Neutrinos from type-II supernovae and the neutrino-driven supernova mechanism

Energy Technology Data Exchange (ETDEWEB)

Janka, H T [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

1996-11-01

Supernova 1987A has confirmed fundamental aspects of our theoretical view of type-II supernovae: Type-II supernovae are a consequence of the collapse of the iron core of a massive evolved star and lead to the formation of a neutron star or black hole. This picture is most strongly supported by the detection of electron antineutrinos in the IMB and Kamiokande II experiments in connection with SN 1987A. However, the mechanism causing the supernova explosion is not yet satisfactorily understood. In this paper the properties of the neutrino emission from supernovae and protoneutron stars will be reviewed; analytical estimates will be derived and results of numerical simulations will be shown. It will be demonstrated that the spectral distributions of the emitted neutrinos show clear and systematic discrepancies compared with thermal (black body-type) emission. This must be taken into account when neutrino observations from supernovae are to be interpreted, or when implications of the neutrino emission on nucleosynthesis processes in mantle and envelope of the progenitor star are to be investigated. Furthermore, the influence of neutrinos on the supernova dynamics will be discussed, in particular their crucial role in causing the explosion by Wilson`s neutrino-driven delayed mechanism. Possible implications of convection inside the newly born neutron star and between surface and the supernova shock will be addressed and results of multi-dimensional simulations will be presented. (author) 7 figs., 1 tab., refs.

NEW EQUATIONS OF STATE IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE

International Nuclear Information System (INIS)

Hempel, M.; Liebendörfer, M.; Fischer, T.; Schaffner-Bielich, J.

2012-01-01

We discuss three new equations of state (EOS) in core-collapse supernova simulations. The new EOS are based on the nuclear statistical equilibrium model of Hempel and Schaffner-Bielich (HS), which includes excluded volume effects and relativistic mean-field (RMF) interactions. We consider the RMF parameterizations TM1, TMA, and FSUgold. These EOS are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics and three-flavor Boltzmann neutrino transport. The results obtained for the new EOS are compared with the widely used EOS of H. Shen et al. and Lattimer and Swesty. The systematic comparison shows that the model description of inhomogeneous nuclear matter is as important as the parameterization of the nuclear interactions for the supernova dynamics and the neutrino signal. Furthermore, several new aspects of nuclear physics are investigated: the HS EOS contains distributions of nuclei, including nuclear shell effects. The appearance of light nuclei, e.g., deuterium and tritium, is also explored, which can become as abundant as alphas and free protons. In addition, we investigate the black hole formation in failed core-collapse supernovae, which is mainly determined by the high-density EOS. We find that temperature effects lead to a systematically faster collapse for the non-relativistic LS EOS in comparison with the RMF EOS. We deduce a new correlation for the time until black hole formation, which allows the determination of the maximum mass of proto-neutron stars, if the neutrino signal from such a failed supernova would be measured in the future. This would give a constraint for the nuclear EOS at finite entropy, complementary to observations of cold neutron stars.

Three-dimensional simulations of supernovae dominated interstellar media in disk galaxies

International Nuclear Information System (INIS)

Cioffi, D.F.

1985-01-01

Evolution of the interstellar media of spiral galaxies was studied, assuming that their dynamical and thermal properties are dominated by supernova remnants (SNRs). To do this, a computer simulation was developed that uses standard SNR evolutionary solutions (Sedov-Taylor, pressure-modified snowplow) to redistribute mass and energy throughout a rectangular, three-level grid which models the interstellar medium (ISM). This comprehensive treatment includes bremsstrahlung or metal cooling, the creation and evaporation of clouds, mass injection and return from a galactic halo, multiple SNRs, and internally determined SNR lifetimes. The importance of spatially correlating supernovae sites, which can increase the global evolution rate of the (ISM), is confirmed. The simulations of primeval (zero metal abundance) galaxies revealed that the enhancement ability of bremsstrahlung-cooled SNR to transport mass can continually agitate the ISM, preventing the establishment of long-lived tunnel networks (i.e., hot rarefied volumes). This demonstrated the inadequacy of porosity theory for predicting the topology of the ISM, because it does not account for mass transport

Measurement of the evolution of type Ia supernovae explosion rate as a function of redshift in the SuperNovae Legacy Survey

International Nuclear Information System (INIS)

Ripoche, Pascal

2007-01-01

This research thesis reports works performed within the frame of the SuperNovae Legacy Survey (SNLS) which is one of the second-generation experiment exploiting Ia supernovae as cosmological source, and allows 8 billions or years of universe expansion to be observed by means of the Canada France Hawaii Telescope and a systematic detection of supernovae. The first part addresses cosmology and supernovae, and notably shows how Ia supernovae can used as cosmological probe to constraint cosmological parameters. Other methods of measurement of these parameters are briefly explained. The SNLS experiment is then presented: description of the experiment and of the supernovae detection chain, image processing. The author then presents a detailed simulation which has been developed to simulate Ia supernovae on the experiment images. He also presents associated tools and tests. This simulation is then used to study the efficiencies and weaknesses of supernovae detection by the SNLS. The measurement of the Ia supernovae explosion rate is then measured with respect to cosmic evolution [fr

Multigroup models of the convective epoch in core collapse supernovae

International Nuclear Information System (INIS)

Swesty, F Douglas; Myra, Eric S

2005-01-01

Understanding the explosion mechanism of core collapse supernovae is a problem that has plagued nuclear astrophysicists since the first computational models of this phenomenon were carried out in the 1960s. Our current theories of this violent phenomenon center around multi-dimensional effects involving radiation-hydrodynamic flows of hot, dense matter and neutrinos. Modeling these multi-dimensional radiative flows presents a computational challenge that will continue to stress high-performance computing beyond the teraflops to the petaflop level. In this paper we describe a few of the scientific discoveries that we have made via terascale computational simulations of supernovae under the auspices of the SciDAC-funded Terascale Supernova Initiative

Supernova Hydrodynamics on the Omega Laser. Final report

International Nuclear Information System (INIS)

Drake, R. Paul

2004-01-01

(B204)The fundamental motivation for our work is that supernovae are not well understood. Recent observations have clarified the depth of our ignorance, by producing observed phenomena that current theory and computer simulations cannot reproduce. Such theories and simulations involve, however, a number of physical mechanisms that have never been studied in isolation. We perform experiments, in compressible hydrodynamics and radiation hydrodynamics, relevant to supernovae and supernova remnants. These experiments produce phenomena in the laboratory that are believed, based on simulations, to be important to astrophysics but that have not been directly observed in either the laboratory or in an astrophysical system. During the period of this grant, we have focused on the scaling of an astrophysically relevant, radiative-precursor shock, on preliminary studies of collapsing radiative shocks, and on the multimode behavior and the three-dimensional, deeply nonlinear evolution of the Rayleigh-Taylor (RT) instability at a decelerating, embedded interface. These experiments required strong compression and decompression, strong shocks (Mach ∼10 or greater), flexible geometries, and very smooth laser beams, which means that the 60-beam Omega laser is the only facility capable of carrying out this program

Accelerating Our Understanding of Supernova Explosion Mechanism via Simulations and Visualizations with GenASiS

Energy Technology Data Exchange (ETDEWEB)

Budiardja, R. D. [University of Tennessee, Knoxville (UTK); Cardall, Christian Y [ORNL; Endeve, Eirik [ORNL

2015-01-01

Core-collapse supernovae are among the most powerful explosions in the Universe, releasing about 1053 erg of energy on timescales of a few tens of seconds. These explosion events are also responsible for the production and dissemination of most of the heavy elements, making life as we know it possible. Yet exactly how they work is still unresolved. One reason for this is the sheer complexity and cost of a self-consistent, multi-physics, and multi-dimensional core-collapse supernova simulation, which is impractical, and often impossible, even on the largest supercomputers we have available today. To advance our understanding we instead must often use simplified models, teasing out the most important ingredients for successful explosions, while helping us to interpret results from higher fidelity multi-physics models. In this paper we investigate the role of instabilities in the core-collapse supernova environment. We present here simulation and visualization results produced by our code GenASiS.

Aspherical supernovae

International Nuclear Information System (INIS)

Kasen, Daniel Nathan

2004-01-01

Although we know that many supernovae are aspherical, the exact nature of their geometry is undetermined. Because all the supernovae we observe are too distant to be resolved, the ejecta structure can't be directly imaged, and asymmetry must be inferred from signatures in the spectral features and polarization of the supernova light. The empirical interpretation of this data, however, is rather limited--to learn more about the detailed supernova geometry, theoretical modeling must been undertaken. One expects the geometry to be closely tied to the explosion mechanism and the progenitor star system, both of which are still under debate. Studying the 3-dimensional structure of supernovae should therefore provide new break throughs in our understanding. The goal of this thesis is to advance new techniques for calculating radiative transfer in 3-dimensional expanding atmospheres, and use them to study the flux and polarization signatures of aspherical supernovae. We develop a 3-D Monte Carlo transfer code and use it to directly fit recent spectropolarimetric observations, as well as calculate the observable properties of detailed multi-dimensional hydrodynamical explosion simulations. While previous theoretical efforts have been restricted to ellipsoidal models, we study several more complicated configurations that are tied to specific physical scenarios. We explore clumpy and toroidal geometries in fitting the spectropolarimetry of the Type Ia supernova SN 2001el. We then calculate the observable consequences of a supernova that has been rendered asymmetric by crashing into a nearby companion star. Finally, we fit the spectrum of a peculiar and extraordinarily luminous Type Ic supernova. The results are brought to bear on three broader astrophysical questions: (1) What are the progenitors and the explosion processes of Type Ia supernovae? (2) What effect does asymmetry have on the observational diversity of Type Ia supernovae, and hence their use in cosmology? (3) And

Radio Evolution of Supernova Remnants Including Nonlinear Particle Acceleration: Insights from Hydrodynamic Simulations

Science.gov (United States)

Pavlović, Marko Z.; Urošević, Dejan; Arbutina, Bojan; Orlando, Salvatore; Maxted, Nigel; Filipović, Miroslav D.

2018-01-01

We present a model for the radio evolution of supernova remnants (SNRs) obtained by using three-dimensional hydrodynamic simulations coupled with nonlinear kinetic theory of cosmic-ray (CR) acceleration in SNRs. We model the radio evolution of SNRs on a global level by performing simulations for a wide range of the relevant physical parameters, such as the ambient density, supernova (SN) explosion energy, acceleration efficiency, and magnetic field amplification (MFA) efficiency. We attribute the observed spread of radio surface brightnesses for corresponding SNR diameters to the spread of these parameters. In addition to our simulations of Type Ia SNRs, we also considered SNR radio evolution in denser, nonuniform circumstellar environments modified by the progenitor star wind. These simulations start with the mass of the ejecta substantially higher than in the case of a Type Ia SN and presumably lower shock speed. The magnetic field is understandably seen as very important for the radio evolution of SNRs. In terms of MFA, we include both resonant and nonresonant modes in our large-scale simulations by implementing models obtained from first-principles, particle-in-cell simulations and nonlinear magnetohydrodynamical simulations. We test the quality and reliability of our models on a sample consisting of Galactic and extragalactic SNRs. Our simulations give Σ ‑ D slopes between ‑4 and ‑6 for the full Sedov regime. Recent empirical slopes obtained for the Galactic samples are around ‑5, while those for the extragalactic samples are around ‑4.

Galactic Winds Driven by Supernovae and Radiation Pressure: Theory and Simulations

Science.gov (United States)

Zhang, Dong; Davis, Shane

2018-01-01

Galactic winds are ubiquitous in most rapidly star-forming galaxies. They are crucial to the process of galaxy formation and evolution, regulating star formation, shaping the stellar mass function and the mass-metallicity relation, and enriching the intergalactic medium with metals. Although important, the physics of galactic winds is still unclear. Winds may be driven by many mechanisms including overlapping supernovae explosions, radiation pressure of starlight on dust grains, and cosmic rays. However, the growing observations of multiphase structure in galactic winds in a large number of galaxies have not been well explained by any models. In this talk I will focus on the models of supernova- and radiation-pressure-driven winds. Using the state-of-the-art numerical simulations, I will assess the relative merits of these driving mechanisms for accelerating cold and warm clouds to observed velocities, and momentum flux boost during wind propagation.

Disturbance Ecology from nearby Supernovae

OpenAIRE

Hartmann, D. H.; Kretschmer, K.; Diehl, R.

2002-01-01

Monte Carlo simulations of Galactic Supernovae are carried out to study the rate of nearby events, which may have a direct effect on Earth's ecology though ionizing radiation and cosmic ray bombardment. A nearby supernova may have left a radioactive imprint (60Fe) in recent galactic history.

Understanding Core-Collapse Supernovae

Science.gov (United States)

Hix, W. R.; Lentz, E. J.; Baird, M.; Messer, O. E. B.; Mezzacappa, A.; Lee, C.-T.; Bruenn, S. W.; Blondin, J. M.; Marronetti, P.

2010-03-01

Our understanding of core-collapse supernovae continues to improve as better microphysics is included in increasingly realistic neutrino-radiationhydrodynamic simulations. Recent multi-dimensional models with spectral neutrino transport, which slowly develop successful explosions for a range of progenitors between 12 and 25 solar mass, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progresses on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.

Supernova neutrino detection in LZ

Science.gov (United States)

Khaitan, D.

2018-02-01

In the first 10 seconds of a core-collapse supernova, almost all of its progenitor's gravitational potential, O(1053 ergs), is carried away in the form of neutrinos. These neutrinos, with O(10 MeV) kinetic energy, can interact via coherent elastic neutrino-nucleus scattering (CEνNS) depositing O(1 keV) in detectors. In this work we describe the performances of low-background dark matter detectors, such as LUX-ZEPLIN (LZ), optimized for detecting low-energy depositions, in detecting these neutrino interactions. For instance, a 27 Msolar supernova at 10 kpc is expected to produce ~350 neutrino interactions in the 7-tonne liquid xenon active volume of LZ. Based on the LS220 EoS neutrino flux model for a SN, the Noble Element Simulation Technique (NEST), and predicted CEνNS cross-sections for xenon, to study energy deposition and detection of SN neutrinos in LZ. We simulate the response of the LZ data acquisition system (DAQ) and demonstrate its capability and limitations in handling this interaction rate. We present an overview of the LZ detector, focusing on the benefits of liquid xenon for supernova neutrino detection. We discuss energy deposition and detector response simulations and their results. We present an analysis technique to reconstruct the total number of neutrinos and the time of the supernova core bounce.

Supernova ejecta with a relativistic wind from a central compact object: a unified picture for extraordinary supernovae

Science.gov (United States)

Suzuki, Akihiro; Maeda, Keiichi

2017-04-01

The hydrodynamical interaction between freely expanding supernova ejecta and a relativistic wind injected from the central region is studied in analytic and numerical ways. As a result of the collision between the ejecta and the wind, a geometrically thin shell surrounding a hot bubble forms and expands in the ejecta. We use a self-similar solution to describe the early dynamical evolution of the shell and carry out a two-dimensional special relativistic hydrodynamic simulation to follow further evolution. The Rayleigh-Taylor instability inevitably develops at the contact surface separating the shocked wind and ejecta, leading to the complete destruction of the shell and the leakage of hot gas from the hot bubble. The leaking hot materials immediately catch up with the outermost layer of the supernova ejecta and thus different layers of the ejecta are mixed. We present the spatial profiles of hydrodynamical variables and the kinetic energy distributions of the ejecta. We stop the energy injection when a total energy of 1052 erg, which is 10 times larger than the initial kinetic energy of the supernova ejecta, is deposited into the ejecta and follow the subsequent evolution. From the results of our simulations, we consider expected emission from supernova ejecta powered by the energy injection at the centre and discuss the possibility that superluminous supernovae and broad-lined Ic supernovae could be produced by similar mechanisms.

Fluid Instabilities of Magnetar-Powered Supernovae

Science.gov (United States)

Chen, Ke-Jung

2017-05-01

Magnetar-powered supernova explosions are competitive models for explaining very luminous optical transits. Until recently, these explosion models were mainly calculated in 1D. Radiation emitted from the magnetar snowplows into the previous supernovae ejecta and causes a nonphysical dense shell (spike) found in previous 1D studies. This suggests that strong fluid instabilities may have developed within the magnetar-powered supernovae. Such fluid instabilities emerge at the region where luminous transits later occur, so they can affect the consequent observational signatures. We examine the magnetar-powered supernovae with 2D hydrodynamics simulations and find that the 1D dense shell transforms into the development of Rayleigh-Taylor and thin shell instabilities in 2D. The resulting mixing is able to fragment the entire shell and break the spherical symmetry of supernovae ejecta.

Constraining the supersaturation density equation of state from core-collapse supernova simulations? Excluded volume extension of the baryons

International Nuclear Information System (INIS)

Fischer, Tobias

2016-01-01

In this article the role of the supersaturation density equation of state (EOS) is explored in simulations of failed core-collapse supernova explosions. Therefore the nuclear EOS is extended via a one-parameter excluded-volume description for baryons, taking into account their finite and increasing volume with increasing density in excess of saturation density. Parameters are selected such that the resulting supernova EOS represent extreme cases, with high pressure variations at supersaturation density which feature extreme stiff and soft EOS variants of the reference case, i.e. without excluded-volume corrections. Unlike in the interior of neutron stars with central densities in excess of several times saturation density, central densities of core-collapse supernovae reach only slightly above saturation density. Hence, the impact of the supersaturation density EOS on the supernova dynamics as well as the neutrino signal is found to be negligible. It is mainly determined from the low- and intermediate-density domain, which is left unmodified within this generalized excluded volume approach. (orig.)

The ν process in the innermost supernova ejecta

Energy Technology Data Exchange (ETDEWEB)

Sieverding, Andre [Institut für Kernphysik, Technische Universität Darmstadt, Germany; Martínez-Pinedo, Gabriel [Institut für Kernphysik, Technische Universität Darmstadt, Germany; Langanke, Karlheinz [Gesellschaft fur Schwerionenforschung (GSI), Germany; Harris, James Austin [ORNL; Hix, William Raphael [ORNL

2017-12-01

The neutrino-induced nucleosynthesis (ν process) in supernova explosions of massive stars of solar metallicity with initial main sequence masses between 13 and 30 M⊙ has been studied with an analytic explosion model using a new extensive set of neutrino-nucleus cross-sections and spectral properties that agree with modern supernova simulations. The production factors for the nuclei 7Li, 11B, 19F, 138La and 180Ta, are still significantly enhanced but do not reproduce the full solar abundances. We study the possible contribution of the innermost supernova eject to the production of the light elements 7Li and 11B with tracer particles based on a 2D supernova simulation of a 12 M⊙ progenitor and conclude, that a contribution exists but is negligible for the total yield for this explosion model.

Nucleosynthesis in Core-Collapse Supernovae

Science.gov (United States)

Stevenson, Taylor Shannon; Viktoria Ohstrom, Eva; Harris, James Austin; Hix, William R.

2018-01-01

The nucleosynthesis which occurs in core-collapse supernovae (CCSN) is one of the most important sources of elements in the universe. Elements from Oxygen through Iron come predominantly from supernovae, and contributions of heavier elements are also possible through processes like the weak r-process, the gamma process and the light element primary process. The composition of the ejecta depends on the mechanism of the explosion, thus simulations of high physical fidelity are needed to explore what elements and isotopes CCSN can contribute to Galactic Chemical Evolution. We will analyze the nucleosynthesis results from self-consistent CCSN simulations performed with CHIMERA, a multi-dimensional neutrino radiation-hydrodynamics code. Much of our understanding of CCSN nucleosynthesis comes from parameterized models, but unlike CHIMERA these fail to address essential physics, including turbulent flow/instability and neutrino-matter interaction. We will present nucleosynthesis predictions for the explosion of a 9.6 solar mass first generation star, relying both on results of the 160 species nuclear reaction network used in CHIMERA within this model and on post-processing with a more extensive network. The lowest mass iron core-collapse supernovae, like this model, are distinct from their more massive brethren, with their explosion mechanism and nucleosynthesis being more like electron capture supernovae resulting from Oxygen-Neon white dwarves. We will highlight the differences between the nucleosynthesis in this model and more massive supernovae. The inline 160 species network is a feature unique to CHIMERA, making this the most sophisticated model to date for a star of this type. We will discuss the need and mechanism to extrapolate the post-processing to times post-simulation and analyze the uncertainties this introduces for supernova nucleosynthesis. We will also compare the results from the inline 160 species network to the post-processing results to study further

Impact of Neutrino Opacities on Core-collapse Supernova Simulations

Science.gov (United States)

Kotake, Kei; Takiwaki, Tomoya; Fischer, Tobias; Nakamura, Ko; Martínez-Pinedo, Gabriel

2018-02-01

The accurate description of neutrino opacities is central to both the core-collapse supernova (CCSN) phenomenon and the validity of the explosion mechanism itself. In this work, we study in a systematic fashion the role of a variety of well-selected neutrino opacities in CCSN simulations where the multi-energy, three-flavor neutrino transport is solved using the isotropic diffusion source approximation (IDSA) scheme. To verify our code, we first present results from one-dimensional (1D) simulations following the core collapse, bounce, and ∼250 ms postbounce of a 15 {M}ȯ star using a standard set of neutrino opacities by Bruenn. A detailed comparison with published results supports the reliability of our three-flavor IDSA scheme using the standard opacity set. We then investigate in 1D simulations how individual opacity updates lead to differences with the baseline run with the standard opacity set. Through detailed comparisons with previous work, we check the validity of our implementation of each update in a step-by-step manner. Individual neutrino opacities with the largest impact on the overall evolution in 1D simulations are selected for systematic comparisons in our two-dimensional (2D) simulations. Special attention is given to the criterion of explodability in the 2D models. We discuss the implications of these results as well as its limitations and the requirements for future, more elaborate CCSN modeling.

Neutrino-pair emission from nuclear de-excitation in core-collapse supernova simulations

Science.gov (United States)

Fischer, T.; Langanke, K.; Martínez-Pinedo, G.

2013-12-01

We study the impact of neutrino-pair production from the de-excitation of highly excited heavy nuclei on core-collapse supernova simulations, following the evolution up to several 100 ms after core bounce. Our study is based on the agile-boltztransupernova code, which features general relativistic radiation hydrodynamics and accurate three-flavor Boltzmann neutrino transport in spherical symmetry. In our simulations the nuclear de-excitation process is described in two different ways. At first we follow the approach proposed by Fuller and Meyer [Astrophys. J.AJLEEY0004-637X10.1086/170317 376, 701 (1991)], which is based on strength functions derived in the framework of the nuclear Fermi-gas model of noninteracting nucleons. Second, we parametrize the allowed and forbidden strength distributions in accordance with measurements for selected nuclear ground states. We determine the de-excitation strength by applying the Brink hypothesis and detailed balance. For both approaches, we find that nuclear de-excitation has no effect on the supernova dynamics. However, we find that nuclear de-excitation is the leading source for the production of electron antineutrinos as well as heavy-lepton-flavor (anti)neutrinos during the collapse phase. At sufficiently high densities, the associated neutrino spectra are influenced by interactions with the surrounding matter, making proper simulations of neutrino transport important for the determination of the neutrino-energy loss rate. We find that, even including nuclear de-excitations, the energy loss during the collapse phase is overwhelmingly dominated by electron neutrinos produced by electron capture.

Multi-dimensional relativistic simulations of core-collapse supernovae with energy-dependent neutrino transport

International Nuclear Information System (INIS)

Mueller, Bernhard

2009-01-01

In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)

Multi-dimensional relativistic simulations of core-collapse supernovae with energy-dependent neutrino transport

Energy Technology Data Exchange (ETDEWEB)

Mueller, Bernhard

2009-05-07

In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)

Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction

Science.gov (United States)

Zapartas, E.; de Mink, S. E.; Izzard, R. G.; Yoon, S.-C.; Badenes, C.; Götberg, Y.; de Koter, A.; Neijssel, C. J.; Renzo, M.; Schootemeijer, A.; Shrotriya, T. S.

2017-05-01

Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, %, of core-collapse supernovae are "late", that is, they occur 50-200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4-8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by % because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star - white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution.

The ν process in the innermost supernova ejecta

Directory of Open Access Journals (Sweden)

Sieverding Andre

2017-01-01

Full Text Available The neutrino-induced nucleosynthesis (ν process in supernova explosions of massive stars of solar metallicity with initial main sequence masses between 13 and 30 M⊙ has been studied with an analytic explosion model using a new extensive set of neutrino-nucleus cross-sections and spectral properties that agree with modern supernova simulations. The production factors for the nuclei 7Li, 11B, 19F, 138La and 180Ta, are still significantly enhanced but do not reproduce the full solar abundances. We study the possible contribution of the innermost supernova eject to the production of the light elements 7Li and 11B with tracer particles based on a 2D supernova simulation of a 12 M⊙ progenitor and conclude, that a contribution exists but is negligible for the total yield for this explosion model.

SHOULD ONE USE THE RAY-BY-RAY APPROXIMATION IN CORE-COLLAPSE SUPERNOVA SIMULATIONS?

International Nuclear Information System (INIS)

Skinner, M. Aaron; Burrows, Adam; Dolence, Joshua C.

2016-01-01

We perform the first self-consistent, time-dependent, multi-group calculations in two dimensions (2D) to address the consequences of using the ray-by-ray+ transport simplification in core-collapse supernova simulations. Such a dimensional reduction is employed by many researchers to facilitate their resource-intensive calculations. Our new code (Fornax) implements multi-D transport, and can, by zeroing out transverse flux terms, emulate the ray-by-ray+ scheme. Using the same microphysics, initial models, resolution, and code, we compare the results of simulating 12, 15, 20, and 25 M ⊙ progenitor models using these two transport methods. Our findings call into question the wisdom of the pervasive use of the ray-by-ray+ approach. Employing it leads to maximum post-bounce/pre-explosion shock radii that are almost universally larger by tens of kilometers than those derived using the more accurate scheme, typically leaving the post-bounce matter less bound and artificially more “explodable.” In fact, for our 25 M ⊙ progenitor, the ray-by-ray+ model explodes, while the corresponding multi-D transport model does not. Therefore, in two dimensions, the combination of ray-by-ray+ with the axial sloshing hydrodynamics that is a feature of 2D supernova dynamics can result in quantitatively, and perhaps qualitatively, incorrect results.

ON THE REQUIREMENTS FOR REALISTIC MODELING OF NEUTRINO TRANSPORT IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Mezzacappa, Anthony; Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [Computer Science and Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Liebendoerfer, Matthias [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Bruenn, Stephen W., E-mail: elentz@utk.edu, E-mail: mezzacappaa@ornl.gov [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

2012-03-01

We have conducted a series of numerical experiments with the spherically symmetric, general relativistic, neutrino radiation hydrodynamics code AGILE-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general relativistic gravity, hydrodynamics, and transport; (2) using a reduced set of weak interactions, including the omission of non-isoenergetic neutrino scattering, versus the current state-of-the-art; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has noticeable effects on the outcomes of our simulations. Of these, we find that the omission of observer corrections is particularly detrimental to the potential for neutrino-driven explosions and exhibits a failure to conserve lepton number. Finally, we discuss the impact of these results on our understanding of current, and the requirements for future, multidimensional models.

ON THE REQUIREMENTS FOR REALISTIC MODELING OF NEUTRINO TRANSPORT IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE

International Nuclear Information System (INIS)

Lentz, Eric J.; Mezzacappa, Anthony; Hix, W. Raphael; Messer, O. E. Bronson; Liebendörfer, Matthias; Bruenn, Stephen W.

2012-01-01

We have conducted a series of numerical experiments with the spherically symmetric, general relativistic, neutrino radiation hydrodynamics code AGILE-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general relativistic gravity, hydrodynamics, and transport; (2) using a reduced set of weak interactions, including the omission of non-isoenergetic neutrino scattering, versus the current state-of-the-art; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has noticeable effects on the outcomes of our simulations. Of these, we find that the omission of observer corrections is particularly detrimental to the potential for neutrino-driven explosions and exhibits a failure to conserve lepton number. Finally, we discuss the impact of these results on our understanding of current, and the requirements for future, multidimensional models.

Matching Supernovae to Galaxies

Science.gov (United States)

Kohler, Susanna

2016-12-01

developed a new automated algorithm for matching supernovae to their host galaxies. Their work builds on currently existing algorithms and makes use of information about the nearby galaxies, accounts for the uncertainty of the match, and even includes a machine learning component to improve the matching accuracy.Gupta and collaborators test their matching algorithm on catalogs of galaxies and simulated supernova events to quantify how well the algorithm is able to accurately recover the true hosts.Successful MatchingThe matching algorithms accuracy (purity) as a function of the true supernova-host separation, the supernova redshift, the true hosts brightness, and the true hosts size. [Gupta et al. 2016]The authors find that when the basic algorithm is run on catalog data, it matches supernovae to their hosts with 91% accuracy. Including the machine learning component, which is run after the initial matching algorithm, improves the accuracy of the matching to 97%.The encouraging results of this work which was intended as a proof of concept suggest that methods similar to this could prove very practical for tackling future survey data. And the method explored here has use beyond matching just supernovae to their host galaxies: it could also be applied to other extragalactic transients, such as gamma-ray bursts, tidal disruption events, or electromagnetic counterparts to gravitational-wave detections.CitationRavi R. Gupta et al 2016 AJ 152 154. doi:10.3847/0004-6256/152/6/154

Supernova Photometric Lightcurve Classification

Science.gov (United States)

Zaidi, Tayeb; Narayan, Gautham

2016-01-01

This is a preliminary report on photometric supernova classification. We first explore the properties of supernova light curves, and attempt to restructure the unevenly sampled and sparse data from assorted datasets to allow for processing and classification. The data was primarily drawn from the Dark Energy Survey (DES) simulated data, created for the Supernova Photometric Classification Challenge. This poster shows a method for producing a non-parametric representation of the light curve data, and applying a Random Forest classifier algorithm to distinguish between supernovae types. We examine the impact of Principal Component Analysis to reduce the dimensionality of the dataset, for future classification work. The classification code will be used in a stage of the ANTARES pipeline, created for use on the Large Synoptic Survey Telescope alert data and other wide-field surveys. The final figure-of-merit for the DES data in the r band was 60% for binary classification (Type I vs II).Zaidi was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

SHOULD ONE USE THE RAY-BY-RAY APPROXIMATION IN CORE-COLLAPSE SUPERNOVA SIMULATIONS?

Energy Technology Data Exchange (ETDEWEB)

Skinner, M. Aaron; Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolence, Joshua C., E-mail: burrows@astro.princeton.edu, E-mail: askinner@astro.princeton.edu, E-mail: jdolence@lanl.gov [CCS-2, Los Alamos National Laboratory, P.O. Box 1663 Los Alamos, NM 87545 (United States)

2016-11-01

We perform the first self-consistent, time-dependent, multi-group calculations in two dimensions (2D) to address the consequences of using the ray-by-ray+ transport simplification in core-collapse supernova simulations. Such a dimensional reduction is employed by many researchers to facilitate their resource-intensive calculations. Our new code (Fornax) implements multi-D transport, and can, by zeroing out transverse flux terms, emulate the ray-by-ray+ scheme. Using the same microphysics, initial models, resolution, and code, we compare the results of simulating 12, 15, 20, and 25 M {sub ⊙} progenitor models using these two transport methods. Our findings call into question the wisdom of the pervasive use of the ray-by-ray+ approach. Employing it leads to maximum post-bounce/pre-explosion shock radii that are almost universally larger by tens of kilometers than those derived using the more accurate scheme, typically leaving the post-bounce matter less bound and artificially more “explodable.” In fact, for our 25 M {sub ⊙} progenitor, the ray-by-ray+ model explodes, while the corresponding multi-D transport model does not. Therefore, in two dimensions, the combination of ray-by-ray+ with the axial sloshing hydrodynamics that is a feature of 2D supernova dynamics can result in quantitatively, and perhaps qualitatively, incorrect results.

Supernova explosions

CERN Document Server

Branch, David

2017-01-01

Targeting advanced students of astronomy and physics, as well as astronomers and physicists contemplating research on supernovae or related fields, David Branch and J. Craig Wheeler offer a modern account of the nature, causes and consequences of supernovae, as well as of issues that remain to be resolved. Owing especially to (1) the appearance of supernova 1987A in the nearby Large Magellanic Cloud, (2) the spectacularly successful use of supernovae as distance indicators for cosmology, (3) the association of some supernovae with the enigmatic cosmic gamma-ray bursts, and (4) the discovery of a class of superluminous supernovae, the pace of supernova research has been increasing sharply. This monograph serves as a broad survey of modern supernova research and a guide to the current literature. The book’s emphasis is on the explosive phases of supernovae. Part 1 is devoted to a survey of the kinds of observations that inform us about supernovae, some basic interpreta tions of such data, and an overview of t...

Kinetic Energy from Supernova Feedback in High-resolution Galaxy Simulations

Science.gov (United States)

Simpson, Christine M.; Bryan, Greg L.; Hummels, Cameron; Ostriker, Jeremiah P.

2015-08-01

We describe a new method for adding a prescribed amount of kinetic energy to simulated gas modeled on a cartesian grid by directly altering grid cells’ mass and velocity in a distributed fashion. The method is explored in the context of supernova (SN) feedback in high-resolution (˜10 pc) hydrodynamic simulations of galaxy formation. Resolution dependence is a primary consideration in our application of the method, and simulations of isolated explosions (performed at different resolutions) motivate a resolution-dependent scaling for the injected fraction of kinetic energy that we apply in cosmological simulations of a 109 M⊙ dwarf halo. We find that in high-density media (≳50 cm-3) with coarse resolution (≳4 pc per cell), results are sensitive to the initial kinetic energy fraction due to early and rapid cooling. In our galaxy simulations, the deposition of small amounts of SN energy in kinetic form (as little as 1%) has a dramatic impact on the evolution of the system, resulting in an order-of-magnitude suppression of stellar mass. The overall behavior of the galaxy in the two highest resolution simulations we perform appears to converge. We discuss the resulting distribution of stellar metallicities, an observable sensitive to galactic wind properties, and find that while the new method demonstrates increased agreement with observed systems, significant discrepancies remain, likely due to simplistic assumptions that neglect contributions from SNe Ia and stellar winds.

Petascale supernova simulation with CHIMERA

Energy Technology Data Exchange (ETDEWEB)

Messer, O E B [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6008 (United States); Bruenn, S W [Department of Physics, Florida Atlantic University, 777 W Glades Road, Boca Raton, FL 33431-0991 (United States); Blondin, J M [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Hix, W R [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6354 (United States); Mezzacappa, A [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6354 (United States); Dirk, C J [Department of Physics, Florida Atlantic University, 777 W Glades Road, Boca Raton, FL 33431-0991 (United States)

2007-07-15

CHIMERA is a multi-dimensional radiation hydrodynamics code designed to study core-collapse supernovae. The code is made up of three essentially independent parts: a hydrodynamics module, a nuclear burning module, and a neutrino transport solver combined within an operator-split approach. We describe some major algorithmic facets of the code and briefly discuss some recent results. The multi-physics nature of the problem, and the specific implementation of that physics in CHIMERA, provide a rather straightforward path to effective use of multi-core platforms in the near future.

Neutrinos in supernovae

International Nuclear Information System (INIS)

Cooperstein, J.

1986-10-01

The role of neutrinos in Type II supernovae is discussed. An overall view of the neutrino luminosity as expected theoretically is presented. The different weak interactions involved are assessed from the standpoint of how they exchange energy, momentum, and lepton number. Particular attention is paid to entropy generation and the path to thermal and chemical equilibration, and to the phenomenon of trapping. Various methods used to calculate the neutrino flows are considered. These include trapping and leakage schemes, distribution-averaged transfer, and multi-energy group methods. The information obtained from the neutrinos caught from Supernova 1987a is briefly evaluated. 55 refs., 7 figs

Weak Interaction processes in core-collapse supernova

International Nuclear Information System (INIS)

Martinez-Pinedo, Gabriel

2008-01-01

In this manuscript we review the role that weak interaction processes play in supernova. This includes electron captures and inelastic neutrino-nucleus scattering (INNS). Electron captures during the collapse occur mainly in heavy nuclei, however the proton contribution is responsible for the convergence of different models to a 'norm' stellar trajectory. Neutrino-nucleus cross sections at supernova neutrino energies can be determined from precise data on the magnetic dipole strength. The results agree well with large-scale shell-model calculations. When incorporated in core-collapse simulations INNS increases the neutrino opacities noticeably and strongly reduces the high-energy part of the supernova spectrum

Core-Collapse Supernovae: Explosion dynamics, neutrinos and gravitational waves

OpenAIRE

Müller, Bernhard; Janka, Hans-Thomas; Marek, Andreas; Hanke, Florian; Wongwathanarat, Annop; Müller, Ewald

2011-01-01

The quest for the supernova explosion mechanism has been one of the outstanding challenges in computational astrophysics for several decades. Simulations have now progressed to a stage at which the solution appears close and neutrino and gravitational wave signals from self-consistent explosion models are becoming available. Here we focus one of the recent advances in supernova modeling, the inclusion of general relativity in multi-dimensional neutrino hydrodynamics simulations, and present t...

Physical processes in collapse driven supernova

International Nuclear Information System (INIS)

Mayle, R.W.

1985-11-01

A model of the supernova explosion is discussed. The method of neutrino transport is discussed, since the explosive mechanism depends on neutrino heating of the material behind the accretion shock. The core region of these exploding stars becomes unstable to convective motions during the supernova evolution. Convective mixing allows more neutrinos to escape from under the neutrinosphere, and thus increases the amount of heating by neutrinos. An approximate method of incorporating convection is described, and some results of including convection in a computer model is presented. Another phenomena is seen in computer simulations of supernova, oscillations in the neutrino luminosity and mass accretion rate onto the protoneutron star. The last topic discussed in this thesis describes the attempt to understand this oscillation by perturbation of the steady state solution to equations approximating the complex physical processes occurring in the late time supernova. 42 refs., 31 figs

Physical processes in collapse driven supernova

Energy Technology Data Exchange (ETDEWEB)

Mayle, R.W.

1985-11-01

A model of the supernova explosion is discussed. The method of neutrino transport is discussed, since the explosive mechanism depends on neutrino heating of the material behind the accretion shock. The core region of these exploding stars becomes unstable to convective motions during the supernova evolution. Convective mixing allows more neutrinos to escape from under the neutrinosphere, and thus increases the amount of heating by neutrinos. An approximate method of incorporating convection is described, and some results of including convection in a computer model is presented. Another phenomena is seen in computer simulations of supernova, oscillations in the neutrino luminosity and mass accretion rate onto the protoneutron star. The last topic discussed in this thesis describes the attempt to understand this oscillation by perturbation of the steady state solution to equations approximating the complex physical processes occurring in the late time supernova. 42 refs., 31 figs.

Supernova 1604, Kepler’s Supernova, and Its Remnant

NARCIS (Netherlands)

Vink, J.; Alsabti, A.W.; Murdin, P.

2016-01-01

Supernova 1604 is the last galactic supernova for which historical records exist. Johannes Kepler’s name is attached to it, as he published a detailed account of the observations made by himself and European colleagues. Supernova 1604 was very likely a type Ia supernova, which exploded 350–750 pc

REAL-TIME ANALYSIS AND SELECTION BIASES IN THE SUPERNOVA LEGACY SURVEY

International Nuclear Information System (INIS)

Perrett, K.; Conley, A.; Carlberg, R.; Balam, D.; Hook, I. M.; Sullivan, M.; Pritchet, C.; Astier, P.; Balland, C.; Guy, J.; Hardin, D.; Pain, R.; Regnault, N.; Basa, S.; Fouchez, D.; Howell, D. A.

2010-01-01

The Supernova Legacy Survey (SNLS) has produced a high-quality, homogeneous sample of Type Ia supernovae (SNe Ia) out to redshifts greater than z = 1. In its first four years of full operation (to 2007 June), the SNLS discovered more than 3000 transient candidates, 373 of which have been spectroscopically confirmed as SNe Ia. Use of these SNe Ia in precision cosmology critically depends on an analysis of the observational biases incurred in the SNLS survey due to the incomplete sampling of the underlying SN Ia population. This paper describes our real-time supernova detection and analysis procedures, and uses detailed Monte Carlo simulations to examine the effects of Malmquist bias and spectroscopic sampling. Such sampling effects are found to become apparent at z ∼ 0.6, with a significant shift in the average magnitude of the spectroscopically confirmed SN Ia sample toward brighter values for z ∼> 0.75. We describe our approach to correct for these selection biases in our three-year SNLS cosmological analysis (SNLS3) and present a breakdown of the systematic uncertainties involved.

Supernova VLBI

Science.gov (United States)

Bartel, N.

2009-08-01

We review VLBI observations of supernovae over the last quarter century and discuss the prospect of imaging future supernovae with space VLBI in the context of VSOP-2. From thousands of discovered supernovae, most of them at cosmological distances, ˜50 have been detected at radio wavelengths, most of them in relatively nearby galaxies. All of the radio supernovae are Type II or Ib/c, which originate from the explosion of massive progenitor stars. Of these, 12 were observed with VLBI and four of them, SN 1979C, SN 1986J, SN 1993J, and SN 1987A, could be imaged in detail, the former three with VLBI. In addition, supernovae or young supernova remnants were discovered at radio wavelengths in highly dust-obscured galaxies, such as M82, Arp 299, and Arp 220, and some of them could also be imaged in detail. Four of the supernovae so far observed were sufficiently bright to be detectable with VSOP-2. With VSOP-2 the expansion of supernovae can be monitored and investigated with unsurpassed angular resolution, starting as early as the time of the supernova's transition from its opaque to transparent stage. Such studies can reveal, in a movie, the aftermath of a supernova explosion shortly after shock break out.

Type II supernovae modelisation: neutrinos transport simulation

International Nuclear Information System (INIS)

Mellor, P.

1988-10-01

A modelisation of neutrino transport in type II supernovae is presented. The first part is a description of hydrodynamics and radiative processes responsible of supernovae explosions. Macroscopic aspects of these are displayed in part two. Neutrino transport theory and usual numerical methods are also developed. A new technic of coherent scattering of neutrinos on nuclei or free nucleons is proposed in the frame work of the Lorentz bifluid approximation. This method deals with all numerical artifices (flux limiting schemes, closure relationship of Eddington moments) and allows a complete and consistent determination of the time-dependent neutrino distribution function for any value of the opacity, gradient of opacity and for all (relativistic) velocity fields of the diffusive medium. Part three is dedicated to microscopic phenomena (electronic capture, chimical composition, etc) which rule neutrinos emission-absorption mechanisms. The numerical treatments of those are presented, and some applications are useful for their parametrization. Finally, an extension of the method to inelastic scattering on light particules (electrons) is described in view to study neutrinos thermalization mechanism [fr

Type II supernovae: How do they explode?

International Nuclear Information System (INIS)

Baron, E.

1988-01-01

I discuss what has been learned from the neutrino observations of Supernova 1987A. The neutrino detections confirmed our basic theoretical scenario that Type II supernovae involve the gravitational collapse of a massive star. The small number of events makes it difficult to infer details about the actual mechanism of collapse. I discuss the current theoretical situation on the mechanism of explosion

Cutting-edge issues of core-collapse supernova theory

International Nuclear Information System (INIS)

Kotake, Kei; Nakamura, Ko; Kuroda, Takami; Takiwaki, Tomoya

2014-01-01

Based on multi-dimensional neutrino-radiation hydrodynamic simulations, we report several cutting-edge issues about the long-veiled explosion mechanism of core-collapse supernovae (CCSNe). In this contribution, we pay particular attention to whether three-dimensional (3D) hydrodynamics and/or general relativity (GR) would or would not help the onset of explosions. By performing 3D simulations with spectral neutrino transport, we show that it is more difficult to obtain an explosion in 3D than in 2D. In addition, our results from the first generation of full general relativistic 3D simulations including approximate neutrino transport indicate that GR can foster the onset of neutrino-driven explosions. Based on our recent parametric studies using a light-bulb scheme, we discuss impacts of nuclear energy deposition behind the supernova shock and stellar rotation on the neutrino-driven mechanism, both of which have yet to be included in the self-consistent 3D supernova models. Finally we give an outlook with a summary of the most urgent tasks to extract the information about the explosion mechanisms from multi-messenger CCSN observables

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation.

Science.gov (United States)

Jiang, Ji-An; Doi, Mamoru; Maeda, Keiichi; Shigeyama, Toshikazu; Nomoto, Ken'ichi; Yasuda, Naoki; Jha, Saurabh W; Tanaka, Masaomi; Morokuma, Tomoki; Tominaga, Nozomu; Ivezić, Željko; Ruiz-Lapuente, Pilar; Stritzinger, Maximilian D; Mazzali, Paolo A; Ashall, Christopher; Mould, Jeremy; Baade, Dietrich; Suzuki, Nao; Connolly, Andrew J; Patat, Ferdinando; Wang, Lifan; Yoachim, Peter; Jones, David; Furusawa, Hisanori; Miyazaki, Satoshi

2017-10-04

Type Ia supernovae arise from the thermonuclear explosion of white-dwarf stars that have cores of carbon and oxygen. The uniformity of their light curves makes these supernovae powerful cosmological distance indicators, but there have long been debates about exactly how their explosion is triggered and what kind of companion stars are involved. For example, the recent detection of the early ultraviolet pulse of a peculiar, subluminous type Ia supernova has been claimed as evidence for an interaction between a red-giant or a main-sequence companion and ejecta from a white-dwarf explosion. Here we report observations of a prominent but red optical flash that appears about half a day after the explosion of a type Ia supernova. This supernova shows hybrid features of different supernova subclasses, namely a light curve that is typical of normal-brightness supernovae, but with strong titanium absorption, which is commonly seen in the spectra of subluminous ones. We argue that this early flash does not occur through previously suggested mechanisms such as the companion-ejecta interaction. Instead, our simulations show that it could occur through detonation of a thin helium shell either on a near-Chandrasekhar-mass white dwarf, or on a sub-Chandrasekhar-mass white dwarf merging with a less-massive white dwarf. Our finding provides evidence that one branch of previously proposed explosion models-the helium-ignition branch-does exist in nature, and that such a model may account for the explosions of white dwarfs in a mass range wider than previously supposed.

zBEAMS: a unified solution for supernova cosmology with redshift uncertainties

International Nuclear Information System (INIS)

Roberts, Ethan; Lochner, Michelle; Bassett, Bruce A.; Lablanche, Pierre-Yves; Agarwal, Shankar; Fonseca, José

2017-01-01

Supernova cosmology without spectra will be an important component of future surveys such as LSST. This lack of supernova spectra results in uncertainty in the redshifts which, if ignored, leads to significantly biased estimates of cosmological parameters. Here we present a hierarchical Bayesian formalism— zBEAMS—that addresses this problem by marginalising over the unknown or uncertain supernova redshifts to produce unbiased cosmological estimates that are competitive with supernova data with spectroscopically confirmed redshifts. zBEAMS provides a unified treatment of both photometric redshifts and host galaxy misidentification (occurring due to chance galaxy alignments or faint hosts), effectively correcting the inevitable contamination in the Hubble diagram. Like its predecessor BEAMS, our formalism also takes care of non-Ia supernova contamination by marginalising over the unknown supernova type. We illustrate this technique with simulations of supernovae with photometric redshifts and host galaxy misidentification. A novel feature of the photometric redshift case is the important role played by the redshift distribution of the supernovae.

zBEAMS: a unified solution for supernova cosmology with redshift uncertainties

Energy Technology Data Exchange (ETDEWEB)

Roberts, Ethan; Lochner, Michelle; Bassett, Bruce A.; Lablanche, Pierre-Yves; Agarwal, Shankar [African Institute for Mathematical Sciences, 6 Melrose Road, Muizenberg, 7945, Cape Town (South Africa); Fonseca, José, E-mail: rbreth001@myuct.ac.za, E-mail: michelle@aims.ac.za, E-mail: jfonseca@uwc.ac.za, E-mail: bruce.a.bassett@gmail.com, E-mail: plablanche@aims.ac.za, E-mail: agarwalshankar@aims.ac.za [Department of Physics and Astronomy, University of the Western Cape, Cape Town 7535 (South Africa)

2017-10-01

Supernova cosmology without spectra will be an important component of future surveys such as LSST. This lack of supernova spectra results in uncertainty in the redshifts which, if ignored, leads to significantly biased estimates of cosmological parameters. Here we present a hierarchical Bayesian formalism— zBEAMS—that addresses this problem by marginalising over the unknown or uncertain supernova redshifts to produce unbiased cosmological estimates that are competitive with supernova data with spectroscopically confirmed redshifts. zBEAMS provides a unified treatment of both photometric redshifts and host galaxy misidentification (occurring due to chance galaxy alignments or faint hosts), effectively correcting the inevitable contamination in the Hubble diagram. Like its predecessor BEAMS, our formalism also takes care of non-Ia supernova contamination by marginalising over the unknown supernova type. We illustrate this technique with simulations of supernovae with photometric redshifts and host galaxy misidentification. A novel feature of the photometric redshift case is the important role played by the redshift distribution of the supernovae.

