthesis and the progenitor-remnant connection. Here we give an overview of the method, compare the results to multi-dimensional simulations and investigate the effects of the progenitor and the equation of state on black hole formation.
We present advances in modeling Type IIP supernovae using MESA for evolution to shock breakout coupled with STELLA for generating light and radial velocity curves. Explosion models and synthetic light curves can be used to translate observable properties of supernovae (such as the luminosity at day 50 and the duration of the plateau, as well as the observable quantity $ET$, defined as the time-weighted integrated luminosity that would have been generated if there was no ${\rm ^{56}Ni}$ in the ejecta) into families of explosions which produce the same light curve and velocities on the plateau. …
In this fifth paper of the series, we use the parametrized, spherically symmetric explosion method PUSH to investigate the impact of eight different nuclear equations of state (EOS). We present and discuss the explosion properties and the detailed nucleosynthesis yields, and predict the remnant (neutron star or black hole) for all our simulations. For this, we perform two sets of simulations. One, a complete study of non-rotating stars from 11 to 40 M$_{\odot}$ at three different metallicities using the SFHo EOS. And two, a suite of simulations for four progenitors (16 M$_{\odot}$ at three met…
The explosion outcome and diagnostics of core-collapse supernovae depend sensitively on the nature of the stellar progenitor, but most studies to date have focused exclusively on one-dimensional, spherically-symmetric massive star progenitors. We present some of the first core-collapse supernovae simulations of three-dimensional massive star supernovae progenitors, a 12.5- and a 15-M$_{\odot}$ model, evolved in three-dimensions from collapse to bounce through explosion with the radiation-hydrodynamic code F{\sc{ornax}}. We compare the results using those starting from three-dimensional progeni…
In a previously presented proof-of-principle study we established a parametrized spherically symmetric explosion method (PUSH) that can reproduce many features of core-collapse supernovae. The present paper goes beyond a specific application that is able to reproduce observational properties of SN1987A and performs a systematic study of the explosion properties for an extensive set of non-rotating, solar metallicity stellar progenitor models in the mass range from 10.8 to 120 M$_\odot$.This includes the transition from neutron stars to black holes as the final result of the collapse of massive…
We present results of a systematic study of the mass-loss properties of Type IIn supernova progenitors within decades before their explosion. We apply an analytic light curve model to 11 Type IIn supernova bolometric light curves to derive the circumstellar medium properties. We reconstruct the mass-loss histories based on the estimated circumstellar medium properties. The estimated mass-loss rates are mostly higher than 1e-3 Msun/yr and they are consistent with those obtained by other methods. The mass-loss rates are often found to be constantly high within decades before their explosion. Thi…
Details of the explosion mechanism of core-collapse supernovae (CCSNe) are not yet fully understood. There is an increasing number of numerical examples by ab-initio core-collapse simulations leading to an explosion. Most, if not all, of the ab-initio core-collapse simulations represent a `slow' explosion in which the observed explosion energy ($\sim 10^{51}$ ergs) is reached in a timescale of $\gtrsim1$ second. It is, however, unclear whether such a slow explosion is consistent with observations. In this work, by performing nuclear reaction network calculations for a range of the explosion ti…
We find that the remnant of supernova (SN) 1987A share some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular mom…
The observed distribution of neutron star (NS) masses reflects the physics of core-collapse supernova explosions and the structure of the massive stars that produce them at the end of their evolution. We present a Bayesian analysis that directly compares the NS mass distribution observed in double NS systems to theoretical models of NS formation. We find that models with standard binary mass ratio distributions are strongly preferred over independently picking the masses from the initial mass function, although the strength of the inference depends on whether current assumptions for identifyin…
Type Ia supernovae are associated with thermonuclear explosions of white dwarf stars. Combustion processes convert material in nuclear reactions and release the energy required to explode the stars. At the same time, they produce the radioactive species that power radiation and give rise to the formation of the observables. Therefore, the physical mechanism of the combustion processes, as reviewed here, is the key to understand these astrophysical events. Theory establishes two distinct modes of propagation for combustion fronts: subsonic deflagrations and supersonic detonations. Both are assu…