An Updated Nuclear Equation of State for Neutron Stars and Supernova Simulations

Science.gov (United States)

Meixner, M. A.; Mathews, G. J.; Dalhed, H. E.; Lan, N. Q.

2011-10-01

We present an updated and improved Equation of State based upon the framework originally developed by Bowers & Wilson. The details of the EoS and improvements are described along with a description of how to access this EOS for numerical simulations. Among the improvements are an updated compressibility based upon recent measurements, the possibility of the formation of proton excess (Ye> 0.5) material and an improved treatment of the nuclear statistical equilibrium and the transition to pasta nuclei as the density approaches nuclear matter density. The possibility of a QCD chiral phase transition is also included at densities above nuclear matter density. We show comparisons of this EOS with the other two publicly available equations of state used in supernova collapse simulations. The advantages of the present EoS is that it is easily amenable to phenomenological parameterization to fit observed explosion properties and to accommodate new physical parameters.

Pulsar Wind Bubble Blowout from a Supernova

Energy Technology Data Exchange (ETDEWEB)

Blondin, John M. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Chevalier, Roger A., E-mail: blondin@ncsu.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2017-08-20

For pulsars born in supernovae, the expansion of the shocked pulsar wind nebula is initially in the freely expanding ejecta of the supernova. While the nebula is in the inner flat part of the ejecta density profile, the swept-up, accelerating shell is subject to the Rayleigh–Taylor instability. We carried out two- and three-dimensional simulations showing that the instability gives rise to filamentary structure during this initial phase but does not greatly change the dynamics of the expanding shell. The flow is effectively self-similar. If the shell is powered into the outer steep part of the density profile, the shell is subject to a robust Rayleigh–Taylor instability in which the shell is fragmented and the shocked pulsar wind breaks out through the shell. The flow is not self-similar in this phase. For a wind nebula to reach this phase requires that the deposited pulsar energy be greater than the supernova energy, or that the initial pulsar period be in the ms range for a typical 10{sup 51} erg supernova. These conditions are satisfied by some magnetar models for Type I superluminous supernovae. We also consider the Crab Nebula, which may be associated with a low energy supernova for which this scenario applies.

Neutrino signal from pair-instability supernovae

Science.gov (United States)

Wright, Warren P.; Gilmer, Matthew S.; Fröhlich, Carla; Kneller, James P.

2017-11-01

A very massive star with a carbon-oxygen core in the range of 64M ⊙Earth from two, one-dimensional pair-instability supernova simulations which bracket the mass range of stars which explode by this mechanism taking into account the full time and energy dependence of the neutrino emission and the flavor evolution through the outer layers of the star. We calculate the neutrino signals in five different detectors chosen to represent present or near future designs. We find the more massive progenitors explode as pair-instability supernova which can easily be detected in multiple different neutrino detectors at the "standard" supernova distance of 10 kpc producing several events in DUNE, JUNO, and Super-Kamiokande, while the lightest progenitors produce only a handful of events (if any) in the same detectors. The proposed Hyper-Kamiokande detector would detect neutrinos from a large pair-instability supernova as far as ˜50 kpc allowing it to reach the Megallanic Clouds and the several very high mass stars known to exist there.

supernovae: Photometric classification of supernovae

Science.gov (United States)

Charnock, Tom; Moss, Adam

2017-05-01

Supernovae classifies supernovae using their light curves directly as inputs to a deep recurrent neural network, which learns information from the sequence of observations. Observational time and filter fluxes are used as inputs; since the inputs are agnostic, additional data such as host galaxy information can also be included.

Multidimensional pair-instability supernova simulations and their multi-messenger signals

Science.gov (United States)

Gilmer, Matthew; Kozyreva, Alexandra; Hirschi, Raphael; Fröhlich, Carla; Wright, Warren; Kneller, James P.; Yusof, Norhasliza

2018-01-01

Pair-Instability supernovae (PISNe) are an exotic class of supernovae which, in addition to being fascinating in its own right (its very existence is a topic of debate), may be important for many areas of astrophysics (early stellar populations, galaxy/chemical evolution, cosmic reionization, etc.). At present, PISNe are one of the three proposed mechanisms for explaining superluminous supernovae, though one major drawback is that PISN models predict longer rise times to peak luminosity than seen in observations of superluminous supernovae. Model rise times can be reduced by having shallower progenitor envelopes and/or outward mixing of radioactive material during the explosions. Here, we present explosions and light curves for four progenitor models, with relatively shallow envelopes, that span the PISN mass range. Our light curves exhibit significantly shorter rise times than other PISNe light curves. In addition, we investigate the effects of a multidimensional treatment during the explosive burning phase of PISNe, including the first such treatment in 3D. We find a small amount of outward mixing of radioactive Ni-56 that increases with the number of dimensions, however this mixing is insufficient to significantly alter the light curve rise time. We find significant mixing between the silicon and oxygen rich layers, especially in 3D, that may affect model spectra and should be investigated in the future. Finally, we present the neutrino signals expected from our most massive and least massive PISN models. Accounting for neutrino oscillations, we compute the expected event rates for current and future neutrino detectors.

Supernovae

International Nuclear Information System (INIS)

Petschek, A.

1990-01-01

This book offers papers incorporating the latest results and understanding about supernovae, including SN1987A. There are several chapters reviewing all the radio through infrared, visible, and ultraviolet to X-rays and gamma-rays but also neutrinos. Other chapters deal with the classification of supernovae, depending on their spectra and light curves. Three chapters treat supernovae theory, including an idea of a fractal burning front and another on the behavior of neutron stars

How To Model Supernovae in Simulations of Star and Galaxy Formation

Science.gov (United States)

Hopkins, Philip F.; Wetzel, Andrew; Kereš, Dušan; Faucher-Giguére, Claude-André; Quataert, Eliot; Boylan-Kolchin, Michael; Murray, Norman; Hayward, Christopher C.; El-Badry, Kareem

2018-03-01

We study the implementation of mechanical feedback from supernovae (SNe) and stellar mass loss in galaxy simulations, within the Feedback In Realistic Environments (FIRE) project. We present the FIRE-2 algorithm for coupling mechanical feedback, which can be applied to any hydrodynamics method (e.g. fixed-grid, moving-mesh, and mesh-less methods), and black hole as well as stellar feedback. This algorithm ensures manifest conservation of mass, energy, and momentum, and avoids imprinting "preferred directions" on the ejecta. We show that it is critical to incorporate both momentum and thermal energy of mechanical ejecta in a self-consistent manner, accounting for SNe cooling radii when they are not resolved. Using idealized simulations of single SN explosions, we show that the FIRE-2 algorithm, independent of resolution, reproduces converged solutions in both energy and momentum. In contrast, common "fully-thermal" (energy-dump) or "fully-kinetic" (particle-kicking) schemes in the literature depend strongly on resolution: when applied at mass resolution ≳ 100 M⊙, they diverge by orders-of-magnitude from the converged solution. In galaxy-formation simulations, this divergence leads to orders-of-magnitude differences in galaxy properties, unless those models are adjusted in a resolution-dependent way. We show that all models that individually time-resolve SNe converge to the FIRE-2 solution at sufficiently high resolution (simulations and cosmological galaxy-formation simulations, the FIRE-2 algorithm converges much faster than other sub-grid models without re-tuning parameters.

Core-Collapse Supernovae, Neutrinos, and Gravitational Waves

Energy Technology Data Exchange (ETDEWEB)

Ott, C.D. [TAPIR, California Institute of Technology, Pasadena, California (United States); Kavli Institute for the Physics and Mathematics of the Universe, Kashiwa, Chiba (Japan); O' Connor, E.P. [Canadian Institute for Theoretical Astrophysics, Toronto, Ontario (Canada); Gossan, S.; Abdikamalov, E.; Gamma, U.C.T. [TAPIR, California Institute of Technology, Pasadena, California (United States); Drasco, S. [Grinnell College, Grinnell, Iowa (United States); TAPIR, California Institute of Technology, Pasadena, California (United States)

2013-02-15

Core-collapse supernovae are among the most energetic cosmic cataclysms. They are prodigious emitters of neutrinos and quite likely strong galactic sources of gravitational waves. Observation of both neutrinos and gravitational waves from the next galactic or near extragalactic core-collapse supernova will yield a wealth of information on the explosion mechanism, but also on the structure and angular momentum of the progenitor star, and on aspects of fundamental physics such as the equation of state of nuclear matter at high densities and low entropies. In this contribution to the proceedings of the Neutrino 2012 conference, we summarize recent progress made in the theoretical understanding and modeling of core-collapse supernovae. In this, our emphasis is on multi-dimensional processes involved in the explosion mechanism such as neutrino-driven convection and the standing accretion shock instability. As an example of how supernova neutrinos can be used to probe fundamental physics, we discuss how the rise time of the electron antineutrino flux observed in detectors can be used to probe the neutrino mass hierarchy. Finally, we lay out aspects of the neutrino and gravitational-wave signature of core-collapse supernovae and discuss the power of combined analysis of neutrino and gravitational wave data from the next galactic core-collapse supernova.

Core-Collapse Supernovae, Neutrinos, and Gravitational Waves

International Nuclear Information System (INIS)

Ott, C.D.; O'Connor, E.P.; Gossan, S.; Abdikamalov, E.; Gamma, U.C.T.; Drasco, S.

2013-01-01

Core-collapse supernovae are among the most energetic cosmic cataclysms. They are prodigious emitters of neutrinos and quite likely strong galactic sources of gravitational waves. Observation of both neutrinos and gravitational waves from the next galactic or near extragalactic core-collapse supernova will yield a wealth of information on the explosion mechanism, but also on the structure and angular momentum of the progenitor star, and on aspects of fundamental physics such as the equation of state of nuclear matter at high densities and low entropies. In this contribution to the proceedings of the Neutrino 2012 conference, we summarize recent progress made in the theoretical understanding and modeling of core-collapse supernovae. In this, our emphasis is on multi-dimensional processes involved in the explosion mechanism such as neutrino-driven convection and the standing accretion shock instability. As an example of how supernova neutrinos can be used to probe fundamental physics, we discuss how the rise time of the electron antineutrino flux observed in detectors can be used to probe the neutrino mass hierarchy. Finally, we lay out aspects of the neutrino and gravitational-wave signature of core-collapse supernovae and discuss the power of combined analysis of neutrino and gravitational wave data from the next galactic core-collapse supernova

Theoretical models for supernovae

International Nuclear Information System (INIS)

Woosley, S.E.; Weaver, T.A.

1981-01-01

The results of recent numerical simulations of supernova explosions are presented and a variety of topics discussed. Particular emphasis is given to (i) the nucleosynthesis expected from intermediate mass (10sub solar less than or equal to M less than or equal to 100 Msub solar) Type II supernovae and detonating white dwarf models for Type I supernovae, (ii) a realistic estimate of the γ-line fluxes expected from this nucleosynthesis, (iii) the continued evolution, in one and two dimensions, of intermediate mass stars wherein iron core collapse does not lead to a strong, mass-ejecting shock wave, and (iv) the evolution and explosion of vary massive stars M greater than or equal to 100 Msub solar of both Population I and III. In one dimension, nuclear burning following a failed core bounce does not appear likely to lead to a supernova explosion although, in two dimensions, a combination of rotation and nuclear burning may do so. Near solar proportions of elements from neon to calcium and very brilliant optical displays may be created by hypernovae, the explosions of stars in the mass range 100 M/sub solar/ to 300 M/sub solar/. Above approx. 300 M/sub solar/ a black hole is created by stellar collapse following carbon ignition. Still more massive stars may be copious producers of 4 He and 14 N prior to their collapse on the pair instability

Supernova Explosions Stay In Shape

Science.gov (United States)

2009-12-01

At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular

How supernovae launch galactic winds?

Science.gov (United States)

Fielding, Drummond; Quataert, Eliot; Martizzi, Davide; Faucher-Giguère, Claude-André

2017-09-01

We use idealized three-dimensional hydrodynamic simulations of global galactic discs to study the launching of galactic winds by supernovae (SNe). The simulations resolve the cooling radii of the majority of supernova remnants (SNRs) and thus self-consistently capture how SNe drive galactic winds. We find that SNe launch highly supersonic winds with properties that agree reasonably well with expectations from analytic models. The energy loading (η _E= \\dot{E}_wind/ \\dot{E}_SN) of the winds in our simulations are well converged with spatial resolution while the wind mass loading (η _M= \\dot{M}_wind/\\dot{M}_\\star) decreases with resolution at the resolutions we achieve. We present a simple analytic model based on the concept that SNRs with cooling radii greater than the local scaleheight break out of the disc and power the wind. This model successfully explains the dependence (or lack thereof) of ηE (and by extension ηM) on the gas surface density, star formation efficiency, disc radius and the clustering of SNe. The winds our simulations are weaker than expected in reality, likely due to the fact that we seed SNe preferentially at density peaks. Clustering SNe in time and space substantially increases the wind power.

GALAXY OUTFLOWS WITHOUT SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Sur, Sharanya [Indian Institute of Astrophysics, 2nd Block, Koramangala, Bangalore 560034 (India); Scannapieco, Evan [School of Earth and Space Exploration, Arizona State University, P.O. Box 876004, Tempe-85287 (United States); Ostriker, Eve C., E-mail: sharanya.sur@iiap.res.in, E-mail: sharanya.sur@asu.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2016-02-10

High surface density, rapidly star-forming galaxies are observed to have ≈50–100 km s{sup −1} line of sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale gravitational instabilities. Using three-dimensional simulations of local regions of the interstellar medium, we explore the impact of high velocity dispersions that arise from these disk instabilities. Parametrizing disks by their surface densities and epicyclic frequencies, we conduct a series of simulations that probe a broad range of conditions. Turbulence is driven purely horizontally and on large scales, neglecting any energy input from supernovae. We find that such motions lead to strong global outflows in the highly compact disks that were common at high redshifts, but weak or negligible mass loss in the more diffuse disks that are prevalent today. Substantial outflows are generated if the one-dimensional horizontal velocity dispersion exceeds ≈35 km s{sup −1}, as occurs in the dense disks that have star-formation rate (SFR) densities above ≈0.1 M{sub ⊙} yr{sup −1} kpc{sup −2}. These outflows are triggered by a thermal runaway, arising from the inefficient cooling of hot material coupled with successive heating from turbulent driving. Thus, even in the absence of stellar feedback, a critical value of the SFR density for outflow generation can arise due to a turbulent heating instability. This suggests that in strongly self-gravitating disks, outflows may be enhanced by, but need not caused by, energy input from supernovae.

Multidimensional, multiphysics simulations of core-collapse supernovae

Energy Technology Data Exchange (ETDEWEB)

Messer, O E B [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6008 (United States); Bruenn, S W [Department of Physics, Florida Atlantic University, Boca Raton, FL 33431-0991 (United States); Blondin, J M [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Hix, W R; Mezzacappa, A [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6354 (United States)

2008-07-15

CHIMERA is a multi-dimensional radiation hydrodynamics code designed to study core-collapse supernovae. The code is made up of three essentially independent parts: a hydrodynamics module, a nuclear burning module, and a neutrino transport solver combined within an operator-split approach. We review the code's architecture and some recently improved implementations used in the code. We also briefly discuss preliminary results obtained with the code in three spatial dimensions.

Magnetorotational Explosions of Core-Collapse Supernovae

Directory of Open Access Journals (Sweden)

Gennady S. Bisnovatyi-Kogan

2014-12-01

Full Text Available 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 eld 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 dierential rotation. When the twisted toroidal component strongly exceeds the poloidal eld, magneto-rotational instability develops, leading to a drastic acceleration in the growth of magnetic energy. Finally, a fast MHD shock is formed, producing a supernova explosion. Mildly collimated jet is produced for dipole-like type of the initial field. At very high initial magnetic field no MRI development was found.

THREE-DIMENSIONAL CORE-COLLAPSE SUPERNOVA SIMULATED USING A 15 M{sub ⊙} PROGENITOR

Energy Technology Data Exchange (ETDEWEB)

Lentz, Eric J.; Mezzacappa, Anthony; Harris, J. Austin; Yakunin, Konstantin N. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Bruenn, Stephen W. [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States); Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [National Center for Computational Sciences, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Endeve, Eirik [Computer Science and Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Blondin, John M. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Marronetti, Pedro, E-mail: elentz@utk.edu [Physics Division, National Science Foundation, Arlington, VA 22207 (United States)

2015-07-10

We have performed ab initio neutrino radiation hydrodynamics simulations in three and two spatial dimensions (3D and 2D) of core-collapse supernovae from the same 15 M{sub ☉} progenitor through 440 ms after core bounce. Both 3D and 2D models achieve explosions; however, the onset of explosion (shock revival) is delayed by ∼100 ms in 3D relative to the 2D counterpart and the growth of the diagnostic explosion energy is slower. This is consistent with previously reported 3D simulations utilizing iron-core progenitors with dense mantles. In the ∼100 ms before the onset of explosion, diagnostics of neutrino heating and turbulent kinetic energy favor earlier explosion in 2D. During the delay, the angular scale of convective plumes reaching the shock surface grows and explosion in 3D is ultimately lead by a single, large-angle plume, giving the expanding shock a directional orientation not dissimilar from those imposed by axial symmetry in 2D simulations. We posit that shock revival and explosion in the 3D simulation may be delayed until sufficiently large plumes form, whereas such plumes form more rapidly in 2D, permitting earlier explosions.

Handbook of supernovae

CERN Document Server

Murdin, Paul

2017-01-01

This reference work gathers all of the latest research in the supernova field areas to create a definitive source book on supernovae, their remnants and related topics. It includes each distinct subdiscipline, including stellar types, progenitors, stellar evolution, nucleosynthesis of elements, supernova types, neutron stars and pulsars, black holes, swept up interstellar matter, cosmic rays, neutrinos from supernovae, supernova observations in different wavelengths, interstellar molecules and dust. While there is a great deal of primary and specialist literature on supernovae, with a great many scientific groups around the world focusing on the phenomenon and related subdisciplines, nothing else presents an overall survey. This handbook closes that gap at last. As a comprehensive and balanced collection that presents the current state of knowledge in the broad field of supernovae, this is to be used as a basis for further work and study by graduate students, astronomers and astrophysicists working in close/r...

Variety of Polarized Line Profiles in Interacting Supernovae

Science.gov (United States)

Hoffman, Jennifer L.; Huk, L. N.; Peters, C. L.

2013-01-01

The dense circumstellar material that creates strong emission lines in the spectra of interacting supernovae also gives rise to complex line polarization behavior. Viewed in polarized light, the emission line profiles of these supernovae encode information about the geometrical and optical characteristics of their surrounding circumstellar material (CSM) that is inaccessible by other observational techniques. To facilitate quantitative interpretation of these spectropolarimetric signatures, we have created a large grid of model polarized line profiles using a three-dimensional radiative transfer code that simulates polarization via electron and resonant/fluorescent line scattering. The simulated polarized lines take on an array of profile shapes that vary with viewing angle and CSM properties. We present the major results from the grid and investigate the dependence of polarized line profiles on CSM characteristics including temperature, optical depth, and geometry. These results will allow more straightforward interpretation of polarized line profiles in interacting supernovae than has previously been possible. This research is supported by the National Science Foundation through the AAG program and the XSEDE collaboration, and uses the resources of the Texas Advanced Computing Center.

INTERPLAY OF NEUTRINO OPACITIES IN CORE-COLLAPSE SUPERNOVA SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Mezzacappa, Anthony; Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [National Center for Computational Sciences, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Bruenn, Stephen W., E-mail: elentz@utk.edu [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

2012-11-20

We have conducted a series of numerical experiments using spherically symmetric, general relativistic, neutrino radiation hydrodynamics with the code Agile-BOLTZTRAN to examine the effects of modern neutrino opacities on the development of supernova simulations. We test the effects of opacities by removing opacities or by undoing opacity improvements for individual opacities and groups of opacities. We find that improvements to electron capture (EC) on nuclei, namely EC on an ensemble of nuclei using modern nuclear structure models rather than the simpler independent-particle approximation (IPA) for EC on a mean nucleus, plays the most important role during core collapse of all tested neutrino opacities. Low-energy neutrinos emitted by modern nuclear EC preferentially escape during collapse without the energy downscattering on electrons required to enhance neutrino escape and deleptonization for the models with IPA nuclear EC. During shock breakout the primary influence on the emergent neutrinos arises from non-isoenergetic scattering (NIS) on electrons. For the accretion phase, NIS on free nucleons and pair emission by e {sup +} e {sup -} annihilation have the largest impact on the neutrino emission and shock evolution. Other opacities evaluated, including nucleon-nucleon bremsstrahlung and especially neutrino-positron scattering, have little measurable impact on neutrino emission or shock dynamics. Modern treatments of nuclear EC, e {sup +} e {sup -}-annihilation pair emission, and NIS on electrons and free nucleons are critical elements of core-collapse simulations of all dimensionality.

How to model supernovae in simulations of star and galaxy formation

Science.gov (United States)

Hopkins, Philip F.; Wetzel, Andrew; Kereš, Dušan; Faucher-Giguère, Claude-André; Quataert, Eliot; Boylan-Kolchin, Michael; Murray, Norman; Hayward, Christopher C.; El-Badry, Kareem

2018-06-01

We study the implementation of mechanical feedback from supernovae (SNe) and stellar mass loss in galaxy simulations, within the Feedback In Realistic Environments (FIRE) project. We present the FIRE-2 algorithm for coupling mechanical feedback, which can be applied to any hydrodynamics method (e.g. fixed-grid, moving-mesh, and mesh-less methods), and black hole as well as stellar feedback. This algorithm ensures manifest conservation of mass, energy, and momentum, and avoids imprinting `preferred directions' on the ejecta. We show that it is critical to incorporate both momentum and thermal energy of mechanical ejecta in a self-consistent manner, accounting for SNe cooling radii when they are not resolved. Using idealized simulations of single SN explosions, we show that the FIRE-2 algorithm, independent of resolution, reproduces converged solutions in both energy and momentum. In contrast, common `fully thermal' (energy-dump) or `fully kinetic' (particle-kicking) schemes in the literature depend strongly on resolution: when applied at mass resolution ≳100 M⊙, they diverge by orders of magnitude from the converged solution. In galaxy-formation simulations, this divergence leads to orders-of-magnitude differences in galaxy properties, unless those models are adjusted in a resolution-dependent way. We show that all models that individually time-resolve SNe converge to the FIRE-2 solution at sufficiently high resolution (models without re-tuning parameters.

Masses of supernova progenitors

International Nuclear Information System (INIS)

Tinsley, B.M.

1977-01-01

The possible nature and masses of supernovae progenitors, and the bearing of empirical results on some unsolved theoretical problems concerning the origin of supernovae, are discussed. The author concentrates on two main questions: what is the lower mass limit for stars to die explosively and what stars initiate type I supernovae. The evidence considered includes local supernova rates, empirical estimates of msub(w) (the upper mass limit for death as a white dwarf), the distributions of supernovae among stellar populations in galaxies and the colors of supernova producing galaxies. (B.D.)

Rayleigh-Taylor mixing in supernova experiments

International Nuclear Information System (INIS)

Swisher, N. C.; Abarzhi, S. I.; Kuranz, C. C.; Arnett, D.; Hurricane, O.; Remington, B. A.; Robey, H. F.

2015-01-01

We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study core-collapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blast-wave with helium-hydrogen interface, and the induced Rayleigh-Taylor instability and Rayleigh-Taylor mixing of the denser and lighter fluids with time-dependent acceleration. We analyze all available experimental images of the Rayleigh-Taylor flow in supernova experiments and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By properly accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are reported to describe asymptotic dynamics of Rayleigh-Taylor flow with time-dependent acceleration by applying theoretical analysis that considers symmetries and momentum transport. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments Rayleigh-Taylor flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; Rayleigh-Taylor mixing keeps order

Supernovae theory: study of electro-weak processes during gravitational collapse of massive stars

International Nuclear Information System (INIS)

Fantina, A.F.

2010-01-01

The physics of supernova requires the understanding of both the complex hydrodynamical phenomena (such as transfer of energy, neutrino transport, shock) as well as the microphysics related to the dense and hot matter. In the framework of type II Supernovae theory, currently most of numerical simulations that simulate the supernova core collapse up to the formation and propagation of the shock wave fail to reproduce the observed explosion of the outer layers of massive stars. The reason for that could be due both to hydrodynamical phenomena such as rotation, convection, and general relativity, and to some micro-physical processes involved in the picture and not yet completely understood. The aim of this work is to investigate some of these micro-physical inputs, namely the electro-weak processes, that play a crucial role during the gravitational collapse and to analyse their effects by means of hydrodynamical simulations. Among nuclear processes which occur in core-collapse supernova, the most important electro-weak process taking place during the collapse is the electron capture; it occurs both on free protons and on protons bound in nuclei. This capture is essential to determine the evolution of the lepton fraction of the core during the neutronization phase. It affects the efficiency of the bounce and, as a consequence, the strength of the shock wave. Moreover, both the equation of state of supernova matter and electron capture rates in nuclei are modified by the effective mass of nucleons in nuclei, induced by many-body correlations in the dense medium, and its temperature dependence. In the first part of the thesis, a nuclear model aimed at studying the nuclear effective mass is presented. We show how we have included in a energy density functional (EDF) approach a surface-peaked nucleon effective mass to mimic some effects beyond Hartree-Fock. We have added a term to the Skyrme functional, in order to reproduce the enhancement of the effective mass at the

3D Simulations of Supernova Remnants from Type Ia Supernova Models

Science.gov (United States)

Johnson, Heather; Reynolds, S. P.; Frohlich, C.; Blondin, J. M.

2014-01-01

Type Ia supernovae (SNe) originate from thermonuclear explosions of white dwarfs. A great deal is still unknown about the explosion mechanisms, particularly the degree of asymmetry. However, Type Ia supernova remnants (SNRs) can bear the imprint of asymmetry long after the explosion. A SNR of interest is G1.9+0.3, the youngest Galactic SNR, which demonstrates an unusual spatial distribution of elements in the ejecta. While its X-ray spectrum is dominated by synchrotron emission, spectral lines of highly ionized Si, S, and Fe are seen in a few locations, with Fe near the edge of the remnant and with strongly varying Fe/Si ratios. An asymmetric explosion within the white dwarf progenitor may be necessary to explain these unusual features of G1.9+0.3, in particular the shocked Fe at large radii. We use the VH-1 hydrodynamics code to evolve initial Type Ia explosion models in 1, 2, and 3 dimensions at an age of 100 seconds provided by other researchers to study asymmetry, the ignition properties, and the nucleosynthesis resulting from these explosions. We follow the evolution of these models interacting with a uniform external medium to a few hundred years in age. We find the abundance and location of ejecta elements from our models to be inconsistent with the observations of G1.9+0.3; while our models show asymmetric element distributions, we find no tendency for iron-group elements to be found beyond intermediate-mass elements, or for significant iron to be reverse-shocked at all at the age of G1.9+0.3. We compare the amounts of shocked iron-group and intermediate-mass elements as a function of time in the different models. Some new kind of explosion asymmetry may be required to explain G1.9+0.3. This work was performed as part of NC State University's Undergraduate Research in Computational Astrophysics (URCA) program, an REU program supported by the National Science Foundation through award AST-1032736.

Could there be a hole in type Ia supernovae?

International Nuclear Information System (INIS)

Kasen, Daniel; Nugent, Peter; Thomas, R.C.; Wang, Lifan

2004-01-01

In the favored progenitor scenario, Type Ia supernovae (SNe Ia) arise from a white dwarf accreting material from a non-degenerate companion star. Soon after the white dwarf explodes, the ejected supernova material engulfs the companion star; two-dimensional hydrodynamical simulations by Marietta et al. (2001) show that, in the interaction, the companion star carves out a conical hole of opening angle 30-40 degrees in the supernova ejecta. In this paper we use multi-dimensional Monte Carlo radiative transfer calculations to explore the observable consequences of an ejecta-hole asymmetry. We calculate the variation of the spectrum, luminosity, and polarization with viewing angle for the aspherical supernova near maximum light. We find that the supernova looks normal from almost all viewing angles except when one looks almost directly down the hole. In the latter case, one sees into the deeper, hotter layers of ejecta. The supernova is relatively brighter and has a peculiar spectrum characterized by more highly ionized species, weaker absorption features, and lower absorption velocities. The spectrum viewed down the hole is comparable to the class of SN 1991T-like supernovae. We consider how the ejecta-hole asymmetry may explain the current spectropolarimetric observations of SNe Ia, and suggest a few observational signatures of the geometry. Finally, we discuss the variety currently seen in observed SNe Ia and how an ejecta-hole asymmetry may fit in as one of several possible sources of diversity

Smoking supernovae

OpenAIRE

Gomez, Haley Louise; Eales, Stephen Anthony; Dunne, L.

2007-01-01

The question ‘Are supernovae important sources of dust?’ is a contentious one. Observations with the Infrared Astronomical Satellite (IRAS) and the Infrared Space Observatory (ISO) only detected very small amounts of hot dust in supernova remnants. Here, we review observations of two young Galactic remnants with the Submillimetre Common User Bolometer Array (SCUBA), which imply that large quantities of dust are produced by supernovae. The association of dust with the Cassiopeia A remnant is i...

Modelling neutrino and gamma-ray fluxes in supernova remnants

International Nuclear Information System (INIS)

Ballet, J; Cassam-Chenai, G; Maurin, G; Naumann, C

2008-01-01

Supernova remnants (SNRs) are believed to accelerate charged particles by diffusive shock acceleration (DSA) and to produce the majority of galactic cosmic rays, at least up to the 'knee' at 3-10 15 electron volts. In the framework of a hydrodynamic self-similar simulation of the evolution of young supernova remnants, its interaction with the ambient matter as well as the microwave and infrared background is studied. The photon spectra resulting from synchrotron and inverse Compton emission as well as from hadronic processes are calculated, as are the accompanying neutrino fluxes. Applying this method to the particular case of the SNR RXJ-1713, 7-3946, we find that its TeV emission can in principle be explained by pion decay if the ambient density is assumed to grow with increasing distance from the centre. The neutrino flux associated with this hadronic model is of a magnitude that may be detectable by a cubic-kilometre sized deep-sea neutrino telescope in the northern hemisphere. In this poster, a description of the supernova remnant simulation is given together with the results concerning RXJ-1713.

2D RADIATION-HYDRODYNAMIC SIMULATIONS OF SUPERNOVA SHOCK BREAKOUT IN BIPOLAR EXPLOSIONS OF A BLUE SUPERGIANT PROGENITOR

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Akihiro; Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 (Japan); Shigeyama, Toshikazu [Research Center for the Early Universe, School of Science, University of Tokyo, Bunkyo-ku, Tokyo, 113-0033 (Japan)

2016-07-10

A two-dimensional special relativistic radiation-hydrodynamics code is developed and applied to numerical simulations of supernova shock breakout in bipolar explosions of a blue supergiant. Our calculations successfully simulate the dynamical evolution of a blast wave in the star and its emergence from the surface. Results of the model with spherical energy deposition show a good agreement with previous simulations. Furthermore, we calculate several models with bipolar energy deposition and compare their results with the spherically symmetric model. The bolometric light curves of the shock breakout emission are calculated by a ray-tracing method. Our radiation-hydrodynamic models indicate that the early part of the shock breakout emission can be used to probe the geometry of the blast wave produced as a result of the gravitational collapse of the iron core.

The historical supernovae

CERN Document Server

Clark, David H

1977-01-01

The Historical Supernovae is an interdisciplinary study of the historical records of supernova. This book is composed of 12 chapters that particularly highlight the history of the Far East. The opening chapter briefly describes the features of nova and supernova, stars which spontaneously explode with a spectacular and rapid increase in brightness. The succeeding chapter deals with the search for the historical records of supernova from Medieval European monastic chronicles, Arabic chronicles, astrological works etc., post renaissance European scientific writings, and Far Eastern histories and

Offline analysis of the SuperNova Legacy Survey data

International Nuclear Information System (INIS)

Bazin, Gurvan

2008-01-01

This thesis aims at developing a photometry-based procedure for the selection of Type Ia Supernovae. More precisely, a first objective is to confirm possible biases in the spectroscopic selection of the SuperNova Legacy Survey (SNLS), and to determine their consequence on the distance module. A second one is to to study the feasibility of a purely photometric analysis within the perspective of future large projects in cosmology. After a presentation of supernovae, of their physical properties, and more particularly those which are used in cosmology, i.e. Type Ia Supernovae (SNe Ia), the author presents the cosmological framework, and the parameters of the standard cosmological model (Hubble constant, matter density, black energy density). The experimental context is then presented with measurements of the Canada France Hawaii Telescope Legacy Survey (CFHTLS), and a method used to search for SNe Ia. In the next part, the author describes the different steps of the differed procedure of data processing, from raw images directly extracted from the telescope to the characterisation of light curves of detected objects. Different tools are presented: the SALT2 model of light curves, the simulation of SNe Ia light curves, and an image simulation. The purely photometric selection of SNe Ia is then presented along with steps used to eliminate background noise. Obtained results are then discussed and compared with real time analysis [fr

Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets and Supernova Remnants

Science.gov (United States)

Nishikawa, K.-I.; Hartmann, D. H.; Hardee, P.; Hededal, C.; Mizunno, Y.; Fishman, G. J.

2006-01-01

We performed numerical simulations of particle acceleration, magnetic field generation, and emission from shocks in order to understand the observed emission from relativistic jets and supernova remnants. The investigation involves the study of collisionless shocks, where the Weibel instability is responsible for particle acceleration as well as magnetic field generation. A 3-D relativistic particle-in-cell (RPIC) code has been used to investigate the shock processes in electron-positron plasmas. The evolution of theWeibe1 instability and its associated magnetic field generation and particle acceleration are studied with two different jet velocities (0 = 2,5 - slow, fast) corresponding to either outflows in supernova remnants or relativistic jets, such as those found in AGNs and microquasars. Slow jets have intrinsically different structures in both the generated magnetic fields and the accelerated particle spectrum. In particular, the jet head has a very weak magnetic field and the ambient electrons are strongly accelerated and dragged by the jet particles. The simulation results exhibit jitter radiation from inhomogeneous magnetic fields, generated by the Weibel instability, which has different spectral properties than standard synchrotron emission in a homogeneous magnetic field.

The Impact of the Nuclear Equation of State in Core Collapse Supernovae

Science.gov (United States)

Baird, M. L.; Lentz, E. J.; Hix, W. R.; Mezzacappa, A.; Messer, O. E. B.; Liebendoerfer, M.; TeraScale Supernova Initiative Collaboration

2005-12-01

One of the key ingredients to the core collapse supernova mechanism is the physics of matter at or near nuclear density. Included in simulations as part of the Equation of State (EOS), nuclear repulsion experienced at high densities are responsible for the bounce shock, which initially causes the outer envelope of the supernova to expand, as well as determining the structure of the newly formed proto-neutron star. Recent years have seen renewed interest in this fundamental piece of supernova physics, resulting in several promising candidate EOS parameterizations. We will present the impact of these variations in the nuclear EOS using spherically symmetric, Newtonian and General Relativistic neutrino transport simulations of stellar core collapse and bounce. This work is supported in part by SciDAC grants to the TeraScale Supernovae Initiative from the DOE Office of Science High Energy, Nuclear, and Advanced Scientific Computing Research Programs. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for U.S. Department of Energy under contract DEAC05-00OR22725

Computational models of stellar collapse and core-collapse supernovae

International Nuclear Information System (INIS)

Ott, Christian D; O'Connor, Evan; Schnetter, Erik; Loeffler, Frank; Burrows, Adam; Livne, Eli

2009-01-01

Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani which is based on the open-source HPC Cactus framework and provides a scalable AMR approach for 3D fully general-relativistic modeling of stellar collapse, core-collapse supernovae and black hole formation on current and future massively-parallel HPC systems. We show Zelmani's scaling properties to more than 16,000 compute cores and discuss first 3D general-relativistic core-collapse results.

Radio emission from Supernovae and High Precision Astrometry

Science.gov (United States)

Perez-Torres, M. A.

1999-11-01

The present thesis work makes contributions in two scientific fronts: differential astrometry over the largest angular scales ever attempted (approx. 15 arcdegrees) and numerical simulations of radio emission from very young supernovae. In the first part, we describe the results of the use of very-long-baseline interferometry (VLBI) in one experiment designed to measure with very high precision the angular distance between the radio sources 1150+812 (QSO) and 1803+784 (BL Lac). We observed the radio sources on 19 November 1993 using an intercontinental array of radio telescopes, which simultaneously recorded at 2.3 and 8.4 GHz. VLBI differential astrometry is capable, Nature allowing, of yielding source positions with precisions well below the milliarcsecond level. To achieve this precision, we first had to accurately model the rotation of the interferometric fringes via the most precise models of Earth Orientation Parameters (EOP; precession, polar motion and UT1, nutation). With this model, we successfully connected our phase delay data at both frequencies and, using difference astrometric techniques, determined the coordinates of 1803+784 relative to those of 1150+812-within the IERS reference frame--with an standard error of about 0.6 mas in each coordinate. We then corrected for several effects including propagation medium (mainly the atmosphere and ionosphere), and opacity and source-structure effects within the radio sources. We stress that our dual-frequency measurements allowed us to accurately subtract the ionosphere contribution from our data. We also used GPS-based TEC measurements to independently find the ionosphere contribution, and showed that these contributions agree with our dual-frequency measurements within about 2 standard deviations in the less favorables cases (the longest baselines), but are usually well within one standard deviation. Our estimates of the relative positions, whether using dual-frequency-based or GPS-based ionosphere

Evolution of Supernova Remnants

Science.gov (United States)

Arbutina, B.

2017-12-01

This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

Supernova neutrinos

International Nuclear Information System (INIS)

Anon.

1990-01-01

In the first part of his in-depth article on the 1987 supernova, David Schramm of the University of Chicago and the NASA/Fermilab Astrophysics Centre reviewed the background to supernovae, the composition of massive stars and the optical history of SN 1987A, and speculated on what the 1987 remnant might be. In such a Type II supernova, gravitational pressure crushes the atoms of the star's interior producing neutron matter, or even a black hole, and releasing an intense burst of neutrinos. 1987 was the first time that physicists were equipped (but not entirely ready!) to intercept these particles, and in the second part of his article, David Schramm covers the remarkable new insights from the science of supernova neutrino astronomy, born on 23 February 1987

Supernovae and neutrinos

International Nuclear Information System (INIS)

Totsuka, Y.

1991-01-01

On February 25, 1987, a sheet of telefax came to us from S. A. Bludman, saying Supernova went off in Large Magellanic Clouds. Can you see it? This is what we have been waiting 350 years for exclamation point In few hours, more information arrived. But it was still too early to definitely identify the supernova as type I or type II. This paper reports that the type I supernova is an explosion of a complete star due to uncontrolled nuclear fusion, while the type II supernova is triggered by gravitational collapse of the Fe core of a massive star (≥8 solar mass). It is this type II supernova that would leave a neutron star or a black hole after the liberation of an enormous amount of energy (3 x 10 53 erg) in the form of neutrinos. Therefore only the type II supernova is a relevant place to look for neutrino signals. It was also frustrating that the time when the stellar collapse actually took place was not definitely determined, because it was believed that the supernova brightened up about a day after the collapse and there was an ambiguity in a time lag of the optical observation. There was a possibility that it had happened well before February 24

Dust in Supernovae and Supernova Remnants II: Processing and Survival

Science.gov (United States)

Micelotta, E. R.; Matsuura, M.; Sarangi, A.

2018-03-01

Observations have recently shown that supernovae are efficient dust factories, as predicted for a long time by theoretical models. The rapid evolution of their stellar progenitors combined with their efficiency in precipitating refractory elements from the gas phase into dust grains make supernovae the major potential suppliers of dust in the early Universe, where more conventional sources like Asymptotic Giant Branch (AGB) stars did not have time to evolve. However, dust yields inferred from observations of young supernovae or derived from models do not reflect the net amount of supernova-condensed dust able to be expelled from the remnants and reach the interstellar medium. The cavity where the dust is formed and initially resides is crossed by the high velocity reverse shock which is generated by the pressure of the circumstellar material shocked by the expanding supernova blast wave. Depending on grain composition and initial size, processing by the reverse shock may lead to substantial dust erosion and even complete destruction. The goal of this review is to present the state of the art about processing and survival of dust inside supernova remnants, in terms of theoretical modelling and comparison to observations.

Nearby supernova factory announces 34 supernovae in one year'; best Rookie year ever for supernova search

CERN Multimedia

2003-01-01

The Nearby Supernova Factory (SNfactory), an international collaboration based at Lawrence Berkeley National Laboratory, announced that it had discovered 34 supernovae during the first year of the prototype system's operation (2 pages).

Supernova cosmology

International Nuclear Information System (INIS)

Leibundgut, B.

2005-01-01

Supernovae have developed into a versatile tool for cosmology. Their impact on the cosmological model has been profound and led to the discovery of the accelerated expansion. The current status of the cosmological model as perceived through supernova observations will be presented. Supernovae are currently the only astrophysical objects that can measure the dynamics of the cosmic expansion during the past eight billion years. Ongoing experiments are trying to determine the characteristics of the accelerated expansion and give insight into what might be the physical explanation for the acceleration. (author)

Supernova models

International Nuclear Information System (INIS)

Woosley, S.E.; Weaver, T.A.

1980-01-01

Recent progress in understanding the observed properties of Type I supernovae as a consequence of the thermonuclear detonation of white dwarf stars and the ensuing decay of the 56 Ni produced therein is reviewed. Within the context of this model for Type I explosions and the 1978 model for Type II explosions, the expected nucleosynthesis and gamma-line spectra from both kinds of supernovae are presented. Finally, a qualitatively new approach to the problem of massive star death and Type II supernovae based upon a combination of rotation and thermonuclear burning is discussed

PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

2012-05-01

Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

Computational models of stellar collapse and core-collapse supernovae

Energy Technology Data Exchange (ETDEWEB)

Ott, Christian D; O' Connor, Evan [TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA (United States); Schnetter, Erik; Loeffler, Frank [Center for Computation and Technology, Louisiana State University, Baton Rouge, LA (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States); Livne, Eli, E-mail: cott@tapir.caltech.ed [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

2009-07-01

Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani which is based on the open-source HPC Cactus framework and provides a scalable AMR approach for 3D fully general-relativistic modeling of stellar collapse, core-collapse supernovae and black hole formation on current and future massively-parallel HPC systems. We show Zelmani's scaling properties to more than 16,000 compute cores and discuss first 3D general-relativistic core-collapse results.

How the First Stars Regulated Star Formation. II. Enrichment by Nearby Supernovae

Energy Technology Data Exchange (ETDEWEB)

Chen, Ke-Jung [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Tokyo 181-8588 (Japan); Whalen, Daniel J. [Institute of Cosmology and Gravitation, Portsmouth University, Portsmouth (United Kingdom); Wollenberg, Katharina M. J.; Glover, Simon C. O.; Klessen, Ralf S., E-mail: ken.chen@nao.ac.jp [Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg (Germany)

2017-08-01

Metals from Population III (Pop III) supernovae led to the formation of less massive Pop II stars in the early universe, altering the course of evolution of primeval galaxies and cosmological reionization. There are a variety of scenarios in which heavy elements from the first supernovae were taken up into second-generation stars, but cosmological simulations only model them on the largest scales. We present small-scale, high-resolution simulations of the chemical enrichment of a primordial halo by a nearby supernova after partial evaporation by the progenitor star. We find that ejecta from the explosion crash into and mix violently with ablative flows driven off the halo by the star, creating dense, enriched clumps capable of collapsing into Pop II stars. Metals may mix less efficiently with the partially exposed core of the halo, so it might form either Pop III or Pop II stars. Both Pop II and III stars may thus form after the collision if the ejecta do not strip all the gas from the halo. The partial evaporation of the halo prior to the explosion is crucial to its later enrichment by the supernova.

Hydrogen-Poor Core-Collapse Supernovae

Science.gov (United States)

Pian, Elena; Mazzali, Paolo A.

Hydrogen-poor core-collapse supernovae (SNe) signal the explosive death of stars more massive than the progenitors of hydrogen-rich core-collapse supernovae, i.e., approximately in the range 15-50 M⊙ in main sequence. Since hydrogen-poor core-collapse supernovae include those that accompany gamma-ray bursts (GRBs), which were all rigorously identified with type Ic supernovae, their explosion energies cover almost two decades. The light curves and spectra are consequently very heterogeneous and often bear the signature of an asymmetric, i.e., aspherical, explosion. Asphericity is best traced by early-time (within days of the explosion) optical spectropolarimetry and by late-epoch (more than ˜ 100 days after explosion) low-resolution spectroscopy. While the relationship between hydrogen-poor core-collapse supernovae to hydrogen-poor super-luminous supernovae is not understood, a known case of association between an ultra-long gamma-ray burst and a very luminous hydrogen-poor supernova may help unraveling the connection. This is tantalizingly pointing to a magnetar powering source for both phenomena, although this scenario is still highly speculative. Host galaxies of hydrogen-poor supernovae are always star forming; in those of completely stripped supernovae and gamma-ray burst supernovae, the spatial distribution of the explosions follows the blue/ultraviolet light, with a correlation that is more than linear.

Type Ia Supernovae: Energetics, Neutronization and Nucleosynthesis

International Nuclear Information System (INIS)

Truran, James W.; Calder, Alan C.; Townsley, Dean M.; Seitenzahl, Ivo R.; Peng, Fang; Vladimirova, Natalia; Lamb, Donald Q.; Brown, Edward F.

2007-01-01

The utility of Type Ia supernovae, not simply as probes of the distance scale but also as a means of constraining the properties of dark energy, demands a significant improvement in theoretical predictions of their properties in outburst. To this end, we have given substantial effort to quantifying the energetics and nucleosynthesis properties of deflagration fronts in the interiors of the putative carbon-oxygen white dwarf progenitors of Type Ia thermonuclear supernovae. We briefly review some essential features of our flame model and its properties in this paper and discuss its implications both for our multidimensional numerical simulations of SNe Ia and for nucleosynthesis (specifically 56Ni production) in SNe Ia and Galactic chemical evolution

Peculiar Supernovae

Science.gov (United States)

Milisavljevic, Dan; Margutti, Raffaella

2018-06-01

What makes a supernova truly "peculiar?" In this review we attempt to address this question by tracing the history of the use of "peculiar" as a descriptor of non-standard supernovae back to the original binary spectroscopic classification of Type I vs. Type II proposed by Minkowski (Publ. Astron. Soc. Pac., 53:224, 1941). A handful of noteworthy examples are highlighted to illustrate a general theme: classes of supernovae that were once thought to be peculiar are later seen as logical branches of standard events. This is not always the case, however, and we discuss ASASSN-15lh as an example of a transient with an origin that remains contentious. We remark on how late-time observations at all wavelengths (radio-through-X-ray) that probe 1) the kinematic and chemical properties of the supernova ejecta and 2) the progenitor star system's mass loss in the terminal phases preceding the explosion, have often been critical in understanding the nature of seemingly unusual events.

Shedding New Light on Exploding Stars: Tera-Scale Simulation of Neutrino-Driven Supernovae and their Nucleosynthesis. Final Report

International Nuclear Information System (INIS)

Fuller, George M.

2006-01-01

Goals: I took seriously the charge to SciDAC P.I.'s to go after outstanding and key physics problems with cutting-edge numerical science. I proposed solving a key problem in core collapse supernova physics: the evolution of neutrino flavors in the supernova environment. A great deal may be riding on the solution to this problem. First, laboratory physics outstripped the supernova theorists, providing us with neutrino mass-squared differences and two of the three vacuum mixing angles. This data had not been incorporated into core collapse supernova models before, but it clearly pointed to the possibility of major changes to our existing supernova neutrino paradigm. Second, knowing how the neutrino and antineutrino energy spectra and fluxes evolved through flavor inter-conversion could be crucial for determining and understanding the supernova neutrino signal, light p-process, and r-process nucleosynthesis, and possibly even the shock re-heating problem. Moreover, much about fundamental neutrino properties remains unresolved by terrestrial experiment (e.g., the neutrino mass hierarchy, θ 13 , etc.). Unraveling the supernova neutrino flavor evolution problem coupled with a future Galactic supernova signal could allow determination of these unknown neutrino properties. Results and Findings: We solved the problem of coherent neutrino flavor evolution (both 2 x 2 and 3 x 3) in the supernova environment, for the first time incorporating self-consistently the nonlinear geometric and quantum trajectory coupling outlined above. The results were unexpected and surprising. These results hold out the possibility that a future Galactic supernova neutrino signal could give us significant insights into both fundamental neutrino physics, otherwise inacces- sible in the lab (e.g., the neutrino mass hierarchy, θ 13 ), and key issues in supernova physics (e.g., distinguishing between Fe core collapse and O-Ne-Mg core collapse events). First, the numerical solution to this problem

Type Ia Supernova Cosmology

Science.gov (United States)

Leibundgut, B.; Sullivan, M.

2018-03-01

The primary agent for Type Ia supernova cosmology is the uniformity of their appearance. We present the current status, achievements and uncertainties. The Hubble constant and the expansion history of the universe are key measurements provided by Type Ia supernovae. They were also instrumental in showing time dilation, which is a direct observational signature of expansion. Connections to explosion physics are made in the context of potential improvements of the quality of Type Ia supernovae as distance indicators. The coming years will see large efforts to use Type Ia supernovae to characterise dark energy.

Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning

Energy Technology Data Exchange (ETDEWEB)

Möller, A. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Ruhlmann-Kleider, V.; Leloup, C.; Neveu, J.; Palanque-Delabrouille, N.; Rich, J. [Irfu, SPP, CEA Saclay, F-91191 Gif sur Yvette Cedex (France); Carlberg, R. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H8 (Canada); Lidman, C. [Australian Astronomical Observatory, North Ryde, NSW 2113 (Australia); Pritchet, C., E-mail: anais.moller@anu.edu.au, E-mail: vanina.ruhlmann-kleider@cea.fr, E-mail: clement.leloup@cea.fr, E-mail: jneveu@lal.in2p3.fr, E-mail: nathalie.palanque-delabrouille@cea.fr, E-mail: james.rich@cea.fr, E-mail: raymond.carlberg@utoronto.ca, E-mail: chris.lidman@aao.gov.au, E-mail: pritchet@uvic.ca [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6 (Canada)

2016-12-01

In the era of large astronomical surveys, photometric classification of supernovae (SNe) has become an important research field due to limited spectroscopic resources for candidate follow-up and classification. In this work, we present a method to photometrically classify type Ia supernovae based on machine learning with redshifts that are derived from the SN light-curves. This method is implemented on real data from the SNLS deferred pipeline, a purely photometric pipeline that identifies SNe Ia at high-redshifts (0.2 < z < 1.1). Our method consists of two stages: feature extraction (obtaining the SN redshift from photometry and estimating light-curve shape parameters) and machine learning classification. We study the performance of different algorithms such as Random Forest and Boosted Decision Trees. We evaluate the performance using SN simulations and real data from the first 3 years of the Supernova Legacy Survey (SNLS), which contains large spectroscopically and photometrically classified type Ia samples. Using the Area Under the Curve (AUC) metric, where perfect classification is given by 1, we find that our best-performing classifier (Extreme Gradient Boosting Decision Tree) has an AUC of 0.98.We show that it is possible to obtain a large photometrically selected type Ia SN sample with an estimated contamination of less than 5%. When applied to data from the first three years of SNLS, we obtain 529 events. We investigate the differences between classifying simulated SNe, and real SN survey data. In particular, we find that applying a thorough set of selection cuts to the SN sample is essential for good classification. This work demonstrates for the first time the feasibility of machine learning classification in a high- z SN survey with application to real SN data.

Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning

International Nuclear Information System (INIS)

Möller, A.; Ruhlmann-Kleider, V.; Leloup, C.; Neveu, J.; Palanque-Delabrouille, N.; Rich, J.; Carlberg, R.; Lidman, C.; Pritchet, C.

2016-01-01

In the era of large astronomical surveys, photometric classification of supernovae (SNe) has become an important research field due to limited spectroscopic resources for candidate follow-up and classification. In this work, we present a method to photometrically classify type Ia supernovae based on machine learning with redshifts that are derived from the SN light-curves. This method is implemented on real data from the SNLS deferred pipeline, a purely photometric pipeline that identifies SNe Ia at high-redshifts (0.2 < z < 1.1). Our method consists of two stages: feature extraction (obtaining the SN redshift from photometry and estimating light-curve shape parameters) and machine learning classification. We study the performance of different algorithms such as Random Forest and Boosted Decision Trees. We evaluate the performance using SN simulations and real data from the first 3 years of the Supernova Legacy Survey (SNLS), which contains large spectroscopically and photometrically classified type Ia samples. Using the Area Under the Curve (AUC) metric, where perfect classification is given by 1, we find that our best-performing classifier (Extreme Gradient Boosting Decision Tree) has an AUC of 0.98.We show that it is possible to obtain a large photometrically selected type Ia SN sample with an estimated contamination of less than 5%. When applied to data from the first three years of SNLS, we obtain 529 events. We investigate the differences between classifying simulated SNe, and real SN survey data. In particular, we find that applying a thorough set of selection cuts to the SN sample is essential for good classification. This work demonstrates for the first time the feasibility of machine learning classification in a high- z SN survey with application to real SN data.

Modeling supernova remnants: effects of diffusive cosmic-ray acceleration on the evolution and application to observations

NARCIS (Netherlands)

Kosenko, D.; Blinnikov, S.; Vink, J.

2011-01-01

We present numerical models for supernova remnant evolution, using a new version of the hydrodynamical code SUPREMNA. We added a cosmic-ray diffusion equation to the code scheme, employing a two-fluid approximation. We investigate the dynamics of the simulated supernova remnants with different

Two-dimensional PIC simulations of ion beam instabilities in Supernova-driven plasma flows

Energy Technology Data Exchange (ETDEWEB)

Dieckmann, M E; Shukla, P K [Institut fuer Theoretische Physik IV, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Meli, A; Mastichiadis, A [Department of Physics, National University of Athens, Panepistimiopolis, Zografos 15783 (Greece); Drury, L O C [Dublin Institute for Advanced Studies, Dublin 2 (Ireland)], E-mail: markd@tp4.rub.de

2008-06-15

Supernova remnant blast shells can reach the flow speed v{sub s} = 0.1c and shocks form at its front. Instabilities driven by shock-reflected ion beams heat the plasma in the foreshock, which may inject particles into diffusive acceleration. The ion beams can have the speed v{sub b} {approx} v{sub s}. For v{sub b} << v{sub s} the Buneman or upper-hybrid instabilities dominate, while for v{sub b} >> v{sub s} the filamentation and mixed modes grow faster. Here the relevant waves for v{sub b} {approx} v{sub s} are examined and how they interact nonlinearly with the particles. The collision of two plasma clouds at the speed v{sub s} is modelled with particle-in-cell simulations, which convect with them magnetic fields oriented perpendicular to their flow velocity vector. One simulation models equally dense clouds and the other one uses a density ratio of 2. Both simulations show upper-hybrid waves that are planar over large spatial intervals and that accelerate electrons to {approx}10 keV. The symmetric collision yields only short oscillatory wave pulses, while the asymmetric collision also produces large-scale electric fields, probably through a magnetic pressure gradient. The large-scale fields destroy the electron phase space holes and they accelerate the ions, which facilitates the formation of a precursor shock.

Deflagration to detonation transition in thermonuclear supernovae

International Nuclear Information System (INIS)

Charignon, Camille

2013-01-01

Type Ia supernovae are an important tool to determine the expansion history of our Universe. Thus, considerable attention has been given to both observations and models of these events. The most popular explosion model is the central ignition of a deflagration in the dense C+O interior of a Chandrasekhar mass white dwarf, followed by a transition to a detonation (TDD). We study in this thesis a new mechanism for this transition. The most robust and studied progenitor model and the postulated mechanism for the TDD, the so called 'Zel'dovich gradient mechanism', are presented. State of the art 3D simulations of such a delayed detonation, at the price of some adjustments, can indeed reproduce observables. But due to largely unresolved physical scales, such simulations cannot explain the TDD by themselves, and especially, the physical mechanism which triggers this transition - which is not yet understood, even on Earth, for unconfined media. It is then discussed why the current Zel'dovich mechanism might be too constraining for a SN Ia model, pointing to a new approach, which is the core result of this thesis.In the final part, our alternative model for DDT in supernovae, the acoustic heating of the pre-supernova envelope, is presented. A planar model first proves that small amplitude acoustic perturbations (generated by a turbulent flame) are actually amplified in a steep density gradient, up to a point where they turn into shocks able to trigger a detonation. Then, this mechanism is applied to more realistic models, taking into account, in spherical geometry, the expanding envelope. A parametric study demonstrates the validity of the model for a reasonable range of acoustic wave amplitudes and frequencies.To conclude, some exploratory 2D and 3D MHD simulations, seeking for realistic acoustic source compatible with our mechanism, are presented. (author) [fr

Supernovae, Neutrinos and the Chirality of Amino Acids

Directory of Open Access Journals (Sweden)

Toshitaka Kajino

2011-05-01

Full Text Available A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth’s proteinaceous amino acids.

A solar-type star polluted by calcium-rich supernova ejecta inside the supernova remnant RCW 86

Science.gov (United States)

Gvaramadze, Vasilii V.; Langer, Norbert; Fossati, Luca; Bock, Douglas C.-J.; Castro, Norberto; Georgiev, Iskren Y.; Greiner, Jochen; Johnston, Simon; Rau, Arne; Tauris, Thomas M.

2017-06-01

When a massive star in a binary system explodes as a supernova, its companion star may be polluted with heavy elements from the supernova ejecta. Such pollution has been detected in a handful of post-supernova binaries 1 , but none of them is associated with a supernova remnant. We report the discovery of a binary G star strongly polluted with calcium and other elements at the position of the candidate neutron star [GV2003] N within the young galactic supernova remnant RCW 86. Our discovery suggests that the progenitor of the supernova that produced RCW 86 could have been a moving star, which exploded near the edge of its wind bubble and lost most of its initial mass because of common-envelope evolution shortly before core collapse, and that the supernova explosion might belong to the class of calcium-rich supernovae — faint and fast transients 2,3 , the origin of which is strongly debated 4-6 .

Nucleosynthesis in Supernovae

Science.gov (United States)

Thielemann, Friedrich-Karl; Isern, Jordi; Perego, Albino; von Ballmoos, Peter

2018-04-01

We present the status and open problems of nucleosynthesis in supernova explosions of both types, responsible for the production of the intermediate mass, Fe-group and heavier elements (with the exception of the main s-process). Constraints from observations can be provided through individual supernovae (SNe) or their remnants (e.g. via spectra and gamma-rays of decaying unstable isotopes) and through surface abundances of stars which witness the composition of the interstellar gas at their formation. With a changing fraction of elements heavier than He in these stars (known as metallicity) the evolution of the nucleosynthesis in galaxies over time can be determined. A complementary way, related to gamma-rays from radioactive decays, is the observation of positrons released in β+-decays, as e.g. from ^{26}Al, ^{44}Ti, ^{56,57}Ni and possibly further isotopes of their decay chains (in competition with the production of e+e- pairs in acceleration shocks from SN remnants, pulsars, magnetars or even of particle physics origin). We discuss (a) the role of the core-collapse supernova explosion mechanism for the composition of intermediate mass, Fe-group (and heavier?) ejecta, (b) the transition from neutron stars to black holes as the final result of the collapse of massive stars, and the relation of the latter to supernovae, faint supernovae, and gamma-ray bursts/hypernovae, (c) Type Ia supernovae and their nucleosynthesis (e.g. addressing the ^{55}Mn puzzle), plus (d) further constraints from galactic evolution, γ-ray and positron observations. This is complemented by the role of rare magneto-rotational supernovae (related to magnetars) in comparison with the nucleosynthesis of compact binary mergers, especially with respect to forming the heaviest r-process elements in galactic evolution.

Hydromagnetic instabilities and magnetic field amplification in core collapse supernovae

Energy Technology Data Exchange (ETDEWEB)

Cerda-Duran, P; Obergaulinger, M; Mueller, E [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-st. 1, 85748 Garching (Germany); Aloy, M A; Font, J A, E-mail: cerda@mpa-garching.mpg.de [Departamento de Astronomia y Astrofisica, Universidad de Valencia, 46100 Burjassot, Valencia (Spain)

2011-09-22

Some of the most violent events in the universe, the gamma ray burst, could be related to the gravitational collapse of massive stellar cores. The recent association of long GRBs to some class of type Ic supernova seems to support this view. In such scenario fast rotation, strong magnetic fields and general relativistic effects are key ingredients. It is thus important to understand the mechanism that amplifies the magnetic field under that conditions. I present global simulations of the magneto-rotational collapse of stellar cores in general relativity and semi-global simulations of hydromagnetic instabilities under core collapse conditions. I discuss effect of the magneto-rotational instability and the magnetic field amplification during the collapse, the uncertainties in this process and the dynamical effects in the supernova explosion.

Type Ia supernova rate studies from the SDSS-II Supernova Study

Energy Technology Data Exchange (ETDEWEB)

Dilday, Benjamin [Univ. of Chicago, IL (United States)

2008-08-01

The author presents new measurements of the type Ia SN rate from the SDSS-II Supernova Survey. The SDSS-II Supernova Survey was carried out during the Fall months (Sept.-Nov.) of 2005-2007 and discovered ~ 500 spectroscopically confirmed SNe Ia with densely sampled (once every ~ 4 days), multi-color light curves. Additionally, the SDSS-II Supernova Survey has discovered several hundred SNe Ia candidates with well-measured light curves, but without spectroscopic confirmation of type. This total, achieved in 9 months of observing, represents ~ 15-20% of the total SNe Ia discovered worldwide since 1885. The author describes some technical details of the SN Survey observations and SN search algorithms that contributed to the extremely high-yield of discovered SNe and that are important as context for the SDSS-II Supernova Survey SN Ia rate measurements.

Assessing the link between recent supernovae near Earth and the iron-60 anomaly in a deep-sea crust

Science.gov (United States)

Schulreich, Michael M.; Breitschwerdt, Dieter

2016-06-01

Some time ago, an enhanced concentration of the radionuclide 60Fe was discovered in a deep-sea ferromanganese crust, isolated in layers dating from about 2.2, Myr ago. Since 60Fe (half-life of 2.6, Myr) is not naturally produced on Earth, such an excess can only be attributed to extraterrestrial sources, particularly one or several nearby supernovae in the recent past. It has been speculated that these supernovae might have been involved in the formation of the Local Superbubble, our Galactic habitat. The aim of this talk is to provide a quantitative evidence for this scenario. For that purpose, I will present results from high-resolution hydrodynamical simulations of the Local Superbubble and its neighbour Loop I in different environments, including a self-consistently evolved supernova-driven interstellar medium. For the superbubble modelling, the time sequence and locations of the generating core-collapse supernova explosions are taken into account, which are derived from the mass spectrum of the perished members of certain, carefully preselected stellar moving groups. The release and turbulent mixing of 60Fe is followed via passive scalars, where the yields of the decaying radioisotope were adjusted according to recent stellar evolution calculations. The models are able to reproduce both the timing and the intensity of the 60Fe excess observed with rather high precision.

SUPERNOVA 1987A: A TEMPLATE TO LINK SUPERNOVAE TO THEIR REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana”, Piazza del Parlamento 1, I-90134 Palermo (Italy)

2015-09-10

The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2–1.4 × 10{sup 51} erg and the envelope mass in the range 15–17 M{sub ⊙}. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = −8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

MAGNETAR-POWERED SUPERNOVAE IN TWO DIMENSIONS. I. SUPERLUMINOUS SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Chen, Ke-Jung [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Tokyo 181-8588 (Japan); Woosley, S. E.; Sukhbold, Tuguldur, E-mail: ken.chen@nao.ac.jp [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

2016-11-20

Previous studies have shown that the radiation emitted by a rapidly rotating magnetar embedded in a young supernova can greatly amplify its luminosity. These one-dimensional studies have also revealed the existence of an instability arising from the piling up of radiatively accelerated matter in a thin dense shell deep inside the supernova. Here, we examine the problem in two dimensions and find that, while instabilities cause mixing and fracture this shell into filamentary structures that reduce the density contrast, the concentration of matter in a hollow shell persists. The extent of the mixing depends upon the relative energy input by the magnetar and the kinetic energy of the inner ejecta. The light curve and spectrum of the resulting supernova will be appreciably altered, as will the appearance of the supernova remnant, which will be shellular and filamentary. A similar pile up and mixing might characterize other events where energy is input over an extended period by a centrally concentrated source, e.g., a pulsar, radioactive decay, a neutrino-powered wind, or colliding shells. The relevance of our models to the recent luminous transient ASASSN-15lh is briefly discussed.

Neutrino nucleosynthesis in core-collapse Supernova explosions

Directory of Open Access Journals (Sweden)

Sieverding A.

2016-01-01

Full Text Available The neutrino-induced nucleosynthesis (ν process in supernova explosions of massive stars of solar metallicity with initial main sequence masses between 15 and 40 M⊙ has been studied. A new extensive set of neutrino-nucleus cross-sections for all the nuclei included in the reaction network is used and the average neutrino energies are reduced to agree with modern supernova simulations. Despite these changes the ν process is found to contribute still significantly to the production of the nuclei 7Li, 11B, 19F, 138La and 180Ta, even though the total yields for those nuclei are reduced. Furthermore we study in detail contributions of the ν process to the production of radioactive isotopes 26Al, 22Na and confirm the production of 92Nb and 98Tc.

Neutrino nucleosynthesis in core-collapse Supernova explosions

Science.gov (United States)

Sieverding, A.; Huther, L.; Martínez-Pinedo, G.; Langanke, K.; Heger, A.

2018-01-01

The neutrino-induced nucleosynthesis (v process) in supernova explosions of massive stars of solar metallicity with initial main sequence masses between 15 and 40 M⨀ has been studied. A new extensive set of neutrino-nucleus cross-sections for all the nuclei included in the reaction network is used and the average neutrino energies are reduced to agree with modern supernova simulations. Despite these changes the v process is found to contribute still significantly to the production of the nuclei 7Li, 11B, 19F, 138La and 180Ta, even though the total yields for those nuclei are reduced. Furthermore we study in detail contributions of the v process to the production of radioactive isotopes 26Al, 22Na and confirm the production of 92Nb and 98Tc.

Probing Neutrino Mass Hierarchy with Supernova

International Nuclear Information System (INIS)

Chakraborty, Sovan

2013-01-01

The rise time of electron antineutrino lightcurve from a Galactic supernova (SN), observable at the IceCube Cherenkov detector, can provide signature of the neutrino mass hierarchy at “large” 1-3 leptonic mixing angle ϑ 13 . In the early accretion phase of the SN, the neutrino oscillations are nontrivial. Due to the matter suppression of collective effects at these early post bounce times, only the MSW resonances in the outer layers of the SN influence the neutrino flux. When the oscillations are taken into account, the signal in IceCube shows sufficiently fast rise time for the inverted mass hierarchy compared to the normal hierarchy. An investigation with an extensive set of stellar core-collapse simulations, provides both qualitative and quantitative robustness of these features. Thus opening another avenue to explore the neutrino mass hierarchy with the rise time of a supernova burst

Sensitivity studies for supernovae type Ia

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thien Tam; Goebel, Kathrin; Reifarth, Rene [Goethe University Frankfurt am Main (Germany); Calder, Alan [SUNY - Department of Physics and Astronomy, New York (United States); Pignatari, Marco [Konkoly Observatory of the Hungarian Academy of Sciences (Hungary); Townsley, Dean [The University of Alabama (United States); Travaglio, Claudia [INAF - Astrophysical Observatory, Turin (Italy); Collaboration: NuGrid collaboration

2016-07-01

The NuGrid research platform provides a simulation framework to study the nucleosynthesis in multi-dimensional Supernovae Type Ia models. We use a large network of over 5,000 isotopes and more than 60,000 reactions. The nucleosynthesis is investigated in post-processing simulations with temperature and density profiles, initial abundance distributions and a set of reaction rates as input. The sensitivity of the isotopic abundances to α-, proton-, and neutron-capture reaction, their inverse reactions, as well as fusion reactions were investigated. First results have been achieved for different mass coordinates of the exploding star.

Berkeley automated supernova search

Energy Technology Data Exchange (ETDEWEB)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.; Crawford, F.S.; Burns, M.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982.

Berkeley automated supernova search

International Nuclear Information System (INIS)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982

Explosive nucleosynthesis in a neutrino-driven core collapse supernova

International Nuclear Information System (INIS)

Fujimoto, Shin-ichiro; Kotake, Kei; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

2010-01-01

We investigate explosive nucleosynthesis in a delayed neutrino-driven, supernova explosion aided by standing accretion shock instability (SASI), based on two-dimensional hydrodynamic simulations of the explosion of a 15 M · star. We take into accounts neutrino heating and cooling as well as change in electron fraction due to weak interactions appropriately, in the two-dimensional simulations. We assume the isotropic emission of neutrinos from the neutrino spheres with given luminosities. and the Fermi-Dirac distribution of given temperatures. We find that the stalled shock revives due to the neutrino heating aided by SASI for cases with L νe ≥3.9x10 52 ergss -1 and the as-pherical shock passes through the outer layers of the star (≥10,000 km), with the explosion energies of ∼10 51 ergs.Next we examine abundances and masses of the supernova ejecta. We find that masses of the ejecta and 56 Ni correlate with the neutrino luminosity, and 56 Ni mass is comparable to that observed in SN 1987A. We also find that abundance pattern of the supernova ejecta is similar to that of the solar system, for cases with high explosion energies of >10 51 ergs. We emphasize that 64 Zn, which is underproduced in the spherical case, is abundantly produced in slightly neutron-rich ejecta.

Supernova blast wave within a stellar cluster outflow

Science.gov (United States)

Rodríguez-Ramírez, J. C.; Raga, A. C.; Velázquez, P. F.; Rodríguez-González, A.; Toledo-Roy, J. C.

2014-11-01

In this paper, we develop a semi-analytic model of a supernova which goes off in the centre of a stellar cluster. The supernova remnant interacts with a stratified, pre-existent outflow produced by the winds of the cluster stars. We compare our semi-analytic model with numerical simulations using the spherically symmetric Euler equations with appropriate mass and energy source terms. We find good agreement between these two approaches, and we find that for typical parameters the blast wave is likely to reach the Taylor-Sedov regime outside the cluster radius. We also calculate the predicted X-ray luminosity of the flow as a function of time, and we obtain its dependence on the outer radius and the number of stars of the cluster.

Nurseries of Supernovae

DEFF Research Database (Denmark)

Frederiksen, Teddy

Type Ia supernovae (SNe) have long been the gold standard for precision cosmology and after several decades of intense research the supernova (SN) community was in 2011 honored by giving the Nobel Prize in physics for the discovery of Dark Energy to the leaders of the two big SN collaborations: S...

The past, present and future supernova threat to Earth's biosphere

Science.gov (United States)

Beech, Martin

2011-12-01

A brief review of the threat posed to Earth's biosphere via near-by supernova detonations is presented. The expected radiation dosage, cosmic ray flux and expanding blast wave collision effects are considered, and it is argued that a typical supernova must be closer than ˜10-pc before any appreciable and potentially harmful atmosphere/biosphere effects are likely to occur. In contrast, the critical distance for Gamma-ray bursts is of order 1-kpc. In spite of the high energy effects potentially involved, the geological record provides no clear-cut evidence for any historic supernova induced mass extinctions and/or strong climate change episodes. This, however, is mostly a reflection of their being numerous possible (terrestrial and astronomical) forcing mechanisms acting upon the biosphere and the difficulty of distinguishing between competing scenarios. Key to resolving this situation, it is suggested, is the development of supernova specific extinction and climate change linked ecological models. Moving to the future, we estimate that over the remaining lifetime of the biosphere (˜2 Gyr) the Earth might experience 1 GRB and 20 supernova detonations within their respective harmful threat ranges. There are currently at least 12 potential pre-supernova systems within 1-kpc of the Sun. Of these systems IK Pegasi is the closest Type Ia pre-supernova candidate and Betelgeuse is the closest potential Type II supernova candidate. We review in some detail the past, present and future behavior of these two systems. Developing a detailed evolutionary model we find that IK Pegasi will likely not detonate until some 1.9 billion years hence, and that it affords absolutely no threat to Earth's biosphere. Betelgeuse is the closest, reasonably well understood, pre-supernova candidate to the Sun at the present epoch, and may undergo detonation any time within the next several million years. The stand-off distance of Betelgeuse at the time of its detonation is estimated to fall

Prompt effects of supernovae

International Nuclear Information System (INIS)

Colgate, S.A.

1975-01-01

Conflicting theories on the mechanisms of supernova production are examined. Supernova as sources of other phenomena such as comic rays, gamma rays, x-rays, and electromagnetic pulses are considered. 32 references

EmpiriciSN: Re-sampling Observed Supernova/Host Galaxy Populations Using an XD Gaussian Mixture Model

Science.gov (United States)

Holoien, Thomas W.-S.; Marshall, Philip J.; Wechsler, Risa H.

2017-06-01

We describe two new open-source tools written in Python for performing extreme deconvolution Gaussian mixture modeling (XDGMM) and using a conditioned model to re-sample observed supernova and host galaxy populations. XDGMM is new program that uses Gaussian mixtures to perform density estimation of noisy data using extreme deconvolution (XD) algorithms. Additionally, it has functionality not available in other XD tools. It allows the user to select between the AstroML and Bovy et al. fitting methods and is compatible with scikit-learn machine learning algorithms. Most crucially, it allows the user to condition a model based on the known values of a subset of parameters. This gives the user the ability to produce a tool that can predict unknown parameters based on a model that is conditioned on known values of other parameters. EmpiriciSN is an exemplary application of this functionality, which can be used to fit an XDGMM model to observed supernova/host data sets and predict likely supernova parameters using a model conditioned on observed host properties. It is primarily intended to simulate realistic supernovae for LSST data simulations based on empirical galaxy properties.

EmpiriciSN: Re-sampling Observed Supernova/Host Galaxy Populations Using an XD Gaussian Mixture Model

Energy Technology Data Exchange (ETDEWEB)

Holoien, Thomas W.-S.; /Ohio State U., Dept. Astron. /Ohio State U., CCAPP /KIPAC, Menlo Park /SLAC; Marshall, Philip J.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

2017-05-11

We describe two new open-source tools written in Python for performing extreme deconvolution Gaussian mixture modeling (XDGMM) and using a conditioned model to re-sample observed supernova and host galaxy populations. XDGMM is new program that uses Gaussian mixtures to perform density estimation of noisy data using extreme deconvolution (XD) algorithms. Additionally, it has functionality not available in other XD tools. It allows the user to select between the AstroML and Bovy et al. fitting methods and is compatible with scikit-learn machine learning algorithms. Most crucially, it allows the user to condition a model based on the known values of a subset of parameters. This gives the user the ability to produce a tool that can predict unknown parameters based on a model that is conditioned on known values of other parameters. EmpiriciSN is an exemplary application of this functionality, which can be used to fit an XDGMM model to observed supernova/host data sets and predict likely supernova parameters using a model conditioned on observed host properties. It is primarily intended to simulate realistic supernovae for LSST data simulations based on empirical galaxy properties.

PROGENITOR-DEPENDENT EXPLOSION DYNAMICS IN SELF-CONSISTENT, AXISYMMETRIC SIMULATIONS OF NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Summa, Alexander; Hanke, Florian; Janka, Hans-Thomas; Melson, Tobias [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Marek, Andreas [Max Planck Computing and Data Facility (MPCDF), Gießenbachstr. 2, D-85748 Garching (Germany); Müller, Bernhard, E-mail: asumma@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN (United Kingdom)

2016-07-01

We present self-consistent, axisymmetric core-collapse supernova simulations performed with the Prometheus-Vertex code for 18 pre-supernova models in the range of 11–28 M {sub ⊙}, including progenitors recently investigated by other groups. All models develop explosions, but depending on the progenitor structure, they can be divided into two classes. With a steep density decline at the Si/Si–O interface, the arrival of this interface at the shock front leads to a sudden drop of the mass-accretion rate, triggering a rapid approach to explosion. With a more gradually decreasing accretion rate, it takes longer for the neutrino heating to overcome the accretion ram pressure and explosions set in later. Early explosions are facilitated by high mass-accretion rates after bounce and correspondingly high neutrino luminosities combined with a pronounced drop of the accretion rate and ram pressure at the Si/Si–O interface. Because of rapidly shrinking neutron star radii and receding shock fronts after the passage through their maxima, our models exhibit short advection timescales, which favor the efficient growth of the standing accretion-shock instability. The latter plays a supportive role at least for the initiation of the re-expansion of the stalled shock before runaway. Taking into account the effects of turbulent pressure in the gain layer, we derive a generalized condition for the critical neutrino luminosity that captures the explosion behavior of all models very well. We validate the robustness of our findings by testing the influence of stochasticity, numerical resolution, and approximations in some aspects of the microphysics.

[FeII] as a tracer supernova rate

International Nuclear Information System (INIS)

Rosenberg, M J F; Van der Werf, P P; Israel, F P

2012-01-01

Supernovae play an integral role in the feedback of processed material into the ISM of galaxies and are responsible for most of the chemical enrichment of the universe. The rate of supernovae can also reveal the star formation histories. Supernova rate is usually measured through the non-thermal radio continuum luminosity, but in this paper we establish a quantitative relationship between the [FeII] 1.26 luminosity and supernova rate in a sample of 11 near-by starburst galaxies. SINFONI data cubes are used to perform a pixel pixel analysis of this correlation. Using Bry equivalent width and luminosity as the only observational inputs into Starburst 99, the supernova rate is derived at each pixel and a map of supernova rate is created. This is then compared morphologically and quantitatively to [FeII] 1.26 luminosity map. We find a strong linear and morphological correlation between supernova rate and [FeII] 1.26 on a pixel-pixel basis. The Starburst 99 derived supernova rates are also in good agreement with the radio derived supernova rates, which further demonstrates the strength of [FeII] as a tracer of supernova rate. With the strong correlation found in this sample of galaxies, we now qualitatively use [FeII] 1.26 to derive supernova rate on either a pixel-pixel or integrated galactic basis.

Synoptic sky surveys and the diffuse supernova neutrino background: Removing astrophysical uncertainties and revealing invisible supernovae

International Nuclear Information System (INIS)

Lien, Amy; Fields, Brian D.; Beacom, John F.

2010-01-01

The cumulative (anti)neutrino production from all core-collapse supernovae within our cosmic horizon gives rise to the diffuse supernova neutrino background (DSNB), which is on the verge of detectability. The observed flux depends on supernova physics, but also on the cosmic history of supernova explosions; currently, the cosmic supernova rate introduces a substantial (±40%) uncertainty, largely through its absolute normalization. However, a new class of wide-field, repeated-scan (synoptic) optical sky surveys is coming online, and will map the sky in the time domain with unprecedented depth, completeness, and dynamic range. We show that these surveys will obtain the cosmic supernova rate by direct counting, in an unbiased way and with high statistics, and thus will allow for precise predictions of the DSNB. Upcoming sky surveys will substantially reduce the uncertainties in the DSNB source history to an anticipated ±5% that is dominated by systematics, so that the observed high-energy flux thus will test supernova neutrino physics. The portion of the universe (z < or approx. 1) accessible to upcoming sky surveys includes the progenitors of a large fraction (≅87%) of the expected 10-26 MeV DSNB event rate. We show that precision determination of the (optically detected) cosmic supernova history will also make the DSNB into a strong probe of an extra flux of neutrinos from optically invisible supernovae, which may be unseen either due to unexpected large dust obscuration in host galaxies, or because some core-collapse events proceed directly to black hole formation and fail to give an optical outburst.

Finding the first cosmic explosions. III. Pulsational pair-instability supernovae

International Nuclear Information System (INIS)

Whalen, Daniel J.; Smidt, Joseph; Even, Wesley; Fryer, Chris L.; Woosley, S. E.; Heger, Alexander; Stiavelli, Massimo

2014-01-01

Population III supernovae have been the focus of growing attention because of their potential to directly probe the properties of the first stars, particularly the most energetic events that can be seen at the edge of the observable universe. But until now pulsational pair-instability supernovae, in which explosive thermonuclear burning in massive stars fails to unbind them but can eject their outer layers into space, have been overlooked as cosmic beacons at the earliest redshifts. These shells can later collide and, like Type IIn supernovae, produce superluminous events in the UV at high redshifts that could be detected in the near infrared today. We present numerical simulations of a 110 M ☉ pulsational pair-instability explosion done with the Los Alamos radiation hydrodynamics code Radiation Adaptive Grid Eulerian. We find that collisions between consecutive pulsations are visible in the near infrared out to z ∼ 15-20 and can probe the earliest stellar populations at cosmic dawn.

Explosions and light curves of supernovae

International Nuclear Information System (INIS)

Gaffet, B.

1975-01-01

The models developed to explain supernovae explosions are reviewed. The first one is thermonuclear explosion (simple or preceded by an implosion phase); the neutrino emission which results of such an explosion can have an important dynamical effect, according as the star is opaque or transparent to them; another theory involves the radiation pressure of the pulsar which is formed in the center of the star. The origin of the supernovae brightness is also uncertain: the initial heat due to the explosion does not seem to be sufficient; the brightness can result from the diffusion of the heat through the ejected matter or can be transported more rapidly by a shock wave. A model in which the heat is produced by the pulsar seems compatible with most observations (shapes of the brightness curves and the continuum spectra, expansion velocities, temperature and luminosity at the peak, total kinetic energy) [fr

CORE-COLLAPSE SUPERNOVA EQUATIONS OF STATE BASED ON NEUTRON STAR OBSERVATIONS

International Nuclear Information System (INIS)

Steiner, A. W.; Hempel, M.; Fischer, T.

2013-01-01

Many of the currently available equations of state for core-collapse supernova simulations give large neutron star radii and do not provide large enough neutron star masses, both of which are inconsistent with some recent neutron star observations. In addition, one of the critical uncertainties in the nucleon-nucleon interaction, the nuclear symmetry energy, is not fully explored by the currently available equations of state. In this article, we construct two new equations of state which match recent neutron star observations and provide more flexibility in studying the dependence on nuclear matter properties. The equations of state are also provided in tabular form, covering a wide range in density, temperature, and asymmetry, suitable for astrophysical simulations. These new equations of state are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics with three-flavor Boltzmann neutrino transport. The results are compared with commonly used equations of state in supernova simulations of 11.2 and 40 M ☉ progenitors. We consider only equations of state which are fitted to nuclear binding energies and other experimental and observational constraints. We find that central densities at bounce are weakly correlated with L and that there is a moderate influence of the symmetry energy on the evolution of the electron fraction. The new models also obey the previously observed correlation between the time to black hole formation and the maximum mass of an s = 4 neutron star

Low-z Type Ia Supernova Calibration

Science.gov (United States)

Hamuy, Mario

The discovery of acceleration and dark energy in 1998 arguably constitutes one of the most revolutionary discoveries in astrophysics in recent years. This paradigm shift was possible thanks to one of the most traditional cosmological tests: the redshift-distance relation between galaxies. This discovery was based on a differential measurement of the expansion rate of the universe: the current one provided by nearby (low-z) type Ia supernovae and the one in the past measured from distant (high-z) supernovae. This paper focuses on the first part of this journey: the calibration of the type Ia supernova luminosities and the local expansion rate of the universe, which was made possible thanks to the introduction of digital CCD (charge-coupled device) digital photometry. The new technology permitted us in the early 1990s to convert supernovae as precise tools to measure extragalactic distances through two key surveys: (1) the "Tololo Supernova Program" which made possible the critical discovery of the "peak luminosity-decline rate" relation for type Ia supernovae, the key underlying idea today behind precise cosmology from supernovae, and (2) the Calán/Tololo project which provided the low - z type Ia supernova sample for the discovery of acceleration.

The Interplay of Opacities and Rotation in Promoting the Explosion of Core-Collapse Supernovae

Science.gov (United States)

Vartanyan, David; Burrows, Adam; Radice, David

2018-01-01

For over five decades, the mechanism of explosion in core-collapse supernovae has been a central unsolved problem in astrophysics, challenging both our computational capabilities and our understanding of relevant physics. Current simulations often produce explosions, but they are at times underenergetic. The neutrino mechanism, wherein a fraction of emitted neutrinos is absorbed in the mantle of the star to reignite the stalled shock, remains the dominant model for reviving explosions in massive stars undergoing core collapse. We present here a diverse suite of 2D axisymmetric simulations produced by FORNAX, a highly parallelizable multidimensional supernova simulation code. We explore the effects of various corrections, including the many-body correction, to neutrino-matter opacities and the possible role of rotation in promoting explosion amongst various core-collapse progenitors.

Multimessengers from Core-Collapse Supernovae: Multidimensionality as a Key to Bridge Theory and Observation

Directory of Open Access Journals (Sweden)

Kei Kotake

2012-01-01

Full Text Available Core-collapse supernovae are dramatic explosions marking the catastrophic end of massive stars. The only means to get direct information about the supernova engine is from observations of neutrinos emitted by the forming neutron star, and through gravitational waves which are produced when the hydrodynamic flow or the neutrino flux is not perfectly spherically symmetric. The multidimensionality of the supernova engine, which breaks the sphericity of the central core such as convection, rotation, magnetic fields, and hydrodynamic instabilities of the supernova shock, is attracting great attention as the most important ingredient to understand the long-veiled explosion mechanism. Based on our recent work, we summarize properties of gravitational waves, neutrinos, and explosive nucleosynthesis obtained in a series of our multidimensional hydrodynamic simulations and discuss how the mystery of the central engines can be unraveled by deciphering these multimessengers produced under the thick veils of massive stars.

Simulations of the WFIRST Supernova Survey and Forecasts of Cosmological Constraints

Energy Technology Data Exchange (ETDEWEB)

Hounsell, R. [Illinois U., Urbana, Astron. Dept.; Scolnic, D. [Chicago U., KICP; Foley, R. J. [UC, Santa Cruz; Kessler, R. [Chicago U., KICP; Miranda, V. [Pennsylvania U.; Avelino, A. [Harvard-Smithsonian Ctr. Astrophys.; Bohlin, R. C. [Baltimore, Space Telescope Sci.; Filippenko, A. V. [UC, Berkeley; Frieman, J. [Fermilab; Jha, S. W. [Rutgers U., Piscataway; Kelly, P. L. [UC, Berkeley; Kirshner, R. P. [Xerox, Palo Alto; Mandel, K. [Harvard-Smithsonian Ctr. Astrophys.; Rest, A. [Baltimore, Space Telescope Sci.; Riess, A. G. [Johns Hopkins U.; Rodney, S. A. [South Carolina U.; Strolger, L. [Baltimore, Space Telescope Sci.

2017-02-06

The Wide Field InfraRed Survey Telescope (WFIRST) was the highest rankedlarge space-based mission of the 2010 New Worlds, New Horizons decadal survey.It is now a NASA mission in formulation with a planned launch in themid-2020's. A primary mission objective is to precisely constrain the nature ofdark energy through multiple probes, including Type Ia supernovae (SNe Ia).Here, we present the first realistic simulations of the WFIRST SN survey basedon current hardware specifications and using open-source tools. We simulate SNlight curves and spectra as viewed by the WFIRST wide-field channel (WFC)imager and integral field channel (IFC) spectrometer, respectively. We examine11 survey strategies with different time allocations between the WFC and IFC,two of which are based upon the strategy described by the WFIRST ScienceDefinition Team, which measures SN distances exclusively from IFC data. Wepropagate statistical and, crucially, systematic uncertainties to predict thedark energy task force figure of merit (DETF FoM) for each strategy. Theincrease in FoM values with SN search area is limited by the overhead times foreach exposure. For IFC-focused strategies the largest individual systematicuncertainty is the wavelength-dependent calibration uncertainty, whereas forWFC-focused strategies, it is the intrinsic scatter uncertainty. We find thatthe best IFC-focused and WFC-exclusive strategies have comparable FoM values.Even without improvements to other cosmological probes, the WFIRST SN surveyhas the potential to increase the FoM by more than an order of magnitude fromthe current values. Although the survey strategies presented here have not beenfully optimized, these initial investigations are an important step in thedevelopment of the final hardware design and implementation of the WFIRSTmission.

An Open Catalog for Supernova Data

International Nuclear Information System (INIS)

Guillochon, James; Parrent, Jerod; Kelley, Luke Zoltan; Margutti, Raffaella

2017-01-01

We present the Open Supernova Catalog , an online collection of observations and metadata for presently 36,000+ supernovae and related candidates. The catalog is freely available on the web (https://sne.space), with its main interface having been designed to be a user-friendly, rapidly searchable table accessible on desktop and mobile devices. In addition to the primary catalog table containing supernova metadata, an individual page is generated for each supernova, which displays its available metadata, light curves, and spectra spanning X-ray to radio frequencies. The data presented in the catalog is automatically rebuilt on a daily basis and is constructed by parsing several dozen sources, including the data presented in the supernova literature and from secondary sources such as other web-based catalogs. Individual supernova data is stored in the hierarchical, human- and machine-readable JSON format, with the entirety of each supernova’s data being contained within a single JSON file bearing its name. The setup we present here, which is based on open-source software maintained via git repositories hosted on github, enables anyone to download the entirety of the supernova data set to their home computer in minutes, and to make contributions of their own data back to the catalog via git. As the supernova data set continues to grow, especially in the upcoming era of all-sky synoptic telescopes, which will increase the total number of events by orders of magnitude, we hope that the catalog we have designed will be a valuable tool for the community to analyze both historical and contemporary supernovae.

An Open Catalog for Supernova Data

Energy Technology Data Exchange (ETDEWEB)

Guillochon, James; Parrent, Jerod; Kelley, Luke Zoltan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Margutti, Raffaella, E-mail: jguillochon@cfa.harvard.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astrophysics, Northwestern University, Evanston, IL 60208 (United States)

2017-01-20

We present the Open Supernova Catalog , an online collection of observations and metadata for presently 36,000+ supernovae and related candidates. The catalog is freely available on the web (https://sne.space), with its main interface having been designed to be a user-friendly, rapidly searchable table accessible on desktop and mobile devices. In addition to the primary catalog table containing supernova metadata, an individual page is generated for each supernova, which displays its available metadata, light curves, and spectra spanning X-ray to radio frequencies. The data presented in the catalog is automatically rebuilt on a daily basis and is constructed by parsing several dozen sources, including the data presented in the supernova literature and from secondary sources such as other web-based catalogs. Individual supernova data is stored in the hierarchical, human- and machine-readable JSON format, with the entirety of each supernova’s data being contained within a single JSON file bearing its name. The setup we present here, which is based on open-source software maintained via git repositories hosted on github, enables anyone to download the entirety of the supernova data set to their home computer in minutes, and to make contributions of their own data back to the catalog via git. As the supernova data set continues to grow, especially in the upcoming era of all-sky synoptic telescopes, which will increase the total number of events by orders of magnitude, we hope that the catalog we have designed will be a valuable tool for the community to analyze both historical and contemporary supernovae.

Supernova observations at McDonald Observatory

International Nuclear Information System (INIS)

Wheeler, J.C.

1984-01-01

The programs to obtain high quality spectra and photometry of supernovae at McDonald Observatory are reviewed. Spectra of recent Type I supernovae in NGC 3227, NGC 3625, and NGC 4419 are compared with those of SN 1981b in NGC 4536 to quantitatively illustrate both the homogeneity of Type I spectra at similar epochs and the differences in detail which will serve as a probe of the physical processes in the explosions. Spectra of the recent supernova in NGC 0991 give for the first time quantitative confirmation of a spectrally homogeneous, but distinct subclass of Type I supernovae which appears to be less luminous and to have lower excitation at maximum light than classical Type I supernovae

Particle simulation study of electron heating by counter-streaming ion beams ahead of supernova remnant shocks

International Nuclear Information System (INIS)

Dieckmann, M E; Sarri, G; Kourakis, I; Borghesi, M; Bret, A; Perez Alvaro, E

2012-01-01

The growth and saturation of Buneman-type instabilities is examined with a particle-in-cell (PIC) simulation for parameters that are representative for the foreshock region of fast supernova remnant shocks. A dense ion beam and the electrons correspond to the upstream plasma and a fast ion beam to the shock-reflected ions. The purpose of the 2D simulation is to identify the nonlinear saturation mechanisms, the electron heating and potential secondary instabilities that arise from anisotropic electron heating and result in the growth of magnetic fields. We confirm that the instabilities between both ion beams and the electrons saturate by the formation of phase space holes by the beam-aligned modes. The slower oblique modes accelerate some electrons, but they cannot heat up the electrons significantly before they are trapped by the faster beam-aligned modes. Two circular electron velocity distributions develop, which are centred around the velocity of each ion beam. They develop due to the scattering of the electrons by the electrostatic wave potentials. The growth of magnetic fields is observed, but their amplitude remains low. (paper)

Supernova real-time monitor system in Kamiokande

International Nuclear Information System (INIS)

Oyama, Y.; Yamada, M.; Ishida, T.; Yamaguchi, T.; Yokoyama, H.

1994-01-01

A data-analysis program to discover possible supernova neutrino bursts has been installed in the online data-acquisition computer of the Kamiokande experiment. The program automatically analyzes data within 20 min and gives an alarm to collaborators if a possible supernova neutrino burst is found. The detection efficiency of the program is 96% for a typical supernova located 50 kpc from Earth. After a careful analysis by the Kamiokande collaborators, it will be possible to inform all optical observatories in the world about the occurrence of a supernova within 3 h from the time of first detecting the neutrino burst. Information concerning the celestial position of a supernova will also be available for supernovae having a distance less than ∼ 10 kpc. This information will be helpful for observing the first optical emissions from the newly born supernova. (orig.)

Nearby supernova host galaxies from the CALIFA survey. II. Supernova environmental metallicity

NARCIS (Netherlands)

Galbany, L.; Stanishev, V.; Mourão, A. M.; Rodrigues, M.; Flores, H.; Walcher, C. J.; Sánchez, S. F.; García-Benito, R.; Mast, D.; Badenes, C.; González Delgado, R. M.; Kehrig, C.; Lyubenova, M.; Marino, R. A.; Mollá, M.; Meidt, S.; Pérez, E.; van de Ven, G.; Vílchez, J. M.

2016-01-01

The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule the progenitor's fate. We present the second study of nearby supernova (SN) host galaxies (0.005 ⊙) > 10 dex) by targeted searches. We neither found evidence that the metallicity at the SN

Multi-dimensional explorations in supernova theory

International Nuclear Information System (INIS)

Burrows, Adam; Dessart, Luc; Ott, Christian D.; Livne, Eli

2007-01-01

In this paper, we bring together various of our published and unpublished findings from our recent 2D multi-group, flux-limited radiation hydrodynamic simulations of the collapse and explosion of the cores of massive stars. Aided by 2D and 3D graphical renditions, we motivate the acoustic mechanism of core-collapse supernova explosions and explain, as best we currently can, the phases and phenomena that attend this mechanism. Two major foci of our presentation are the outer shock instability and the inner core g-mode oscillations. The former sets the stage for the latter, which damp by the generation of sound. This sound propagates outward to energize the explosion and is relevant only if the core has not exploded earlier by some other means. Hence, it is a more delayed mechanism than the traditional neutrino mechanism that has been studied for the last twenty years since it was championed by Bethe and Wilson. We discuss protoneutron star convection, accretion-induced-collapse, gravitational wave emissions, pulsar kicks, the angular anisotropy of the neutrino emissions, a subset of numerical issues, and a new code we are designing that should supercede our current supernova code VULCAN/2D. Whatever ideas last from this current generation of numerical results, and whatever the eventual mechanism(s), we conclude that the breaking of spherical symmetry will survive as one of the crucial keys to the supernova puzzle

REVIVAL OF THE STALLED CORE-COLLAPSE SUPERNOVA SHOCK TRIGGERED BY PRECOLLAPSE ASPHERICITY IN THE PROGENITOR STAR

International Nuclear Information System (INIS)

Couch, Sean M.; Ott, Christian D.

2013-01-01

Multi-dimensional simulations of advanced nuclear burning stages of massive stars suggest that the Si/O layers of presupernova stars harbor large deviations from the spherical symmetry typically assumed for presupernova stellar structure. We carry out three-dimensional core-collapse supernova simulations with and without aspherical velocity perturbations to assess their potential impact on the supernova hydrodynamics in the stalled-shock phase. Our results show that realistic perturbations can qualitatively alter the postbounce evolution, triggering an explosion in a model that fails to explode without them. This finding underlines the need for a multi-dimensional treatment of the presupernova stage of stellar evolution

REVIVAL OF THE STALLED CORE-COLLAPSE SUPERNOVA SHOCK TRIGGERED BY PRECOLLAPSE ASPHERICITY IN THE PROGENITOR STAR

Energy Technology Data Exchange (ETDEWEB)

Couch, Sean M. [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Ott, Christian D., E-mail: smc@flash.uchichago.edu, E-mail: cott@tapir.caltech.edu [TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-11-20

Multi-dimensional simulations of advanced nuclear burning stages of massive stars suggest that the Si/O layers of presupernova stars harbor large deviations from the spherical symmetry typically assumed for presupernova stellar structure. We carry out three-dimensional core-collapse supernova simulations with and without aspherical velocity perturbations to assess their potential impact on the supernova hydrodynamics in the stalled-shock phase. Our results show that realistic perturbations can qualitatively alter the postbounce evolution, triggering an explosion in a model that fails to explode without them. This finding underlines the need for a multi-dimensional treatment of the presupernova stage of stellar evolution.