We study the impact of a small-scale dynamo in core-collapse supernovae using a 3D neutrino magnetohydrodynamics simulation of a $15 M_\odot$ progenitor. The weak seed field is amplified exponentially in the gain region once neutrino-driven convection develops, and remains dominated by small-scale structures. About $250\, \mathrm{ms}$ after bounce, the field energy in the gain region reaches $\mathord{\sim} 50\%$ of kinetic equipartition. This supports the development of a neutrino-driven explosion with modest global anisotropy, which does not occur in a corresponding model without magnetic fi…
In a previously presented proof-of-principle study, we established a parametrized spherically symmetric explosion method (PUSH) that can reproduce many features of core-collapse supernovae for a wide range of pre-explosion models. The method is based on the neutrino-driven mechanism and follows collapse, bounce and explosion. There are two crucial aspects of our model for nucleosynthesis predictions. First, the mass cut and explosion energy emerge simultaneously from the simulation (determining, for each stellar model, the amount of Fe-group ejecta). Second, the interactions between neutrinos …
Helium star - carbon-oxygen white dwarf (CO WD) binaries are potential single-degenerate progenitor systems of thermonuclear supernovae. Revisiting a set of binary evolution calculations using the stellar evolution code $\texttt{MESA}$, we refine our previous predictions about which systems can lead to a thermonuclear supernova and then characterize the properties of the helium star donor at the time of explosion. We convert these model properties to NUV/optical magnitudes assuming a blackbody spectrum and support this approach using a matched stellar atmosphere model. These models will be val…
An important result in core-collapse supernova (CCSN) theory is that spherically-symmetric, one-dimensional simulations routinely fail to explode, yet multi-dimensional simulations often explode. Numerical investigations suggest that turbulence eases the condition for explosion, but how is not fully understood. We develop a turbulence model for neutrino-driven convection, and show that this turbulence model reduces the condition for explosions by about 30%, in concordance with multi-dimensional simulations. In addition, we identify which turbulent terms enable explosions. Contrary to prior sug…
An electron-capture supernova (ECSN) is a core-collapse supernova (CCSN) explosion of a super-asymptotic giant branch (SAGB) star with a main-sequence mass $M_{\rm ms}\sim7-9.5M_\odot$. The explosion takes place in accordance with core bounce and subsequent neutrino heating and is a unique example successfully produced by first-principle simulations. This allows us to derive a first self-consistent multicolor light curves of a CCSN. Adopting the explosion properties derived by the first-principle simulation, i.e., the low explosion energy of $1.5\times10^{50}$ erg and the small $^{56}$Ni mass …
We present the SuperNova Explosion Code (SNEC), an open-source Lagrangian code for the hydrodynamics and equilibrium-diffusion radiation transport in the expanding envelopes of supernovae. Given a model of a progenitor star, an explosion energy, and an amount and distribution of radioactive nickel, SNEC generates the bolometric light curve, as well as the light curves in different broad bands assuming black body emission. As a first application of SNEC, we consider the explosions of a grid of 15 Msun (at zero-age main sequence) stars whose hydrogen envelopes are stripped to different extents a…
I raise the possibility that the pre-explosion outburst (PEO) of the type IIn supernova 2010mc (PTF 10tel) was energized by mass accretion onto an O main-sequence stellar companion. According to this suggestion the SN progenitor suffered a rapid expansion within months before explosion. The expansion was driven by leakage of energy from the core where vigorous oxygen nuclear burning takes place within a year prior to explosion. This expansion triggered mass transfer onto the secondary star. Most of the extra energy of the outburst comes from the accretion of ~0.1Mo onto the secondary star. As …
Most supernova explosions accompany the death of a massive star. These explosions give birth to neutron stars and black holes and eject solar masses of heavy elements. However, determining the mechanism of explosion has been a half-century journey of great complexity. In this paper, we present our perspective of the status of this theoretical quest and the physics and astrophysics upon which its resolution seems to depend. The delayed neutrino-heating mechanism is emerging as a robust solution, but there remain many issues to address, not the least of which involves the chaos of the dynamics, …
The observed sub-class of "superluminous" Type Ia supernovae lacks a convincing theoretical explanation. If the emission of such objects were powered exclusively by radioactive decay of 56Ni formed in the explosion, a progenitor mass close to or even above the Chandrasekhar limit for a non-rotating white dwarf star would be required. Masses significantly exceeding this limit can be supported by differential rotation. We, therefore, explore explosions and predict observables for various scenarios resulting from differentially rotating carbon-oxygen white dwarfs close to their respective limit o…
We present a new approach to understand the landscape of supernova explosion energies, ejected nickel masses, and neutron star birth masses. In contrast to other recent parametric approaches, our model predicts the properties of neutrino-driven explosions based on the pre-collapse stellar structure without the need for hydrodynamic simulations. The model is based on physically motivated scaling laws and simple differential equations describing the shock propagation, the contraction of the neutron star, the neutrino emission, the heating conditions, and the explosion energetics. Using model par…
We find that convective regions of collapsing massive stellar cores possess sufficient stochastic angular momentum to form intermittent accretion disks around the newly born neutron star (NS) or black hole (BH), as required by the jittering-jets model for core-collapse supernova (CCSN) explosions. To reach this conclusion we derive an approximate expression for stochastic specific angular momentum in convection layers of stars, and using the mixing-length theory apply it to four stellar models at core-collapse epoch. In all models, evolved using the stellar evolution code MESA, the convective …
The explosion mechanism of core-collapse supernovae is a long-standing problem in stellar astrophysics. We briefly outline the main contenders for a solution and review recent efforts to model core-collapse supernova explosions by means of multi-dimensional simulations. We discuss several suggestions for solving the problem of missing or delayed neutrino-driven explosions in three-dimensional supernova models, including -- among others -- variations in the microphysics and large seed perturbations in convective burning shells. Focusing on the neutrino-driven mechanism, we summarise currents ef…
Recent observational data on the type Ia supernova rates are in excellent agreement with the old prediction of the population synthesis of binary stars and confirm that the overwhelming majority of type Ia supernovas (~99%) in elliptical galaxies form via mergers of binary white dwarfs with the total mass exceeding the Chandrasekhar limit.
We investigate effects of aspherical energy deposition in core-collapse supernovae on the light curve of the supernova shock breakout. We performed two-dimensional hydrodynamical calculations of an aspherical supernova explosion to obtain the time when a shock wave generated in the stellar interior reaches the stellar surface in each radial direction. Using results of the calculations, light curves during the shock breakout are derived in an approximate way. We show that the light curve during the shock breakout can be a strong indicator of aspherical properties of core-collapse supernovae.
Under the assumption that jets explode core collapse supernovae in a negative jet feedback mechanism (JFM), I show that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation reads Espin/Eexp~(Eexp/1e52erg). It shows that within the frame of the JFM explo…
I analyse some properties of the luminous transient event SN 2019zrk and conclude that jets were the main powering sources of the pre-explosion outburst (precursor) and ejection of a massive circumstellar matter (CSM), of the very energetic explosion itself, and of the post-explosion bump in the light curve. The pre-explosion energy source is mainly a companion (main sequence, Wolf-Rayet, neutron star or black hole) star that accreted mass and launched jets. I find that the fast expansion of the CSM after acceleration by the explosion ejecta requires the explosion energy to be >10^{52} erg. On…
The widespread detection of 60Fe in geological and lunar archives provides compelling evidence for recent nearby supernova explosions within $\sim 100$ pc around 3 Myr and 7 Myr ago. The blasts from these explosions had a profound effect on the heliosphere. We perform new calculations to study the compression of the heliosphere due to a supernova blast. Assuming a steady but non-isotropic solar wind, we explore a range of properties appropriate for supernova distances inspired by recent 60Fe data, and for a 20 pc supernova proposed to account for mass extinctions at the end-Devonian period. We…
Type Ibn supernova SN~2010al is explored to infer parameters of supernova and a circumstellar (CS) shell. The CS interaction model combined with the spectral model of 4600Å blend suggests the explosion of a WR star with the energy of $(1-1.5)\times10^{51}$ erg inside a dense confined CS shell with the mass of $\sim0.1$\msun\ and kinetic energy of $\sim 10^{48}$ erg. The confined CS shell has been formed during the last 0.4 yr prior to the core collapse.