Presupernova models and supernovae

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, D [Tokyo Univ. (Japan). Dept. of Earth Science and Astronomy; Nomoto, K I [Ibaraki Univ., Mito (Japan). Dept. of Physics

1980-02-01

Present status of the theories for presupernova evolution and triggering mechanisms of supernova explosions are summarized and discussed from the standpoint of the theory of stellar structure and evolution. It is not intended to collect every detail of numerical results thus far obtained, but to extract physically clear-cut understanding from complexities of the numerical stellar models. For this purpose the evolution of stellar cores is discussed in a generalized fashion. The following types of the supernova explosions are discussed. The carbon deflagration supernova of intermediate mass star which results in the total disruption of the star. Massive star evolves into a supernova triggered by photo-dissociation of iron nuclei which results in a formation of a neutron star or a black hole depending on its mass. These two are typical types of the supernova. Between them there remains a range of mass for which collapse of the stellar core is triggered by electron captures, which has been recently shown to leave a neutron star despite oxygen deflagration competing with the electron captures. Also discussed are combustion and detonation of helium or carbon which take place in accreting white dwarfs, and the collapse which is triggered by electron-pair creation in very massive stars.

Type I supernova models vs observations

International Nuclear Information System (INIS)

Weaver, T.A.; Axelrod, T.S.; Woosley, S.E.

1980-01-01

This paper explores tHe observational consequences of models for Type I supernovae based on the detonation (or deflagration) of the degenerate cores of white dwarfs or intermediate mass (approx. = 9 M/sub sun/) stars. Such nuclear burning can be initiated either at the center of the core or near its edge. The model examined in most detail is that of a 0.5M/sub sun/ C/O white dwarf which undergoes an edge-lit He/C/O detonation after accreting 0.62 M/sub sun/ of he at 10 -8 M/sub sun//yr. The light curve resulting from this model is found to be in excellent agreement with those observed for Type I supernovae, particularly those in the fast subclass. The physical processes involved in the detailed numerical calculations which lead to this conclusion are quantitatively elucidated by simple analytic models, and effects of uncertainties in the input physics are explored

Systematic thermal reduction of neutronization in core-collapse supernovae

International Nuclear Information System (INIS)

Fantina, A.F.; Donati, P.; Pizzochero, P.M.

2009-01-01

We investigate to what extent the temperature dependence of the nuclear symmetry energy can affect the neutronization of the stellar core prior to neutrino trapping during gravitational collapse. To this end, we implement a one-zone simulation to follow the collapse until β-equilibrium is reached and the lepton fraction remains constant. Since the strength of electron capture on the neutron-rich nuclei associated to the supernova scenario is still an open issue, we keep it as a free parameter. We find that the temperature dependence of the symmetry energy consistently yields a small reduction of deleptonization, which corresponds to a systematic effect on the shock wave energetics: the gain in dissociation energy of the shock has a small yet non-negligible value of about 0.4 foe (1 foe=10 51 erg) and this result is almost independent from the strength of nuclear electron capture. The presence of such a systematic effect and its robustness under changes of the parameters of the one-zone model are significant enough to justify further investigations with detailed numerical simulations of supernova explosions.

The supernova-gamma-ray burst-jet connection.

Science.gov (United States)

Hjorth, Jens

2013-06-13

The observed association between supernovae and gamma-ray bursts represents a cornerstone in our understanding of the nature of gamma-ray bursts. The collapsar model provides a theoretical framework for this connection. A key element is the launch of a bipolar jet (seen as a gamma-ray burst). The resulting hot cocoon disrupts the star, whereas the (56)Ni produced gives rise to radioactive heating of the ejecta, seen as a supernova. In this discussion paper, I summarize the observational status of the supernova-gamma-ray burst connection in the context of the 'engine' picture of jet-driven supernovae and highlight SN 2012bz/GRB 120422A--with its luminous supernova but intermediate high-energy luminosity--as a possible transition object between low-luminosity and jet gamma-ray bursts. The jet channel for supernova explosions may provide new insights into supernova explosions in general.

Direct numerical simulations of type Ia supernovae flames II: The Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

2004-01-01

A Type Ia supernova explosion likely begins as a nuclear runaway near the center of a carbon-oxygen white dwarf. The outward propagating flame is unstable to the Landau-Darrieus, Rayleigh-Taylor, and Kelvin-Helmholtz instabilities, which serve to accelerate it to a large fraction of the speed of sound. We investigate the Rayleigh-Taylor unstable flame at the transition from the flamelet regime to the distributed-burning regime, around densities of 10e7 gm/cc, through detailed, fully resolved simulations. A low Mach number, adaptive mesh hydrodynamics code is used to achieve the necessary resolution and long time scales. As the density is varied, we see a fundamental change in the character of the burning--at the low end of the density range the Rayleigh-Taylor instability dominates the burning, whereas at the high end the burning suppresses the instability. In all cases, significant acceleration of the flame is observed, limited only by the size of the domain we are able to study. We discuss the implications of these results on the potential for a deflagration to detonation transition

Practical Aspects of X-ray Imaging Polarimetry of Supernova Remnants and Other Extended Sources

Directory of Open Access Journals (Sweden)

Jacco Vink

2018-04-01

Full Text Available The new generation of X-ray polarisation detectors, the gas pixel detectors, which will be employed by the future space missions IXPE and eXTP, allows for spatially resolved X-ray polarisation studies. This will be of particular interest for X-ray synchrotron emission from extended sources like young supernova remnants and pulsar wind nebulae. Here we report on employing a polarisation statistic that can be used to makes maps in the Stokes I, Q, and U parameters, a method that we expand by correcting for the energy-dependent instrumental modulation factor, using optimal weighting of the signal. In order to explore the types of Stokes maps that can be obtained, we present a Monte Carlo simulation program called xpolim, with which different polarisation weighting schemes are explored. We illustrate its use with simulations of polarisation maps of young supernova remnants, after having described the general science case for polarisation studies of supernova remnants, and its connection to magnetic-field turbulence. We use xpolim simulations to show that in general deep, ~2 Ms observations are needed to recover polarisation signals, in particular for Cas A, for which in the polarisation fraction may be as low as 5%.

Fast neutrino flavor conversions near the supernova core with realistic flavor-dependent angular distributions

Energy Technology Data Exchange (ETDEWEB)

Dasgupta, Basudeb; Sen, Manibrata [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005 (India); Mirizzi, Alessandro, E-mail: bdasgupta@theory.tifr.res.in, E-mail: alessandro.mirizzi@ba.infn.it, E-mail: manibrata.sen@gmail.com [Dipartimento Interateneo di Fisica ' Michelangelo Merlin' , Via Amendola 173, 70126 Bari (Italy)

2017-02-01

It has been recently pointed out that neutrino fluxes from a supernova can show substantial flavor conversions almost immediately above the core. Using linear stability analyses and numerical solutions of the fully nonlinear equations of motion, we perform a detailed study of these fast conversions , focussing on the region just above the supernova core. We carefully specify the instabilities for evolution in space or time, and find that neutrinos travelling towards the core make fast conversions more generic, i.e., possible for a wider range of flux ratios and angular asymmetries that produce a crossing between the zenith-angle spectra of ν {sub e} and ν-bar {sub e} . Using fluxes and angular distributions predicted by supernova simulations, we find that fast conversions can occur within tens of nanoseconds, only a few meters away from the putative neutrinospheres. If these fast flavor conversions indeed take place, they would have important implications for the supernova explosion mechanism and nucleosynthesis.

Automated search for supernovae

Energy Technology Data Exchange (ETDEWEB)

Kare, J.T.

1984-11-15

This thesis describes the design, development, and testing of a search system for supernovae, based on the use of current computer and detector technology. This search uses a computer-controlled telescope and charge coupled device (CCD) detector to collect images of hundreds of galaxies per night of observation, and a dedicated minicomputer to process these images in real time. The system is now collecting test images of up to several hundred fields per night, with a sensitivity corresponding to a limiting magnitude (visual) of 17. At full speed and sensitivity, the search will examine some 6000 galaxies every three nights, with a limiting magnitude of 18 or fainter, yielding roughly two supernovae per week (assuming one supernova per galaxy per 50 years) at 5 to 50 percent of maximum light. An additional 500 nearby galaxies will be searched every night, to locate about 10 supernovae per year at one or two percent of maximum light, within hours of the initial explosion.

Automated search for supernovae

International Nuclear Information System (INIS)

Kare, J.T.

1984-01-01

This thesis describes the design, development, and testing of a search system for supernovae, based on the use of current computer and detector technology. This search uses a computer-controlled telescope and charge coupled device (CCD) detector to collect images of hundreds of galaxies per night of observation, and a dedicated minicomputer to process these images in real time. The system is now collecting test images of up to several hundred fields per night, with a sensitivity corresponding to a limiting magnitude (visual) of 17. At full speed and sensitivity, the search will examine some 6000 galaxies every three nights, with a limiting magnitude of 18 or fainter, yielding roughly two supernovae per week (assuming one supernova per galaxy per 50 years) at 5 to 50 percent of maximum light. An additional 500 nearby galaxies will be searched every night, to locate about 10 supernovae per year at one or two percent of maximum light, within hours of the initial explosion

Decays of supernova neutrinos

International Nuclear Information System (INIS)

Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

2002-01-01

Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

Neutrino Emission from Supernovae

Science.gov (United States)

Janka, Hans-Thomas

Supernovae are the most powerful cosmic sources of MeV neutrinos. These elementary particles play a crucial role when the evolution of a massive star is terminated by the collapse of its core to a neutron star or a black hole and the star explodes as supernova. The release of electron neutrinos, which are abundantly produced by electron captures, accelerates the catastrophic infall and causes a gradual neutronization of the stellar plasma by converting protons to neutrons as dominant constituents of neutron star matter. The emission of neutrinos and antineutrinos of all flavors carries away the gravitational binding energy of the compact remnant and drives its evolution from the hot initial to the cold final state. The absorption of electron neutrinos and antineutrinos in the surroundings of the newly formed neutron star can power the supernova explosion and determines the conditions in the innermost supernova ejecta, making them an interesting site for the nucleosynthesis of iron-group elements and trans-iron nuclei.

Positron Survival in Type II Supernovae

Science.gov (United States)

1989-05-01

B: Computer Program and Flow Diagram 53 References 59 I. Introduction Since the discovery of Supernova 1987A (a Type II supernova) in February of 1987...the fewer number of decays depositing energy within the supernova. The rate of this cooling is unknown because it is uncertain whether a pulsar was

NEUTRINO-DRIVEN CONVECTION IN CORE-COLLAPSE SUPERNOVAE: HIGH-RESOLUTION SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Radice, David; Ott, Christian D. [TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Abdikamalov, Ernazar [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan); Couch, Sean M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Haas, Roland [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, D-14476 Golm (Germany); Schnetter, Erik, E-mail: dradice@caltech.edu [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada)

2016-03-20

We present results from high-resolution semiglobal simulations of neutrino-driven convection in core-collapse supernovae. We employ an idealized setup with parameterized neutrino heating/cooling and nuclear dissociation at the shock front. We study the internal dynamics of neutrino-driven convection and its role in redistributing energy and momentum through the gain region. We find that even if buoyant plumes are able to locally transfer heat up to the shock, convection is not able to create a net positive energy flux and overcome the downward transport of energy from the accretion flow. Turbulent convection does, however, provide a significant effective pressure support to the accretion flow as it favors the accumulation of energy, mass, and momentum in the gain region. We derive an approximate equation that is able to explain and predict the shock evolution in terms of integrals of quantities such as the turbulent pressure in the gain region or the effects of nonradial motion of the fluid. We use this relation as a way to quantify the role of turbulence in the dynamics of the accretion shock. Finally, we investigate the effects of grid resolution, which we change by a factor of 20 between the lowest and highest resolution. Our results show that the shallow slopes of the turbulent kinetic energy spectra reported in previous studies are a numerical artifact. Kolmogorov scaling is progressively recovered as the resolution is increased.

NEUTRINO-DRIVEN CONVECTION IN CORE-COLLAPSE SUPERNOVAE: HIGH-RESOLUTION SIMULATIONS

International Nuclear Information System (INIS)

Radice, David; Ott, Christian D.; Abdikamalov, Ernazar; Couch, Sean M.; Haas, Roland; Schnetter, Erik

2016-01-01

We present results from high-resolution semiglobal simulations of neutrino-driven convection in core-collapse supernovae. We employ an idealized setup with parameterized neutrino heating/cooling and nuclear dissociation at the shock front. We study the internal dynamics of neutrino-driven convection and its role in redistributing energy and momentum through the gain region. We find that even if buoyant plumes are able to locally transfer heat up to the shock, convection is not able to create a net positive energy flux and overcome the downward transport of energy from the accretion flow. Turbulent convection does, however, provide a significant effective pressure support to the accretion flow as it favors the accumulation of energy, mass, and momentum in the gain region. We derive an approximate equation that is able to explain and predict the shock evolution in terms of integrals of quantities such as the turbulent pressure in the gain region or the effects of nonradial motion of the fluid. We use this relation as a way to quantify the role of turbulence in the dynamics of the accretion shock. Finally, we investigate the effects of grid resolution, which we change by a factor of 20 between the lowest and highest resolution. Our results show that the shallow slopes of the turbulent kinetic energy spectra reported in previous studies are a numerical artifact. Kolmogorov scaling is progressively recovered as the resolution is increased

Towards asteroseismology of core-collapse supernovae with gravitational-wave observations - I. Cowling approximation

Science.gov (United States)

Torres-Forné, Alejandro; Cerdá-Durán, Pablo; Passamonti, Andrea; Font, José A.

2018-03-01

Gravitational waves from core-collapse supernovae are produced by the excitation of different oscillation modes in the protoneutron star (PNS) and its surroundings, including the shock. In this work we study the relationship between the post-bounce oscillation spectrum of the PNS-shock system and the characteristic frequencies observed in gravitational-wave signals from core-collapse simulations. This is a fundamental first step in order to develop a procedure to infer astrophysical parameters of the PNS formed in core-collapse supernovae. Our method combines information from the oscillation spectrum of the PNS, obtained through linear perturbation analysis in general relativity of a background physical system, with information from the gravitational-wave spectrum of the corresponding non-linear, core-collapse simulation. Using results from the simulation of the collapse of a 35 M⊙ pre-supernova progenitor we show that both types of spectra are indeed related and we are able to identify the modes of oscillation of the PNS, namely g-modes, p-modes, hybrid modes, and standing accretion shock instability (SASI) modes, obtaining a remarkably close correspondence with the time-frequency distribution of the gravitational-wave modes. The analysis presented in this paper provides a proof of concept that asteroseismology is indeed possible in the core-collapse scenario, and it may serve as a basis for future work on PNS parameter inference based on gravitational-wave observations.

Dimming supernovae without cosmic acceleration

International Nuclear Information System (INIS)

Csaki, Csaba; Terning, John; Kaloper, Nemanja

2002-01-01

We present a simple model where photons propagating in extragalactic magnetic fields can oscillate into very light axions. The oscillations may convert some of the photons, departing a distant supernova, into axions, making the supernova appear dimmer and hence more distant than it really is. Averaging over different configurations of the magnetic field we find that the dimming saturates at about one-third of the light from the supernovae at very large redshifts. This results in a luminosity distance versus redshift curve almost indistinguishable from that produced by the accelerating Universe, if the axion mass and coupling scale are m∼10 -16 eV , M∼4x10 11 GeV . This phenomenon may be an alternative to the accelerating Universe for explaining supernova observations

Estimating dust distances to Type Ia supernovae from colour excess time evolution

Science.gov (United States)

Bulla, M.; Goobar, A.; Amanullah, R.; Feindt, U.; Ferretti, R.

2018-01-01

We present a new technique to infer dust locations towards reddened Type Ia supernovae and to help discriminate between an interstellar and a circumstellar origin for the observed extinction. Using Monte Carlo simulations, we show that the time evolution of the light-curve shape and especially of the colour excess E(B - V) places strong constraints on the distance between dust and the supernova. We apply our approach to two highly reddened Type Ia supernovae for which dust distance estimates are available in the literature: SN 2006X and SN 2014J. For the former, we obtain a time-variable E(B - V) and from this derive a distance of 27.5^{+9.0}_{-4.9} or 22.1^{+6.0}_{-3.8} pc depending on whether dust properties typical of the Large Magellanic Cloud (LMC) or the Milky Way (MW) are used. For the latter, instead, we obtain a constant E(B - V) consistent with dust at distances larger than ∼50 and 38 pc for LMC- and MW-type dust, respectively. Values thus extracted are in excellent agreement with previous estimates for the two supernovae. Our findings suggest that dust responsible for the extinction towards these supernovae is likely to be located within interstellar clouds. We also discuss how other properties of reddened Type Ia supernovae - such as their peculiar extinction and polarization behaviour and the detection of variable, blue-shifted sodium features in some of these events - might be compatible with dust and gas at interstellar-scale distances.

Cosmogenic Secondary Radiation from a Nearby Supernova

Science.gov (United States)

Overholt, Andrew

2017-01-01

Increasing evidence has been found for multiple supernovae within 100 pc of the solar system. Supernovae produce large amounts of cosmic rays which upon striking Earth's atmosphere, produce a cascade of secondary particles. Among these cosmic ray secondaries are neutrons and muons, which penetrate far within the atmosphere to sea level and even below sea level. Muons and neutrons are both forms of ionizing radiation which have been linked to increases in cancer, congenital malformations, and other maladies. This work focuses on the impact of muons, as they penetrate into ocean water to impact the lowest levels of the aquatic food chain. We have used monte carlo simulations (CORSIKA, MCNPx, and FLUKA) to determine the ionizing radiation dose due to cosmic ray secondaries. This information shows that although most astrophysical events do not supply the necessary radiation flux to prove dangerous; there may be other impacts such as an increase to mutation rate.

A blowout numerical model for the supernova remnant G352.7-0.1

OpenAIRE

Toledo Roy, J. C.; Velazquez, P. F.; Esquivel, A.; Giacani, Elsa Beatriz

2017-01-01

We present 3D hydrodynamical simulations of the Galactic supernova remnant G352.7−0.1. This remnant is peculiar for having a shell-like inner ring structure and an outer arc in radio observations. In our model, the supernova explosion producing the remnant occurs inside and near the border of a spherical cloud with a density higher than that of the surrounding interstellar medium. A blowout is produced when the remnant reaches the border of the cloud. We have then used the results of our hydr...

SHADOWS OF OUR FORMER COMPANIONS: HOW THE SINGLE-DEGENERATE BINARY TYPE IA SUPERNOVA SCENARIO AFFECTS REMNANTS

International Nuclear Information System (INIS)

Gray, William J.; Raskin, Cody; Owen, J. Michael

2016-01-01

Here we present three-dimensional high-resolution simulations of Type Ia supernova in the presence of a non-degenerate companion. We find that the presence of a nearby companion leaves a long-lived hole in the supernova ejecta. In particular, we aim to study the long-term evolution of this hole as the supernova ejecta interacts with the surrounding interstellar medium (ISM). Using estimates for the X-ray emission, we find that the hole generated by the companion remains for many centuries after the interaction between the ejecta and the ISM. We also show that the hole is discernible over a wide range of viewing angles and companion masses.

SHADOWS OF OUR FORMER COMPANIONS: HOW THE SINGLE-DEGENERATE BINARY TYPE IA SUPERNOVA SCENARIO AFFECTS REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Gray, William J.; Raskin, Cody; Owen, J. Michael [Lawrence Livermore National Laboratory, P.O. Box 808, L-038, Livermore, CA 94550 (United States)

2016-12-10

Here we present three-dimensional high-resolution simulations of Type Ia supernova in the presence of a non-degenerate companion. We find that the presence of a nearby companion leaves a long-lived hole in the supernova ejecta. In particular, we aim to study the long-term evolution of this hole as the supernova ejecta interacts with the surrounding interstellar medium (ISM). Using estimates for the X-ray emission, we find that the hole generated by the companion remains for many centuries after the interaction between the ejecta and the ISM. We also show that the hole is discernible over a wide range of viewing angles and companion masses.

Rates and progenitors of type Ia supernovae

Energy Technology Data Exchange (ETDEWEB)

Wood-Vasey, William Michael [Univ. of California, Berkeley, CA (United States)

2004-01-01

The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence Berkeley National Laboratory and the National Energy Research Supercomputing Center. An automated search had never been attempted on this scale. A number of planned future large supernovae projects are predicated on the ability to find supernovae quickly, reliably, and efficiently in large datasets. A prototype run of the SNfactory search pipeline conducted from 2002 to 2003 discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search of this scale offers an excellent opportunity to measure the rate of Type Ia supernovae. This thesis presents a new method for

Rates and progenitors of type Ia supernovae

International Nuclear Information System (INIS)

Wood-Vasey, William Michael

2004-01-01

The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence Berkeley National Laboratory and the National Energy Research Supercomputing Center. An automated search had never been attempted on this scale. A number of planned future large supernovae projects are predicated on the ability to find supernovae quickly, reliably, and efficiently in large datasets. A prototype run of the SNfactory search pipeline conducted from 2002 to 2003 discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search of this scale offers an excellent opportunity to measure the rate of Type Ia supernovae. This thesis presents a new method for

The ASAS-SN bright supernova catalogue - III. 2016

Science.gov (United States)

Holoien, T. W.-S.; Brown, J. S.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Prieto, J. L.; Dong, Subo; Brimacombe, J.; Bishop, D. W.; Bose, S.; Beacom, J. F.; Bersier, D.; Chen, Ping; Chomiuk, L.; Falco, E.; Godoy-Rivera, D.; Morrell, N.; Pojmanski, G.; Shields, J. V.; Strader, J.; Stritzinger, M. D.; Thompson, Todd A.; Woźniak, P. R.; Bock, G.; Cacella, P.; Conseil, E.; Cruz, I.; Fernandez, J. M.; Kiyota, S.; Koff, R. A.; Krannich, G.; Marples, P.; Masi, G.; Monard, L. A. G.; Nicholls, B.; Nicolas, J.; Post, R. S.; Stone, G.; Wiethoff, W. S.

2017-11-01

This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (mpeak ≤ 17), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-infrared through ultraviolet magnitudes of all host galaxies and the offsets of the supernovae from the centres of their hosts from public data bases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogues, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.

The great supernova of 1987

International Nuclear Information System (INIS)

Woosley, S.E.

1989-01-01

Seven hundred day after the explosion of the brightest supernova in four centuries, astronomers continue to be both excited and perplexed by its behavior. By now, the supernova has received considerably attention in the literature. This paper emphasizes several aspects of the supernova that continue to be of special interest. These include: the evolution of the presupernova star, why it was blue, what its composition and core structure were; the iron core mass, explosion mechanism, and certain aspects of the neutrino burst; the detailed isotopic composition of the ejecta; the light curve and the requirement for mixing; the expected continued evolution of the supernova at all wavelengths given both the presence of several radioactivities as well as a central collapsed object as a power source; and late breaking news regarding the pulsar

Are crab-type supernova remnants (plerions) short-lived

International Nuclear Information System (INIS)

Weiler, K.W.; Panagia, N.

1978-01-01

Arguments are given for a possible picture of the origin, maintenance, and lifetimes of the so-called Crab-like supernova remnants. It is suggested that these objects imply the existence of at least two distinct types of supernova events. A possible connection of the remnant types with the optically defined supernovae of Type I and Type II is discussed. Accepting that a pulsar is formed in at least some supernova events, the proposal is made that a rapidly rotating, rapidly slowing pulsar is necessary to create and maintain a Crab-like supernova remnant. Finally, arguments are presented that such a supernova remnant will be relatively short lived with respect to the more common shell-type of supernova remnant, perhaps surviving only 10000-20000 yr before fading into the Galactic background. The name of plerion is proposed for these filled-center supernova remnants and observational possiblities for confirming their nature are suggested. (orig.) [de

PHOTOMETRIC SUPERNOVA CLASSIFICATION WITH MACHINE LEARNING

Energy Technology Data Exchange (ETDEWEB)

Lochner, Michelle; Peiris, Hiranya V.; Lahav, Ofer; Winter, Max K. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); McEwen, Jason D., E-mail: dr.michelle.lochner@gmail.com [Mullard Space Science Laboratory, University College London, Surrey RH5 6NT (United Kingdom)

2016-08-01

Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k -nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.

PHOTOMETRIC SUPERNOVA CLASSIFICATION WITH MACHINE LEARNING

International Nuclear Information System (INIS)

Lochner, Michelle; Peiris, Hiranya V.; Lahav, Ofer; Winter, Max K.; McEwen, Jason D.

2016-01-01

Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k -nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.

Overview of the nearby supernova factory

International Nuclear Information System (INIS)

Aldering, Greg; Adam, Gilles; Antilogus, Pierre; Astier, Pierre; Bacon, Roland; Bongard, S.; Bonnaud, C.; Copin, Yannick; Hardin, D.; Howell, D. Andy; Lemmonnier, Jean-Pierre; Levy, J.-M.; Loken, S.; Nugent, Peter; Pain, Reynald; Pecontal, Arlette; Pecontal, Emmanuel; Perlmutter, Saul; Quimby, Robert; Schahmaneche, Kyan; Smadja, Gerard; Wood-Vasey, W. Michael

2002-01-01

The Nearby Supernova Factory (SNfactory) is an international experiment designed to lay the foundation for the next generation of cosmology experiments (such as CFHTLS, wP, SNAP and LSST) which will measure the expansion history of the Universe using Type Ia supernovae. The SNfactory will discover and obtain frequent lightcurve spectrophotometry covering 3200-10000 (angstrom) for roughly 300 Type Ia supernovae at the loW--redshift end of the smooth Hubble flow. The quantity, quality, breadth of galactic environments, and homogeneous nature of the SNfactory dataset will make it the premier source of calibration for the Type Ia supernova width-brightness relation and the intrinsic supernova colors used for K-correction and correction for extinction by host-galaxy dust. This dataset will also allow an extensive investigation of additional parameters which possibly influence the quality of Type Ia supernovae as cosmological probes. The SNfactory search capabilities and folloW--up instrumentation include wide-field CCD imagers on two 1.2-m telescopes (via collaboration with the Near Earth Asteroid Tracking team at JPL and the QUEST team at Yale), and a two-channel integral-field-unit optical spectrograph/imager being fabricated for the University of Hawaii 2.2-m telescope. In addition to ground-based folloW--up, UV spectra for a subsample of these supernovae will be obtained with HST. The pipeline to obtain, transfer via wireless and standard internet, and automatically process the search images is in operation. Software and hardware development is now underway to enable the execution of folloW--up spectroscopy of supernova candidates at the Hawaii 2.2-m telescope via automated remote control of the telescope and the IFU spectrograph/imager

Gravitational collapse and supernovae

International Nuclear Information System (INIS)

Lattimer, J.M.

1989-01-01

The collapse of the core of a massive star and the subsequent birth of a neutron star in a supernova explosion are discussed, and a model of the supernova mechanism is developed. The basic theory is then compared with the particular case of SN1987A, whose emitted neutrinos permitted the first direct test of the model. (author)

Numerical models of protoneutron stars and type-II supernovae - recent developments

Energy Technology Data Exchange (ETDEWEB)

Janka, H T [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

1996-11-01

The results of recent multi-dimensional simulations of type-II supernovae are reviewed. They show that convective instabilities in the collapsed stellar core might play an important role already during the first second after the formation of the supernovae shock. Convectively unstable situations occur below and near the neutrinosphere as well as in the neutrino-heated region between the nascent neutron star and the supernova shock after the latter has stalled at a radiums of typically 100-200 km. While convective overturn in the layer of neutrino energy deposition clearly helps the explosion to develop and potentially provides an explanation of strong mantle and envelope mixing, asphericities, and non-uniform {sup 56}Ni distribution observed in supernova SN 1987A, its presence and importance depends on the strength of the neutrino heating and thus on the size of the neutrino fluxes from the neutrino star. Convection in the hot-bubble region can only be developed if the growth timescale of the instabilities and the heating timescale are both shorter than the accretion timescale of the matter advected through the stagnant shock. For too small neutrino luminosities this requirement is not fulfilled and convective activity cannot develop, leading to very weak explosions or even fizzling models, just as in the one-dimensional situations. Convectively enhanced neutrino luminosities from the protoneutron star can therefore provide an essential condition for the explosion of the star. Very recent two-dimensional, self-consistent, general relativistic simulations of the cooling of a newly-formed neutron star demonstrate and confirm the possibility that Ledoux convection, driven by negative lepton number and entropy gradients, may encompass the whole protoneutron star within less than one second and can lead to an increase of the neutrino fluxes by up to a factor of two. (author) 9 figs., refs.

Spectroscopic standardisation of Ia type supernovae within the frame of the Supernovae Legacy Survey

International Nuclear Information System (INIS)

Le Du, Jeremy

2008-09-01

This research thesis first proposes an overview of cosmology science since antiquity until modern times, of its fast development during the 20. century (discovery of galaxies, introduction of general relativity), of the standard cosmological model (Friedman-Lemaitre-Robertson-Walker metrics, equations of Friedman-Lemaitre, universe radius and curvature, universe evolution, energetic assessment), of the issue of black matter and black energy, and of cosmological probes (diffuse cosmological background, gravitational lenses). The second part presents supernovae: origin, explosion mechanisms, diversity, Ia supernovae). The third part presents the Supernovae Legacy Survey (SNLS): objectives and instruments of the SNLS program, detection strategy. The fourth part describes the spectroscopy of SNLS candidates to the VLT (Very Large Telescope): reduction of spectral data, subtraction of the host galaxy and identification of the supernova, assessment of method performance, flux and position errors, assessment of VLT observations. The fifth part discusses the variability of spectral characteristics of Ia supernovae: measurement of spectral indicators, study of SiII(4128A) line, study of the CaHandK region, equivalent depth as a new spectral indicator. The sixth part discusses cosmological implications of the SNLS, and the last part briefly reports and comments the measurement of spectroscopic indicators in the SNAP/JDEM experiment

The ASAS-SN bright supernova catalogue - III. 2016

DEFF Research Database (Denmark)

Holoien, T. W. -S.; Brown, J. S.; Stanek, K. Z.

2017-01-01

This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d......This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d...

HIGH-RESOLUTION SIMULATIONS OF CONVECTION PRECEDING IGNITION IN TYPE Ia SUPERNOVAE USING ADAPTIVE MESH REFINEMENT

International Nuclear Information System (INIS)

Nonaka, A.; Aspden, A. J.; Almgren, A. S.; Bell, J. B.; Zingale, M.; Woosley, S. E.

2012-01-01

We extend our previous three-dimensional, full-star simulations of the final hours of convection preceding ignition in Type Ia supernovae to higher resolution using the adaptive mesh refinement capability of our low Mach number code, MAESTRO. We report the statistics of the ignition of the first flame at an effective 4.34 km resolution and general flow field properties at an effective 2.17 km resolution. We find that off-center ignition is likely, with radius of 50 km most favored and a likely range of 40-75 km. This is consistent with our previous coarser (8.68 km resolution) simulations, implying that we have achieved sufficient resolution in our determination of likely ignition radii. The dynamics of the last few hot spots preceding ignition suggest that a multiple ignition scenario is not likely. With improved resolution, we can more clearly see the general flow pattern in the convective region, characterized by a strong outward plume with a lower speed recirculation. We show that the convective core is turbulent with a Kolmogorov spectrum and has a lower turbulent intensity and larger integral length scale than previously thought (on the order of 16 km s –1 and 200 km, respectively), and we discuss the potential consequences for the first flames.

Physics of supernovae

International Nuclear Information System (INIS)

Woosley, S.E.; Weaver, T.A.

1985-01-01

Presupernova models of massive stars are presented and their explosion by ''delayed neutrino transport'' examined. A new form of long duration Type II supernova model is also explored based upon repeated encounter with the electron-positron pair instability in stars heavier than about 60 Msub solar. Carbon deflagration in white dwarfs is discussed as the probable explanation of Type I supernovae and special attention is paid to the physical processes whereby a nuclear flame propagates through degenerate carbon. 89 refs., 12 figs

The Carnegie Supernova Project: The Low-Redshift Survey

Science.gov (United States)

Hamuy, Mario; Folatelli, Gastón; Morrell, Nidia I.; Phillips, Mark M.; Suntzeff, Nicholas B.; Persson, S. E.; Roth, Miguel; Gonzalez, Sergio; Krzeminski, Wojtek; Contreras, Carlos; Freedman, Wendy L.; Murphy, D. C.; Madore, Barry F.; Wyatt, P.; Maza, José; Filippenko, Alexei V.; Li, Weidong; Pinto, P. A.

2006-01-01

Supernovae are essential to understanding the chemical evolution of the universe. Type Ia supernovae also provide the most powerful observational tool currently available for studying the expansion history of the universe and the nature of dark energy. Our basic knowledge of supernovae comes from the study of their photometric and spectroscopic properties. However, the presently available data sets of optical and near-infrared light curves of supernovae are rather small and/or heterogeneous, and employ photometric systems that are poorly characterized. Similarly, there are relatively few supernovae whose spectral evolution has been well sampled, both in wavelength and phase, with precise spectrophotometric observations. The low-redshift portion of the Carnegie Supernova Project (CSP) seeks to remedy this situation by providing photometry and spectrophotometry of a large sample of supernovae taken on telescope/filter/detector systems that are well understood and well characterized. During a 5 year program that began in 2004 September, we expect to obtain high-precision u'g'r'i'BVYJHKs light curves and optical spectrophotometry for about 250 supernovae of all types. In this paper we provide a detailed description of the CSP survey observing and data reduction methodology. In addition, we present preliminary photometry and spectra obtained for a few representative supernovae during the first observing campaign.

Studying explosive phenomena in astrophysics by the example of gamma-ray bursts and supernovae

International Nuclear Information System (INIS)

Filina, Anastasia

2015-01-01

The formation of the first stars hundreds of millions of years after the Big-Bang marks the end of the Dark Ages. Currently, we have no direct observations on how the primordial stars formed, but according to modern theory of stellar evolution these stars should be very massive (about 100 Msun) Population III stars have a potential to produce probably most energetic flashes in the Universe - gamma-ray bursts. GRBs may provide one of the most promising methods to probe directly final stage of life of primordial stars. Today's telescopes cannot look far enough into the cosmic past to observe the formation of the first stars, but the new generation of telescopes will test theoretical ideas about the formation of the first stars.Thanks to many years of observations we have good GRB's data -statistics of occurrence, spectrum, light curves. But there are still a lot of questions in the theory of GRBs. We know that GRBs are related to the death of stars and that they are connected with supernovae. So gamma-ray bursts are one of the classes of explosive processes in stellar physics that should have a lot of common with supernovae explosions. In that case GRBs should follow the same physical laws of explosion as supernovae. This work tries to approach the problem of GRBs as a problem of stellar explosion.Necessary instruments of studying stellar explosion were developed as a part of doctoral research: code for solving systems of nuclear reaction equations was incorporated into hydrodynamical code. These tools were applied for supernovae simulations in order to find possible connection with GRBs. Basing on analysis of supernovae simulations spectral analysis of GRBs was performed. (author)

A 3D View of a Supernova Remnant

Science.gov (United States)

Kohler, Susanna

2017-06-01

Chandra X-ray observations to measure both the knots proper motion in the plane of the sky and their line-of-sight velocity. These two measurements were then combined to build a full 3D map of the motion of the ejecta.3D hydrodynamical simulations of Tycho, stopped at the current epoch. These show that both initially smooth (top) and initially clumpy (bottom) ejecta models are consistent with the current observations of the morphology and dynamics of Tychos ejecta. [Adapted from Williams et al. 2017]Symmetry and ClumpsWilliams and collaborators found that the knots have total velocities that range from 2400 to 6600 km/s. Unlike the forward shock of the supernova, Tychos ejecta display no asymmetries in their motion which suggests that the explosion itself was symmetric. The more likely explanation is a density gradient in the interstellar medium, which could slow the shock wave on one side of the remnant without yet affecting the motion of the clumps of ejecta.As a final exploration, the authors attempt to address the origin of Tychos clumpiness. The fact that some of Tychos ejecta knots precede its outer edge has raised the question of whether the ejecta started out clumpy, or if they began smooth and only clumped during expansion. Williams and collaborators matched the morphological and dynamical data to simulations, demonstrating that neither scenario can be ruled out at this time.This first 3D map of a Type Ia supernova represents an important step in our ability to understand these stellar explosions. The authors suggest that well be able to expand on this map in the future with additional observations from Chandra, as well as with new data from future X-ray observatories that will be able to detect fainter emission.CitationBrian J. Williams et al 2017 ApJ 842 28. doi:10.3847/1538-4357/aa7384

DARK MATTER ADMIXED TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Leung, S.-C.; Chu, M.-C.; Lin, L.-M.

2015-01-01

We perform two-dimensional hydrodynamic simulations for the thermonuclear explosion of Chandrasekhar-mass white dwarfs with dark matter (DM) cores in Newtonian gravity. We include a 19-isotope nuclear reaction network and make use of the pure turbulent deflagration model as the explosion mechanism in our simulations. Our numerical results show that the general properties of the explosion depend quite sensitively on the mass of the DM core M DM : a larger M DM generally leads to a weaker explosion and a lower mass of synthesized iron-peaked elements. In particular, the total mass of produced can drop from about 0.3 to 0.03 M ⊙ as M DM increases from 0.01 to 0.03 M ⊙ . We have also constructed the bolometric light curves obtained from our simulations and found that our results match well with the observational data of sub-luminous Type Ia supernovae

THE ROLE OF TURBULENCE IN NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVA EXPLOSIONS

Energy Technology Data Exchange (ETDEWEB)

Couch, Sean M. [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Ott, Christian D., E-mail: smc@flash.uchichago.edu, E-mail: cott@tapir.caltech.edu [TAPIR, Walter Burke Institute for Theoretical Physics, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States)

2015-01-20

The neutrino-heated ''gain layer'' immediately behind the stalled shock in a core-collapse supernova is unstable to high-Reynolds-number turbulent convection. We carry out and analyze a new set of 19 high-resolution three-dimensional (3D) simulations with a three-species neutrino leakage/heating scheme and compare with spherically symmetric (one-dimensional, 1D) and axisymmetric (two-dimensional, 2D) simulations carried out with the same methods. We study the postbounce supernova evolution in a 15 M {sub ☉} progenitor star and vary the local neutrino heating rate, the magnitude and spatial dependence of asphericity from convective burning in the Si/O shell, and spatial resolution. Our simulations suggest that there is a direct correlation between the strength of turbulence in the gain layer and the susceptibility to explosion. 2D and 3D simulations explode at much lower neutrino heating rates than 1D simulations. This is commonly explained by the fact that nonradial dynamics allows accreting material to stay longer in the gain layer. We show that this explanation is incomplete. Our results indicate that the effective turbulent ram pressure exerted on the shock plays a crucial role by allowing multi-dimensional models to explode at a lower postshock thermal pressure and thus with less neutrino heating than 1D models. We connect the turbulent ram pressure with turbulent energy at large scales and in this way explain why 2D simulations are erroneously exploding more easily than 3D simulations.

THE ROLE OF TURBULENCE IN NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVA EXPLOSIONS

International Nuclear Information System (INIS)

Couch, Sean M.; Ott, Christian D.

2015-01-01

The neutrino-heated ''gain layer'' immediately behind the stalled shock in a core-collapse supernova is unstable to high-Reynolds-number turbulent convection. We carry out and analyze a new set of 19 high-resolution three-dimensional (3D) simulations with a three-species neutrino leakage/heating scheme and compare with spherically symmetric (one-dimensional, 1D) and axisymmetric (two-dimensional, 2D) simulations carried out with the same methods. We study the postbounce supernova evolution in a 15 M ☉ progenitor star and vary the local neutrino heating rate, the magnitude and spatial dependence of asphericity from convective burning in the Si/O shell, and spatial resolution. Our simulations suggest that there is a direct correlation between the strength of turbulence in the gain layer and the susceptibility to explosion. 2D and 3D simulations explode at much lower neutrino heating rates than 1D simulations. This is commonly explained by the fact that nonradial dynamics allows accreting material to stay longer in the gain layer. We show that this explanation is incomplete. Our results indicate that the effective turbulent ram pressure exerted on the shock plays a crucial role by allowing multi-dimensional models to explode at a lower postshock thermal pressure and thus with less neutrino heating than 1D models. We connect the turbulent ram pressure with turbulent energy at large scales and in this way explain why 2D simulations are erroneously exploding more easily than 3D simulations

THE EXTENDED HUBBLE SPACE TELESCOPE SUPERNOVA SURVEY: THE RATE OF CORE COLLAPSE SUPERNOVAE TO z {approx} 1

Energy Technology Data Exchange (ETDEWEB)

Dahlen, Tomas; Riess, Adam G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States); Mattila, Seppo; Kankare, Erkki [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland); Mobasher, Bahram, E-mail: dahlen@stsci.edu [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)

2012-09-20

We use a sample of 45 core collapse supernovae detected with the Advanced Camera for Surveys on board the Hubble Space Telescope to derive the core collapse supernova rate in the redshift range 0.1 < z < 1.3. In redshift bins centered on (z) = 0.39, (z) = 0.73, and (z) = 1.11, we find rates of 3.00{sup +1.28}{sub -0.94} {sup +1.04}{sub -0.57}, 7.39{sup +1.86}{sub -1.52} {sup +3.20}{sub -1.60}, and 9.57{sup +3.76}{sub -2.80} {sup +4.96}{sub -2.80}, respectively, given in units of yr{sup -1} Mpc{sup -3} 10{sup -4} h {sup 3}{sub 70}. The rates have been corrected for host galaxy extinction, including supernovae missed in highly dust-enshrouded environments in infrared bright galaxies. The first errors are statistical while the second ones are the estimated systematic errors. We perform a detailed discussion of possible sources of systematic errors and note that these start to dominate over statistical errors at z > 0.5, emphasizing the need to better control the systematic effects. For example, a better understanding of the amount of dust extinction in the host galaxies and knowledge of the supernova luminosity function, in particular the fraction of faint M {approx}> -15 supernovae, is needed to better constrain the rates. When comparing our results with the core collapse supernova rate based on the star formation rate, we find a good agreement, consistent with the supernova rate following the star formation rate, as expected.

Ultraviolet Light Curves of Gaia16apd in Superluminous Supernova Models

Energy Technology Data Exchange (ETDEWEB)

Tolstov, Alexey; Zhiglo, Andrey; Nomoto, Ken’ichi; Blinnikov, Sergei [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sorokina, Elena [Sternberg Astronomical Institute, M.V.Lomonosov Moscow State University, 119234 Moscow (Russian Federation); Kozyreva, Alexandra, E-mail: alexey.tolstov@ipmu.jp [The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

2017-08-10

Observations of Gaia16apd revealed extremely luminous ultraviolet emission among superluminous supernovae (SLSNe). Using radiation hydrodynamics simulations, we perform a comparison of UV light curves, color temperatures, and photospheric velocities between the most popular SLSN models: pair-instability supernova, magnetar, and interaction with circumstellar medium. We find that the interaction model is the most promising to explain the extreme UV luminosity of Gaia16apd. The differences in late-time UV emission and in color evolution found between the models can be used to link an observed SLSN event to the most appropriate model. Observations at UV wavelengths can be used to clarify the nature of SLSNe and more attention should be paid to them in future follow-up observations.

The Core Collapse Supernova Rate from the SDSS-II Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Taylor, Matt; Cinabro, David; Dilday, Ben; Galbany, Lluis; Gupta, Ravi R.; Kessler, R.; Marriner, John; Nichol, Robert C.; Richmond, Michael; Schneider, Donald P.; Sollerman, Jesper

2014-08-26

We use the Sloan Digital Sky Survey II Supernova Survey (SDSS-II SNS) data to measure the volumetric core collapse supernova (CCSN) rate in the redshift range (0.03 < z < 0.09). Using a sample of 89 CCSN, we find a volume-averaged rate of 1.06 ± 0.19 × 10(–)(4)((h/0.7)(3)/(yr Mpc(3))) at a mean redshift of 0.072 ± 0.009. We measure the CCSN luminosity function from the data and consider the implications on the star formation history.

Detection of supernova neutrinos at spallation neutron sources

Science.gov (United States)

Huang, Ming-Yang; Guo, Xin-Heng; Young, Bing-Lin

2016-07-01

After considering supernova shock effects, Mikheyev-Smirnov-Wolfenstein effects, neutrino collective effects, and Earth matter effects, the detection of supernova neutrinos at the China Spallation Neutron Source is studied and the expected numbers of different flavor supernova neutrinos observed through various reaction channels are calculated with the neutrino energy spectra described by the Fermi-Dirac distribution and the “beta fit” distribution respectively. Furthermore, the numerical calculation method of supernova neutrino detection on Earth is applied to some other spallation neutron sources, and the total expected numbers of supernova neutrinos observed through different reactions channels are given. Supported by National Natural Science Foundation of China (11205185, 11175020, 11275025, 11575023)

Supernovae and cosmology with future European facilities.

Science.gov (United States)

Hook, I M

2013-06-13

Prospects for future supernova surveys are discussed, focusing on the European Space Agency's Euclid mission and the European Extremely Large Telescope (E-ELT), both expected to be in operation around the turn of the decade. Euclid is a 1.2 m space survey telescope that will operate at visible and near-infrared wavelengths, and has the potential to find and obtain multi-band lightcurves for thousands of distant supernovae. The E-ELT is a planned, general-purpose ground-based, 40-m-class optical-infrared telescope with adaptive optics built in, which will be capable of obtaining spectra of type Ia supernovae to redshifts of at least four. The contribution to supernova cosmology with these facilities will be discussed in the context of other future supernova programmes such as those proposed for DES, JWST, LSST and WFIRST.

Supernovae and neutrinos

International Nuclear Information System (INIS)

John F. Beacom

2002-01-01

A long-standing problem in supernova physics is how to measure the total energy and temperature of ν μ , ν τ , (bar ν) μ , and (bar ν) τ . While of the highest importance, this is very difficult because these flavors only have neutral-current detector interactions. We propose that neutrino-proton elastic scattering, ν + p → ν + p, can be used for the detection of supernova neutrinos in scintillator detectors. It should be emphasized immediately that the dominant signal is on free protons. Though the proton recoil kinetic energy spectrum is soft, with T p ≅ 2E ν 2 /M p , and the scintillation light output from slow, heavily ionizing protons is quenched, the yield above a realistic threshold is nearly as large as that from (bar ν) e + p → e + + n. In addition, the measured proton spectrum is related to the incident neutrino spectrum. The ability to detect this signal would give detectors like KamLAND and Borexino a crucial and unique role in the quest to detect supernova neutrinos

Density and energy of supernova remnants

Energy Technology Data Exchange (ETDEWEB)

Canto, J [Manchester Univ. (UK). Dept. of Astronomy

1977-12-01

The effects of an interstellar magnetic field on the gas flow behind a strong shock front are considered. The ambient density and energy of supernova remnants are estimated from the intensity ratio of sulphur lines I(6717)/I(6731). It is found that, on average, the ambient density around galactic supernova remnants is 4 cm/sup -3/. The total energy appears to be the same for all supernova remnants (to within a factor = approximately 5). A mean value of 4 10/sup 51/ erg is found.

Chiral transport of neutrinos in supernovae

Directory of Open Access Journals (Sweden)

Yamamoto Naoki

2017-01-01

Full Text Available The conventional neutrino transport theory for core-collapse supernovae misses one key property of neutrinos: the left-handedness. The chirality of neutrinos modifies the hydrodynamic behavior at the macroscopic scale and leads to topological transport phenomena. We argue that such transport phenomena should play important roles in the evolution of core-collapse supernovae, and, in particular, lead to a tendency toward the inverse energy cascade from small to larger scales, which may be relevant to the origin of the supernova explosion.

Neutron Stars in Supernova Remnants and Beyond

Science.gov (United States)

Gvaramadze, V. V.

We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

Neutron Stars in Supernova Remnants and Beyond

OpenAIRE

Gvaramadze, V. V.

2002-01-01

We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

Constraints on holographic dark energy from type Ia supernova observations

International Nuclear Information System (INIS)

Zhang Xin; Wu Fengquan

2005-01-01

In this paper, we use the type Ia supernovae data to constrain the holographic dark energy model proposed by Li. We also apply a cosmic age test to this analysis. We consider in this paper a spatially flat Friedmann-Robertson-Walker universe with a matter component and a holographic dark energy component. The fit result shows that the case c m 0 =0.28, and h=0.65, which lead to the present equation of state of dark energy w 0 =-1.03 and the deceleration/acceleration transition redshift z T =0.63. Finally, an expected supernova/acceleration probe simulation using ΛCDM as a fiducial model is performed on this model, and the result shows that the holographic dark energy model takes on c<1 (c=0.92) even though the dark energy is indeed a cosmological constant

Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

NARCIS (Netherlands)

Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.; Kaastra, J.S.

2013-01-01

The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially

Supernova brightening from chameleon-photon mixing

International Nuclear Information System (INIS)

Burrage, C.

2008-01-01

Measurements of standard candles and measurements of standard rulers give an inconsistent picture of the history of the universe. This discrepancy can be explained if photon number is not conserved as computations of the luminosity distance must be modified. I show that photon number is not conserved when photons mix with chameleons in the presence of a magnetic field. The strong magnetic fields in a supernova mean that the probability of a photon converting into a chameleon in the interior of the supernova is high, this results in a large flux of chameleons at the surface of the supernova. Chameleons and photons also mix as a result of the intergalactic magnetic field. These two effects combined cause the image of the supernova to be brightened resulting in a model which fits both observations of standard candles and observations of standard rulers

NUMERICAL SIMULATIONS OF SUPERNOVA DUST DESTRUCTION. I. CLOUD-CRUSHING AND POST-PROCESSED GRAIN SPUTTERING

International Nuclear Information System (INIS)

Silvia, Devin W.; Smith, Britton D.; Michael Shull, J.