Supernova explosions are among the most energetic phenomena in the known universe. There are suggestions that cosmic rays up to EeV energies might be accelerated in the young supernova shell on time scales of a few weeks to years, which would lead to TeV neutrino radiation. The data taken with the AMANDA neutrino telescope in the years 2000 to 2006 is analysed with a likelihood approach in order to search for directional and temporal coincidences between neutrino events and optically observed extra-galactic supernovae. The supernovae were stacked in order to enhance the sensitivity. A catalogu…
Understanding how massive stars die as supernovae is a crucial question in modern astrophysics. Supernovae are powerful stellar explosions and key drivers in the cosmic baryonic cycles by injecting their explosion energy and heavy elements to the interstellar medium that forms new stars. After decades of effort, astrophysicists have built up a stand model for the explosion mechanism of massive stars. However, this model is challenged by new kinds of stellar explosions discovered in the recent transit surveys. In particular, the new population called superluminous supernovae, which are a hundre…
Recent progress in numerical simulations of thermonuclear supernova explosions brings up a unique opportunity in studying the progenitors of Type Ia supernovae. Coupling state-of-the-art explosion models with detailed hydrodynamical simulations of the supernova remnant evolution and the most up-to-date atomic data for X-ray emission calculations makes it possible to create realistic synthetic X-ray spectra for the supernova remnant phase. Comparing such spectra with high quality observations of supernova remnants could allow to constrain the explosion mechanism and the progenitor of the supern…
The recent study of SN 2013fs flash spectrum suggests enormous for SN IIP explosion energy, far beyond possibilities of the neutrino mechanism. The issue of the explosion energy of SN 2013fs is revisited making use of effects of the early supernova interaction with the dense circumstellar shell. The velocity of the cold dense shell between reverse and forward shocks is inferred from the analysis of the broad \heii\,4686\,Å on day 2.4. This velocity alongside with other observables provide us with an alternative energy estimate of $\sim1.8\times10^{51}$\,erg for the preferred mass of $\sim10$\m…
Core-collapse supernovae are accompanied by formation of neutron stars. The gravitation energy is transformed into the energy of the explosion, observed as SN II, SN Ib,c type supernovae. We present results of 2-D MHD simulations, where the source of energy is rotation, and magnetic field serves as a "transition belt" for the transformation of the rotation energy into the energy of the explosion. The toroidal part of the magnetic energy initially grows linearly with time due to differential rotation. When the twisted toroidal component strongly exceeds the poloidal field, magneto-rotational in…
Explosion mechanism of core-collapse supernovae is not fully understood yet. In this work, we give constraints on the explosion timescale based on $^{56}$Ni synthesized by supernova explosions. First, we systematically analyze multi-band light curves of 82 stripped-envelope supernovae (SESNe) to obtain bolometric light curves, which is among the largest samples of the bolometric light curves of SESNe derived from the multi-band spectral energy distribution. We measure the decline timescale and the peak luminosity of the light curves and estimate the ejecta mass ($M_{\rm ej}$) and $^{56}$Ni mas…
Core-collapse supernovae presumably explode because trapped neutrinos push the material out of the stellar envelope. This process is directly controlled by the weak scale $v$: we argue that supernova explosions happen only if fundamental constants are tuned within a factor of few as $v \sim Λ_{\rm QCD}^{3/4} M_{\rm Pl}^{1/4}$, such that neutrinos are trapped in supernovae for a time comparable to the gravitational time-scale. We provide analytic arguments and simulations in spherical approximation, that need to be validated by more comprehensive simulations. The above result can be important f…
Motivated by a recent discovery of Supernova 2010gx and numerical results of Fryer et al.(2010), we simulate light curves for several type I supernova models, enshrouded by dense circumstellar shells, or "super-wind", rich in carbon and oxygen and having no hydrogen. We demonstrate that the most luminous events like SN2010gx can be explained by those models at moderate explosion energies (2-3) foe if the total mass of SN ejecta and a shell is (3-5) Msun and the radius of the shell is ~10^{16} cm.