2010-01-01

We investigate through hydrodynamic simulations the destruction of newly formed dust grains by sputtering in the reverse shocks of supernova (SN) remnants. Using an idealized setup of a planar shock impacting a dense, spherical clump, we implant a population of Lagrangian particles into the clump to represent a distribution of dust grains in size and composition. We then post-process the simulation output to calculate the grain sputtering for a variety of species and size distributions. We explore the parameter space appropriate for this problem by altering the overdensity of the ejecta clumps and the speed of the reverse shocks. Since radiative cooling could lower the temperature of the medium in which the dust is embedded and potentially protect the dust by slowing or halting grain sputtering, we study the effects of different cooling methods over the timescale of the simulations. In general, our results indicate that grains with radii less than 0.1 μm are sputtered to much smaller radii and often destroyed completely, while larger grains survive their interaction with the reverse shock. We also find that, for high ejecta densities, the percentage of dust that survives is strongly dependent on the relative velocity between the clump and the reverse shock, causing up to 50% more destruction for the highest velocity shocks. The fraction of dust destroyed varies widely across grain species, ranging from total destruction of Al 2 O 3 grains to minimal destruction of Fe grains (only 20% destruction in the most extreme cases). C and SiO 2 grains show moderate to strong sputtering as well, with 38% and 80% mass loss. The survival rate of grains formed by early SNe is crucial in determining whether or not they can act as the 'dust factories' needed to explain high-redshift dust.

The Foundation Supernova Survey: motivation, design, implementation, and first data release

Science.gov (United States)

Foley, Ryan J.; Scolnic, Daniel; Rest, Armin; Jha, S. W.; Pan, Y.-C.; Riess, A. G.; Challis, P.; Chambers, K. C.; Coulter, D. A.; Dettman, K. G.; Foley, M. M.; Fox, O. D.; Huber, M. E.; Jones, D. O.; Kilpatrick, C. D.; Kirshner, R. P.; Schultz, A. S. B.; Siebert, M. R.; Flewelling, H. A.; Gibson, B.; Magnier, E. A.; Miller, J. A.; Primak, N.; Smartt, S. J.; Smith, K. W.; Wainscoat, R. J.; Waters, C.; Willman, M.

2018-03-01

The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z ≲ 0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ˜3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111 mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.

The physics of flames in Type Ia supernovae

International Nuclear Information System (INIS)

Zingale, M; Woosley, S E; Bell, J B; Day, M S; Rendleman, C A

2005-01-01

We extend a low Mach number hydrodynamics method developed for terrestrial combustion, to the study of thermonuclear flames in Type Ia supernovae. We discuss the differences between 2-D and 3-D Rayleigh-Taylor unstable flame simulations, and give detailed diagnostics on the turbulence, showing that the kinetic energy power spectrum obeys Bolgiano-Obukhov statistics in 2-D, but Kolmogorov statistics in 3-D. Preliminary results from 3-D reacting bubble calculations are shown, and their implications for ignition are discussed

First measurement of σ8 using supernova magnitudes only

Science.gov (United States)

Castro, Tiago; Quartin, Miguel

2014-09-01

A method was recently proposed which allows the conversion of the weak-lensing effects in the Type Ia supernova (SNeIa) Hubble diagram from noise into signal. Such signal is sensitive to the growth of structure in the universe, and in particular can be used as a measurement of σ8 independently from more traditional methods such as those based on the cosmic microwave background, cosmic shear or cluster abundance. We extend here that analysis to allow for intrinsic non-Gaussianities in the supernova probability distribution function, and discuss how this can be best modelled using the Bayes factor. Although it was shown that a precise measurement of σ8 requires ˜105 SNeIa, current data already allow an important proof of principle. In particular, we make use of the 706 supernovae with z ≤ 0.9 of the recent Joint Lightcurve Analysis catalogue and show that a simple treatment of intrinsic non-Gaussianities with a couple of nuisance parameters is enough for our method to yield the values σ _8 = 0.84^{+0.28}_{-0.65} or σ8 < 1.45 at a 2σ confidence level. This result is consistent with mock simulations and it is also in agreement with independent measurements and presents the first ever measurement of σ8 using SNeIa magnitudes alone.

Detecting supernova neutrinos in Daya Bay Neutrino Laboratory

International Nuclear Information System (INIS)

Huang Mingyang; Guo Xinheng; Yang Binglin

2011-01-01

While detecting supernova neutrinos in the Daya Bay neutrino laboratory, several supernova neutrino effects need to be considered, including the supernova shock effects, the neutrino collective effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, and the Earth matter effects. The phenomena of neutrino oscillation is affected by the above effects. Using some ratios of the event numbers of different supernova neutrinos, we propose some possible methods to identify the mass hierarchy and acquire information about the neutrino mixing angle θ13 and neutrino masses. (authors)

Simulation of coherent nonlinear neutrino flavor transformation in the supernova environment: Correlated neutrino trajectories

Science.gov (United States)

Duan, Huaiyu; Fuller, George M.; Carlson, J.; Qian, Yong-Zhong

2006-11-01

We present results of large-scale numerical simulations of the evolution of neutrino and antineutrino flavors in the region above the late-time post-supernova-explosion proto-neutron star. Our calculations are the first to allow explicit flavor evolution histories on different neutrino trajectories and to self-consistently couple flavor development on these trajectories through forward scattering-induced quantum coupling. Employing the atmospheric-scale neutrino mass-squared difference (|δm2|≃3×10-3eV2) and values of θ13 allowed by current bounds, we find transformation of neutrino and antineutrino flavors over broad ranges of energy and luminosity in roughly the “bi-polar” collective mode. We find that this large-scale flavor conversion, largely driven by the flavor off-diagonal neutrino-neutrino forward scattering potential, sets in much closer to the proto-neutron star than simple estimates based on flavor-diagonal potentials and Mikheyev-Smirnov-Wolfenstein evolution would indicate. In turn, this suggests that models of r-process nucleosynthesis sited in the neutrino-driven wind could be affected substantially by active-active neutrino flavor mixing, even with the small measured neutrino mass-squared differences.

Investigating the Nature of Dark Energy using Type Ia Supernovae with WFIRST-AFTA Space Mission

Science.gov (United States)

Perlmutter, Saul

Scientifically, the WFIRST supernova program is unique: it makes possible a dark energy measurement that no other space mission or ground-based project is addressing, a measurement that will set the standard in determining the expansion history of the universe continuously from low to high redshifts (0.1 Definition Team several participants in this proposal have developed a first version of a supernova program, described in the WFIRST SDT Report. While this program was judged to be a robust one, and the estimates of the sensitivity to the cosmological parameters were felt to be reliable, due to limitations of time the analysis was clearly limited in depth on a number of issues. The objective of this proposal is to further develop this program. Technically this is the WFIRST measurement that arguably requires the most advanced project development, since it requires near-real-time analysis and follow-up with WFIRST, and since it is using the IFU spectrograph in the WFI package, the IFU being the WFIRST instrument that does not yet have a completely consistent set of specifications in the design iteration of the SDT report. In this proposal for the WFIRST Scientific Investigation Team, focused primarily on the supernova dark energy measurements, we address these crucial technical needs by bringing the larger supernova community's expertise on the science elements together with a smaller focused team that can produce the specific deliverables. Thus the objectives of this 5 year proposal are the following: 1. Development of scientific performance requirements for the study of Dark Energy using Type Ia supernovae 2. Design an observing strategy using the Wide Field Instrument (WFI) and the Integral Field Spectrometer Unit (IFU) 3. Development of science data analysis techniques and data analysis software 4. Development of ground and space calibration requirements and estimating realistic correlated errors, both statistical and systematic 5. Development of simulations and

Supernova cooling in a dark matter smog

International Nuclear Information System (INIS)

Zhang, Yue

2014-01-01

A light hidden gauge boson with kinetic mixing with the usual photon is a popular setup in theories of dark matter. The supernova cooling via radiating the hidden boson is known to put an important constraint on the mixing. I consider the possible role dark matter, which under reasonable assumptions naturally exists inside supernova, can play in the cooling picture. Because the interaction between the hidden gauge boson and DM is likely unsuppressed, even a small number of dark matter compared to protons inside the supernova could dramatically shorten the free streaming length of the hidden boson. A picture of a dark matter “smog” inside the supernova, which substantially relaxes the cooling constraint, is discussed in detail

Supernova cooling in a dark matter smog

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yue [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA 91125 (United States)

2014-11-27

A light hidden gauge boson with kinetic mixing with the usual photon is a popular setup in theories of dark matter. The supernova cooling via radiating the hidden boson is known to put an important constraint on the mixing. I consider the possible role dark matter, which under reasonable assumptions naturally exists inside supernova, can play in the cooling picture. Because the interaction between the hidden gauge boson and DM is likely unsuppressed, even a small number of dark matter compared to protons inside the supernova could dramatically shorten the free streaming length of the hidden boson. A picture of a dark matter “smog” inside the supernova, which substantially relaxes the cooling constraint, is discussed in detail.

Exposing Hierarchical Parallelism in the FLASH Code for Supernova Simulation on Summit and Other Architectures

Energy Technology Data Exchange (ETDEWEB)

Papatheodore, Thomas L. [ORNL; Messer, Bronson [ORNL

2017-11-01

Since roughly 100 million years after the big bang, the primordial elements hydrogen (H), helium (He), and lithium (Li) have been synthesized into heavier elements by thermonuclear reactions inside of the stars. The change in stellar composition resulting from these reactions causes stars to evolve over the course of their lives. Although most stars burn through their nuclear fuel and end their lives quietly as inert, compact objects, whereas others end in explosive deaths. These stellar explosions are called supernovae and are among the most energetic events known to occur in our universe. Supernovae themselves further process the matter of their progenitor stars and distribute this material into the interstellar medium of their host galaxies. In the process, they generate ∼1051 ergs of kinetic energy by sending shock waves into their surroundings, thereby contributing to galactic dynamics as well.

Supernova will continue to glow

International Nuclear Information System (INIS)

Anon.

1987-01-01

On the night of 23/24 February 1987 a new supernova called SN 1987A, was discovered. Within a few hours of the announcement of the discovery, the South African Astronomical Observatory (SAAO) began a series of observations. In this article, the importance of supernovae-exploding stars, and what the SAAO has discovered so far from SN 1987A are discussed

HUBBLE SPIES MOST DISTANT SUPERNOVA EVER SEEN

Science.gov (United States)

2002-01-01

Using NASA's Hubble Space Telescope, astronomers pinpointed a blaze of light from the farthest supernova ever seen, a dying star that exploded 10 billion years ago. The detection and analysis of this supernova, called 1997ff, is greatly bolstering the case for the existence of a mysterious form of dark energy pervading the cosmos, making galaxies hurl ever faster away from each other. The supernova also offers the first glimpse of the universe slowing down soon after the Big Bang, before it began speeding up. This panel of images, taken with the Wide Field and Planetary Camera 2, shows the supernova's cosmic neighborhood; its home galaxy; and the dying star itself. Astronomers found this supernova in 1997 during a second look at the northern Hubble Deep Field [top panel], a tiny region of sky first explored by the Hubble telescope in 1995. The image shows the myriad of galaxies Hubble spied when it peered across more than 10 billion years of time and space. The white box marks the area where the supernova dwells. The photo at bottom left is a close-up view of that region. The white arrow points to the exploding star's home galaxy, a faint elliptical. Its redness is due to the billions of old stars residing there. The picture at bottom right shows the supernova itself, distinguished by the white dot in the center. Although this stellar explosion is among the brightest beacons in the universe, it could not be seen directly in the Hubble images. The stellar blast is so distant from Earth that its light is buried in the glow of its host galaxy. To find the supernova, astronomers compared two pictures of the 'deep field' taken two years apart. One image was of the original Hubble Deep Field; the other, the follow-up deep-field picture taken in 1997. Using special computer software, astronomers then measured the light from the galaxies in both images. Noting any changes in light output between the two pictures, the computer identified a blob of light in the 1997 picture

Supernova remnants, pulsar wind nebulae and their interaction

NARCIS (Netherlands)

Swaluw, E. van der

2001-01-01

A supernova explosion marks the end of the evolution of a massive star. What remains of the exploded star is a high density neutron star or a black hole. The material which has been ejected by the supernova explosion will manifest itself as a supernova remnant: a hot bubble of gas expanding in the

Observational Constraints on the Nature of the Dark Energy: First Cosmological Results From the ESSENCE Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Wood-Vasey, W.Michael; Miknaitis, G.; Stubbs, C.W.; Jha, S.; Riess, A.G.; Garnavich, P.M.; Kirshner, R.P.; Aguilera, C.; Becker, A.C.; Blackman, J.W.; Blondin, S.; Challis, P.; Clocchiatti, A.; Conley, A.; Covarrubias, R.; Davis, T.M.; Filippenko, A.V.; Foley, R.J.; Garg, A.; Hicken, M.; Krisciunas, K.; /Harvard-Smithsonian Ctr. Astrophys.

2007-01-05

We present constraints on the dark energy equation-of-state parameter, w = P/({rho}c{sup 2}), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy assuming a flat Universe. By including constraints on ({Omega}{sub M}, w) from baryon acoustic oscillations, we obtain a value for a static equation-of-state parameter w = -1.05{sub -0.12}{sup +0.13} (stat 1{sigma}) {+-} 0.13 (sys) and {Omega}{sub M} = 0.274{sub -0.020}{sup +0.033} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.96. These results are consistent with those reported by the Super-Nova Legacy Survey in a similar program measuring supernova distances and redshifts. We evaluate sources of systematic error that afflict supernova observations and present Monte Carlo simulations that explore these effects. Currently, the largest systematic currently with the potential to affect our measurements is the treatment of extinction due to dust in the supernova host galaxies. Combining our set of ESSENCE SNe Ia with the SuperNova Legacy Survey SNe Ia, we obtain a joint constraint of w = -1.07{sub -0.09}{sup +0.09} (stat 1{sigma}) {+-} 0.13 (sys), {Omega}{sub M} = 0.267{sub -0.018}{sup +0.028} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.91. The current SNe Ia data are fully consistent with a cosmological constant.

Supernova neutrinos

International Nuclear Information System (INIS)

John Beacom

2003-01-01

We propose that neutrino-proton elastic scattering, ν + p → ν + p, can be used for the detection of supernova neutrinos. Though the proton recoil kinetic energy spectrum is soft, with T p ≅ 2E ν 2 /M p , and the scintillation light output from slow, heavily ionizing protons is quenched, the yield above a realistic threshold is nearly as large as that from (bar ν) e + p → e + + n. In addition, the measured proton spectrum is related to the incident neutrino spectrum, which solves a long-standing problem of how to separately measure the total energy release and temperature of ν μ , ν τ , (bar ν) μ , and (bar ν) τ . The ability to detect this signal would give detectors like KamLAND and Borexino a crucial and unique role in the quest to detect supernova neutrinos

Supernova cooling in a dark matter smog

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yue, E-mail: yuezhang@theory.caltech.edu [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA 91125 (United States)

2014-11-01

A light hidden gauge boson with kinetic mixing with the usual photon is a popular setup in theories of dark matter. The supernova cooling via radiating the hidden boson is known to put an important constraint on the mixing. I consider the possible role dark matter, which under reasonable assumptions naturally exists inside supernova, can play in the cooling picture. Because the interaction between the hidden gauge boson and DM is likely unsuppressed, even a small number of dark matter compared to protons inside the supernova could dramatically shorten the free streaming length of the hidden boson. A picture of a dark matter ''smog'' inside the supernova, which substantially relaxes the cooling constraint, is discussed in detail.

The CHilean Automatic Supernova sEarch

DEFF Research Database (Denmark)

Hamuy, M.; Pignata, G.; Maza, J.

2012-01-01

The CHilean Automatic Supernova sEarch (CHASE) project began in 2007 with the goal to discover young, nearby southern supernovae in order to (1) better understand the physics of exploding stars and their progenitors, and (2) refine the methods to derive extragalactic distances. During the first...

Molecular clouds near supernova remnants

International Nuclear Information System (INIS)

Wootten, H.A.

1978-01-01

The physical properties of molecular clouds near supernova remnants were investigated. Various properties of the structure and kinematics of these clouds are used to establish their physical association with well-known remmnants. An infrared survey of the most massive clouds revealed embedded objects, probably stars whose formation was induced by the supernova blast wave. In order to understand the relationship between these and other molecular clouds, a control group of clouds was also observed. Excitation models for dense regions of all the clouds are constructed to evaluate molecular abundances in these regions. Those clouds that have embedded stars have lower molecular abundances than the clouds that do not. A cloud near the W28 supernova remnant also has low abundances. Molecular abundances are used to measure an important parameter, the electron density, which is not directly observable. In some clouds extensive deuterium fractionation is observed which confirms electron density measurements in those clouds. Where large deuterium fractionation is observed, the ionization rate in the cloud interior can also be measured. The electron density and ionization rate in the cloud near W28 are higher than in most clouds. The molecular abundances and electron densities are functions of the chemical and dynamical state of evolution of the cloud. Those clouds with lowest abundances are probably the youngest clouds. As low-abundance clouds, some clouds near supernova remnants may have been recently swept from the local interstellar material. Supernova remnants provide sites for star formation in ambient clouds by compressing them, and they sweep new clouds from more diffuse local matter

Oscillation effects and time variation of the supernova neutrino signal

Science.gov (United States)

Kneller, James P.; McLaughlin, Gail C.; Brockman, Justin

2008-02-01

The neutrinos detected from the next galactic core-collapse supernova will contain valuable information on the internal dynamics of the explosion. One mechanism leading to a temporal evolution of the neutrino signal is the variation of the induced neutrino flavor mixing driven by changes in the density profile. With one and two-dimensional hydrodynamical simulations we identify the behavior and properties of prominent features of the explosion. Using these results we demonstrate the time variation of the neutrino crossing probabilities due to changes in the Mikheyev-Smirnov-Wolfenstein (MSW) neutrino transformations as the star explodes by using the S-matrix—Monte Carlo—approach to neutrino propagation. After adopting spectra for the neutrinos emitted from the proto-neutron star we calculate for a galactic supernova the evolution of the positron spectra within a water Cerenkov detector and find that this signal allows us to probe of a number of explosion features.

Collective neutrino flavor transitions in supernovae: analytical and numerical aspects

International Nuclear Information System (INIS)

Fogli, G L; Marrone, A; Mirizzi, A; Lisi, E

2008-01-01

Non-linear effects on supernova neutrino oscillations, associated with neutrino-neutrino interactions, are known to induce collective flavor transformations near the supernova core for θ 13 ≠ 0. For typical electron density profiles (as taken from shock-wave simulations at a few seconds after bounce) these transformations precede ordinary matter effects, and become more amenable to both numerical computations and analytical interpretations in inverted hierarchy-while they basically vanish in normal hierarchy. We numerically evolve the neutrino density matrix in the region relevant for self-interaction effects, using thermal spectra and a representative value sin 2 θ 13 = 10 -4 . Our results neatly show the collective phenomena of synchronization, bipolar oscillations, and spectral split, with analytically understandable features. They also suggest that averaging over neutrino trajectories plays a minor role in the final outcome. The split/swap of (anti)neutrino spectra emerges as an unmistakable signature of the inverted neutrino hierarchy

Spectro-photometric calibration of the SuperNova Integral Field Spectrograph in the Nearby Supernova Factory collaboration framework

International Nuclear Information System (INIS)

Buton, Clement

2009-01-01

Ten years ago, type Ia supernovae used as distances indicators led to the discovery of the accelerating expansion of the universe. Today, a second generation of surveys has significantly increased the high-redshift type Ia supernovae sample. The low-redshift sample was however still limiting the cosmological analysis using SNe. In this framework, the Nearby Supernova Factory has followed 200 nearby type Ia supernovae using the dedicated Supernovae Integral Field Spectrograph with spectro-photometric capacities. My PhD thesis has been carried out at the Institut de Physique Nucleaire de Lyon and at the Lawrence Berkeley National Laboratory in the framework of the international cosmological project SNfactory. In order to reach the design spectrophotometric accuracy, attention has been focused on several key aspects of the calibration procedure, including: determination of a dedicated point spread function for 3D point source extraction, estimating the nightly photometric quality, derivation of the nightly sky extinction over the extended optical domain, its modeling in terms of physical components and its variability within a given night. A full multi-standards calibration pipeline has been implemented using approximately 4000 observations of spectrophotometric standard stars taken throughout the night over nearly 500 individual nights. Preliminary scientific results of the whole SNfactory collaboration will be presented at the end of this thesis. (author)

Preparatory studies for the WFIRST supernova cosmology measurements

Science.gov (United States)

Perlmutter, Saul

In the context of the WFIRST-AFTA Science Definition Team we developed a first version of a supernova program, described in the WFIRST-AFTA SDT report. This program uses the imager to discover supernova candidates and an Integral Field Spectrograph (IFS) to obtain spectrophotometric light curves and higher signal to noise spectra of the supernovae near peak to better characterize the supernovae and thus minimize systematic errors. While this program was judged a robust one, and the estimates of the sensitivity to the cosmological parameters were felt to be reliable, due to limitation of time the analysis was clearly limited in depth on a number of issues. The goal of this proposal is to further develop this program and refine the estimates of the sensitivities to the cosmological parameters using more sophisticated systematic uncertainty models and covariance error matrices that fold in more realistic data concerning observed populations of SNe Ia as well as more realistic instrument models. We propose to develop analysis algorithms and approaches that are needed to build, optimize, and refine the WFIRST instrument and program requirements to accomplish the best supernova cosmology measurements possible. We plan to address the following: a) Use realistic Supernova populations, subclasses and population drift. One bothersome uncertainty with the supernova technique is the possibility of population drift with redshift. We are in a unique position to characterize and mitigate such effects using the spectrophotometric time series of real Type Ia supernovae from the Nearby Supernova Factory (SNfactory). Each supernova in this sample has global galaxy measurements as well as additional local environment information derived from the IFS spectroscopy. We plan to develop methods of coping with this issue, e.g., by selecting similar subsamples of supernovae and allowing additional model flexibility, in order to reduce systematic uncertainties. These studies will allow us to

Neutrino astronomy with supernova neutrinos

Science.gov (United States)

Brdar, Vedran; Lindner, Manfred; Xu, Xun-Jie

2018-04-01

Modern neutrino facilities will be able to detect a large number of neutrinos from the next Galactic supernova. We investigate the viability of the triangulation method to locate a core-collapse supernova by employing the neutrino arrival time differences at various detectors. We perform detailed numerical fits in order to determine the uncertainties of these time differences for the cases when the core collapses into a neutron star or a black hole. We provide a global picture by combining all the relevant current and future neutrino detectors. Our findings indicate that in the scenario of a neutron star formation, supernova can be located with precision of 1.5 and 3.5 degrees in declination and right ascension, respectively. For the black hole scenario, sub-degree precision can be reached.

Methodological studies on the search for Gravitational Waves and Neutrinos from Type II Supernovae

International Nuclear Information System (INIS)

Casentini, Claudio

2016-01-01

Type II SNe, also called Core-collapse SuperNovae have a neutrino (v) emission, as confirmed by SN 1987A, and are also potential sources of gravitational waves. Neutrinos and gravitational waves from these sources reach Earth almost contemporaneously and without relevant interaction with stellar matter and interstellar medium. The upcoming advanced gravitational interferometers would be sensitive enough to detect gravitational waves signals from close galactic Core-collapse SuperNovae events. Nevertheless, significant uncertainties on theoretical models of emission remain. A joint search of coincident low energy neutrinos and gravitational waves events from these sources would bring valuable information from the inner core of the collapsing star and would enhance the detection of the so-called Silent SuperNovae. Recently a project for a joint search involving gravitational wave interferometers and neutrino detectors has started. We discuss the benefits of a joint search and the status of the search project. (paper)

VERTICAL STRUCTURE OF A SUPERNOVA-DRIVEN TURBULENT, MAGNETIZED INTERSTELLAR MEDIUM

International Nuclear Information System (INIS)

Hill, Alex S.; Matthew Haffner, L.; Ryan Joung, M.; Mac Low, Mordecai-Mark; Benjamin, Robert A.; Klingenberg, Christian; Waagan, Knut

2012-01-01

Stellar feedback drives the circulation of matter from the disk to the halo of galaxies. We perform three-dimensional magnetohydrodynamic simulations of a vertical column of the interstellar medium with initial conditions typical of the solar circle in which supernovae drive turbulence and determine the vertical stratification of the medium. The simulations were run using a stable, positivity-preserving scheme for ideal MHD implemented in the FLASH code. We find that the majority (≈90%) of the mass is contained in thermally stable temperature regimes of cold molecular and atomic gas at T 4.2 K, with strong peaks in probability distribution functions of temperature in both the cold and warm regimes. The 200-10 4.2 K gas fills 50%-60% of the volume near the plane, with hotter gas associated with supernova remnants (30%-40%) and cold clouds ( 5 K) gas accounts for most of the mass and volume, while hot gas dominates at |z| > 3 kpc. The magnetic field in our models has no significant impact on the scale heights of gas in each temperature regime; the magnetic tension force is approximately equal to and opposite the magnetic pressure, so the addition of the field does not significantly affect the vertical support of the gas. The addition of a magnetic field does reduce the fraction of gas in the cold ( 4 K) gas. However, our models lack rotational shear and thus have no large-scale dynamo, which reduces the role of the field in the models compared to reality. The supernovae drive oscillations in the vertical distribution of halo gas, with the period of the oscillations ranging from ≈30 Myr in the T 6 K gas, in line with predictions by Walters and Cox.

Adiabatic supernova expansion into the circumstellar medium

International Nuclear Information System (INIS)

Band, D.L.; Liang, E.P.

1987-01-01

We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs

Supernovae, dark energy and the accelerating universe

CERN Multimedia

Perlmutter, Saul

1999-01-01

Based on an analysis of 42 high-redshift supernovae discovered by the supernovae cosmology project, we have found evidence for a positive cosmological constant, Lambda, and hence an accelerating universe. In particular, the data are strongly inconsistent with a Lambda=0 flat cosmology, the simplest inflationary universe model. The size of our supernova sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We will discuss results of these and other studies and the ongoing hunt for further loopholes to evade the apparent consequences of the measurements. We will present further work that begins to constrain the alternative physics theories of "dark energy" that have been proposed to explain these results. Finally, we propose a new concept for a definitive supernova measurement of the cosmological parameters.

Initial Hubble Diagram Results from the Nearby Supernova Factory

Energy Technology Data Exchange (ETDEWEB)

Bailey, S. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aldering, G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Antilogus, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aragon, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Baltay, C. [Yale Univ., New Haven, CT (United States); Bongard, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Buton, C [Inst. of Nuclear Physics of Lyon (France); Childress, M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Copin, Y. [Inst. of Nuclear Physics of Lyon (France); Gangler, E. [Inst. of Nuclear Physics of Lyon (France); Loken, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nugent, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pain, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Pecontal, E. [Center of Research Astrophysics of Lyon (CRAL) (France); Pereira, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Perlmutter, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rabinowitz, D. [Yale Univ., New Haven, CT (United States); Rigaudier, G. [Center of Research Astrophysics of Lyon (CRAL) (France); Ripoche, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Runge, K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Scalzo, R. [Yale Univ., New Haven, CT (United States); Smadja, G. [Inst. of Nuclear Physics of Lyon (France); Tao, C. [Inst. of Nuclear Physics of Lyon (France); Thomas, R. C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, C. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France)

2017-07-06

The use of Type Ia supernovae as distance indicators led to the discovery of the accelerating expansion of the universe a decade ago. Now that large second generation surveys have significantly increased the size and quality of the high-redshift sample, the cosmological constraints are limited by the currently available sample of ~50 cosmologically useful nearby supernovae. The Nearby Supernova Factory addresses this problem by discovering nearby supernovae and observing their spectrophotometric time development. Our data sample includes over 2400 spectra from spectral timeseries of 185 supernovae. This talk presents results from a portion of this sample including a Hubble diagram (relative distance vs. redshift) and a description of some analyses using this rich dataset.

HD271791: dynamical versus binary-supernova ejection scenario

Science.gov (United States)

Gvaramadze, V. V.

2009-05-01

The atmosphere of the extremely high-velocity (530-920kms-1) early B-type star HD271791 is enriched in α-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its surface was polluted by the nucleosynthetic products after the primary star exploded in a supernova. It was proposed that the (asymmetric) supernova explosion unbind the system and that the secondary star (HD271791) was released at its orbital velocity in the direction of Galactic rotation. In this Letter, we show that to explain the Galactic rest-frame velocity of HD271791 within the framework of the binary-supernova scenario, the stellar remnant of the supernova explosion (a =750-1200kms-1. We therefore consider the binary-supernova scenario as highly unlikely and instead propose that HD271791 attained its peculiar velocity in the course of a strong dynamical three- or four-body encounter in the dense core of the parent star cluster. Our proposal implies that by the moment of encounter HD271791 was a member of a massive post-supernova binary.

Supernova models

International Nuclear Information System (INIS)

Woosley, S.E.; California, University, Livermore, CA); Weaver, T.A.

1981-01-01

Recent progress in understanding the observed properties of type I supernovae as a consequence of the thermonuclear detonation of white dwarf stars and the ensuing decay of the Ni-56 produced therein is reviewed. The expected nucleosynthesis and gamma-line spectra for this model of type I explosions and a model for type II explosions are presented. Finally, a qualitatively new approach to the problem of massive star death and type II supernovae based upon a combination of rotation and thermonuclear burning is discussed. While the theoretical results of existing models are predicated upon the assumption of a successful core bounce calculation and the neglect of such two-dimensional effects as rotation and magnetic fields the new model suggests an entirely different scenario in which a considerable portion of the energy carried by an equatorially ejected blob is deposited in the red giant envelope overlying the mantle of the star

Asymmetry of the envelope of supernova 1987A

Energy Technology Data Exchange (ETDEWEB)

Papaliolios, C.; Karovska, M.; Koechlin, L.; Nisenson, P.; Standley, C.; Heathcote, S.

1989-04-13

The supernova SN1987A in the Large Magellanic Cloud has been observed by high-angular-resolution speckle interferometry since 25 March (30 days after the explosion) with the 4-m telescope at the Cerro Tololo Interamerican Observatory. Data obtained on 25 March and 2 April 1987 revealed a second bright 'companion' source separated from the supernova by 60 milliarcseconds and less than three magnitudes fainter than the supernova. Measurements of the average diameter of the supernova envelope have been made from data recorded from March 1987 to April 1988. Here we present a more detailed analysis of these data, which shows that the expanding envelope is asymmetric. (author).

Asymmetry of the envelope of supernova 1987A

International Nuclear Information System (INIS)

Papaliolios, C.; Karovska, M.; Koechlin, L.; Nisenson, P.; Standley, C.; Heathcote, S.

1989-01-01

The supernova SN1987A in the Large Magellanic Cloud has been observed by high-angular-resolution speckle interferometry since 25 March (30 days after the explosion) with the 4-m telescope at the Cerro Tololo Interamerican Observatory. Data obtained on 25 March and 2 April 1987 revealed a second bright 'companion' source separated from the supernova by 60 milliarcseconds and less than three magnitudes fainter than the supernova. Measurements of the average diameter of the supernova envelope have been made from data recorded from March 1987 to April 1988. Here we present a more detailed analysis of these data, which shows that the expanding envelope is asymmetric. (author)

Supernova Remnants with Fermi Large Area Telescope

Directory of Open Access Journals (Sweden)

Caragiulo M.

2017-01-01

Full Text Available The Large Area Telescope (LAT, on-board the Fermi satellite, proved to be, after 8 years of data taking, an excellent instrument to detect and observe Supernova Remnants (SNRs in a range of energies running from few hundred MeV up to few hundred GeV. It provides essential information on physical processes that occur at the source, involving both accelerated leptons and hadrons, in order to understand the mechanisms responsible for the primary Cosmic Ray (CR acceleration. We show the latest results in the observation of Galactic SNRs by Fermi-LAT.

Nonstandard neutrino interactions in supernovae

Science.gov (United States)

Stapleford, Charles J.; Väänänen, Daavid J.; Kneller, James P.; McLaughlin, Gail C.; Shapiro, Brandon T.

2016-11-01

Nonstandard interactions (NSI) of neutrinos with matter can significantly alter neutrino flavor evolution in supernovae with the potential to impact explosion dynamics, nucleosynthesis, and the neutrinos signal. In this paper, we explore, both numerically and analytically, the landscape of neutrino flavor transformation effects in supernovae due to NSI and find a new, heretofore unseen transformation processes can occur. These new transformations can take place with NSI strengths well below current experimental limits. Within a broad swath of NSI parameter space, we observe symmetric and standard matter-neutrino resonances for supernovae neutrinos, a transformation effect previously only seen in compact object merger scenarios; in another region of the parameter space we find the NSI can induce neutrino collective effects in scenarios where none would appear with only the standard case of neutrino oscillation physics; and in a third region the NSI can lead to the disappearance of the high density Mikheyev-Smirnov-Wolfenstein resonance. Using a variety of analytical tools, we are able to describe quantitatively the numerical results allowing us to partition the NSI parameter according to the transformation processes observed. Our results indicate nonstandard interactions of supernova neutrinos provide a sensitive probe of beyond the Standard Model physics complementary to present and future terrestrial experiments.

Neutrino flavor instabilities in a time-dependent supernova model

Energy Technology Data Exchange (ETDEWEB)

Abbar, Sajad; Duan, Huaiyu, E-mail: duan@unm.edu

2015-12-17

A dense neutrino medium such as that inside a core-collapse supernova can experience collective flavor conversion or oscillations because of the neutral-current weak interaction among the neutrinos. This phenomenon has been studied in a restricted, stationary supernova model which possesses the (spatial) spherical symmetry about the center of the supernova and the (directional) axial symmetry around the radial direction. Recently it has been shown that these spatial and directional symmetries can be broken spontaneously by collective neutrino oscillations. In this letter we analyze the neutrino flavor instabilities in a time-dependent supernova model. Our results show that collective neutrino oscillations start at approximately the same radius in both the stationary and time-dependent supernova models unless there exist very rapid variations in local physical conditions on timescales of a few microseconds or shorter. Our results also suggest that collective neutrino oscillations can vary rapidly with time in the regimes where they do occur which need to be studied in time-dependent supernova models.

First-Year Spectroscopy for the SDSS-II Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Zheng, Chen; Romani, Roger W.; Sako, Masao; Marriner, John; Bassett, Bruce; Becker, Andrew; Choi, Changsu; Cinabro, David; DeJongh, Fritz; Depoy, Darren L.; Dilday, Ben; Doi, Mamoru; Frieman, Joshua A.; Garnavich, Peter M.; Hogan, Craig J.; Holtzman, Jon; Im, Myungshin; Jha, Saurabh; Kessler, Richard; Konishi, Kohki; Lampeitl, Hubert

2008-03-25

This paper presents spectroscopy of supernovae discovered in the first season of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for and measures multi-band light curves of supernovae in the redshift range z = 0.05-0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the supernova population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our supernova spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the supernova and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host galaxy contamination existing in the majority of our SN spectra.

The Carnegie Supernova Project I. Photometry data release of low-redshift stripped-envelope supernovae

Science.gov (United States)

Stritzinger, M. D.; Anderson, J. P.; Contreras, C.; Heinrich-Josties, E.; Morrell, N.; Phillips, M. M.; Anais, J.; Boldt, L.; Busta, L.; Burns, C. R.; Campillay, A.; Corco, C.; Castellon, S.; Folatelli, G.; González, C.; Holmbo, S.; Hsiao, E. Y.; Krzeminski, W.; Salgado, F.; Serón, J.; Torres-Robledo, S.; Freedman, W. L.; Hamuy, M.; Krisciunas, K.; Madore, B. F.; Persson, S. E.; Roth, M.; Suntzeff, N. B.; Taddia, F.; Li, W.; Filippenko, A. V.

2018-02-01

The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction and the light-curve and progenitor star properties of the sample. The analysis of an accompanying visual-wavelength spectroscopy sample of 150 spectra will be the subject of a future paper. Based on observations collected at Las Campanas Observatory.Tables 2-8 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A134

Supernovae anisotropy power spectrum

Energy Technology Data Exchange (ETDEWEB)

Ghodsi, Hoda; Baghram, Shant [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Habibi, Farhang, E-mail: h.ghodsi@mehr.sharif.ir, E-mail: baghram@sharif.edu, E-mail: habibi@lal.in2p3.fr [LAL-IN2P3/CNRS, BP 34, 91898 Orsay Cedex (France)

2017-10-01

We contribute another anisotropy study to this field of research using Type Ia supernovae (SNe Ia). In this work, we utilise the power spectrum calculation method and apply it to both the current SNe Ia data and simulation. Using the Union2.1 data set at all redshifts, we compare the spectrum of the residuals of the observed distance moduli to that expected from an isotropic universe affected by the Union2.1 observational uncertainties at low multipoles. Through this comparison we find a dipolar anisotropy with tension of less that 2σ towards l = 171° ± 21° and b = −26° ± 28° which is mainly induced by anisotropic spatial distribution of the SNe with z > 0.2 rather than being a cosmic effect. Furthermore, we find a tension of ∼ 4σ at ℓ = 4 between the two spectra. Our simulations are constructed with the characteristics of the upcoming surveys like the Large Synoptic Survey Telescope (LSST), which shall bring us the largest SNe Ia collection to date. We make predictions for the amplitude of a possible dipolar anisotropy that would be detectable by future SNe Ia surveys.

PULSATING REVERSE DETONATION MODELS OF TYPE Ia SUPERNOVAE. II. EXPLOSION

International Nuclear Information System (INIS)

Bravo, Eduardo; Garcia-Senz, Domingo; Cabezon, Ruben M.; DomInguez, Inmaculada

2009-01-01

Observational evidences point to a common explosion mechanism of Type Ia supernovae based on a delayed detonation of a white dwarf (WD). However, all attempts to find a convincing ignition mechanism based on a delayed detonation in a destabilized, expanding, white dwarf have been elusive so far. One of the possibilities that has been invoked is that an inefficient deflagration leads to pulsation of a Chandrasekhar-mass WD, followed by formation of an accretion shock that confines a carbon-oxygen rich core, while transforming the kinetic energy of the collapsing halo into thermal energy of the core, until an inward moving detonation is formed. This chain of events has been termed Pulsating Reverse Detonation (PRD). In this work, we present three-dimensional numerical simulations of PRD models from the time of detonation initiation up to homologous expansion. Different models characterized by the amount of mass burned during the deflagration phase, M defl , give explosions spanning a range of kinetic energies, K ∼ (1.0-1.2) x 10 51 erg, and 56 Ni masses, M( 56 Ni) ∼ 0.6-0.8 M sun , which are compatible with what is expected for typical Type Ia supernovae. Spectra and light curves of angle-averaged spherically symmetric versions of the PRD models are discussed. Type Ia supernova spectra pose the most stringent requirements on PRD models.

Supernovae-generated high-velocity compact clouds

Science.gov (United States)

Yalinewich, A.; Beniamini, P.

2018-05-01

Context. A previous study claimed the discovery of an intermediate-mass black hole (IMBH). This hypothetical black hole was invoked in order to explain the high-velocity dispersion in one of several dense molecular clouds near the Galactic center. The same study considered the possibility that this cloud was due to a supernova explosion, but disqualified this scenario because no X-rays were detected. Aims: We here check whether a supernova explosion could have produced that cloud, and whether this explanation is more likely than an IMBH. More specifically, we wish to determine whether a supernova inside a dense molecular cloud would emit in the X-rays. Methods: We have approached this problem from two different directions. First, we performed an analytic calculation to determine the cooling rate by thermal bremsstrahlung and compared this time to the lifetime of the cloud. Second, we estimated the creation rate of these dense clouds in the central molecular zone (CMZ) region near the Galactic center, where they were observed. Based on this rate, we can place lower bounds on the total mass of IMBHs and clouds and compare this to the masses of the components of the CMZ. Results: We find that the cooling time of the supernova remnant inside a molecular cloud is shorter than its dynamical time. This means that the temperature in such a remnant would be much lower than that of a typical supernova remnant. At such a low temperature, the remnant is not expected to emit in the X-rays. We also find that to explain the rate at which such dense clouds are created requires fine-tuning the number of IMBHs. Conclusions: We find the supernova model to be a more likely explanation for the formation of high-velocity compact clouds than an IMBH.

Acquiring information about neutrino parameters by detecting supernova neutrinos

Science.gov (United States)

Huang, Ming-Yang; Guo, Xin-Heng; Young, Bing-Lin

2010-08-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle θ13, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about θ13 and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.

Radiative transfer in type I supernovae atmospheres

International Nuclear Information System (INIS)

Isern, J.; Lopez, R.; Simonneau, E.

1987-01-01

Type I Supernovae are thought to be the result of the thermonuclear explosion of a carbon oxygen white dwarf in a close binary system. As the only direct information concerning the physics and the triggering mechanism of supernova explosions comes from the spectrophotometry of the emitted radiation, it is worthwhile to put considerable effort on the understanding of the radiation transfer in the supernovae envelopes in order to set constraints on the theoretical models of such explosions. In this paper we analyze the role played by the layers curvature on the radiative transfer. (Author)

UBVRIz LIGHT CURVES OF 51 TYPE II SUPERNOVAE

International Nuclear Information System (INIS)

Galbany, Lluis; Hamuy, Mario; Jaeger, Thomas de; Moraga, Tania; González-Gaitán, Santiago; Gutiérrez, Claudia P.; Phillips, Mark M.; Morrell, Nidia I.; Thomas-Osip, Joanna; Suntzeff, Nicholas B.; Maza, José; González, Luis; Antezana, Roberto; Wishnjewski, Marina; Krisciunas, Kevin; Krzeminski, Wojtek; McCarthy, Patrick; Anderson, Joseph P.; Stritzinger, Maximilian; Folatelli, Gastón

2016-01-01

We present a compilation of UBVRIz light curves of 51 type II supernovae discovered during the course of four different surveys during 1986–2003: the Cerro Tololo Supernova Survey, the Calán/Tololo Supernova Program (C and T), the Supernova Optical and Infrared Survey (SOIRS), and the Carnegie Type II Supernova Survey (CATS). The photometry is based on template-subtracted images to eliminate any potential host galaxy light contamination, and calibrated from foreground stars. This work presents these photometric data, studies the color evolution using different bands, and explores the relation between the magnitude at maximum brightness and the brightness decline parameter (s) from maximum light through the end of the recombination phase. This parameter is found to be shallower for redder bands and appears to have the best correlation in the B band. In addition, it also correlates with the plateau duration, being shorter (longer) for larger (smaller) s values

UBVRIz LIGHT CURVES OF 51 TYPE II SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Galbany, Lluis; Hamuy, Mario; Jaeger, Thomas de; Moraga, Tania; González-Gaitán, Santiago; Gutiérrez, Claudia P. [Millennium Institute of Astrophysics, Universidad de Chile (Chile); Phillips, Mark M.; Morrell, Nidia I.; Thomas-Osip, Joanna [Carnegie Observatories, Las Campanas Observatory, Casilla 60, La Serena (Chile); Suntzeff, Nicholas B. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Maza, José; González, Luis; Antezana, Roberto; Wishnjewski, Marina [Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile); Krisciunas, Kevin [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Krzeminski, Wojtek [N. Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warszawa (Poland); McCarthy, Patrick [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Anderson, Joseph P. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago (Chile); Stritzinger, Maximilian [Department of Physics and Astronomy, Aarhus University (Denmark); Folatelli, Gastón, E-mail: lgalbany@das.uchile.cl [Instituto de Astrofísica de La Plata (IALP, CONICET) (Argentina); and others

2016-02-15

We present a compilation of UBVRIz light curves of 51 type II supernovae discovered during the course of four different surveys during 1986–2003: the Cerro Tololo Supernova Survey, the Calán/Tololo Supernova Program (C and T), the Supernova Optical and Infrared Survey (SOIRS), and the Carnegie Type II Supernova Survey (CATS). The photometry is based on template-subtracted images to eliminate any potential host galaxy light contamination, and calibrated from foreground stars. This work presents these photometric data, studies the color evolution using different bands, and explores the relation between the magnitude at maximum brightness and the brightness decline parameter (s) from maximum light through the end of the recombination phase. This parameter is found to be shallower for redder bands and appears to have the best correlation in the B band. In addition, it also correlates with the plateau duration, being shorter (longer) for larger (smaller) s values.

Time evolution of gamma rays from supernova remnants

Science.gov (United States)

Gaggero, Daniele; Zandanel, Fabio; Cristofari, Pierre; Gabici, Stefano

2018-04-01

We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.

Neutrino Flavor Evolution in Turbulent Supernova Matter

Science.gov (United States)

Lund, Tina; Kneller, James P.

In order to decode the neutrino burst signal from a Galactic core-collapse supernova and reveal the complicated inner workings of the explosion, we need a thorough understanding of the neutrino flavor evolution from the proto-neutron-star outwards. The flavor content of the signal evolves due to both neutrino collective effects and matter effects which can lead to a highly interesting interplay and distinctive spectral features. In this paper we investigate the supernova neutrino flavor evolution by including collective flavor effects, the evolution of the Mikheyev, Smirnov & Wolfenstein (MSW) matter conversions due to the shock wave passing through the star, and the impact of turbulence. The density profiles utilized in our calculations represent a 10.8 MG progenitor and comes from a 1D numerical simulation by Fischer et al.[1]. We find that small amplitude turbulence, up to 10% of the average potential, leads to a minimal modification of the signal, and the emerging neutrino spectra retain both collective and MSW features. However, when larger amounts of turbulence are added, 30% and 50%, the features of collective and shock wave effects in the high density resonance channel are almost completely obscured at late times. At the same time we find the other mixing channels - the low density resonance channel and the non-resonant channels - begin to develop turbulence signatures. Large amplitude turbulent motions in the outer layers of massive, iron core-collapse supernovae may obscure the most obvious fingerprints of collective and shock wave effects in the neutrino signal but cannot remove them completely, and additionally bring about new features in the signal. We illustrate how the progression of the shock wave is reflected in the changing survival probabilities over time, and we show preliminary results on how some of these collective and shock wave induced signatures appear in a detector signal.

Exploring Cosmology with Supernovae

DEFF Research Database (Denmark)

Li, Xue

distribution of strong gravitational lensing is developed. For Type Ia supernova (SNe Ia), the rate is lower than core-collapse supernovae (CC SNe). The rate of SNe Ia declines beyond z 1:5. Based on these reasons, we investigate a potential candidate to measure cosmological distance: GRB......-SNe. They are a subclass of CC SNe. Light curves of GRB-SNe are obtained and their properties are studied. We ascertain that the properties of GRB-SNe make them another candidate for standardizable candles in measuring the cosmic distance. Cosmological parameters M and are constrained with the help of GRB-SNe. The first...

Type I supernova models

International Nuclear Information System (INIS)

Canal, Ramon; Labay, Javier; Isern, Jordi

1987-01-01

We briefly describe the characteristics of Type I supernova outbursts and we present the theoretical models so far advanced to explain them. We especially insist on models based on the thermonuclear explosion of a white dwarf in a close binary system, even regarding the recent division of Type I supernovae into the Ia and Ib subtypes. Together with models assuming explosive thermonuclear burning in a fluid interior, we consider in some detail those based on partially solid interiors. We finally discuss models that incorporate nonthermonuclear energy contributions, suggested in order to explain Type Ib outbursts. (Author)

Gravitational lensing of the SNLS supernovae

International Nuclear Information System (INIS)

Kronborg, T.