We examine the binding energies of massive stripped-envelope core collapse supernova (SECCSN) progenitors with the stellar evolution code MESA, and find that the jittering jets explosion mechanism is preferred for explosions where carbon-oxygen cores with masses of $>20 M_\odot$ collapse to leave a neutron star (NS) remnant. We calculate the binding energy at core collapse under the assumption that the remnant is a NS. Namely, stellar gas above mass coordinate of $~1.5-2.5 M_\odot$ is ejected in the explosion. We find that the typical binding energy of the ejecta of stripped-envelope progenito…
We investigate the post-explosion phase in core-collapse supernovae with 2D hydrodynamical simulations and a simple neutrino treatment. The latter allows us to perform 46 simulations and follow the evolution of the 32 successful explosions during several seconds. We present a broad study based on three progenitors (11.2 $M_\odot$, 15 $M_\odot$, and 27 $M_\odot$), different neutrino-heating efficiencies, and various rotation rates. We show that the first seconds after shock revival determine the final explosion energy, remnant mass, and properties of ejected matter. Our results suggest that a c…
When a massive star ends its life, its core collapses, forming a neutron star or black hole and producing some of the most energetic explosions in the universe. Core-collapse supernovae and long-duration gamma-ray bursts are the violent signatures of compact remnant formation. As such, both fields are intertwined and, coupled with theory, observations of transients can help us better understand compact remnants just as neutron star and black hole observations can constrain the supernova and gamma-ray burst engine. We review these ties in this paper.
We investigate the possibility of a supernova in supermassive ($5 \times 10^4 \;M_\odot$) population III stars induced by a general relativistic instability occurring in the helium burning phase. This explosion could occur via rapid helium burning during an early contraction of the isentropic core. Such an explosion would be visible to future telescopes and could disrupt the proposed direct collapse formation channel for early universe supermassive black holes. We simulate first the stellar evolution from hydrogen burning using a 1D stellar evolution code with a post Newtonian approximation; a…
Progress in the three-dimensional modeling of supernovae (SN) prompts us to revisit the supernova remnant (SNR) phase. We continue our study of the imprint of a thermonuclear explosion on the SNR it produces, that we started with a delayed-detonation model of a Chandrasekhar-mass white dwarf. Here we compare two different types of explosion models, each with two variants: two delayed detonation models (N100ddt, N5ddt) and two pure deflagration models (N100def, N5def), where the N number parametrizes the ignition. The output of each SN simulation is used as input of a SNR simulation carried on …
Various lines of evidence suggest that very massive stars experience extreme mass-loss episodes shortly before they explode as a supernova. Interestingly, several models predict such pre-explosion outbursts. Establishing a causal connection between these mass-loss episodes and the final supernova explosion will provide a novel way to study pre-supernova massive-star evolution. Here we report on observations of a remarkable mass-loss event detected 40 days prior to the explosion of the Type IIn supernova SN 2010mc (PTF 10tel). Our photometric and spectroscopic data suggest that this event is a …
A detection of a core-collapse supernova signal with an Advanced LIGO and Virgo gravitational-wave detector network will allow us to measure astrophysical parameters of the source. In real advanced gravitational-wave detector data there are transient noise artifacts that may mimic a true gravitational-wave signal. In this paper, we outline a procedure implemented in the Supernova Model Evidence Extractor (SMEE) that determines if a core-collapse supernova signal candidate is a noise artefact, a rapidly-rotating core-collapse supernova signal, or a neutrino explosion mechanism core-collapse sup…
Understanding gravitational wave emission from core-collapse supernovae will be essential for their detection with current and future gravitational wave detectors. This requires a sample of waveforms from modern 3D supernova simulations reaching well into the explosion phase, where gravitational wave emission is expected to peak. However, recent waveforms from 3D simulations with multi-group neutrino transport do not reach far into the explosion phase, and some are still obtained from non-exploding models. We therefore calculate waveforms up to 0.9\,s after bounce using the neutrino hydrodynam…
In this Letter, we report on the gravitational wave signal computed in the context of an $ab$ $initio$, three-dimensional simulation of a core collapse supernova explosion, beginning with a 15M$_\odot$ star and using state-of-the-art weak interactions. The simulation was performed with our neutrino hydrodynamics code Chimera. We discuss the potential for detection of our predicted gravitational signal by the current generation of gravitational wave detectors.