2011-01-01

Type Ia supernovae have become an essential tool of modern observational cosmology. By studying the distance-redshift relation of a large number of supernovae, the nature of dark energy can be unveiled. Distances to Type Ia SNe are however affected by gravitational lensing which can induce systematic effects in the measurement of cosmology. The majority of the supernovae is slightly de-magnified whereas a small fraction is significantly magnified due to the mass distribution along the line of sight. This causes naturally an additional dispersion in the observed magnitudes. There are two different ways to estimate the magnification of a supernova. A first method consists in comparing the supernova luminosity, which is measured to about 15% precision, to the mean SN luminosity at the same redshift. Another estimate can be obtained from predicting the magnification induced by the foreground matter density modeled from the measurements of the luminosity of the galaxies with an initial prior on the mass-luminosity relation of the galaxies. A correlation between these 2 estimates will make it possible to tune the initially used mass-luminosity relation resulting in an independent measurement of the dark matter clustering based on the luminosity of SNe Ia. Evidently, this measurement depends crucially on the detection of this correlation also referred to as the lensing signal. This thesis is dedicated to the measurement of the lensing signal in the SNLS 3-year sample. (author)

Simulating pasta phases by molecular dynamics and cold atoms. Formation in supernovae and superfluid neutrons in neutron stars

International Nuclear Information System (INIS)

Watanabe, Gentaro

2010-01-01

In dense stars such as collapsing cores of supernovae and neutron stars, nuclear 'pasta' such as rod-like and slab-like nuclei are speculated to exist. However, whether or not they are actually formed in supernova cores is still unclear. Here we solve this problem by demonstrating that a lattice of rod-like nuclei is formed from a bcc lattice by compression. We also find that the formation process is triggered by an attractive force between nearest neighbor nuclei, which starts to act when their density profile overlaps, rather than the fission instability. We also discuss the connection between pasta phases in neutron star crusts and ultracold Fermi gases. (author)

Characterizing Dark Energy Through Supernovae

Science.gov (United States)

Davis, Tamara M.; Parkinson, David

Type Ia supernovae are a powerful cosmological probe that gave the first strong evidence that the expansion of the universe is accelerating. Here we provide an overview of how supernovae can go further to reveal information about what is causing the acceleration, be it dark energy or some modification to our laws of gravity. We first review the methods of statistical inference that are commonly used, making a point of separating parameter estimation from model selection. We then summarize the many different approaches used to explain or test the acceleration, including parametric models (like the standard model, ΛCDM), nonparametric models, dark fluid models such as quintessence, and extensions to standard gravity. Finally, we also show how supernova data can be used beyond the Hubble diagram, to give information on gravitational lensing and peculiar velocities that can be used to distinguish between models that predict the same expansion history.

Radioactive Iron Rain: Evidence of a Nearby Supernova Explosion

CERN Multimedia

CERN. Geneva

2016-01-01

A very close supernova explosion could have caused a mass extinction of life in Earth. In 1996, Brian Fields, the late Dave Schramm and the speaker proposed looking for unstable isotopes such as Iron 60 that could have been deposited by a recent nearby supernova explosion. A group from the Technical University of Munich has discovered Iron 60 in deep-ocean sediments and ferromanganese crusts due to one or more supernovae that exploded O(100) parsecs away about 2.5 million years ago. These results have recently been confirmed by a group from the Australian National University, and the Munich group has also discovered supernova Iron 60 in lunar rock samples. This talk will discuss the interpretation of these results in terms of supernova models, and the possible implications for life on Earth.

Density fluctuation effects on collective neutrino oscillations in O-Ne-Mg core-collapse supernovae

International Nuclear Information System (INIS)

Cherry, John F.; Fuller, George M.; Wu Mengru; Qian Yongzhong; Carlson, J.; Duan Huaiyu

2011-01-01

We investigate the effect of matter density fluctuations on supernova collective neutrino flavor oscillations. In particular, we use full multiangle, three-flavor, self-consistent simulations of the evolution of the neutrino flavor field in the envelope of an O-Ne-Mg core-collapse supernova at shock breakout (neutronization neutrino burst) to study the effect of the matter density ''bump'' left by the He-burning shell. We find a seemingly counterintuitive increase in the overall ν e survival probability created by this matter density feature. We discuss this behavior in terms of the interplay between the matter density profile and neutrino collective effects. While our results give new insights into this interplay, they also suggest an immediate consequence for supernova neutrino burst detection: it will be difficult to use a burst signal to extract information on fossil burning shells or other fluctuations of this scale in the matter density profile. Consistent with previous studies, our results also show that the interplay of neutrino self-coupling and matter fluctuation could cause a significant increase in the ν e survival probability at very low energy.

The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

International Nuclear Information System (INIS)

Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F.; Stritzinger, Maximilian; Contreras, Carlos; Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castellón, Sergio; Morrell, Nidia; Salgado, Francisco; Folatelli, Gaston; Suntzeff, Nicholas B.

2014-01-01

We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B – V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R V , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R V , and the color excess, E(B – V), such that larger E(B – V) tends to favor lower R V . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R V or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

Neutrino flavor instabilities in a time-dependent supernova model

Directory of Open Access Journals (Sweden)

Sajad Abbar

2015-12-01

Full Text Available A dense neutrino medium such as that inside a core-collapse supernova can experience collective flavor conversion or oscillations because of the neutral-current weak interaction among the neutrinos. This phenomenon has been studied in a restricted, stationary supernova model which possesses the (spatial spherical symmetry about the center of the supernova and the (directional axial symmetry around the radial direction. Recently it has been shown that these spatial and directional symmetries can be broken spontaneously by collective neutrino oscillations. In this letter we analyze the neutrino flavor instabilities in a time-dependent supernova model. Our results show that collective neutrino oscillations start at approximately the same radius in both the stationary and time-dependent supernova models unless there exist very rapid variations in local physical conditions on timescales of a few microseconds or shorter. Our results also suggest that collective neutrino oscillations can vary rapidly with time in the regimes where they do occur which need to be studied in time-dependent supernova models.

Deep Recurrent Neural Networks for Supernovae Classification

Science.gov (United States)

Charnock, Tom; Moss, Adam

2017-03-01

We apply deep recurrent neural networks, which are capable of learning complex sequential information, to classify supernovae (code available at https://github.com/adammoss/supernovae). The observational time and filter fluxes are used as inputs to the network, but since the inputs are agnostic, additional data such as host galaxy information can also be included. Using the Supernovae Photometric Classification Challenge (SPCC) data, we find that deep networks are capable of learning about light curves, however the performance of the network is highly sensitive to the amount of training data. For a training size of 50% of the representational SPCC data set (around 104 supernovae) we obtain a type-Ia versus non-type-Ia classification accuracy of 94.7%, an area under the Receiver Operating Characteristic curve AUC of 0.986 and an SPCC figure-of-merit F 1 = 0.64. When using only the data for the early-epoch challenge defined by the SPCC, we achieve a classification accuracy of 93.1%, AUC of 0.977, and F 1 = 0.58, results almost as good as with the whole light curve. By employing bidirectional neural networks, we can acquire impressive classification results between supernovae types I, II and III at an accuracy of 90.4% and AUC of 0.974. We also apply a pre-trained model to obtain classification probabilities as a function of time and show that it can give early indications of supernovae type. Our method is competitive with existing algorithms and has applications for future large-scale photometric surveys.

Supernova neutrinos and explosive nucleosynthesis

Science.gov (United States)

Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Mathews, G. J.; Nakamura, K.; Shibagaki, S.; Suzuki, T.

2014-05-01

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes 7Li, 11B, 92Nb, 138La and 180Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ13, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements 11B and 7Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ13, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Supernova neutrinos and explosive nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-05-09

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Recent Hubble Space Telescope Imaging of the Light Echoes of Supernova 2014J in M 82 and Supernova 2016adj in Centaurus A

Science.gov (United States)

Lawrence, Stephen S.; Hyder, Ali; Sugerman, Ben; Crotts, Arlin P. S.

2017-06-01

We report on our ongoing use of Hubble Space Telescope (HST) imaging to monitor the scattered light echoes of recent heavily-extincted supernovae in two nearby, albeit unusual, galaxies.Supernova 2014J was a highly-reddened Type Ia supernova that erupted in the nearby irregular star-forming galaxy M 82 in 2014 January. It was discovered to have light echo by Crotts (2016) in early epoch HST imaging and has been further described by Yang, et al. (2017) based on HST imaging through late 2014. Our ongoing monitoring in the WFC3 F438W, F555W, and F814W filters shows that, consistent with Crotts (2106) and Yang, et al. (2017), throughout 2015 and 2016 the main light echo arc expanded through a dust complex located approximately 230 pc in the foreground of the supernova. This main light echo has, however, faded dramatically in our most recent HST imaging from 2017 March. The supernova itself has also faded to undetectable levels by 2017 March.Supernova 2016adj is a highly-reddened core-collapse supernova that erupted inside the unusual dust lane of the nearby giant elliptical galaxy Centaurus A (NGC 5128) in 2016 February. It was discovered to have a light echo by Sugerman & Lawrence (2016) in early epoch HST imaging in 2016 April. Our ongoing monitoring in the WFC3 F438W, F547M, and F814W filters shows a slightly elliptical series of light echo arc segments hosted by a tilted dust complex ranging approximately 150--225 pc in the foreground of the supernova. The supernova itself has also faded to undetectable levels by 2017 April.References: Crotts, A. P. S., ApJL, 804, L37 (2016); Yang et al., ApJ, 834, 60 (2017); Sugerman, B. and Lawrence, S., ATel #8890 (2016).

HOW TO FIND GRAVITATIONALLY LENSED TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Goldstein, Daniel A.; Nugent, Peter E.

2017-01-01

Type Ia supernovae (SNe Ia) that are multiply imaged by gravitational lensing can extend the SN Ia Hubble diagram to very high redshifts ( z ≳ 2), probe potential SN Ia evolution, and deliver high-precision constraints on H _0, w , and Ω_m via time delays. However, only one, iPTF16geu, has been found to date, and many more are needed to achieve these goals. To increase the multiply imaged SN Ia discovery rate, we present a simple algorithm for identifying gravitationally lensed SN Ia candidates in cadenced, wide-field optical imaging surveys. The technique is to look for supernovae that appear to be hosted by elliptical galaxies, but that have absolute magnitudes implied by the apparent hosts’ photometric redshifts that are far brighter than the absolute magnitudes of normal SNe Ia (the brightest type of supernovae found in elliptical galaxies). Importantly, this purely photometric method does not require the ability to resolve the lensed images for discovery. Active galactic nuclei, the primary sources of contamination that affect the method, can be controlled using catalog cross-matches and color cuts. Highly magnified core-collapse SNe will also be discovered as a byproduct of the method. Using a Monte Carlo simulation, we forecast that the Large Synoptic Survey Telescope can discover up to 500 multiply imaged SNe Ia using this technique in a 10 year z -band search, more than an order of magnitude improvement over previous estimates. We also predict that the Zwicky Transient Facility should find up to 10 multiply imaged SNe Ia using this technique in a 3 year R -band search—despite the fact that this survey will not resolve a single system.

Variable interstellar radiation fields in simulated dwarf galaxies: supernovae versus photoelectric heating

Science.gov (United States)

Hu, Chia-Yu; Naab, Thorsten; Glover, Simon C. O.; Walch, Stefanie; Clark, Paul C.

2017-10-01

We present high-resolution hydrodynamical simulations of isolated dwarf galaxies including self-gravity, non-equilibrium cooling and chemistry, interstellar radiation fields (ISRF) and shielding, star formation, and stellar feedback. This includes spatially and temporally varying photoelectric (PE) heating, photoionization, resolved supernova (SN) blast waves and metal enrichment. A new flexible method to sample the stellar initial mass function allows us to follow the contribution to the ISRF, the metal output and the SN delay times of individual massive stars. We find that SNe play the dominant role in regulating the global star formation rate, shaping the multiphase interstellar medium (ISM) and driving galactic outflows. Outflow rates (with mass-loading factors of a few) and hot gas fractions of the ISM increase with the number of SNe exploding in low-density environments where radiative energy losses are low. While PE heating alone can suppress star formation as efficiently as SNe alone can do, it is unable to drive outflows and reproduce the multiphase ISM that emerges naturally whenever SNe are included. We discuss the potential origins for the discrepancy between our results and another recent study that claimed that PE heating dominates over SNe. In the absence of SNe and photoionization (mechanisms to disperse dense clouds), the impact of PE heating is highly overestimated owing to the (unrealistic) proximity of dense gas to the radiation sources. This leads to a substantial boost of the infrared continuum emission from the UV-irradiated dust and a far-infrared line-to-continuum ratio too low compared to observations.

New approaches for modeling type Ia supernovae

International Nuclear Information System (INIS)

Zingale, Michael; Almgren, Ann S.; Bell, John B.; Day, Marcus S.; Rendleman, Charles A.; Woosley, Stan

2007-01-01

Type Ia supernovae (SNe Ia) are the largest thermonuclear explosions in the Universe. Their light output can be seen across great distances and has led to the discovery that the expansion rate of the Universe is accelerating. Despite the significance of SNe Ia, there are still a large number of uncertainties in current theoretical models. Computational modeling offers the promise to help answer the outstanding questions. However, even with today's supercomputers, such calculations are extremely challenging because of the wide range of length and timescales. In this paper, we discuss several new algorithms for simulations of SNe Ia and demonstrate some of their successes

STRESS Counting Supernovae

Science.gov (United States)

Botticella, M. T.; Cappellaro, E.; Riello, M.; Greggio, L.; Benetti, S.; Patat, F.; Turatto, M.; Altavilla, G.; Pastorello, A.; Valenti, S.; Zampieri, L.; Harutyunyan, A.; Pignata, G.; Taubenberger, S.

2008-12-01

The rate of occurrence of supernovae (SNe) is linked to some of the basic ingredients of galaxy evolution, such as the star formation rate, the chemical enrichment and feedback processes. SN rates at intermediate redshift and their dependence on specific galaxy properties have been investigated in the Southern inTermediate Redshift ESO Supernova Search (STRESS). The rate of core collapse SNe (CC SNe) at a redshift of around 0.25 is found to be a factor two higher than the local value, whereas the SNe Ia rate remains almost constant. SN rates in red and blue galaxies were also measured and it was found that the SNe Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe.

Research in astrophysics: Stellar collapse and supernovae: Termination report, August 1, 1980-November 30, 1986

International Nuclear Information System (INIS)

Burrows, A.; Lattimer, J.M.; Mazurek, T.J.; Yahil, A.

1987-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics has been examined. The chief emphasis of the program was on stellar collapse, Type II supernovae and neutron star formation. Central to these topics are the development of an equation of state of hot, dense matter and numerical simulations of gravitational collapse and neutron star birth. The LLPR compressible liquid drop model is the basis of the former. It has been refined to include curvature corrections to the surface energy and nuclear force parameters which are in better agreement with experimental quantities. Numerically optimized versions were used in supernova simulations. Such studies of the equation of state can also be used to analyze intermediate energy heavy ion collisions, which, in turn, may illuminate the nucleon-nucleon force. A novel hydrodynamical code in which shocks are treated via Riemann resolution rather than with artificial viscosity was developed. We modeled not only the stellar collapse leading up to a supernova, but also the quasi-static deleptonization and cooling of the nascent neutron star. For the latter evolution we also used a hydrostatic code with detailed neutrino transport. Our studies of neutrinos in stellar collapse and neutron star formation concentrated on their detectability and signatures, as neutrinos are the only direct probe of collapse and early supernova dynamics. The neutrino signatures seen from SN1987a are in complete accord with the predictions our group has been making since 1982. Complementary studies included modeling nucleosynthesis and the accretion process in quasars, and investigating the influence of galaxy clustering on the large scale structure of the universe. The last study might impose constraints on high energy theories, such as those of inflation and GUT, which can now only be tested astrophysically. 38 refs

Geological isotope anomalies as signatures of nearby supernovae

CERN Document Server

Ellis, Jonathan Richard; Schramm, David N; Ellis, John; Fields, Brian D; Schramm, David N

1996-01-01

Nearby supernova explosions may cause geological isotope anomalies via the direct deposition of debris or by cosmic-ray spallation in the earth's atmosphere. We estimate the mass of material deposited terrestrially by these two mechanisms, showing the dependence on the supernova distance. A number of radioactive isotopes are identified as possible diagnostic tools, such as Be-10, Al-26, Cl-36, Mn-53, Fe-60, and Ni-59, as well as the longer-lived I-129, Sm-146, and Pu-244. We discuss whether the 35 and 60 kyr-old Be-10 anomalies observed in the Vostok antarctic ice cores could be due to supernova explosions. Combining our estimates for matter deposition with results of recent nucleosynthesis yields, we calculate the expected signal from nearby supernovae using ice cores back to \\sim 300 kyr ago, and we discuss using deep ocean sediments back to several hundred Myr. In particular, we examine the prospects for identifying isotope anomalies due to the Geminga supernova explosion, and signatures of the possibility...

GRAVITATIONAL FIELD SHIELDING AND SUPERNOVA EXPLOSIONS

International Nuclear Information System (INIS)

Zhang, T. X.

2010-01-01

A new mechanism for supernova explosions called gravitational field shielding is proposed, in accord with a five-dimensional fully covariant Kaluza-Klein theory with a scalar field that unifies the four-dimensional Einsteinian general relativity and Maxwellian electromagnetic theory. It is shown that a dense compact collapsing core of a star will suddenly turn off or completely shield its gravitational field when the core collapses to a critical density, which is inversely proportional to the square of mass of the core. As the core suddenly turns off its gravity, the extremely large pressure immediately stops the core collapse and pushes the mantle material of supernova moving outward. The work done by the pressure in the expansion can be the order of energy released in a supernova explosion. The gravity will resume and stop the core from a further expansion when the core density becomes less than the critical density. Therefore, the gravitational field shielding leads a supernova to impulsively explode and form a compact object such as a neutron star as a remnant. It works such that a compressed spring will shoot the oscillator out when the compressed force is suddenly removed.

Particle acceleration and nonthermal radiation in supernova remnants

International Nuclear Information System (INIS)

Zirakashvili, Vladimir

2013-01-01

Cosmic ray acceleration and magnetic amplification in shell-type supernova remnants is shortly reviewed. The results on the modeling of broadband electromagnetic emission from supernova remnants are presented and compared with observations.

GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

Directory of Open Access Journals (Sweden)

Manami Sasaki

2013-12-01

Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

Resonant Spin-Flavor Conversion of Supernova Neutrinos

Science.gov (United States)

Ando, Shin'ichiro; Sato, K.

2003-07-01

We investigate resonant spin-flavor (RSF) conversions of supernova neutrinos which are induced by the interaction of neutrino magnetic moment and supernova magnetic fields. With a new diagram we propose, it is found that four conversions occur in supernovae, two are induced by the RSF effect and two by the pure Mikheyev-Smirnov-Wolfenstein (MSW) effect. The realistic numerical calculation of neutrino conversions indicates that the RSF-induced νe ↔ ντ tran¯ -12 9 -1 sition occurs efficiently, when µν > 10 µB (B0 /5 × 10 G) , where B0 is the strength of the magnetic field at the surface of iron core. We also evaluate the energy spectrum as a function of µν B0 at the super-Kamiokande detector using the calculated conversion probabilities, and find that the spectral deformation might have possibility to provide useful information on the neutrino magnetic moment as well as the magnetic field strength in supernovae.

Supernova 1987A: 18 Months later

International Nuclear Information System (INIS)

Schramm, D.N.

1989-01-01

An overview of the significance for physics of the closest visual supernova in almost 400 years is presented. The supernova occurred in the Large Magellanic Cloud (LMC), /approximately/50 kpc away. The supernova star was a massive star of /approximately/15--20M. Observations now show that it was once a red-giant but lost its outer envelope. The lower than standard luminosity and higher observed velocities are a natural consequence of the pre-supernova star being a blue rather than a red [supergiant]. Of particular importance to physicists is the detection of neutrinos from the event by detectors in the United States and Japan. Not only did this establish extra-solar system neutrino astronomy, but it also constrained the properties of neutrino. It is shown that the well established Kamioka-IMB neutrino burst experimentally implies an event with about 2--4 /times/ 10/sup 53/ergs emitted in neutrinos and a temperature, T/sub /bar /nu/e//, of between 4 and 4.5 MeV. This event is in excellent agreement with what one would expect from the gravitational core collapse of a massive star. A neutrino detection, such as that reported earlier in Mt. Blanc, would require more than the rest mass energy of a neutron star to be converted to neutrinos, if it were to have its origin in the LMC. Thus it is probably unrelated to the supernova. The anticipated frequency of collapse events in our Galaxy, will also be discussed with a rate as high as 1/10 year shown to be not unreasonable. 61 refs

Progenitor's Signatures in Type Ia Supernova Remnants

NARCIS (Netherlands)

Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.

2013-01-01

The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that

A Physical Model of Mass Ejection in Failed Supernovae

Science.gov (United States)

Coughlin, Eric R.; Quataert, Eliot; Fernández, Rodrigo; Kasen, Daniel

2018-03-01

During the core collapse of massive stars, the formation of the protoneutron star is accompanied by the emission of a significant amount of mass-energy (˜0.3 M⊙) in the form of neutrinos. This mass-energy loss generates an outward-propagating pressure wave that steepens into a shock near the stellar surface, potentially powering a weak transient associated with an otherwise-failed supernova. We analytically investigate this mass-loss-induced wave generation and propagation. Heuristic arguments provide an accurate estimate of the amount of energy contained in the outgoing sound pulse. We then develop a general formalism for analyzing the response of the star to centrally concentrated mass loss in linear perturbation theory. To build intuition, we apply this formalism to polytropic stellar models, finding qualitative and quantitative agreement with simulations and heuristic arguments. We also apply our results to realistic pre-collapse massive star progenitors (both giants and compact stars). Our analytic results for the sound pulse energy, excitation radius, and steepening in the stellar envelope are in good agreement with full time-dependent hydrodynamic simulations. We show that prior to the sound pulses arrival at the stellar photosphere, the photosphere has already reached velocities ˜20 - 100% of the local sound speed, thus likely modestly decreasing the stellar effective temperature prior to the star disappearing. Our results provide important constraints on the physical properties and observational appearance of failed supernovae.

A physical model of mass ejection in failed supernovae

Science.gov (United States)

Coughlin, Eric R.; Quataert, Eliot; Fernández, Rodrigo; Kasen, Daniel

2018-06-01

During the core collapse of massive stars, the formation of the proto-neutron star is accompanied by the emission of a significant amount of mass energy (˜0.3 M⊙) in the form of neutrinos. This mass-energy loss generates an outward-propagating pressure wave that steepens into a shock near the stellar surface, potentially powering a weak transient associated with an otherwise-failed supernova. We analytically investigate this mass-loss-induced wave generation and propagation. Heuristic arguments provide an accurate estimate of the amount of energy contained in the outgoing sound pulse. We then develop a general formalism for analysing the response of the star to centrally concentrated mass loss in linear perturbation theory. To build intuition, we apply this formalism to polytropic stellar models, finding qualitative and quantitative agreement with simulations and heuristic arguments. We also apply our results to realistic pre-collapse massive star progenitors (both giants and compact stars). Our analytic results for the sound pulse energy, excitation radius, and steepening in the stellar envelope are in good agreement with full time-dependent hydrodynamic simulations. We show that prior to the sound pulses arrival at the stellar photosphere, the photosphere has already reached velocities ˜ 20-100 per cent of the local sound speed, thus likely modestly decreasing the stellar effective temperature prior to the star disappearing. Our results provide important constraints on the physical properties and observational appearance of failed supernovae.

TURBULENT OXYGEN FLAMES IN TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Aspden, A. J.; Bell, J. B.; Woosley, S. E.

2011-01-01

In previous studies, we examined turbulence-flame interactions in carbon-burning thermonuclear flames in Type Ia supernovae. In this study, we consider turbulence-flame interactions in the trailing oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen flame. Scaling arguments analogous to the carbon flames are presented and then compared against three-dimensional simulations for a range of Damkoehler numbers (Da 16 ) at a fixed Karlovitz number. The simulations suggest that turbulence does not significantly affect the oxygen flame when Da 16 16 >1, turbulence enhances heat transfer and drives the propagation of a flame that is narrower than the corresponding inductive flame would be. Furthermore, burning under these conditions appears to occur as part of a combined carbon-oxygen turbulent flame with complex compound structure. The simulations do not appear to support the possibility of a transition to detonation in the oxygen flame, but do not preclude it either.

Infrared emission from supernova condensates

International Nuclear Information System (INIS)

Dwek, E.; Werner, M.W.

1981-01-01

We examine the possibility of detecting grains formed in supernovae by observations of their emission in the infrared. The basic processes determining the temperature and infrared radiation of grains in supernovae environments are analyzed, and the results are used to estimate the infrared emission from the highly metal enriched ''fast moving knots'' in Cas A. The predicted fluxes lie within the reach of current ground-based facilities at 10 μm, and their emission should be detectable throughout the infrared band with cryogenic space telescopes

The acceleration of cosmic rays in supernova remnants

International Nuclear Information System (INIS)

Bhat, C.L.; Issa, M.R.

1986-01-01

The idea that the bulk of cosmic rays below 10 GeV are accelerated in supernova remnants suggests that cosmic rays should also exhibit intensity variations on a scale comparable with the linear size of a representative remnant. Following the general spirit of shock-wave acceleration models, here Monte Carlo simulations are carried out to predict what this scale should be and then corroborative evidence is presented from an autocorrelation analysis of the COS B and SAS II γ-ray data for the latitude range |b|=10-20 0 ('near Galaxy') and |b| 0 ('far Galaxy'). (author)

Radio and X-ray emission from supernova remnants

International Nuclear Information System (INIS)

Asvarova, A.I.; Novruzova, H.I.; Ahmedova, S.I.

2010-01-01

In this paper it was studied the statistical correlation between radio and X-ray emissions from shell-type supernova remnants (SNR). The primary aim of this study is to test the model of radio emission of shell-type SNRs presented by one of the authors. Based on this model of radio emission, by using the Monte Carlo techniques we have simulated statistical relations radio - X-ray luminosities (not surface brightnesses) which then were compared with the observations. X-ray emission is assumed to be thermal. To have a uniform statistical material it was used observational data on the SNRs in Magellanic Clouds

Energy conditions bounds and supernovae data

International Nuclear Information System (INIS)

Lima, M.P.; Vitenti, S.D.P.; Reboucas, M.J.

2008-01-01

The energy conditions play an important role in the description of some important properties of the Universe, including the current accelerating expansion phase and the possible recent phase of super-acceleration. In a recent work we have provided a detailed study of the energy conditions for the recent past by deriving bounds from energy conditions and by making the confrontation of the bounds with supernovae data. Here, we extend and update these results in two different ways. First, by carrying out a new statistical analysis for q(z) estimates needed for the confrontation between the bounds and supernovae data. Second, by providing a new picture of the energy conditions fulfillment and violation in the light of the recently compiled Union set of 307 type Ia supernovae and by using two different statistical approaches

Probing Exotic Physics With Supernova Neutrinos

Energy Technology Data Exchange (ETDEWEB)

Kelso, Chris; Hooper, Dan

2010-09-01

Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.

The interaction of Type Ia supernovae with their circumstellar medium

NARCIS (Netherlands)

Chiotellis, A.

2013-01-01

This thesis is focused on the study of a specific class of supernovae, named Type Ia (or thermonuclear) supernovae. In particular, we attempt to gain information about their origin through the study of the interaction of these supernovae with circumstellar structures that have been shaped by their

X- or γ-rays from supernovae in glacial ice

International Nuclear Information System (INIS)

Rood, R.T.; Sarazin, C.L.; Zeller, E.J.; Parker, B.C.

1979-01-01

It is reported that in an analysis of N0 3 - in an Antartic ice core, four spikes of high concentration have been found, three of which occur at depths which correspond roughly to the dates of known galactic supernovae. It is shown that the production of the observed N0 3 - peaks by the hard x-rays generated by a supernovae outburst (particularly Type 1) does not seem inconceivable at least from the point of view of energy requirements and current supernovae models. If this hypothesis is correct the bright supernovae of 1006 should be observed about 15 m beyond the end of the current core. (U.K.)

MAGNETOROTATIONAL CORE-COLLAPSE SUPERNOVAE IN THREE DIMENSIONS

Energy Technology Data Exchange (ETDEWEB)

Mösta, Philipp; Richers, Sherwood; Ott, Christian D.; Haas, Roland; Piro, Anthony L.; Boydstun, Kristen; Abdikamalov, Ernazar; Reisswig, Christian [TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Schnetter, Erik, E-mail: pmoesta@tapir.caltech.edu [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada)

2014-04-20

We present results of new three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. These simulations are the first of their kind and include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae are fundamentally different from what was anticipated on the basis of previous simulations in axisymmetry (2D). A strong bipolar jet that develops in a simulation constrained to 2D is crippled by a spiral instability and fizzles in full 3D. While multiple (magneto-)hydrodynamic instabilities may be present, our analysis suggests that the jet is disrupted by an m = 1 kink instability of the ultra-strong toroidal field near the rotation axis. Instead of an axially symmetric jet, a completely new, previously unreported flow structure develops. Highly magnetized spiral plasma funnels expelled from the core push out the shock in polar regions, creating wide secularly expanding lobes. We observe no runaway explosion by the end of the full 3D simulation 185 ms after bounce. At this time, the lobes have reached maximum radii of ∼900 km.

MAGNETOROTATIONAL CORE-COLLAPSE SUPERNOVAE IN THREE DIMENSIONS

International Nuclear Information System (INIS)

Mösta, Philipp; Richers, Sherwood; Ott, Christian D.; Haas, Roland; Piro, Anthony L.; Boydstun, Kristen; Abdikamalov, Ernazar; Reisswig, Christian; Schnetter, Erik

2014-01-01

We present results of new three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. These simulations are the first of their kind and include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae are fundamentally different from what was anticipated on the basis of previous simulations in axisymmetry (2D). A strong bipolar jet that develops in a simulation constrained to 2D is crippled by a spiral instability and fizzles in full 3D. While multiple (magneto-)hydrodynamic instabilities may be present, our analysis suggests that the jet is disrupted by an m = 1 kink instability of the ultra-strong toroidal field near the rotation axis. Instead of an axially symmetric jet, a completely new, previously unreported flow structure develops. Highly magnetized spiral plasma funnels expelled from the core push out the shock in polar regions, creating wide secularly expanding lobes. We observe no runaway explosion by the end of the full 3D simulation 185 ms after bounce. At this time, the lobes have reached maximum radii of ∼900 km

Supernova rates, galaxy emission, and Hubble type

International Nuclear Information System (INIS)

Van Den Bergh, S.

1991-01-01

Supernova discovery frequency is found to correlate with emission-line (H-alpha + forbidden N II line) equivalent width, except for the most active galaxies in which some supernovae might be hidden by dust. SNII occur preferentially in active galaxies with emission-line EW not less than 20 A, whereas SNIa favor less active galaxies with EW less than 20 A. The intrinsic frequency of supernovae is found to be an order of magnitude higher in Sc galaxies than it is in early type spirals. The relatively high frequency of SNIa in late-type galaxies suggests that not all such objects have old progenitors. 13 refs

Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces

Energy Technology Data Exchange (ETDEWEB)

Togashi, H., E-mail: hajime.togashi@riken.jp [Nishina Center for Accelerator-Based Science, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Nakazato, K. [Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Takehara, Y.; Yamamuro, S.; Suzuki, H. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan); Takano, M. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

2017-05-15

A new table of the nuclear equation of state (EOS) based on realistic nuclear potentials is constructed for core-collapse supernova numerical simulations. Adopting the EOS of uniform nuclear matter constructed by two of the present authors with the cluster variational method starting from the Argonne v18 and Urbana IX nuclear potentials, the Thomas–Fermi calculation is performed to obtain the minimized free energy of a Wigner–Seitz cell in non-uniform nuclear matter. As a preparation for the Thomas–Fermi calculation, the EOS of uniform nuclear matter is modified so as to remove the effects of deuteron cluster formation in uniform matter at low densities. Mixing of alpha particles is also taken into account following the procedure used by Shen et al. (1998, 2011). The critical densities with respect to the phase transition from non-uniform to uniform phase with the present EOS are slightly higher than those with the Shen EOS at small proton fractions. The critical temperature with respect to the liquid–gas phase transition decreases with the proton fraction in a more gradual manner than in the Shen EOS. Furthermore, the mass and proton numbers of nuclides appearing in non-uniform nuclear matter with small proton fractions are larger than those of the Shen EOS. These results are consequences of the fact that the density derivative coefficient of the symmetry energy of our EOS is smaller than that of the Shen EOS.

The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

Energy Technology Data Exchange (ETDEWEB)

Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Stritzinger, Maximilian; Contreras, Carlos [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castellón, Sergio; Morrell, Nidia; Salgado, Francisco [Carnegie Institution of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 277-8583 Kashiwa (Japan); Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, College Station, TX 77843 (United States)

2014-07-01

We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B – V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B – V), such that larger E(B – V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

Direct Measurement of the Supernova Rate in Starburst Galaxies

Science.gov (United States)

Bregman, Jesse D.; Temi, Pasquale; Rank, David; DeVincenzi, Donald L. (Technical Monitor)

1999-01-01

Supernovae play a key role in the dynamics, structure, and chemical evolution of galaxies. The massive stars that end their lives as supernovae live for short times. Many are still associated with dusty star formation regions when they explode, making them difficult to observe at visible wavelengths. In active star forming regions (galactic nuclei and starburst regions), dust extintion is especially severe. Thus, determining the supernova rate in the active star forming regions of galaxies, where the supernova rate can be one or two orders of magnitude higher than the average, has proven to be difficult. From observations of SN1987A, we know that the [NiII] 6.63 micron emission line was the strongest line in the infrared spectrum for a period of a year and a half after the explosion. Since dust extintion is much less at 6.63 pm than at visible wavelengths (A(sub 6.63)/A(sub V) = 0.025), the NiII line can be used as a sensitive probe for the detection of recent supernovae. We have observed a sample of starburst galaxies at 6.63 micron using ISOCAM to search for the NiII emission line characteristic of recent supernovae. We did not detect any NiII line emission brighter than a 5sigma limit of 5 mJy. We can set upper limits to the supernova rate in our sample, scaled to the rate in M82, of less than 0.3 per year at the 90% confidence level using Bayesian methods. Assuming that a supernova would have a NiII with the same luminosity as observed in SN1987A, we find less than 0.09 and 0.15 per year at the 50% and 67% confidence levels. These rates are somewhat less if a more normal type II supernovae has a NiII line luminosity greater than the line in SN1987A.

Final Report for DOE Grant DE-FG02-00ER41149 ''Nuclear Physics of Core-Collapse Supernovae''

International Nuclear Information System (INIS)

Yong-Zhong Qian

2004-01-01

During the funding period from August 15, 2000 to August 14, 2004, the main foci of my research have been implications of abundances in metal-poor stars for nucleosynthetic yields of supernovae and chemical evolution of the universe, effects of neutrino oscillations and neutrino-nucleus interactions on r-process nucleosynthesis, physical conditions in neutrino-driven winds from proto-neutron stars, neutrino driven mechanism of supernova explosion, supernova neutrino signals in terrestrial detectors, and constraints on variations of fundamental couplings and astrophysical conditions from properties of nuclear reactions. Personnel (three graduate students and a postdoctoral research associate) involved in my research are listed in section 2. Completed research projects are discussed in section 3. Publications during the funding period are listed in section 4 and oral presentations in section 5. Remarks about the budget are given in section 6

Supernovae and their light emission

International Nuclear Information System (INIS)

Lourens, P.E.

1978-01-01

In this paper a short review of the properties of supernovae is given. The basic radiation theory and hydrodynamics is described. The work of Imshennik and Nadezhin, Astrophysics and Space Science, 10 (1971) 28-51, and their collaborators in connection with the propagation of a shock wave and associated physical effects in a supernova is discussed. Their results are compared with observations reported in the literature. Criticism is given on the boundary conditions for the diffusion flux F at the outer boundary used in their model, and a new condition proposed [af

Velocity Dispersion of Ionized Gas and Multiple Supernova Explosions

Directory of Open Access Journals (Sweden)

Vasiliev E. O.

2015-06-01

Full Text Available We use 3D numerical simulations to study the evolution of the Hα intensity and velocity dispersion for single and multiple supernova (SN explosions. We find that the IHα– σ diagram obtained for simulated gas flows is similar in shape to that observed in dwarf galaxies. We conclude that colliding SN shells with significant difference in age are responsible for high velocity dispersion that reaches up to ≳ 100 km s−1. Such a high velocity dispersion could be hardly obtained for a single SN remnant. Peaks of velocity dispersion in the IHα– σ diagram may correspond to several isolated or merged SN remnants with moderately different ages. Degrading the spatial resolution in the Hα intensity and velocity dispersion maps makes the simulated IHα– σ diagrams close to those observed in dwarf galaxies not only in shape, but also quantitatively.

Type Ia supernovae as speed sensors at intermediate redshifts

International Nuclear Information System (INIS)

Zhang Pengjie; Chen Xuelei

2008-01-01

Large scale peculiar velocity (LSPV) is a crucial probe of dark matter, dark energy, and gravity at cosmological scales. However, its application is severely limited by measurement obstacles. We show that fluctuations in type Ia supernovae fluxes induced by LSPV offer a promising approach to measure LSPV at intermediate redshifts. In the 3D Fourier space, gravitational lensing, the dominant systematical error, is well suppressed, localized, and can be further corrected effectively. Advances in supernova observations can further significantly reduce shot noise induced by supernova intrinsic fluctuations, which is the dominant statistical error. Robust mapping on the motion of the dark universe through type Ia supernovae is thus feasible to z∼0.5.

The interaction of supernova ejecta with an ambient medium

International Nuclear Information System (INIS)

Chevalier, R.A.

1983-01-01

Plausible environments for supernovae are the interstellar medium with constant density or a circumstellar medium built up by mass loss with rho proportional to r -2 . Self-similar solutions for the interaction region between the expanding supernova gas and the ambient gas exist provided that the expanding gas has rho proportional to rsup(-n) with n > 5. The circumstellar medium case is likely to be important for the early evolution of Type II supernovae because their progenitor stars are probably red supergiants. The radio and X-ray emission observed from extragalactic supernovae may be from this interaction region. The early self-similar solutions can also be applied to the young galactic remnants. (Auth.)

Supernovae and nuclear structure: Electron capture and the nuclear incompressibility

International Nuclear Information System (INIS)

Cooperstein, J.

1985-01-01

The author considers the effects of electron capture and the high density equation of state on supernovae. Electron captures on nuclei with 60 s it is helpful for supernovae to have a soft equation of state. Present knowledge of the nuclear matter parameters is considered and implications for supernovae are drawn. (orig.)

Radio emission from supernovae. I. One to twelve year old supernovae

International Nuclear Information System (INIS)

Weiler, K.W.; Panagia, N.; Sramek, R.A.; Van Der Hulst, J.M.; Roberts, M.S.

1989-01-01

All recorded optical supernovae brighter than 14.0 mag from SN 1970A to SN 1981A were observed in May 1982 using VLA at 6 cm. Apart from the known radio supernovae (SN 1970G, SN 1979C, and SN 1980K), radio emissions were not detected from any of the objects to a limit of about 0.5 mJy. Limits on mass-loss rates from the presupernova systems are established. It is found that Type Ia Sns originate in systems which contain very little circumstellar material at the time of explosion. These systems are very different from those which originate Type Ib Sns. With some exceptions, Type II SNs originate with the high presupernova mass-loss rates expected from red supergiant progenitors with original main-sequence masses greater than about 8 solar masses. 16 references

Photometric properties of type II supernovae

Energy Technology Data Exchange (ETDEWEB)

Barbon, R [Osservatorio Astrofisico, Asiago (Italy); Trieste Univ. (Italy). Instituto di Matematica); Ciatti, F; Rosino, L [Osservatorio Astrofisico, Asiago (Italy); Pavia Univ. (Italy))

1979-02-01

An analysis of the available photometric observations for type II supernovae is presented. The possibility of drawing average curves by the fitting method, as previously done for type I supernovae, is indicated. Two basic shapes have been put into evidence, the first one (2/3 of the objects) is characterized by the presence of a plateau at intermediate phase, the second one by an almost linear decline. Average curves have been also built for the intrinsic color indices. Peculiar cases are discussed, including the unusual objects of types III-IV. The mean absolute magnitude at maximum for type II supernovae has been determined about Msub(B) = -16.45 (sigma=0.78), as a calibration for their use as distance indicators. The distribution in different morphological types and luminosity classes of the parent galaxies is briefly discussed.

HOW TO FIND GRAVITATIONALLY LENSED TYPE Ia SUPERNOVAE

Energy Technology Data Exchange (ETDEWEB)

Goldstein, Daniel A.; Nugent, Peter E. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2017-01-01

Type Ia supernovae (SNe Ia) that are multiply imaged by gravitational lensing can extend the SN Ia Hubble diagram to very high redshifts ( z ≳ 2), probe potential SN Ia evolution, and deliver high-precision constraints on H {sub 0}, w , and Ω{sub m} via time delays. However, only one, iPTF16geu, has been found to date, and many more are needed to achieve these goals. To increase the multiply imaged SN Ia discovery rate, we present a simple algorithm for identifying gravitationally lensed SN Ia candidates in cadenced, wide-field optical imaging surveys. The technique is to look for supernovae that appear to be hosted by elliptical galaxies, but that have absolute magnitudes implied by the apparent hosts’ photometric redshifts that are far brighter than the absolute magnitudes of normal SNe Ia (the brightest type of supernovae found in elliptical galaxies). Importantly, this purely photometric method does not require the ability to resolve the lensed images for discovery. Active galactic nuclei, the primary sources of contamination that affect the method, can be controlled using catalog cross-matches and color cuts. Highly magnified core-collapse SNe will also be discovered as a byproduct of the method. Using a Monte Carlo simulation, we forecast that the Large Synoptic Survey Telescope can discover up to 500 multiply imaged SNe Ia using this technique in a 10 year z -band search, more than an order of magnitude improvement over previous estimates. We also predict that the Zwicky Transient Facility should find up to 10 multiply imaged SNe Ia using this technique in a 3 year R -band search—despite the fact that this survey will not resolve a single system.

No evidence for bulk velocity from type Ia supernovae

Energy Technology Data Exchange (ETDEWEB)

Huterer, Dragan; Shafer, Daniel L. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Schmidt, Fabian, E-mail: huterer@umich.edu, E-mail: dlshafer@umich.edu, E-mail: fabians@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)

2015-12-01

We revisit the effect of peculiar velocities on low-redshift type Ia supernovae. Velocities introduce an additional guaranteed source of correlations between supernova magnitudes that should be considered in all analyses of nearby supernova samples but has largely been neglected in the past. Applying a likelihood analysis to the latest compilation of nearby supernovae, we find no evidence for the presence of these correlations, although, given the significant noise, the data is also consistent with the correlations predicted for the standard ΛCDM model. We then consider the dipolar component of the velocity correlations—the frequently studied ''bulk velocity''—and explicitly demonstrate that including the velocity correlations in the data covariance matrix is crucial for drawing correct and unambiguous conclusions about the bulk flow. In particular, current supernova data is consistent with no excess bulk flow on top of what is expected in ΛCDM and effectively captured by the covariance. We further clarify the nature of the apparent bulk flow that is inferred when the velocity covariance is ignored. We show that a significant fraction of this quantity is expected to be noise bias due to uncertainties in supernova magnitudes and not any physical peculiar motion.

No evidence for bulk velocity from type Ia supernovae

International Nuclear Information System (INIS)

Huterer, Dragan; Shafer, Daniel L.; Schmidt, Fabian

2015-01-01

We revisit the effect of peculiar velocities on low-redshift type Ia supernovae. Velocities introduce an additional guaranteed source of correlations between supernova magnitudes that should be considered in all analyses of nearby supernova samples but has largely been neglected in the past. Applying a likelihood analysis to the latest compilation of nearby supernovae, we find no evidence for the presence of these correlations, although, given the significant noise, the data is also consistent with the correlations predicted for the standard ΛCDM model. We then consider the dipolar component of the velocity correlations—the frequently studied ''bulk velocity''—and explicitly demonstrate that including the velocity correlations in the data covariance matrix is crucial for drawing correct and unambiguous conclusions about the bulk flow. In particular, current supernova data is consistent with no excess bulk flow on top of what is expected in ΛCDM and effectively captured by the covariance. We further clarify the nature of the apparent bulk flow that is inferred when the velocity covariance is ignored. We show that a significant fraction of this quantity is expected to be noise bias due to uncertainties in supernova magnitudes and not any physical peculiar motion

Supernova light-curve fitters and dark energy

Energy Technology Data Exchange (ETDEWEB)

Bengochea, Gabriel R., E-mail: gabriel@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio (IAFE), CC 67, Suc. 28, 1428 Buenos Aires (Argentina)

2011-01-24

We show that when a procedure is made to remove the tension between a supernova Ia (SN Ia) data set and observations from BAO and CMB, there might be the case where the same SN Ia set built with two different light-curve fitters behaves as two separate and distinct supernova sets, and the tension found by some authors between supernova sets actually could be due to tension or inconsistency between fitters. We also show that the information of the fitter used in an SN Ia data set could be relevant to determine whether phantom type models are favored or not when such a set is combined with the BAO/CMB joint parameter.

Supernova light-curve fitters and dark energy

International Nuclear Information System (INIS)

Bengochea, Gabriel R.

2011-01-01

We show that when a procedure is made to remove the tension between a supernova Ia (SN Ia) data set and observations from BAO and CMB, there might be the case where the same SN Ia set built with two different light-curve fitters behaves as two separate and distinct supernova sets, and the tension found by some authors between supernova sets actually could be due to tension or inconsistency between fitters. We also show that the information of the fitter used in an SN Ia data set could be relevant to determine whether phantom type models are favored or not when such a set is combined with the BAO/CMB joint parameter.

Merging White Dwarfs and Thermonuclear Supernovae

OpenAIRE

van Kerkwijk, Marten H.

2012-01-01

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure, and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and our suggestion that these supernovae instead resul...

Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

Science.gov (United States)

Bulla, Mattia

2017-02-01

Despite their relevance across a broad range of astrophysical research topics, Type Ia supernova explosions are still poorly understood and answers to the questions of when, why and how these events are triggered remain unclear. In this respect, polarisation offers a unique opportunity to discriminate between the variety of possible scenarios. The observational evidence that Type Ia supernovae are associated with rather low polarisation signals (smaller than a few per cent) places strong constraints for models and calls for modest asphericities in the progenitor system and/or explosion mechanism.The goal of this thesis is to assess the validity of contemporary Type Ia supernova explosion models by testing whether their predicted polarisation signatures can account for the small signals usually observed. To this end, we have implemented and tested an innovative Monte Carlo scheme in the radiative transfer code artis. Compared to previous Monte Carlo approaches, this technique produces synthetic observables (light curves, flux and polarisation spectra) with a substantial reduction in the Monte Carlo noise and therefore in the required computing time. This improvement is particularly crucial for our study as we aim to extract very weak polarisation signals, comparable to those detected in Type Ia supernovae. We have also demonstrated the applicability of this method to other classes of supernovae via a preliminary study of the first spectropolarimetry observations of superluminous supernovae.Using this scheme, we have calculated synthetic spectropolarimetry for three multi-dimensional explosion models recently proposed as promising candidates to explain Type Ia supernovae. Our findings highlight the power of spectropolarimetry in testing and discriminating between different scenarios. While all the three models predict light curves and flux spectra that are similar to each others and reproduce those observed in Type Ia supernovae comparably well, polarisation does

Acquire information about neutrino parameters by detecting supernova neutrinos

OpenAIRE

Huang, Ming-Yang; Guo, Xin-Heng; Young, Bing-Lin

2010-01-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle $\\theta_{13}$, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about $\\theta_{13}$ and neutrino masses ...

Stardust, Supernovae and the Chirality of the Amino Acids

International Nuclear Information System (INIS)

Boyd, R.N.; Kajino, T.; Onaka, T.

2011-01-01

A mechanism for creating enantiomerism in the amino acids, the building blocks of the proteins, that involves global selection of one chirality by interactions between the amino acids and neutrinos from core-collapse supernovae is described. The selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's amino acids.

Search for surviving companions in type Ia supernova remnants

International Nuclear Information System (INIS)

Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E.

2014-01-01

The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

The detectability of supernovae against elliptical galactic disks.

Science.gov (United States)

Pearce, E. C.

A 75 cm telescope has been automated with a Prime 300 mini-computer to search approximately 250 galaxies per hour for young supernovae. The high-speed star-location and comparison algorithms used in the Digitized Astronomy Supernova Search (DASS) system is described.

Progenitors of type Ia supernovae in elliptical galaxies

International Nuclear Information System (INIS)

Gilfanov, M.; Bogdan, A.

2011-01-01

Although there is a nearly universal agreement that type Ia supernovae are associated with the thermonuclear disruption of a CO white dwarf, the exact nature of their progenitors is still unknown. The single degenerate scenario envisages a white dwarf accreting matter from a non-degenerate companion in a binary system. Nuclear energy of the accreted matter is released in the form of electromagnetic radiation or gives rise to numerous classical nova explosions prior to the supernova event. We show that combined X-ray output of supernova progenitors and statistics of classical novae predicted in the single degenerate scenario are inconsistent with X-ray and optical observations of nearby early type galaxies and galaxy bulges. White dwarfs accreting from a donor star in a binary system and detonating at the Chandrasekhar mass limit can account for no more than ∼5% of type Ia supernovae observed in old stellar populations.

MATTER MIXING IN ASPHERICAL CORE-COLLAPSE SUPERNOVAE: A SEARCH FOR POSSIBLE CONDITIONS FOR CONVEYING 56Ni INTO HIGH VELOCITY REGIONS

International Nuclear Information System (INIS)

Ono, Masaomi; Nagataki, Shigehiro; Ito, Hirotaka; Lee, Shiu-Hang; Mao, Jirong; Tolstov, Alexey; Hashimoto, Masa-aki

2013-01-01

We perform two-dimensional axisymmetric hydrodynamic simulations of matter mixing in aspherical core-collapse supernova explosions of a 16.3 M ☉ star with a compact hydrogen envelope. Observations of SN 1987A have provided evidence that 56 Ni synthesized by explosive nucleosynthesis is mixed into fast moving matter (∼>3500 km s –1 ) in the exploding star. In order to clarify the key conditions for reproducing such high velocity of 56 Ni, we revisit matter mixing in aspherical core-collapse supernova explosions. Explosions are initiated artificially by injecting thermal and kinetic energies around the interface between the iron core and the silicon-rich layer. Perturbations of 5% or 30% amplitude in the radial velocities are introduced at several points in time. We find that no high velocity 56 Ni can be obtained if we consider bipolar explosions with perturbations (5% amplitude) of pre-supernova origins. If large perturbations (30% amplitude) are introduced or exist due to some unknown mechanism in a later phase just before the shock wave reaches the hydrogen envelope, 56 Ni with a velocity of 3000 km s –1 can be obtained. Aspherical explosions that are asymmetric across the equatorial plane with clumpy structures in the initial shock waves are investigated. We find that the clump sizes affect the penetration of 56 Ni. Finally, we report that an aspherical explosion model that is asymmetric across the equatorial plane with multiple perturbations of pre-supernova origins can cause the penetration of 56 Ni clumps into fast moving matter of 3000 km s –1 . We show that both aspherical explosions with clumpy structures and perturbations of pre-supernova origins may be necessary to reproduce the observed high velocity of 56 Ni. To confirm this, more robust three-dimensional simulations are required

High energy neutrinos from gamma-ray bursts with precursor supernovae.

Science.gov (United States)

Razzaque, Soebur; Mészáros, Peter; Waxman, Eli

2003-06-20

The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons in the supernova remnant shell and photons entrapped from a supernova explosion or a pulsar wind from a fast-rotating neutron star remnant provide ample targets for protons escaping the internal shocks of the gamma-ray burst to interact and produce high energy neutrinos. We calculate the expected neutrino fluxes, which can be detected by current and future experiments.

An earlier explosion date for the Crab Nebula supernova

Science.gov (United States)

Abt, Helmut A.; Fountain, John W.

2018-04-01

The Chinese first reported the Crab Nebula supernova on 1054 July 5. Ecclesiastical documents from the near east reported it in April and May of 1054. More than 33 petroglyphs made by Native Americans in the US and Mexico are consistent with sightings both before and after conjunction with the Sun on 1054 May 27. We found a petroglyph showing the new star close to Venus and the Moon, which occurred on 1054 April 12 and April 13, respectively. Collins et al., using the four historical dates, derived a light curve that is like that of a Type Ia supernova. The only remaining problem with this identification is that this supernova was near maximum light for 85 d, which is unlike the behavior of any known supernova.

Contribution of infrared observations to the study of supernovae remnants

International Nuclear Information System (INIS)

Douvion, Thomas

2000-01-01

This research thesis addresses the study of dust in young supernovae remnants observed in middle infrared, mainly by means of the ISOCAM instrument installed on the ISO satellite. The author first presents the supernovae physics and the studied young remnants, describes dusts and the main sites of formation and destruction, and outlines the difficulties and benefits of observations performed in the middle infrared. Then, the author reports acquired evidences related to the formation of dusts in supernovae, and the search for a millimetre emission by cold dust contained in regions which are not yet excited by the shock, in order to better assess the overall quantities created by supernovae. He reports the use of observations of dust and neon in Cassiopeia A to perform a diagnosis on the mixture of elements during the supernovae explosion [fr

Generation of Cosmic rays in Historical Supernova Remnants

Directory of Open Access Journals (Sweden)

Sinitsyna V.Y.

2013-06-01

Full Text Available We present the results of observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope of Tien-Shan high-mountain Observatory: the shell-type supernova remnants Tycho, Cas A and IC 443; plerions Crab Nebula, 3c58(SN1181 and Geminga (probably plerion. The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV gamma-rays in Tycho's supernova remnant. The data obtainedsuggest that the very high energy gamma-ray emission in the objects being discussedis different in origin.

Supernova Neutrino-Process and Implication in Neutrino Oscillation

Science.gov (United States)

Kajino, T.; Aoki, W.; Fujiya, W.; Mathews, G. J.; Yoshida, T.; Shaku, K.; Nakamura, K.; Hayakawa, T.

2012-08-01

We studied the supernova nucleosynthesis induced by neutrino interactions and found that several isotopes of rare elements like 7Li, 11B, 138La, 180Ta and many others are predominantly produced by the neutrino-process in core-collapse supernovae. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here propose a new novel method to determine the unknown neutrino oscillation parameters, θ13 and mass hierarchy simultaneously from the supernova neutrino-process, combined with the r-process for heavy-element synthsis and the Galactic chemical evolution on light nuclei.

Dynamical instability of the envelope of red supergiants and the lower mass limit for carbon detonation supernovae

International Nuclear Information System (INIS)

Fujimoto, M.Y.; Nomoto, K.; Sugimoto, D.

1976-01-01

The lower mass limit Msub(l) for the carbon detonation supernovae was investigated by testing the dynamical instability of the envelopes of red supergiants. It was found that the dependence of Msub(l) on the mixing length l of convection is appreciable. As a smaller value of l is assumed, Msub(l) becomes larger. It may be as large as 8 solar masses if l is a third of the pressure scale-height. This is one of the ways to remove the difficulty of overproduction of iron-peak elements involved in the model of the carbon detonation supernovae. (Auth.)

Dynamical instability of the envelope of red supergiants and the lower mass limit for carbon detonation supernovae

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, M Y [Tokyo Univ. (Japan); Nomoto, K; Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education

1976-11-01

The lower mass limit Msub(l) for the carbon detonation supernovae was investigated by testing the dynamical instability of the envelopes of red supergiants. It was found that the dependence of Msub(l) on the mixing length l of convection is appreciable. As a smaller value of l is assumed, Msub(l) becomes larger. It may be as large as 8 solar masses if l is a third of the pressure scale-height. This is one of the ways to remove the difficulty of overproduction of iron-peak elements involved in the model of the carbon detonation supernovae.

TYPE IIb SUPERNOVAE WITH COMPACT AND EXTENDED PROGENITORS

International Nuclear Information System (INIS)

Chevalier, Roger A.; Soderberg, Alicia M.

2010-01-01

The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova that has a more compact progenitor with a lower density, probably fast, wind. Distinguishing features of the compact category are weak optical emission from the shock heated envelope at early times, nonexistent or very weak H emission in the late nebular phase, rapidly evolving radio emission, rapid expansion of the radio shell, and expected nonthermal as opposed to thermal X-ray emission. Type IIb supernovae that have one or more of these features include SNe 1996cb, 2001ig, 2003bg, 2008ax, and 2008bo. All of these with sufficient radio data (the last four) show evidence for presupernova wind variability. We estimate a progenitor envelope radius ∼1 x 10 11 cm for SN 2008ax, a value consistent with a compact Wolf-Rayet progenitor. Supernovae in the SN 1993J extended category include SN 2001gd and probably the Cas A supernova. We suggest that the compact Type IIb events be designated Type cIIb and the extended ones Type eIIb. The H envelope mass dividing these categories is ∼0.1 M sun .

The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions

DEFF Research Database (Denmark)

Krisciunas, Kevin; Contreras, Carlos; Burns, Christopher R.

2017-01-01

We present final natural-system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type. Ia SNe, 5 Type...

Supernova remnants and the origin of cosmic rays

NARCIS (Netherlands)

Vink, J.

2014-01-01

Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the

Three-dimensional Modeling of Type Ia Supernova Explosions

Science.gov (United States)

Khokhlov, Alexei

2001-06-01

A deflagration explosion of a Type Ia Supernova (SNIa) is studied using three-dimensional, high-resolution, adaptive mesh refinement fluid dynamic calculations. Deflagration speed in an exploding Chandrasekhar-mass carbon-oxygen white dwarf (WD) grows exponentially, reaches approximately 30the speed of sound, and then declines due to a WD expansion. Outermost layers of the WD remain unburned. The explosion energy is comparable to that of a Type Ia supernova. The freezing of turbulent motions by expansion appears to be a crucial physical mechanism regulating the strength of a supernova explosion. In contrast to one-dimensional models, three-dimensional calculations predict the formation of Si-group elements and pockets of unburned CO in the middle and in central regions of a supernova ejecta. This, and the presence of unburned outer layer of carbon-oxygen may pose problems for SNIa spectra. Explosion sensitivity to initial conditions and its relation to a diversity of SNIa is discussed.

W Acana Sains Dalam Novel Supernova Episode Ksatria, Puteri, Dan Bintang Jatuh

Directory of Open Access Journals (Sweden)

Ida Nurul Chasanah

2008-12-01

Full Text Available This paper is aimed to describe the stories of Supernova 1 to identify the fiction and non• fiction dialectics and also to represent science aspect in Supernova novel Episode Ksatria, Puteri, dan Bintang Jatuh (Supernova 1 through the relationship of intertextuality. We can find five stories in novel Supernova 1, they are the stories about Ruben-Dhimas, Ferre-Rana-Arwin, Diva, Supernova, and classic fairy tale knight, princess, and falling star. The dialectics between fiction and non-fiction in Supernova I are found through some indications, such as cover, tittle, scientific process of writing method in fiction such as the use of footnote, the insert of bibliography and index, and also preface, the dynamic of character, events arragernent that make plot, mentioning 'keping' to change chapter. Science aspect in Supernova 1 are not only a pacth but they are represented in text structure. The transformation of science elements in novel Supernova 1 are more affirmative with hypogram that is referred by some expansion. That science elements are astronomy, chaos theory (it covers Lorenz butterflies and fractal geometri, Schrodinger, co-evolution, and non-linear theories.

Probing Late-Stage Stellar Evolution through Robotic Follow-Up of Nearby Supernovae

Science.gov (United States)

Hosseinzadeh, Griffin

2018-01-01

Many of the remaining uncertainties in stellar evolution can be addressed through immediate and long-term photometry and spectroscopy of supernovae. The early light curves of thermonuclear supernovae can contain information about the nature of the binary companion to the exploding white dwarf. Spectra of core-collapse supernovae can reveal material lost by massive stars in their final months to years. Thanks to a revolution in technology—robotic telescopes, high-speed internet, machine learning—we can now routinely discover supernovae within days of explosion and obtain well-sampled follow-up data for months and years. Here I present three major results from the Global Supernova Project at Las Cumbres Observatory that take advantage of these technological advances. (1) SN 2017cbv is a Type Ia supernova discovered within a day of explosion. Early photometry shows a bump in the U-band relative to previously observed Type Ia light curves, possibly indicating the presence of a nondegenerate binary companion. (2) SN 2016bkv is a low-luminosity Type IIP supernova also caught very young. Narrow emission lines in the earliest spectra indicate interaction between the ejecta and a dense shell of circumstellar material, previously observed only in the brightest Type IIP supernovae. (3) Type Ibn supernovae are a rare class that interact with hydrogen-free circumstellar material. An analysis of the largest-yet sample of this class has found that their light curves are much more homogeneous and faster-evolving than their hydrogen-rich counterparts, Type IIn supernovae, but that their maximum-light spectra are more diverse.

Cosmological analogy between the big bang and a supernova

Energy Technology Data Exchange (ETDEWEB)

Sen, S. (Hamburg, Germany, F.R.)

1983-10-01

The author presents an objection to Brown's (1981) analogy between a supernova and the Big Bang. According to Brown an expanding spherical shell is quite similar to an ejected supernova shell. However, the fragmented shell of a supernova moves outward in pre-existing space. The force of repulsion which makes the fragments of the shell drift apart can be regarded as equivalent to the force of attraction of the rest of the universe on the supernova. By definition, such a force of attraction is absent in the case of the Big Bang. Energy is supposed suddenly to appear simultaneously at all points throughout the universe at the time of the Big Bang. As the universe expands, space expands too. In the relativistic cosmology, the universe cannot expand in pre-existing space.

Measuring q0 using supernovae at z ∼ 0.3

International Nuclear Information System (INIS)

Newberg, H.J.M.

1992-07-01

The measurement of q o is extremely important for understanding the quantity of matter in our universe. The measurement of q o using supernovae of type Ia as standard candles is appealing because it requires less modeling than other methods using galaxies. The challenge with using supernovae to measure q o is in finding enough of them. In order to find supernovas, we have constructed a very popular f/1 camera for the 3.9m Anglo-Australian Telescope. The camera uses reducing optics that put a 17 in. x 17 in. field on a 1024 x 1024 pixel Thomson CCD. Using this system, we image to 23rd magnitude in five minutes. We have developed a software package that uses image subtraction to find supernovae that are approximately magnitude 22.4 or brighter in these images. One field can be processed every 6.6 minutes on a relatively unloaded VAX 6000-6510. We estimate that this system should find one supernova in every 105--139 images (about two nights of observation on the AAT). Throughout the two years of operation, we observed the equivalent of about four nights with seeing better than two arc seconds. Although we found many candidates, we were unable to confirm any supemovae. The next generation of this search is currently using the 2.5m Isaac Newton Telescope in the Canary Islands. We have solved many problems encountered with the AAT search by targeting distant clusters of galaxies, by operating at a site that allows higher resolution imaging, and by scheduling follow-up observations. This system, although still in its infancy, has yielded one event that could be a high redshift supernova. We estimate that it will require 36 type Ia supernovae, discovered at or before maximum, to find q o to within 0.2, and 144 such supernovae to measure q o within 0.1. Clearly, the program will have to be expanded to find this quantity of supernovae

MATTER MIXING IN ASPHERICAL CORE-COLLAPSE SUPERNOVAE: A SEARCH FOR POSSIBLE CONDITIONS FOR CONVEYING {sup 56}Ni INTO HIGH VELOCITY REGIONS

Energy Technology Data Exchange (ETDEWEB)

Ono, Masaomi; Nagataki, Shigehiro; Ito, Hirotaka; Lee, Shiu-Hang; Mao, Jirong; Tolstov, Alexey [Astrophysical Big Bang Laboratory, RIKEN, Saitama 351-0198 (Japan); Hashimoto, Masa-aki, E-mail: masaomi.ono@riken.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2013-08-20

We perform two-dimensional axisymmetric hydrodynamic simulations of matter mixing in aspherical core-collapse supernova explosions of a 16.3 M{sub Sun} star with a compact hydrogen envelope. Observations of SN 1987A have provided evidence that {sup 56}Ni synthesized by explosive nucleosynthesis is mixed into fast moving matter ({approx}>3500 km s{sup -1}) in the exploding star. In order to clarify the key conditions for reproducing such high velocity of {sup 56}Ni, we revisit matter mixing in aspherical core-collapse supernova explosions. Explosions are initiated artificially by injecting thermal and kinetic energies around the interface between the iron core and the silicon-rich layer. Perturbations of 5% or 30% amplitude in the radial velocities are introduced at several points in time. We find that no high velocity {sup 56}Ni can be obtained if we consider bipolar explosions with perturbations (5% amplitude) of pre-supernova origins. If large perturbations (30% amplitude) are introduced or exist due to some unknown mechanism in a later phase just before the shock wave reaches the hydrogen envelope, {sup 56}Ni with a velocity of 3000 km s{sup -1} can be obtained. Aspherical explosions that are asymmetric across the equatorial plane with clumpy structures in the initial shock waves are investigated. We find that the clump sizes affect the penetration of {sup 56}Ni. Finally, we report that an aspherical explosion model that is asymmetric across the equatorial plane with multiple perturbations of pre-supernova origins can cause the penetration of {sup 56}Ni clumps into fast moving matter of 3000 km s{sup -1}. We show that both aspherical explosions with clumpy structures and perturbations of pre-supernova origins may be necessary to reproduce the observed high velocity of {sup 56}Ni. To confirm this, more robust three-dimensional simulations are required.

Progress report on the Berkeley/Anglo-Australian Observatory high-redshift supernova search

International Nuclear Information System (INIS)

Goldhaber, G.; Perlmutter, S.; Pennypacker, C.; Marvin, H.; Muller, R.A.; Couch, W.; Boyle, B.

1990-11-01

There are two main efforts related to supernovae in progress at Berkeley. The first is an automated supernova search for nearby supernovae, which was already discussed by Carl Pennypacker at this conference. The second is a search for distant supernovae, in the z = 0.3 to 0.5 region, aimed at measuring Ω. It is the latter that I want to discuss in this paper. 3 refs., 18 figs

Mechanisms for supernova explosions

International Nuclear Information System (INIS)

Epstein, R.I.

1977-01-01

This report discusses some of the recent developments in the study of one supernova mechanism, the neutrino transport mechanism, and indicates what future developments are needed before this model can be adequately understood. (Auth.)

Binary progenitors of supernovae

Science.gov (United States)

Trimble, V.

1984-12-01

Among the massive stars that are expected to produce Type II, hydrogen-rich supernovae, the presence of a close companion can increase the main sequence mass needed to yield a collapsing core. In addition, due to mass transfer from the primary to the secondary, the companion enhances the stripping of the stellar hydrogen envelope produced by single star winds and thereby makes it harder for the star to give rise to a typical SN II light curve. Among the less massive stars that may be the basis for Type I, hydrogen-free supernovae, a close companion could be an innocent bystander to carbon detonation/deflagration in the primary. It may alternatively be a vital participant which transfers material to a white dwarf primary and drives it to explosive conditions.

Electron-capture and Low-mass Iron-core-collapse Supernovae: New Neutrino-radiation-hydrodynamics Simulations

Science.gov (United States)

Radice, David; Burrows, Adam; Vartanyan, David; Skinner, M. Aaron; Dolence, Joshua C.

2017-11-01

We present new 1D (spherical) and 2D (axisymmetric) simulations of electron-capture (EC) and low-mass iron-core-collapse supernovae (SN). We consider six progenitor models: the ECSN progenitor from Nomoto; two ECSN-like low-mass low-metallicity iron-core progenitors from A. Heger (2016, private communication); and the 9, 10, and 11 {M}⊙ (zero-age main-sequence) progenitors from Sukhbold et al. We confirm that the ECSN and ESCN-like progenitors explode easily even in 1D with explosion energies of up to a 0.15 Bethes (1 {{B}}\\equiv {10}51 {erg}), and are a viable mechanism for the production of very-low-mass neutron stars. However, the 9, 10, and 11 {M}⊙ progenitors do not explode in 1D and are not even necessarily easier to explode than higher-mass progenitor stars in 2D. We study the effect of perturbations and of changes to the microphysics and we find that relatively small changes can result in qualitatively different outcomes, even in 1D, for models sufficiently close to the explosion threshold. Finally, we revisit the impact of convection below the protoneutron star (PNS) surface. We analyze 1D and 2D evolutions of PNSs subject to the same boundary conditions. We find that the impact of PNS convection has been underestimated in previous studies and could result in an increase of the neutrino luminosity by up to factors of two.

Deep-Ocean Crusts as Telescopes: Using Live Radioisotopes to Probe Supernova Nucleosynthesis

CERN Document Server

Fields, B D; Ellis, Jonathan Richard; Fields, Brian D.; Hochmuth, Kathrin A.; Ellis, John

2005-01-01

Live 60Fe has recently been detected in a deep-ocean ferromanganese crust, isolated in layers dating from about 3 Myr ago. Since 60Fe has a mean life of 2.2 Myr, a near-Earth supernova is the only likely source for such a signal, and we explore here the consequences of a supernova origin. We combine the 60Fe data with several supernova nucleosynthesis models to calculate the supernova distance as a function of progenitor mass, finding an allowed range of 15-120 pc. We also predict the signals expected for several other radioisotopes, which are independent of the supernova distance. Species likely to be present near or above background levels are 10Be, 26Al, 53Mn, 182Hf and 244Pu. Of these, 182Hf and 244Pu are nearly background-free, presenting the best opportunities to provide strong confirmation of the supernova origin of the 60Fe signal, and to demonstrate that at least some supernovae are the source for the r-process. The accuracies of our predictions are hampered by large uncertainties in the predicted 60...

On supernovae as a source of interstellar dust. The current observational picture

International Nuclear Information System (INIS)

Dinerstein, H.L.

1984-01-01

Supernovae have been generally thought of as being effective agents for the destruction of ambient interstellar dust. The idea that supernovae may also be a source of dust has been of interest recently, and is attractive for a couple of reasons. The main motivation is to explain meteoritic inclusions with peculiar isotopic abundance ratios as supernova dust condensates predating the solar nebula. In addition, although the nucleation process is not fully understood, the high concentration of condensable elements in the supernova mantle suggests the possibility that grain formation could be very efficient. In this case, supernovae could be a major source of new grain cores to the interstellar medium. (author)

Supernova Cosmology Project

Science.gov (United States)

, i.e. with the cosmology hidden. Looking Beyond Lambda with the Union Supernova Compilation by Rubin et Matrix Description Covariance Matrix with Systematics Description Full Table of All SNe Description Beyond Lambda Figures Updated 11-18-11 Contact: drubin at physics dot fsu dot edu, saul at lbl dot gov

Neutrino-driven supernovae: An accretion instability in a nuclear physics controlled environment

International Nuclear Information System (INIS)

Janka, H.-T.; Buras, R.; Kitaura Joyanes, F.S.; Marek, A.; Rampp, M.; Scheck, L.

2005-01-01

New simulations demonstrate that low-mode, nonradial hydrodynamic instabilities of the accretion shock help starting hot-bubble convection in supernovae and thus support explosions by the neutrino-heating mechanism. The prevailing conditions depend on the high-density equation of state which governs stellar core collapse, core bounce, and neutron star formation. Tests of this sensitivity to nuclear physics variations are shown for spherically symmetric models. Implications of current explosion models for r-process nucleosynthesis are addressed

Interacting Supernovae: Types IIn and Ibn

Science.gov (United States)

Smith, Nathan

Supernovae that show evidence of strong shock interaction between their ejecta and pre-existing slower circumstellar material (CSM) constitute an interesting, diverse, and still poorly understood category of explosive transients. The chief reason they are extremely interesting is because they tell us that in a subset of stellar deaths, the progenitor star becomes wildly unstable in the years, decades, or centuries before explosion. This is something that has not been included in standard stellar evolution models but may significantly change the end product and yield of that evolution and complicates our attempts to map SNe to their progenitors. Another reason they are interesting is because CSM interaction is an efficient engine for making bright transients, allowing superluminous transients to arise from normal SN explosion energy, and transients of normal supernova luminosity to arise from sub-energetic explosions or low radioactivity yield. CSM interaction shrouds the fast ejecta in bright shock emission, obscuring our view of the underlying explosion, and the radiation hydrodynamics is challenging to model. The CSM interaction may also be highly nonspherical, perhaps linked to binary interaction in the progenitor system. In some cases, these complications make it difficult to tell the difference between a core-collapse and thermonuclear explosion or to discern between a nonterminal eruption, failed supernova, or weak supernova. Efforts to uncover the physical parameters of individual events and connections to progenitor stars make this a rapidly evolving topic that challenges paradigms of stellar evolution.

Late time optical spectra from the 56Ni model for Type I supernovae

International Nuclear Information System (INIS)

Axelrod, T.S.

1980-07-01

The hypothesis that the optical luminosity of Type I supernovae results from the radioactive decay of 56 Ni synthesized and ejected by the explosion has been investigated by numerical simulation of the optical spectrum resulting from a homologously expanding shell composed initially of pure 56 Ni core. This model, which neglects the effects of material external to the 56 Ni core, is expected to provide a reasonable representation of the supernova at late times when the star is nearly transparent to optical photons. The numerical simulation determines the temperature, ionization state, and non-LTE level populations which result from energy deposition by the radioactive decay products of 56 Ni and 56 Co. The optical spectrum includes the effects of both allowed and forbidden lines. The optical spectra resulting from the simulation are found to be sensitive to the mass and ejection velocity of the 56 Ni shell. A range of these parameters has been found which results in good agreement with the observed spectra of SN1972e over a considerable range of time. In particular, evidence for the expected decaying abundance of 56 Co has been found in the spectra of SN1972e. These results are used to assess the validity of the 56 Ni model and set limits on the mass and explosion mechanism of the Type I progenitor. The possibilities for improvement of the numerical model are discussed and future atomic data requirements defined

An integral view of fast shocks around supernova 1006

NARCIS (Netherlands)

Nikolic, S.; Heng, K.; Kupko, D.; Husemann, B.; Raymond, J.C.; Hughes, J.P.; Falcon-Barroso, J.; Ven, G. van de

2013-01-01

Supernova remnants are among the most spectacular examples of astrophysical pistons in our cosmic neighborhood. The gas expelled by the supernova explosion is launched with velocities ~1000 kilometers per second into the ambient, tenuous interstellar medium, producing shocks that excite hydrogen

Are young supernova remnants interacting with circumstellar gas

International Nuclear Information System (INIS)

Chevalier, R.A.

1982-01-01

The young remnants of galactic Type I supernovae (SN 1006, SN 1572, and SN 1604) appear to be interacting with moderately dense gas (n/sub O/> or =0.1 cm -3 ). If the gas in the ambient interstellar medium, the observations suggest that gas of this density is fairly pervasive. If the gas is circumstellar, there are important implications for the progenitors of Type I supernovae. A plausible density distribution for circumstellar gas is rhoinfinityr -2 . The expansion of a supernova into such a medium is examined and is compared with expansion into a uniform medium. The two cases can be distinguished on the basis of their density profiles and their rates of expansion. Currently available data factor the hypothesis of expansion in a uniform medium for all three Type I remnants; the evidence is the strongest for SN 1572 and the weakest for SN 1604. Further X-ray and radio observations of the galactic remnants and of extragalactic Type I supernovae should serve to test this hypothesis

On neutron star/supernova remnant associations

OpenAIRE

Gvaramadze, V. V.

2000-01-01

It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1757-24, SGR0525-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possibl...

Resolving neutrino mass hierarchy from supernova (anti)neutrino-nucleus reactions

Science.gov (United States)

Vale, Deni; Paar, Nils

2015-10-01

Recently a hybrid method has been introduced to determine neutrino mass hierarchy by simultaneous measurements of detector responses induced by antineutrino and neutrino fluxes from accretion and cooling phase of type II supernova. The (anti)neutrino-nucleus cross sections for 12C, 16O, 56Fe and 208Pb are calculated in the framework of relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons in mineral oil and water, p (v¯e,e+)n are obtained using heavy-baryon chiral perturbation theory. The simulations of (anti)neutrino fluxes emitted from a proto-neutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside star. It is shown that simultaneous use of ve/v¯e detectors with different target material allow to determine the neutrino mass hierarchy from the ratios of ve/v¯e induced particle emissions. The hybrid method favors detectors with heavier target nuclei (208Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil and water is more appropriate.

KamLAND Sensitivity to Neutrinos from Pre-supernova Stars

Science.gov (United States)

Asakura, K.; Gando, A.; Gando, Y.; Hachiya, T.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, T.; Ishio, S.; Koga, M.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakamura, K.; Obara, S.; Oura, T.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Tachibana, H.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Piepke, A.; Banks, T. I.; Berger, B. E.; Fujikawa, B. K.; O'Donnell, T.; Learned, J. G.; Maricic, J.; Matsuno, S.; Sakai, M.; Winslow, L. A.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; KamLAND Collaboration

2016-02-01

In the late stages of nuclear burning for massive stars (M > 8 M⊙), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 M⊙ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

Photometry of High-Redshift Gravitationally Lensed Type Ia Supernovae

Science.gov (United States)

Haynie, Annastasia

2018-01-01

Out of more than 1100 well-identified Type Ia Supernovae, only roughly 10 of them are at z> 1.5. High redshift supernovae are hard to detect but this is made easier by taking advantage of the effects of gravitational lensing, which magnifies objects in the background field of massive galaxy clusters. Supernova Nebra (z= ~1.8), among others, was discovered during observations taken as part of the RELICS survey, which focused on fields of view that experience strong gravitational lensing effects. SN Nebra, which sits behind galaxy cluster Abell 1763, is magnified and therefore appears closer and easier to see than with HST alone. Studying high-redshift supernovae like SN Nebra is an important step towards creating cosmological models that accurately describe the behavior of dark energy in the early Universe. Recent efforts have been focused on improving photometry and the building and fitting of preliminary light curves.

Astrophysical and terrestrial neutrinos in Supernova detectors

International Nuclear Information System (INIS)

Lagage, P.O.

1985-09-01

Supernova (SN) explosions are the place of very fundamental phenomena, whose privileged messengers are neutrinos. But such events are very rare. Then, SN detection has to be combined with other purposes. The recent developments of SN detectors have been associated with developments of underground particle physics (proton decay, monopoles ...). But here, I will restrict myself to discuss the possibilities for a supernova detector to be sensitive to other sources of neutrinos, astrophysical or terrestrial

A Model of the Vela Supernova Remnant

Science.gov (United States)

Gvaramadze, Vasilii

2000-10-01

A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created by the SN progenitor (15-20 M_solar) star. A possible origin of the nebula of hard X-ray emission detected around the Vela pulsar is discussed.

LIKELIHOOD-FREE COSMOLOGICAL INFERENCE WITH TYPE Ia SUPERNOVAE: APPROXIMATE BAYESIAN COMPUTATION FOR A COMPLETE TREATMENT OF UNCERTAINTY

Energy Technology Data Exchange (ETDEWEB)

Weyant, Anja; Wood-Vasey, W. Michael [Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), Physics and Astronomy Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Schafer, Chad, E-mail: anw19@pitt.edu [Department of Statistics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

2013-02-20

Cosmological inference becomes increasingly difficult when complex data-generating processes cannot be modeled by simple probability distributions. With the ever-increasing size of data sets in cosmology, there is an increasing burden placed on adequate modeling; systematic errors in the model will dominate where previously these were swamped by statistical errors. For example, Gaussian distributions are an insufficient representation for errors in quantities like photometric redshifts. Likewise, it can be difficult to quantify analytically the distribution of errors that are introduced in complex fitting codes. Without a simple form for these distributions, it becomes difficult to accurately construct a likelihood function for the data as a function of parameters of interest. Approximate Bayesian computation (ABC) provides a means of probing the posterior distribution when direct calculation of a sufficiently accurate likelihood is intractable. ABC allows one to bypass direct calculation of the likelihood but instead relies upon the ability to simulate the forward process that generated the data. These simulations can naturally incorporate priors placed on nuisance parameters, and hence these can be marginalized in a natural way. We present and discuss ABC methods in the context of supernova cosmology using data from the SDSS-II Supernova Survey. Assuming a flat cosmology and constant dark energy equation of state, we demonstrate that ABC can recover an accurate posterior distribution. Finally, we show that ABC can still produce an accurate posterior distribution when we contaminate the sample with Type IIP supernovae.

The many sides of RCW 86: a Type Ia supernova remnant evolving in its progenitor's wind bubble

Science.gov (United States)

Broersen, Sjors; Chiotellis, Alexandros; Vink, Jacco; Bamba, Aya

2014-07-01

We present the results of a detailed investigation of the Galactic supernova remnant RCW 86 using the XMM-Newton X-ray telescope. RCW 86 is the probable remnant of SN 185 A.D., a supernova that likely exploded inside a wind-blown cavity. We use the XMM-Newton Reflection Grating Spectrometer to derive precise temperatures and ionization ages of the plasma, which are an indication of the interaction history of the remnant with the presumed cavity. We find that the spectra are well fitted by two non-equilibrium ionization models, which enables us to constrain the properties of the ejecta and interstellar matter plasma. Furthermore, we performed a principal component analysis on EPIC MOS and pn data to find regions with particular spectral properties. We present evidence that the shocked ejecta, emitting Fe K and Si line emission, are confined to a shell of approximately 2 pc width with an oblate spheroidal morphology. Using detailed hydrodynamical simulations, we show that general dynamical and emission properties at different portions of the remnant can be well reproduced by a Type Ia supernova that exploded in a non-spherically symmetric wind-blown cavity. We also show that this cavity can be created using general wind properties for a single degenerate system. Our data and simulations provide further evidence that RCW 86 is indeed the remnant of SN 185, and is the likely result of a Type Ia explosion of single degenerate origin.

LIKELIHOOD-FREE COSMOLOGICAL INFERENCE WITH TYPE Ia SUPERNOVAE: APPROXIMATE BAYESIAN COMPUTATION FOR A COMPLETE TREATMENT OF UNCERTAINTY

International Nuclear Information System (INIS)

Weyant, Anja; Wood-Vasey, W. Michael; Schafer, Chad

2013-01-01

Cosmological inference becomes increasingly difficult when complex data-generating processes cannot be modeled by simple probability distributions. With the ever-increasing size of data sets in cosmology, there is an increasing burden placed on adequate modeling; systematic errors in the model will dominate where previously these were swamped by statistical errors. For example, Gaussian distributions are an insufficient representation for errors in quantities like photometric redshifts. Likewise, it can be difficult to quantify analytically the distribution of errors that are introduced in complex fitting codes. Without a simple form for these distributions, it becomes difficult to accurately construct a likelihood function for the data as a function of parameters of interest. Approximate Bayesian computation (ABC) provides a means of probing the posterior distribution when direct calculation of a sufficiently accurate likelihood is intractable. ABC allows one to bypass direct calculation of the likelihood but instead relies upon the ability to simulate the forward process that generated the data. These simulations can naturally incorporate priors placed on nuisance parameters, and hence these can be marginalized in a natural way. We present and discuss ABC methods in the context of supernova cosmology using data from the SDSS-II Supernova Survey. Assuming a flat cosmology and constant dark energy equation of state, we demonstrate that ABC can recover an accurate posterior distribution. Finally, we show that ABC can still produce an accurate posterior distribution when we contaminate the sample with Type IIP supernovae.

Supernova research with VLBI

Science.gov (United States)

Bartel, Norbert; Bietenholz, Michael F.

2016-06-01

Core-collapse supernovae have been monitored with VLBI from shortly after the explosion to many years thereafter. Radio emission is produced as the ejecta hit the stellar wind left over from the dyingstar. Images show the details of the interaction as the shock front expands into the circumstellar medium. Measurements of the velocity and deceleration of the expansion provide information on both the ejecta and the circumstellar medium. VLBI observations can also search for the stellar remnant of the explosion, a neutron star or a black hole. Combining the transverse expansion rate with the radial expansion rate from optical spectra allows a geometric determination of the distance to the host galaxy. We will present results from recent VLBI observations, focus on their interpretations, and show updated movies of supernovae from soon after their explosion to the present.

Supernova Remnants as the Sources of Galactic Cosmic Rays

NARCIS (Netherlands)

Vink, J.

2013-01-01

The origin of cosmic rays holds still manymysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate

A surge of light at the birth of a supernova

Science.gov (United States)

Bersten, M. C.; Folatelli, G.; García, F.; van Dyk, S. D.; Benvenuto, O. G.; Orellana, M.; Buso, V.; Sánchez, J. L.; Tanaka, M.; Maeda, K.; Filippenko, A. V.; Zheng, W.; Brink, T. G.; Cenko, S. B.; de Jaeger, T.; Kumar, S.; Moriya, T. J.; Nomoto, K.; Perley, D. A.; Shivvers, I.; Smith, N.

2018-02-01

It is difficult to establish the properties of massive stars that explode as supernovae. The electromagnetic emission during the first minutes to hours after the emergence of the shock from the stellar surface conveys important information about the final evolution and structure of the exploding star. However, the unpredictable nature of supernova events hinders the detection of this brief initial phase. Here we report the serendipitous discovery of a newly born, normal type IIb supernova (SN 2016gkg), which reveals a rapid brightening at optical wavelengths of about 40 magnitudes per day. The very frequent sampling of the observations allowed us to study in detail the outermost structure of the progenitor of the supernova and the physics of the emergence of the shock. We develop hydrodynamical models of the explosion that naturally account for the complete evolution of the supernova over distinct phases regulated by different physical processes. This result suggests that it is appropriate to decouple the treatment of the shock propagation from the unknown mechanism that triggers the explosion.

TIME VARIATION OF AV AND RV FOR TYPE Ia SUPERNOVAE BEHIND INTERSTELLAR DUST

Science.gov (United States)

Huang, Xiaosheng; Biederman, M.; Herger, B.; Aldering, G. S.

2014-01-01

TIME VARIATION OF AV AND RV FOR TYPE Ia SUPERNOVAE BEHIND NON-UNIFORM INTERSTELLAR DUST ABSTRACT We investigate the time variation of the visual extinction, AV, and the total-to-selective extinction ratio, RV, resulting from interstellar dust in front of an expanding photospheric disk of a type Ia supernova (SN Ia). We simulate interstellar dust clouds according to a power law power spectrum and produce extinction maps that either follow a pseudo-Gaussian distribution or a lognormal distribution. The RV maps are produced through a correlation between AV and RV. With maps of AV and RV generated in each case (pseudo-Gaussian and lognormal), we then compute the effective AV and RV for a SN as its photospheric disk expands behind the dust screen. We find for a small percentage of SNe the AV and RV values can vary by a large factor from day to day in the first 40 days after explosion.

From the advective-acoustic instability to the asymmetric explosions of Core Collapse Supernovae

International Nuclear Information System (INIS)

Galletti, Pascal

2005-01-01

The advective-acoustic cycle is a hydrodynamical mechanism fed by the coupling between advected waves (entropy, vorticity) and an acoustic feedback. Already studied in physics (rumble instability in ramjet, whistling tea kettle), it was introduced in astrophysics in the frame of the instability of the Bondi-Hoyle-Lyttleton accretion flow. In this thesis, we propose this cycle as an explanation for the asymmetry of the explosion of Core Collapse Supernovae. The evaluation of Eigenmodes for the classical accretion above a solid surface (white dwarfs, neutron stars) and the use of a toy-model reveal the importance of the advective-acoustic cycle in such an instable accretion flow. Following these results and the comparison with numerical simulations, a modelization of the flow when the shock stalls during a Core Collapse Supernova, shows that the advective-acoustic cycle is a natural mechanism to explain the non-spherical instability of the shock. The domination of l = 1 modes may be responsible for the observed pulsar kicks. (author) [fr

Supernovae Discovery Efficiency

Science.gov (United States)

John, Colin

2018-01-01

Abstract:We present supernovae (SN) search efficiency measurements for recent Hubble Space Telescope (HST) surveys. Efficiency is a key component to any search, and is important parameter as a correction factor for SN rates. To achieve an accurate value for efficiency, many supernovae need to be discoverable in surveys. This cannot be achieved from real SN only, due to their scarcity, so fake SN are planted. These fake supernovae—with a goal of realism in mind—yield an understanding of efficiency based on position related to other celestial objects, and brightness. To improve realism, we built a more accurate model of supernovae using a point-spread function. The next improvement to realism is planting these objects close to galaxies and of various parameters of brightness, magnitude, local galactic brightness and redshift. Once these are planted, a very accurate SN is visible and discoverable by the searcher. It is very important to find factors that affect this discovery efficiency. Exploring the factors that effect detection yields a more accurate correction factor. Further inquires into efficiency give us a better understanding of image processing, searching techniques and survey strategies, and result in an overall higher likelihood to find these events in future surveys with Hubble, James Webb, and WFIRST telescopes. After efficiency is discovered and refined with many unique surveys, it factors into measurements of SN rates versus redshift. By comparing SN rates vs redshift against the star formation rate we can test models to determine how long star systems take from the point of inception to explosion (delay time distribution). This delay time distribution is compared to SN progenitors models to get an accurate idea of what these stars were like before their deaths.

Nonthermal Radiation from Supernova Remnant Shocks

Directory of Open Access Journals (Sweden)

Hyesung Kang

2013-09-01

Full Text Available Most of high energy cosmic rays (CRs are thought to be produced by diffusive shock acceleration (DSA at supernova remnants (SNRs within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the timedependent evolution of the self-amplified magnetic fields, Alfvénic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and γ-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

Supernova remnant S 147 and its associated neutron star(s)

Science.gov (United States)

Gvaramadze, V. V.

2006-07-01

The supernova remnant S 147 harbors the pulsar PSR J 0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J 0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic age. Our proposal implies that S 147 is the diffuse remnant of the second supernova explosion (that disrupted the binary system) and that a much younger second neutron star (not necessarily manifesting itself as a radio pulsar) should be associated with S 147. We use the existing observational data on the system to suggest that the progenitor of the supernova that formed S 147 was a Wolf-Rayet star (so that the supernova explosion occurred within a wind bubble surrounded by a massive shell) and to constrain the parameters of the binary system. We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector should not strongly deviate from the orbital plane of the binary system.

Models for Type Ia Supernovae and Related Astrophysical Transients

Science.gov (United States)

Röpke, Friedrich K.; Sim, Stuart A.

2018-06-01

We give an overview of recent efforts to model Type Ia supernovae and related astrophysical transients resulting from thermonuclear explosions in white dwarfs. In particular we point out the challenges resulting from the multi-physics multi-scale nature of the problem and discuss possible numerical approaches to meet them in hydrodynamical explosion simulations and radiative transfer modeling. We give examples of how these methods are applied to several explosion scenarios that have been proposed to explain distinct subsets or, in some cases, the majority of the observed events. In case we comment on some of the successes and shortcoming of these scenarios and highlight important outstanding issues.

Pair production of helicity-flipped neutrinos in supernovae

Energy Technology Data Exchange (ETDEWEB)

Perez, A. (NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Box 500, Batavia, Illinois 60510-0500 (USA) Departamento de Fisica Teorica, Universidad de Valencia, 46100 Burjassot (Valencia) (Spain)); Gandhi, R. (Department of Physics and Astronomy, University of Arizona, Tucson, AZ (USA))

1990-04-15

We calculate the emissivity for the pair production of helicity-flipped neutrinos, in a way that can be used in supernova calculations. We also present some simple estimates which show that such a process can act as an efficient energy-loss mechanism in the shocked supernova core, and we use this fact to estimate neutrino mass limits from SN 1987A neutrino observations.

Supernova explosion in a very massive star

International Nuclear Information System (INIS)

El Eid, M.F.

1986-07-01

We describe the final evolution of a 100 solar mass following an evolutionary scenario during which the star evolves from a Wolf-Rayet stage through the electron- positron pair creation supernova. We find that the star is completely disrupted by explosive oxygen burning, and this type of explosion as a possible scenario for the Cassiopeia A remnant. This scenario seems to be also applicable to the supernova 1985f according to the recent observations of this object

A problem with the analysis of type Ia supernovae

Directory of Open Access Journals (Sweden)

Crawford David F.

2017-12-01

Full Text Available Type Ia supernovae have light curves that have widths and magnitudes that can be used for testing cosmologies and they provide one of the few direct measurements of time dilation. It is shown that the standard analysis that calibrates the light curve against a rest-frame average (such as SALT2 removes all the cosmological information from the calibrated light curves. Consequently type Ia supernovae calibrated with these methods cannot be used to investigate cosmology. The major evidence that supports the hypothesis of a static universe is that the measurements of the widths of the rawlight curves of type Ia supernovae do not show any time dilation. The intrinsicwavelength dependence shown by the SALT2 calibration templates is also consistent with no time dilation. Using a static cosmological model the peak absolute magnitudes of raw type Ia supernovae observations are also independent of redshift. These results support the hypothesis of a static universe.

SUPERNOVA LIGHT CURVES POWERED BY FALLBACK ACCRETION

Energy Technology Data Exchange (ETDEWEB)

Dexter, Jason; Kasen, Daniel, E-mail: jdexter@berkeley.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)

2013-07-20

Some fraction of the material ejected in a core collapse supernova explosion may remain bound to the compact remnant, and eventually turn around and fall back. We show that the late time ({approx}>days) power potentially associated with the accretion of this 'fallback' material could significantly affect the optical light curve, in some cases producing super-luminous or otherwise peculiar supernovae. We use spherically symmetric hydrodynamical models to estimate the accretion rate at late times for a range of progenitor masses and radii and explosion energies. The accretion rate onto the proto-neutron star or black hole decreases as M-dot {proportional_to}t{sup -5/3} at late times, but its normalization can be significantly enhanced at low explosion energies, in very massive stars, or if a strong reverse shock wave forms at the helium/hydrogen interface in the progenitor. If the resulting super-Eddington accretion drives an outflow which thermalizes in the outgoing ejecta, the supernova debris will be re-energized at a time when photons can diffuse out efficiently. The resulting light curves are different and more diverse than previous fallback supernova models which ignored the input of accretion power and produced short-lived, dim transients. The possible outcomes when fallback accretion power is significant include super-luminous ({approx}> 10{sup 44} erg s{sup -1}) Type II events of both short and long durations, as well as luminous Type I events from compact stars that may have experienced significant mass loss. Accretion power may unbind the remaining infalling material, causing a sudden decrease in the brightness of some long duration Type II events. This scenario may be relevant for explaining some of the recently discovered classes of peculiar and rare supernovae.

SUPERNOVA CONSTRAINTS AND SYSTEMATIC UNCERTAINTIES FROM THE FIRST THREE YEARS OF THE SUPERNOVA LEGACY SURVEY

International Nuclear Information System (INIS)

Conley, A.; Carlberg, R. G.; Perrett, K. M.; Guy, J.; Regnault, N.; Astier, P.; Balland, C.; Hardin, D.; Pain, R.; Sullivan, M.; Hook, I. M.; Basa, S.; Fouchez, D.; Howell, D. A.; Palanque-Delabrouille, N.; Rich, J.; Ruhlmann-Kleider, V.; Pritchet, C. J.; Balam, D.; Baumont, S.

2011-01-01

We combine high-redshift Type Ia supernovae from the first three years of the Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample of 472 SNe (123 low-z, 93 SDSS, 242 SNLS, and 14 Hubble Space Telescope). SN data alone require cosmic acceleration at >99.999% confidence, including systematic effects. For the dark energy equation of state parameter (assumed constant out to at least z = 1.4) in a flat universe, we find w = -0.91 +0.16 -0.20 (stat) +0.07 -0.14 (sys) from SNe only, consistent with a cosmological constant. Our fits include a correction for the recently discovered relationship between host-galaxy mass and SN absolute brightness. We pay particular attention to systematic uncertainties, characterizing them using a systematic covariance matrix that incorporates the redshift dependence of these effects, as well as the shape-luminosity and color-luminosity relationships. Unlike previous work, we include the effects of systematic terms on the empirical light-curve models. The total systematic uncertainty is dominated by calibration terms. We describe how the systematic uncertainties can be reduced with soon to be available improved nearby and intermediate-redshift samples, particularly those calibrated onto USNO/SDSS-like systems.

A cosmological analogy between the big bang and a supernova

International Nuclear Information System (INIS)

Sen, S.

1983-01-01

The author presents an objection to Brown's (1981) analogy between a supernova and the Big Bang. According to Brown an expanding spherical shell is quite similar to an ejected supernova shell. However, the fragmented shell of a supernova moves outward in pre-existing space. The force of repulsion which makes the fragments of the shell drift apart can be regarded as equivalent to the force of attraction of the rest of the universe on the supernova. By definition, such a force of attraction is absent in the case of the Big Bang. Energy is supposed suddenly to appear simultaneously at all points throughout the universe at the time of the Big Bang. As the universe expands, space expands too. In the relativistic cosmology, the universe cannot expand in pre-existing space. (Auth.)

Nucleosynthesis in neutrino-driven, aspherical supernova explosion of a massive star

International Nuclear Information System (INIS)

Fujimoto, S.; Hashimoto, M.; Ono, M.; Kotake, K.; Ohnishi, N.

2011-01-01

We examine explosive nucleosynthesis of p-nuclei during a delayed neutrino-driven, aspherical supernova explosion aided by standing accretion shock instability, based on two-dimensional hydrodynamic simulations of the explosion of a 15M · star. We find that p-nuclei are mainly produced through γ-processes, and that the nuclei lighter than 92 Mo are abundantly synthesized in slightly neutron-rich bubbles with electron fractions of Y e ≤0.48. 94 Mo, 96 Ru, and 98 Ru, are underproduced compared with the solar system, as in the spherical model.

Nuclear reactions in ultra-magnetized supernovae

International Nuclear Information System (INIS)

Kondratyev, V.N.

2002-06-01

The statistical model is employed to investigate nuclear reactions in ultrastrong magnetic fields relevant for supernovae and neutron stars. For radiative capture processes the predominant mechanisms are argued to correspond to modifications of nuclear level densities, and γ-transition energies due to interactions of the field with magnetic moments of nuclei. The density of states reflects the nuclear structure and results in oscillations of reaction cross sections as a function of field strength, while magnetic interaction energy enhances radiative neutron capture process. Implications in the synthesis of r-process nuclei in supernova site are discussed. (author)

Cosmic Ray Acceleration in Supernova Remnants

International Nuclear Information System (INIS)

O'C Drury, Luke

2005-01-01

This paper describes some recent developments in our understanding of cosmic ray acceleration in supernova remnant shocks. It is pointed out that while good agreement now exists as to steady nonlinear modifications to the shock structure, there is also growing evidence that the mesoscopic scales may not in fact be steady and that significant instabilities associated with magnetic field amplification may be a feature of strong collisionless plasma shocks. There is strong observational evidence for such magnetic field amplification, and it appears to solve a number of long-standing issues concerned with acceleration of cosmic rays in supernova remnants

Evolution of Supernova Remnants Near the Galactic Center

Energy Technology Data Exchange (ETDEWEB)

Yalinewich, A.; Piran, T.; Sari, R. [Racah Institute of Physics, the Hebrew University, 91904, Jerusalem (Israel)

2017-03-20

Supernovae near the Galactic center (GC) evolve differently from regular Galactic supernovae. This is mainly due to the environment into which the supernova remnants (SNRs) propagate. SNRs near the GC propagate into a wind swept environment with a velocity directed away from the GC, and a graded density profile. This causes these SNRs to be non-spherical, and to evolve faster than their Galactic counterparts. We develop an analytic theory for the evolution of explosions within a stellar wind, and verify it using a hydrodynamic code. We show that such explosions can evolve in one of three possible morphologies. Using these results we discuss the association between the two SNRs (SGR East and SGR A’s bipolar radio/X-ray lobes) and the two neutron stars (the Cannonball and SGR J1745-2900) near the GC. We show that, given the morphologies of the SNR and positions of the neutron stars, the only possible association is between SGR A’s bipolar radio/X-ray lobes and SGR J1745-2900. If a compact object was created in the explosion of SGR East, it remains undetected, and the SNR of the supernova that created the Cannonball has already disappeared.