Progenitors of long GRBs, and core-collapse supernovae in general, may have two separate mechanisms driving the outflows: quasi-isotropic neutrino-driven supernova explosions followed by a highly collimated relativistic outflow driven by the GRB central engine, a black hole or a magnetar. We consider the dynamics of the second GRB-driven explosion propagating through expanding envelope generated by the passage of the primary supernova shock. Beyond the central core, in the region of steep density gradient created by the SN shock breakout, the accelerating secondary quasi-spherical GRB shock be…
The nature of core-collapse supernova (SN) explosions is yet incompletely understood. The present article revisits the scenario in which the release of latent heat due to a first-order phase transition, from normal nuclear matter to the quark-gluon plasma, liberates the necessary energy to explain observed SN explosions. Here, the role of the metallicity of the stellar progenitor is investigated, comparing a solar metallicity and a low-metallicity case, both having a zero-age main sequence (ZAMS) mass of 75 $M_\odot$. It is found that low-metallicity models belong exclusively to the failed SN …
Gamma ray lines are expected to be emitted as part of the afterglow of supernova explosions, because radioactive decay of freshly synthesised nuclei occurs. Significant radioactive gamma ray line emission is expected from 56Ni and 44Ti decay on time scales of the initial explosion (56Ni, tau~days) and the young supernova remnant (44Ti,tau~90 years). Less specific, and rather informative for the supernova population as a whole, are lessons from longer lived isotopes such as 26Al and 60Fe. From isotopes of elements heavier than iron group elements, any interesting gamma-ray line emission is too …
In the meeting SN 1987A 30 years later, I presented my minority view that the majority (or even all) of core collapse supernovae (CCSNe) are driven by jets rather than by neutrinos, and that the majority of type Ia supernovae (SN Ia) reach their explosion via the core degenerate scenario. New simulations presented at the meeting did not achieve an explosion of CCSNe. I critically examine other arguments that where presented in support of the neutrino-driven model, and present counter arguments that support the jet-driven explosion mechanism. The jets operate via a negative jet feedback mechani…
Upcoming high-cadence transient survey programmes will produce a wealth of observational data for Type Ia supernovae. These data sets will contain numerous events detected very early in their evolution, shortly after explosion. Here, we present synthetic light curves, calculated with the radiation hydrodynamical approach Stella for a number of different explosion models, specifically focusing on these first few days after explosion. We show that overall the early light curve evolution is similar for most of the investigated models. Characteristic imprints are induced by radioactive material lo…
We propose a new constraint on light (sub-GeV) particles beyond the Standard Model that can be produced inside the proto-neutron star core resulting from the core-collapse supernova explosion. It is derived by demanding that the energy carried by exotic particles being transferred to the progenitor stellar envelopes must not exceed the explosion energy of $\lesssim 2\cdot 10^{51}$ erg of observed supernovae. We show specifically that for the case of a dark photon which kinetically mixes with the SM photon and decays predominantly to an $e^\pm$ pair, a smaller mixing parameter of one order of m…
Type Ia supernovae (SNe) are believed to be caused by the thermonuclear explosion of a white dwarf (WD), but the nature of the progenitor system(s) is still unclear. Recent theoretical and observational developments have led to renewed interest in double degenerate models, in particular the "helium-ignited violent merger" or "dynamically-driven double-degenerate double-detonation" (D$^6$). In this paper we take the output of an existing D$^6$ SN model and carry it into the supernova remnant (SNR) phase up to 4000 years after the explosion, past the time when all the ejecta have been shocked. A…