Chaos and turbulent nucleosynthesis prior to a supernova explosion

Directory of Open Access Journals (Sweden)

W. D. Arnett

2014-03-01

Full Text Available Three-dimensional (3D, time dependent numerical simulations of flow of matter in stars, now have sufficient resolution to be fully turbulent. The late stages of the evolution of massive stars, leading up to core collapse to a neutron star (or black hole, and often to supernova explosion and nucleosynthesis, are strongly convective because of vigorous neutrino cooling and nuclear heating. Unlike models based on current stellar evolutionary practice, these simulations show a chaotic dynamics characteristic of highly turbulent flow. Theoretical analysis of this flow, both in the Reynolds-averaged Navier-Stokes (RANS framework and by simple dynamic models, show an encouraging consistency with the numerical results. It may now be possible to develop physically realistic and robust procedures for convection and mixing which (unlike 3D numerical simulation may be applied throughout the long life times of stars. In addition, a new picture of the presupernova stages is emerging which is more dynamic and interesting (i.e., predictive of new and newly observed phenomena than our previous one.

A constraint on prompt supernova cosmic ray production from γ-ray observations

International Nuclear Information System (INIS)

Morfill, G.E.; Drury, L.O'C.

1981-01-01

The consequences of prompt cosmic ray production intrinsic to supernovae are examined for supernova explosions occurring in dense molecular clouds. For reasonable parameters it is shown that prompt cosmic ray production cannot exceed 10 48 erg per supernova. This suggests that cosmic ray production takes place mainly in the intercloud medium. (author)

A PRECISION PHOTOMETRIC COMPARISON BETWEEN SDSS-II AND CSP TYPE Ia SUPERNOVA DATA

International Nuclear Information System (INIS)

Mosher, J.; Sako, M.; Corlies, L.; Folatelli, G.; Frieman, J.; Kessler, R.; Holtzman, J.; Jha, S. W.; Marriner, J.; Phillips, M. M.; Morrell, N.; Stritzinger, M.; Schneider, D. P.

2012-01-01

Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023 mag level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011 mag in ugri, with rms scatter ranging from 0.043 to 0.077 mag. The u-band agreement is promising, with the caveat that only four of the nine supernovae are well observed in u and these four exhibit an 0.038 mag supernova-to-supernova scatter in this filter.

Supernova remnant S147 and its associated neutron star(s)

OpenAIRE

Gvaramadze, V. V.

2005-01-01

The supernova remnant S147 harbors the pulsar PSR J0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic...

AXISYMMETRIC AB INITIO CORE-COLLAPSE SUPERNOVA SIMULATIONS OF 12-25 M{sub Sun} STARS

Energy Technology Data Exchange (ETDEWEB)

Bruenn, Stephen W.; Yakunin, Konstantin N. [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States); Mezzacappa, Anthony; Hix, W. Raphael; Lingerfelt, Eric J. [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Messer, O. E. Bronson [National Center for Computational Sciences, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Blondin, John M. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Endeve, Eirik [Computer Science and Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Marronetti, Pedro, E-mail: bruenn@fau.edu [Physics Division, National Science Foundation, Arlington, VA 22207 (United States)

2013-04-10

We present an overview of four ab initio axisymmetric core-collapse supernova simulations employing detailed spectral neutrino transport computed with our CHIMERA code and initiated from Woosley and Heger progenitors of mass 12, 15, 20, and 25 M{sub Sun }. All four models exhibit shock revival over {approx}200 ms (leading to the possibility of explosion), driven by neutrino energy deposition. Hydrodynamic instabilities that impart substantial asymmetries to the shock aid these revivals, with convection appearing first in the 12 M{sub Sun} model and the standing accretion shock instability appearing first in the 25 M{sub Sun} model. Three of the models have developed pronounced prolate morphologies (the 20 M{sub Sun} model has remained approximately spherical). By 500 ms after bounce the mean shock radii in all four models exceed 3000 km and the diagnostic explosion energies are 0.33, 0.66, 0.65, and 0.70 Bethe (B = 10{sup 51} erg) for the 12, 15, 20, and 25 M{sub Sun} models, respectively, and are increasing. The three least massive of our models are already sufficiently energetic to completely unbind the envelopes of their progenitors (i.e., to explode), as evidenced by our best estimate of their explosion energies, which first become positive at 320, 380, and 440 ms after bounce. By 850 ms the 12 M{sub Sun} diagnostic explosion energy has saturated at 0.38 B, and our estimate for the final kinetic energy of the ejecta is {approx}0.3 B, which is comparable to observations for lower mass progenitors.

Research in nuclear astrophysics: Stellar collapse and supernovae

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1991-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics is examined. We are actively researching the astrophysics of gravitational collapse, neutron star birth and neutrino emission, and neutron star cooling, on the one hand, and the nuclear physics of the equation of state of hot, dense matter on the other hand. There is close coupling between nuclear theory and supernova and neutron star phenomenon; some nuclear matter properties might be best delineated by astrophysical considerations. Our research has focused on the neutrinos emitted from supernovae, since they are the only available observables of the internal supernova mechanism. We are modifying our hydrodynamical code to use implicit differencing and to include multi-group neutrino diffusion and general relativity. In parallel, we are extending calculations of core collapse supernovae to long times after collapse by using a hybrid explicit-implicit hydrodynamical code and by using simplified neutrino transport. We hope to establish the existence or non-existence of the so-called long-term supernova mechanism. We are also extending models of the neutrino emission and cooling of neutron stars to include the effects of rotation and the direct Urca process that we recently discovered to be crucial. We have developed a rapid version of the dense matter equation of state for use in hydrodynamic codes that retains essentially all the physics of earlier, more detailed equations of state. This version also has the great advantage that nuclear physics inputs, such as the nuclear incompressibility, symmetry, energy, and specific heat, can be specified

Late time optical spectra from the /sup 56/Ni model for Type I supernovae

Energy Technology Data Exchange (ETDEWEB)

Axelrod, T.S.

1980-07-01

The hypothesis that the optical luminosity of Type I supernovae results from the radioactive decay of /sup 56/Ni synthesized and ejected by the explosion has been investigated by numerical simulation of the optical spectrum resulting from a homologously expanding shell composed initially of pure /sup 56/Ni core. This model, which neglects the effects of material external to the /sup 56/Ni core, is expected to provide a reasonable representation of the supernova at late times when the star is nearly transparent to optical photons. The numerical simulation determines the temperature, ionization state, and non-LTE level populations which result from energy deposition by the radioactive decay products of /sup 56/Ni and /sup 56/Co. The optical spectrum includes the effects of both allowed and forbidden lines. The optical spectra resulting from the simulation are found to be sensitive to the mass and ejection velocity of the /sup 56/Ni shell. A range of these parameters has been found which results in good agreement with the observed spectra of SN1972e over a considerable range of time. In particular, evidence for the expected decaying abundance of /sup 56/Co has been found in the spectra of SN1972e. These results are used to assess the validity of the /sup 56/Ni model and set limits on the mass and explosion mechanism of the Type I progenitor. The possibilities for improvement of the numerical model are discussed and future atomic data requirements defined.

Absolute-magnitude distributions of supernovae

Energy Technology Data Exchange (ETDEWEB)

Richardson, Dean; Wright, John [Department of Physics, Xavier University of Louisiana, New Orleans, LA 70125 (United States); Jenkins III, Robert L. [Applied Physics Department, Richard Stockton College, Galloway, NJ 08205 (United States); Maddox, Larry, E-mail: drichar7@xula.edu [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States)

2014-05-01

The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

Nuclear astrophysics of supernovae

International Nuclear Information System (INIS)

Cooperstein, J.

1988-01-01

In this paper, I'll give a general introduction to Supernova Theory, beginning with the presupernova evolution and ending with the later stages of the explosion. This will be distilled from a colloquium type of talk. It is necessary to have the whole supernova picture in one's mind's eye when diving into some of its nooks and crannies, as it is quite a mess of contradictory ingredients. We will have some discussion of supernova 1987a, but will keep our discussion more general. Second, we'll look at the infall and bounce of the star, seeing why it goes unstable, what dynamics it follows as it collapses, and how and why it bounces back. From there, we will go on to look at the equation of state (EOS) in more detail. We'll consider the cases T = 0 and T > 0. We'll focus on /rho/ 0 , and then /rho/ > /rho/ 0 and the EOS of neutron stars, and whether or not they contain cores of strange matter. There are many things we could discuss here and not enough time. If I had more lectures, the remaining time would focus on two more questions of special interest to nuclear physicists: the electron capture reactions and neutrino transport. If time permitted, we'd have some discussion of the nucleosynthetic reactions in the explosion's debris as well. However, we cannot cover such material adequately, and I have chosen these topics because they are analytically tractable, pedagogically useful, and rather important. 23 refs., 14 figs., 3 tabs

Pair production of helicity-flipped neutrinos in supernovae

Energy Technology Data Exchange (ETDEWEB)

Perez, A.; Gandhi, R.

1989-07-03

We calculate the emissivity for the pair production of helicity-flipped neutrinos, in a way that can be used in supernova calculations. We also present some simple estimates which show that such processes can act as an efficient energy-loss mechanism in the shocked supernova core, and we use this fact to extract neutrino mass limits from SN1987A neutrino observations. 24 refs., 2 figs.

Physics, SN1987A, and the next nearby supernova

International Nuclear Information System (INIS)

Burrows, A.

1989-01-01

The scientific community has extracted quite a bit of information from SN1987A, some of it enduring. I will summarize what I believe we learned, what we did not learn, and what we can learn about supernovae, neutrinos, and particle physics when the next galactic supernova explodes onto the news

A Precision Photometric Comparison between SDSS-II and CSP Type Ia Supernova Data

DEFF Research Database (Denmark)

Mosher, J.; Sako, M.; Corlies, L.

2012-01-01

Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data...

Revealing the supernova-gamma-ray burst connection with TeV neutrinos.

Science.gov (United States)

Ando, Shin'ichiro; Beacom, John F

2005-08-05

Gamma-ray bursts (GRBs) are rare, powerful explosions displaying highly relativistic jets. It has been suggested that a significant fraction of the much more frequent core-collapse supernovae are accompanied by comparably energetic but mildly relativistic jets, which would indicate an underlying supernova-GRB connection. We calculate the neutrino spectra from the decays of pions and kaons produced in jets in supernovae, and show that the kaon contribution is dominant and provides a sharp break near 20 TeV, which is a sensitive probe of the conditions inside the jet. For a supernova at 10 Mpc, 30 events above 100 GeV are expected in a 10 s burst in the IceCube detector.

SLOW-SPEED SUPERNOVAE FROM THE PALOMAR TRANSIENT FACTORY: TWO CHANNELS

Energy Technology Data Exchange (ETDEWEB)

White, Christopher J. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Kasliwal, Mansi M.; Piro, Anthony L. [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Gal-Yam, Avishay; Ofek, Eran O.; Ben-Ami, Sagi [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Howell, D. Andrew [Department of Physics, University of California, Santa Barbara, Broida Hall, Mail Code 9530, Santa Barbara, CA 93106-9530 (United States); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Goobar, Ariel [The Oskar Klein Centre, Department of Physics, AlbaNova, Stockholm University, SE-106 91 Stockholm (Sweden); Bloom, Joshua S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Kulkarni, Shrinivas R.; Cao, Yi [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Laher, Russ R.; Masci, Frank; Surace, Jason [Spitzer Science Center, California Institute of Technology, M/S 314-6, Pasadena, CA 91125 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Hook, Isobel M. [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Jönsson, Jakob [Savantic AB, Rosenlundsgatan 50, SE-118 63 Stockholm (Sweden); Matheson, Thomas [National Optical Astronomy Observatory, Tucson, AZ 85719-4933 (United States); and others

2015-01-20

Since the discovery of the unusual prototype SN 2002cx, the eponymous class of Type I (hydrogen-poor) supernovae with low ejecta speeds has grown to include approximately two dozen members identified from several heterogeneous surveys, in some cases ambiguously. Here we present the results of a systematic study of 1077 Type I supernovae discovered by the Palomar Transient Factory, leading to nine new members of this peculiar class. Moreover, we find there are two distinct subclasses based on their spectroscopic, photometric, and host galaxy properties: ''SN 2002cx-like'' supernovae tend to be in later-type or more irregular hosts, have more varied and generally dimmer luminosities, have longer rise times, and lack a Ti II trough when compared to ''SN 2002es-like'' supernovae. None of our objects show helium, and we counter a previous claim of two such events. We also find that the occurrence rate of these transients relative to Type Ia supernovae is 5.6{sub −3.8}{sup +22}% (90% confidence), lower compared to earlier estimates. Combining our objects with the literature sample, we propose that these subclasses have two distinct physical origins.

Density profiles of supernova matter and determination of neutrino parameters

Science.gov (United States)

Chiu, Shao-Hsuan

2007-08-01

The flavor conversion of supernova neutrinos can lead to observable signatures related to the unknown neutrino parameters. As one of the determinants in dictating the efficiency of resonant flavor conversion, the local density profile near the Mikheyev-Smirnov-Wolfenstein (MSW) resonance in a supernova environment is, however, not so well understood. In this analysis, variable power-law functions are adopted to represent the independent local density profiles near the locations of resonance. It is shown that the uncertain matter density profile in a supernova, the possible neutrino mass hierarchies, and the undetermined 1-3 mixing angle would result in six distinct scenarios in terms of the survival probabilities of νe and ν¯e. The feasibility of probing the undetermined neutrino mass hierarchy and the 1-3 mixing angle with the supernova neutrinos is then examined using several proposed experimental observables. Given the incomplete knowledge of the supernova matter profile, the analysis is further expanded to incorporate the Earth matter effect. The possible impact due to the choice of models, which differ in the average energy and in the luminosity of neutrinos, is also addressed in the analysis.

Supernovae and the origin of the solar system

International Nuclear Information System (INIS)

Clayton, D.D.

1979-01-01

This review concentrates on recent ideas involving a relationship between the early solar system and supernovae explosions. It summarizes briefly the data that has helped inspire those ideas. Because the true relationship is still unknown and generates controversy, the distinct ideas are introduced singly in the historical context of their origins, and the active sense of surprise and controversy is visible. Quotations from pivotal papers are used as part of the exposition. The subject involves equally the isotopic anomalies detected in meteorites and the dynamic events of galactic evolution, nucleosynthesis, and protosolar collapse. Whatever the correct situation is, new connections have been found between the origin of the elements and the formation of the solar system. The objective of this review is to enable interested space scientists to quickly identify the competing points of view and the experiments and theories that have led to them. (Auth.)

Neutron stars, fast pulsars, supernovae and the equation of state of dense matter

International Nuclear Information System (INIS)

Glendening, N.K.

1989-01-01

We discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neutron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general theory of relativity is correct at the macroscopic scale. If the millisecond pulses briefly observed in the remnant of SN1987A can be attributed to uniform rotation of a pulsar, then a very severe constraint is placed on the equation of state. The theory again is very secure. The precise nature of the constraint is not yet understood, but it appears that the equation of state must be neither too soft nor stiff, and it may be that there is information not only on the stiffness of the equation of state but on its shape. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Not even the broad category of mechanism for the explosion is agreed upon (prompt shock, delayed shock, or nuclear explosion). In connection with very fast pulsars, we include some speculations on pure quark matter stars, and on possible scenarios for understanding the disappearance of the fast pulsar in SN1987A. 47 refs., 16 figs., 1 tab

Neutron stars, fast pulsars, supernovae and the equation of state of dense matter

Energy Technology Data Exchange (ETDEWEB)

Glendening, N.K.

1989-06-01

We discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neutron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general theory of relativity is correct at the macroscopic scale. If the millisecond pulses briefly observed in the remnant of SN1987A can be attributed to uniform rotation of a pulsar, then a very severe constraint is placed on the equation of state. The theory again is very secure. The precise nature of the constraint is not yet understood, but it appears that the equation of state must be neither too soft nor stiff, and it may be that there is information not only on the stiffness of the equation of state but on its shape. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Not even the broad category of mechanism for the explosion is agreed upon (prompt shock, delayed shock, or nuclear explosion). In connection with very fast pulsars, we include some speculations on pure quark matter stars, and on possible scenarios for understanding the disappearance of the fast pulsar in SN1987A. 47 refs., 16 figs., 1 tab.

Neutrinos and nucleosynthesis in supernova

Energy Technology Data Exchange (ETDEWEB)

Solis, U [Instituto de Ciencias Nucleares, Departamento de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D.F. (Mexico); D' Olivo, J C [Instituto de Ciencias Nucleares, Departamento de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D.F. (Mexico); Cabral-Rosetti, L G [Departamento de Posgrado, Centro Interdisciplinario de Investigacion y Docencia en Educacion Tecnica (CIIDET), Av. Universidad 282 Pte., Col. Centro, A. Postal 752, C.P. 76000, Santiago de Queretaro, Qro. (Mexico)

2006-05-15

The type II supernova is considered as a candidate site for the production of heavy elements. The nucleosynthesis occurs in an intense neutrino flux, we calculate the electron fraction in this environment.

Neutrinos and nucleosynthesis in supernova

International Nuclear Information System (INIS)

Solis, U; D'Olivo, J C; Cabral-Rosetti, L G

2006-01-01

The type II supernova is considered as a candidate site for the production of heavy elements. The nucleosynthesis occurs in an intense neutrino flux, we calculate the electron fraction in this environment

Supernova neutrino detection

International Nuclear Information System (INIS)

Selvi, M.

2005-01-01

Neutrinos emitted during a supernova core collapse represent a unique feature to study both stellar and neutrino properties. After discussing the details of the neutrino emission in the star and the effect of neutrino oscillations on the expected neutrino fluxes at Earth, a review of the detection techniques is presented in this paper, with particular attention to the problem of electron neutrino detection

The VLT Measures the Shape of a Type Ia Supernova

Science.gov (United States)

2003-08-01

First Polarimetric Detection of Explosion Asymmetry has Cosmological Implications Summary An international team of astronomers [2] has performed new and very detailed observations of a supernova in a distant galaxy with the ESO Very Large Telescope (VLT) at the Paranal Observatory (Chile). They show for the first time that a particular type of supernova, caused by the explosion of a "white dwarf", a dense star with a mass around that of the Sun, is asymmetric during the initial phases of expansion . The significance of this observation is much larger than may seem at a first glance . This particular kind of supernova, designated "Type Ia", plays a very important role in the current attempts to map the Universe. It has for long been assumed that Type Ia supernovae all have the same intrinsic brightness , earning them a nickname as "standard candles". If so, differences in the observed brightness between individual supernovae of this type simply reflect their different distances. This, and the fact that the peak brightness of these supernovae rivals that of their parent galaxy, has allowed to measure distances of even very remote galaxies . Some apparent discrepancies that were recently found have led to the discovery of cosmic acceleration . However, this first clearcut observation of explosion asymmetry in a Type Ia supernova means that the exact brightness of such an object will depend on the angle from which it is seen. Since this angle is unknown for any particular supernova, this obviously introduces an amount of uncertainty into this kind of basic distance measurements in the Universe which must be taken into account in the future. Fortunately, the VLT data also show that if you wait a little - which in observational terms makes it possible to look deeper into the expanding fireball - then it becomes more spherical. Distance determinations of supernovae that are performed at this later stage will therefore be more accurate. PR Photo 24a/03 : Spiral galaxy NGC

Dynamics of supernova remnants in the Galactic centre.

Science.gov (United States)

Bortolas, E.; Mapelli, M.; Spera, M.

The Galactic centre (GC) is a unique place to study the extreme dynamical processes occurring near a super-massive black hole (SMBH). Here we simulate a large set of binaries orbiting the SMBH while the primary member undergoes a supernova (SN) explosion, in order to study the impact of SN kicks on the orbits of stars and dark remnants in the GC. We find that SN explosions are efficient in scattering neutron stars and other light stars on new (mostly eccentric) orbits, while black holes (BHs) tend to retain memory of the orbit of their progenitor star. SN kicks are thus unable to eject BHs from the GC: a cusp of dark remnants may be lurking in the central parsec of our Galaxy.

How to Find More Supernovae with Less Work: Object ClassificationTechniques for Difference Imaging

Energy Technology Data Exchange (ETDEWEB)

Bailey, Stephen; Aragon, Cecilia; Romano, Raquel; Thomas, RollinC.; Weaver, Benjamin A.; Wong, Daniel

2007-05-02

We present the results of applying new object classificationtechniques to difference images in the context of the Nearby SupernovaFactory supernova search. Most current supernova searches subtractreference images from new images, identify objects in these differenceimages, and apply simple threshold cuts on parameters such as statisticalsignificance, shape, and motionto reject objects such as cosmic rays,asteroids, and subtraction artifacts. Although most static objectssubtract cleanly, even a very low false positive detection rate can leadto hundreds of non-supernova candidates which must be vetted by humaninspection before triggering additional followup. In comparison to simplethreshold cuts, more sophisticated methods such as Boosted DecisionTrees, Random Forests, and Support Vector Machines provide dramaticallybetter object discrimination. At the Nearby Supernova Factory, we reducedthe number of non-supernova candidates by a factor of 10 while increasingour supernova identification efficiency. Methods such as these will becrucial for maintaining a reasonable false positive rate in the automatedtransient alert pipelines of upcoming projects such as PanSTARRS andLSST.

Ionizing radiations in the natural history of the Earth: role of supernova flares

International Nuclear Information System (INIS)

Byakov, V.M.

1996-01-01

Paper discusses the role of supernova flares in the natural history of the Earth. Probability of the solar system occurrence in the residual of supernova explosion is estimated Possible effects of the Earth occurrence in the supernova residual are studied. 29 refs., 3 tabs

Neutron star kicks and asymmetric supernovae

International Nuclear Information System (INIS)

Lai, D.

2001-01-01

Observational advances over the last decade have left little doubt that neutron stars received a large kick velocity (of order a few hundred to a thousand km s -1 ) at birth. The physical origin of the kicks and the related supernova asymmetry is one of the central unsolved mysteries of supernova research. We review the physics of different kick mechanisms, including hydrodynamically driven, neutrino - magnetic field driven, and electromagnetically driven kicks. The viabilities of the different kick mechanisms are directly related to the other key parameters characterizing nascent neutron stars, such as the initial magnetic field and the initial spin. Recent observational constraints on kick mechanisms are also discussed. (orig.)

Neutrino Observation of Core Collapse Supernovae

Science.gov (United States)

Nakazato, Ken'ichiro

The event rate of the supernova neutrinos are predicted for the future SK-Gd experiment. With an eye on the neutron tagging by Gd, the energy and angular distributions are calculated both for tagged events from inverse β decay reaction and untagged events from other reactions. As a result, it is indicated that the shock revival in the supernova is detectable through the decrease of the event rate and decline of the average energy of events. It is also implied that a careful treatment for the neutrino spectra is needed to investigate the untagged events owing to the high neutrino threshold energy of 16O reactions.

Merging white dwarfs and thermonuclear supernovae.

Science.gov (United States)

van Kerkwijk, M H

2013-06-13

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.

The nearby supernova factory

International Nuclear Information System (INIS)

Wood-Vasey, W.M.; Aldering, G.; Lee, B.C.; Loken, S.; Nugent, P.; Perlmutter, S.; Siegrist, J.; Wang, L.; Antilogus, P.; Astier, P.; Hardin, D.; Pain, R.; Copin, Y.; Smadja, G.; Gangler, E.; Castera, A.; Adam, G.; Bacon, R.; Lemonnier, J.-P.; Pecontal, A.; Pecontal, E.; Kessler, R.

2004-01-01

The Nearby Supernova Factory (SNfactory) is an ambitious project to find and study in detail approximately 300 nearby Type Ia supernovae (SNe Ia) at redshifts 0.03 < z < 0.08. This program will provide an exceptional data set of well-studied SNe in the nearby smooth Hubble flow that can be used as calibration for the current and future programs designed to use SNe to measure the cosmological parameters. The first key ingredient for this program is a reliable supply of Hubble-flow SNe systematically discovered in unprecedented numbers using the same techniques as those used in distant SNe searches. In 2002, 35 SNe were found using our test-bed pipeline for automated SN search and discovery. The pipeline uses images from the asteroid search conducted by the Near Earth Asteroid Tracking group at JPL. Improvements in our subtraction techniques and analysis have allowed us to increase our effective SN discovery rate to ∼12 SNe/month in 2003

On the Possibility of Fast Radio Bursts from Inside Supernovae: The Case of SN 1986J

Science.gov (United States)

Bietenholz, Michael F.; Bartel, Norbert

2017-12-01

We discuss the possibility of obtaining fast radio bursts (FRBs) from the interior of supernovae, in particular SN 1986J. Young neutron stars are involved in many of the possible scenarios for the origin of FRBs, and it has been suggested that the high dispersion measures observed in FRBs might be produced by the ionized material in the ejecta of associated supernovae. Using VLA and VLBI measurements of the Type IIn SN 1986J, which has a central compact component not seen in other supernovae, we can directly observe for the first time radio signals, which originate in the interior of a young (∼30 year old) supernova. We show that at an age of 30 years, any FRB signal at ∼1 GHz would still be largely absorbed by the ejecta. By the time the ejecta have expanded so that a 1 GHz signal would be visible, the internal dispersion measure due to the SN ejecta would be below the values typically seen for FRBs. The high dispersion measures seen for the FRBs detected so far could of course be due to propagation through the intergalactic medium provided that the FRBs are at distances much larger than that of SN 1986J, which is 10 Mpc. We conclude that if FRBs originate in Type II SNe/SNRs, they would likely not become visible until 60 ∼ 200 years after the SN explosion.

Measurements of Ω and Λ from 42 High-Redshift Supernovae

International Nuclear Information System (INIS)

Perlmutter, S.; Aldering, G.; Goldhaber, G.; Knop, R.A.; Nugent, P.; Castro, P.G.; Deustua, S.; Fabbro, S.; Goobar, A.; Groom, D.E.; Hook, I.M.; Kim, A.G.; Kim, M.Y.; Lee, J.C.; Nunes, N.J.; Pain, R.; Pennypacker, C.R.; Quimby, R.; Lidman, C.; Ellis, R.S.; Irwin, M.; McMahon, R.G.; Ruiz-Lapuente, P.; Walton, N.; Schaefer, B.; Boyle, B.J.; Filippenko, A.V.; Matheson, T.; Fruchter, A.S.; Panagia, N.; Newberg, H.J.; Couch, W.J.

1999-01-01

We report measurements of the mass density, Ω M , and cosmological-constant energy density, Ω Λ , of the universe based on the analysis of 42 type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these supernovae, at redshifts between 0.18 and 0.83, are fitted jointly with a set of supernovae from the Calacute an/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. All supernova peak magnitudes are standardized using a SN Ia light-curve width-luminosity relation. The measurement yields a joint probability distribution of the cosmological parameters that is approximated by the relation 0.8Ω M -0.6Ω Λ ∼-0.2±0.1 in the region of interest (Ω M approx-lt 1.5). For a flat (Ω M +Ω Λ =1) cosmology we find Ω flat M =0.28 +0.09 -0.08 (1 σ statistical) +0.05 -0.04 (identified systematics). The data are strongly inconsistent with a Λ=0 flat cosmology, the simplest inflationary universe model. An open, Λ=0 cosmology also does not fit the data well: the data indicate that the cosmological constant is nonzero and positive, with a confidence of P(Λ>0)=99%, including the identified systematic uncertainties. The best-fit age of the universe relative to the Hubble time is t flat 0 =14.9 +1.4 -1.1 (0.63/h) Gyr for a flat cosmology. The size of our sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We find no significant differences in either the host reddening distribution or Malmquist bias between the low-redshift Calacute an/Tololo sample and our high-redshift sample. Excluding those few supernovae that are outliers in color excess or fit residual does not significantly change the results. The conclusions are also robust whether or not a width-luminosity relation is used to standardize the supernova peak magnitudes. We discuss and constrain, where possible, hypothetical alternatives to a cosmological constant

Limits on an optical pulsar in supernova 1987A

International Nuclear Information System (INIS)

Pennypacker, C.R.; Morris, D.E.; Muller, R.A.

1989-01-01

Since March 1987 the optical flux from supernova 1987A for periodic pulsations has been sought. As of August 1988, after 38 separate observations, no pulsar has been detected. The typical upper limit placed on the pulsed fraction optical light from the supernova is 0.0002, for pulse frequencies in the range 0.03-5000 Hz. The best limit on the pulsed fraction of supernova light is 7 x 10 to the -6th, on January 22, 1988. On August 28, 1988 the faintest limit for the magnitude of the pulsar, dimmer than 20th mag is reached. These limits are based on Fourier transforms of up to 67 million points, covering a range of spindown rates. 25 refs

Research in nuclear astrophysics: Stellar collapse and supernovae

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1990-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics has been examined. We have been actively researching both the astrophysics of gravitational collapse, neutron star birth, and the emission of neutrinos from supernovae, on the one hand, and the nuclear physics of the equation of state of hot, dense matter on the other hand. There is close coupling between nuclear theory and supernova and neutron star phenomenon; in fact, nuclear matter properties, especially supernuclear densities, might be best delineated by astrophysical considerations. Our research has also focused on the neutrinos emitted from supernovae, since they are the only available observables of the internal supernova mechanism. The recent observations of neutrinos from SN 1987A proved to be in remarkable agreement with models we pioneered prior to its explosion. We have also developed a novel hydrodynamical code in which shocks are treated via Riemann resolution rather than with artificial viscosity. We have also extended models of the neutrino emission and cooling of neutron stars to include the effects of rotation. The Lattimer compressible liquid drop model is the basis of our equation of state. We have developed a rapid version for use in hydrodynamic codes that retains essentially all the physics of earlier, more detailed equations of state. We have also focused on the nuclei-nuclear matter phase transition just below nuclear matter density, including the probable nuclear deformations and the possible ''inside-out'' phase of bubbles, which could be of major importance in supernovae models. Work also progressed toward understanding the origin of the r-process elements, through focusing on the neutron star decompression model

Physics of type Ia supernovae

International Nuclear Information System (INIS)

Hoeflich, Peter

2006-01-01

The last decade has witnessed an explosive growth of high-quality data for thermonuclear explosions of a white dwarf star, the type Ia supernovae (SNe Ia). Advances in computational methods provide new insights into the physics of the phenomenon and a direct, quantitative link between observables and explosion physics. Both trends combined provided spectacular results, allowed to address, to identify specific problems and to narrow down the range of scenarios. Current topics include the relation between SNe Ia and their progenitors, the influence of the metallicities and accretion on the explosion, and details of the burning front. How can we understand the apparent homogeneity and probe for the diversity of SNe Ia? Here, we want give an overview of the current status of our understanding of supernovae physics in light of recent results

Supernovae from Wolf-Rayet stars

International Nuclear Information System (INIS)

Schaeffer, R.

1986-01-01

Wolf-Rayet stars are known to originate from the most massive stars. Under the assumption that these stripped stars explode at the end of their evolution through the same instability mechanism as type II supernovae, we calculate their light curve. The latter is found to be quite similar to the typical SN I light curves but is fainter by about 2 magnitudes. A detailed study of its shape leads to identify the WR supernovae with the SNIp (or SNIb) subclass. The more massive WR stars should explode via the e + e - pair production mechanism, with negligible 56 Ni formation. Their rather dim light curve is predicted to have a ∼ 2 month plateau and afterwards a very sharp decline. A delayed manifestation of such an event might be the Cas A remnant

IceCube Sensitivity for Low-Energy Neutrinos from Nearby Supernovae

Science.gov (United States)

Stamatikos, M.; Abbasi, R.; Berghaus, P.; Chirkin, D.; Desiati, P.; Diaz-Velez, J.; Dumm, J. P.; Eisch, J.; Feintzeig, J.; Hanson, K.;

Crucial Physical Dependencies of the Core-Collapse Supernova Mechanism

Science.gov (United States)

Burrows, A.; Vartanyan, D.; Dolence, J. C.; Skinner, M. A.; Radice, D.

2018-02-01

We explore with self-consistent 2D F ornax simulations the dependence of the outcome of collapse on many-body corrections to neutrino-nucleon cross sections, the nucleon-nucleon bremsstrahlung rate, electron capture on heavy nuclei, pre-collapse seed perturbations, and inelastic neutrino-electron and neutrino-nucleon scattering. Importantly, proximity to criticality amplifies the role of even small changes in the neutrino-matter couplings, and such changes can together add to produce outsized effects. When close to the critical condition the cumulative result of a few small effects (including seeds) that individually have only modest consequence can convert an anemic into a robust explosion, or even a dud into a blast. Such sensitivity is not seen in one dimension and may explain the apparent heterogeneity in the outcomes of detailed simulations performed internationally. A natural conclusion is that the different groups collectively are closer to a realistic understanding of the mechanism of core-collapse supernovae than might have seemed apparent.

Cosmological and supernova neutrinos

Science.gov (United States)

Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Shibagaki, S.; Suzuki, T.

2014-06-01

The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial 7Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and 7Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and 180Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ13 with predicted and observed supernova-produced abundance ratio 11B/7Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

The 1974 Type I supernova in NGC 4414

International Nuclear Information System (INIS)

Patchett, B.; Wood, R.

1976-01-01

Spectra of Miss Burgat's supernova in NGC 4414 were taken with the Isaac Newton 2.5-m reflector during 1974 April and May. The spectra cover the period from just before maximum light to 20 days post-maximum, and show many features typical of Type I supernovae. In addition secondary features in the spectrum indicate the presence of thin shell or filamentary structure. A photographic light curve and direct plate are presented. (author)

Supernova 1987A in the Large Magellanic Cloud

Science.gov (United States)

Kafatos, Minas; Michalitsianos, Andrew G.

2006-11-01

Foreword; Acknowledgements; Workshop participants; 1. Images and spectrograms of Sanduleak - 69º202, the SN 1987a progenitor N. R. Walborn; 2. The progenitor of SN 1987A G. Sonneborn; 3. Another supernova with a blue progenitor C. M. Gaskell and W. C. Keel; 4. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory M. M. Phillips; 5. SN 1987A: observational results obtained at ESO I. J. Danziger, P. Bouchet, R. A. E. Fosbury, C. Gouiffes, L. B. Lucy, A. F. M. Moorwood, E. Oliva and F. Rufener; 6. Observations of SN 1987A at the South African Astronomical Observatory (SAAO) M. W. Feast; 7. Observations of SN 1987A at the Anglo-Australian Telescope W. J. Couch; 8. Linear polarimetric study of SN 1987A A. Clocchiatti, M. Méndez, O. Benvenuto, C. Feinstein, H. Marraco, B. García and N. Morrell; 9. Infrared spectroscopy of SN 1987A from the NASA Kuiper Airborne Observatory H. P. Larson, S. Drapatz, M. J. Mumma and H. A. Weaver; 10. Radio observations of SN 1987A N. Bartel et al.; 11. Ultraviolet observations of SN 1987A: clues to mass loss R. P. Kirshner; 12. On the energetics of SN 1987A N. Panagia; 13. On the nature and apparent uniqueness of SN 1987A A. V. Filippenko; 14. A comparison of the SN 1987A light curve with other type II supernovae, and the detectability of similar supernovae M. F. Schmitz and C. M. Gaskell; 15. P-Cygni features and photospheric velocities L. Bildsten and J. C. L. Wang; 16. The Neutrino burst from SN 1987A detected in the Mont Blanc LSD experiment M. Aglietta et al.; 17. Toward observational neutrino astrophysics M. Koshiba; 18. The discovery of neutrinos from SN 1987A with the IMB detector J. Matthews; 19. Peering into the abyss: the neutrinos from SN 1987A A. Burrows; 20. Phenomenological analysis of neutrino emission from SN 1987A J. N. Bahcall, D. N. Spergel and W. H. Press; 21. Mass determination of neutrinos H. Y. Chiu; 22. Neutrino transport in a type II supernova D. C. Ellison, P. M. Giovanoni

HOST GALAXIES OF TYPE Ia SUPERNOVAE FROM THE NEARBY SUPERNOVA FACTORY

International Nuclear Information System (INIS)

Childress, M.; Aldering, G.; Aragon, C.; Bailey, S.; Fakhouri, H. K.; Hsiao, E. Y.; Kim, A. G.; Loken, S.; Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Guy, J.; Baltay, C.; Buton, C.; Kerschhaggl, M.; Kowalski, M.; Chotard, N.; Copin, Y.; Gangler, E.

2013-01-01

We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory. Combining Galaxy Evolution Explorer (GALEX) UV data with optical and near-infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high-precision redshifts, gas-phase metallicities, and Hα-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from Sloan Digital Sky Survey (SDSS) for stellar masses log(M * /M ☉ ) > 8.5 where the relation is well defined. The star formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, though this comparison is limited by systematic uncertainties in SFR measurements. Our analysis indicates that SN Ia host galaxies are, on average, typical representatives of normal field galaxies.

A network of neutral current spherical TPCs for dedicated supernova detection

International Nuclear Information System (INIS)

Giomataris, Y.; Vergados, J.D.

2006-01-01

The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current offers a realistic prospect of detecting supernova neutrinos. As a matter of fact for a typical supernova at 10 kpc, about 1000 events are expected using a spherical gaseous detector of radius 4 m and employing Xe gas at a pressure of 10 atm. We propose a world wide network of several such simple, stable and low cost supernova detectors with a running time of a few centuries

A prompt radio burst from supernova 1987A in the Large Magellanic Cloud

International Nuclear Information System (INIS)

Turtle, A.J.; Campbell-Wilson, D.; Bunton, J.D.; Jauncey, D.L.; Kesteven, M.J.; Manchester, R.N.; Norris, R.P.; Storey, M.C.; Reynolds, J.E.

1987-01-01

The paper concerns a prompt radio burst from supernova 1987A in the Large Magellanic Cloud. Radio emission from the supernova was detected at Australian observatories within two days of the increase in optical brightness. Observations of radio emission at four frequencies i.e. 0.843, 1.415, 2.29 and 8.41 GHz are presented for the region of the Large Magellanic Cloud supernova. At frequencies around 1 GHz the peak flux density was about 150mJy and occurred within four days of the supernova. (U.K.)

Could a nearby supernova explosion have caused a mass extinction?

CERN Document Server

Ellis, Jonathan Richard

1995-01-01

We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by palaeontologists. We discuss the likely rate of such events in the light of the recent identification of Geminga as a supernova remnant less than 100 pc away and the discovery of a millisecond pulsar about 150 pc away, and observations of SN 1987A. The fluxes of $\\gamma$ radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer discussed. A supernova explosion of the order of 10 pc away could be expected every few hundred million years, and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs.

NEW EQUATIONS OF STATE BASED ON THE LIQUID DROP MODEL OF HEAVY NUCLEI AND QUANTUM APPROACH TO LIGHT NUCLEI FOR CORE-COLLAPSE SUPERNOVA SIMULATIONS

International Nuclear Information System (INIS)

Furusawa, Shun; Yamada, Shoichi; Sumiyoshi, Kohsuke; Suzuki, Hideyuki

2013-01-01

We construct new equations of state for baryons at subnuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to ∼1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell effects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum-theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nuclei are taken into account in the same way as in the previous model. We find that the abundances of heavy nuclei are modified by the shell effects of nuclei and temperature dependence of bulk energies. These changes may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. The abundances of light nuclei are also modified by the new mass evaluation, which may affect the heating and cooling rates of supernova cores and shocked envelopes

New Equations of State Based on the Liquid Drop Model of Heavy Nuclei and Quantum Approach to Light Nuclei for Core-collapse Supernova Simulations

Science.gov (United States)

Furusawa, Shun; Sumiyoshi, Kohsuke; Yamada, Shoichi; Suzuki, Hideyuki

2013-08-01

We construct new equations of state for baryons at subnuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to ~1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell effects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum-theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nuclei are taken into account in the same way as in the previous model. We find that the abundances of heavy nuclei are modified by the shell effects of nuclei and temperature dependence of bulk energies. These changes may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. The abundances of light nuclei are also modified by the new mass evaluation, which may affect the heating and cooling rates of supernova cores and shocked envelopes.

NEW EQUATIONS OF STATE BASED ON THE LIQUID DROP MODEL OF HEAVY NUCLEI AND QUANTUM APPROACH TO LIGHT NUCLEI FOR CORE-COLLAPSE SUPERNOVA SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Furusawa, Shun; Yamada, Shoichi [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Sumiyoshi, Kohsuke [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Suzuki, Hideyuki, E-mail: furusawa@heap.phys.waseda.ac.jp [Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan)

2013-08-01

We construct new equations of state for baryons at subnuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to {approx}1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell effects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum-theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nuclei are taken into account in the same way as in the previous model. We find that the abundances of heavy nuclei are modified by the shell effects of nuclei and temperature dependence of bulk energies. These changes may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. The abundances of light nuclei are also modified by the new mass evaluation, which may affect the heating and cooling rates of supernova cores and shocked envelopes.

Coherent and Incoherent Neutral Current Scattering for Supernova Detection

Directory of Open Access Journals (Sweden)

P. C. Divari

2012-01-01

Full Text Available The total cross sections as well as the neutrino event rates are calculated in the neutral current neutrino scattering off 40Ar and 132Xe isotopes at neutrino energies (Ev<100 MeV. The individual contribution coming from coherent and incoherent channels is taking into account. An enhancement of the neutral current component is achieved via the coherent (0gs+→0gs+ channel which is dominant with respect to incoherent (0gs+→Jf one. The response of the above isotopes as a supernova neutrino detection has been considered, assuming a two parameter Fermi-Dirac distribution for the supernova neutrino energy spectra. The calculated total cross sections are tested on a gaseous spherical TPC detector dedicated for supernova neutrino detection.

Aspherical Supernovae: Effects on Early Light Curves

Science.gov (United States)

Afsariardchi, Niloufar; Matzner, Christopher D.

2018-04-01

Early light from core-collapse supernovae, now detectable in high-cadence surveys, holds clues to a star and its environment just before it explodes. However, effects that alter the early light have not been fully explored. We highlight the possibility of nonradial flows at the time of shock breakout. These develop in sufficiently nonspherical explosions if the progenitor is not too diffuse. When they do develop, nonradial flows limit ejecta speeds and cause ejecta–ejecta collisions. We explore these phenomena and their observational implications using global, axisymmetric, nonrelativistic FLASH simulations of simplified polytropic progenitors, which we scale to representative stars. We develop a method to track photon production within the ejecta, enabling us to estimate band-dependent light curves from adiabatic simulations. Immediate breakout emission becomes hidden as an oblique flow develops. Nonspherical effects lead the shock-heated ejecta to release a more constant luminosity at a higher, evolving color temperature at early times, effectively mixing breakout light with the early light curve. Collisions between nonradial ejecta thermalize a small fraction of the explosion energy; we will address emission from these collisions in a subsequent paper.

On the mass ejected by supernova explosions

International Nuclear Information System (INIS)

Bohigas, J.

1984-01-01

A simple model is developed in order to calculate the mass ejected by superonovae. We find that the 185, 1006, 1572 and 1604 AD events, all of them classified as either probable or possible type I supernovae, ejected between 0.1 and 0.4 solar masses with an expansion velocity of roughly 10,000 km s -1 . This range of masses suggests that a collapsed object is at the center of the remnants produced by these supernovae if the precursor was a white dwarf whose mass was closed to the Chandrasekhar limit. For the Crab we obtain an ejected mass of 0.45 Msub(sun) and point out that this value is not in contradiction with a proposal in which the moderate helium stars are good candidates for producing this kind of supernovae. Finally we obtain an ejected mass of 3.1 Msub(sun) for Cas A, indicating that a type II event produced this remnant. This ejected mass is closed to what would be expected for a progenitor like an OBN star. (author)

THE DOMINANCE OF NEUTRINO-DRIVEN CONVECTION IN CORE-COLLAPSE SUPERNOVAE

International Nuclear Information System (INIS)

Murphy, Jeremiah W.; Dolence, Joshua C.; Burrows, Adam

2013-01-01

Multi-dimensional instabilities have become an important ingredient in core-collapse supernova (CCSN) theory. Therefore, it is necessary to understand the driving mechanism of the dominant instability. We compare our parameterized three-dimensional CCSN simulations with other buoyancy-driven simulations and propose scaling relations for neutrino-driven convection. Through these comparisons, we infer that buoyancy-driven convection dominates post-shock turbulence in our simulations. In support of this inference, we present four major results. First, the convective fluxes and kinetic energies in the neutrino-heated region are consistent with expectations of buoyancy-driven convection. Second, the convective flux is positive where buoyancy actively drives convection, and the radial and tangential components of the kinetic energy are in rough equipartition (i.e., K r ∼ K θ + K φ ). Both results are natural consequences of buoyancy-driven convection, and are commonly observed in simulations of convection. Third, buoyant driving is balanced by turbulent dissipation. Fourth, the convective luminosity and turbulent dissipation scale with the driving neutrino power. In all, these four results suggest that in neutrino-driven explosions, the multi-dimensional motions are consistent with neutrino-driven convection.

Prompt mechanism of type II supernovae

International Nuclear Information System (INIS)

Burrows, A.; Lattimer, J.M.

1985-01-01

We report in this Letter on an extensive set of hydrodynamical simulations of the stellar collapse of the cores of massive stars. A new hydro technique and a series of state-of-the art equations of state were employed. The purpose of this project was to understand in detail core implosion and immediate postbounce behavior (first 25 ms) and to investigate the viability of the hydrodynamic mechanism for Type II supernovae. We find that the bounce-shock always stalls upon encountering the massive infalling outer core for the calculated cores of stars between 8 and 25 M/sub sun/ and the standard input physics. In particular, it is found that Nomoto's 8l8 m/sub sun/ star and Woosley, Weaver, and Taam's 10 M/sub sun/ star do not explode via the prompt mechanism. Our conclusions appear to depend not on the details of the progenitor structure calculated by others but rather on the generic nature of these structures

Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

International Nuclear Information System (INIS)

Volpe, C.; Welzel, J.

2007-01-01

We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic ν e and ν-bar e fluxes and on the number of events for ν e + C 12 , ν e + O 16 , ν e + Ar 40 and ν-bar e + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

THE ENGINES BEHIND SUPERNOVAE AND GAMMA-RAY BURSTS

Energy Technology Data Exchange (ETDEWEB)

FRYER, CHRISTOPHER LEE [Los Alamos National Laboratory

2007-01-23

The authors review the different engines behind supernova (SNe) and gamma-ray bursts (GRBs), focusing on those engines driving explosions in massive stars: core-collapse SNe and long-duration GRBs. Convection and rotation play important roles in the engines of both these explosions. They outline the basic physics and discuss the wide variety of ways scientists have proposed that this physics can affect the supernova explosion mechanism, concluding with a review of the current status in these fields.

LAD Early Career Prize Talk:Laboratory astrophysics experiments investigating the effects of high energy fluxes on Rayleigh-Taylor instability growth relevant to young supernova remnants

Science.gov (United States)

Kuranz, Carolyn C.; Drake, R. Paul; Park, Hye Sook; Huntington, Channing; Miles, Aaron R.; Remington, Bruce A.; Plewa, Tomek; Trantham, Matt; Shvarts, Dov; Raman, Kumar; MacLaren, Steven; Wan, Wesley; Doss, Forrest; Kline, John; Flippos, Kirk; Malamud, Guy; Handy, Timothy; Prisbey, Shon; Grosskopf, Michael; Krauland, Christine; Klein, Sallee; Harding, Eric; Wallace, Russell; Marion, Donna; Kalantar, Dan

2017-06-01

Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh Taylor (RT) instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter (CSM), based on simple models and hydrodynamic simulations. When a blast wave emerges from an exploding star, it drives a forward shock into the CSM and a reverse shock forms in the expanding stellar ejecta, creating a young supernova remnant (SNR). As mass accumulates in the shocked layers, the interface between these two shocks decelerates, becoming unstable to the RT instability. Simulations predict that RT produces structures at this interface, having a range of spatial scales. When the CSM is dense enough, as in the case of SN 1993J, the hot shocked matter can produce significant radiative fluxes that affect the emission from the SNR. Here we report experimental results from the National Ignition Facility (NIF) to explore how large energy fluxes, which are present in supernovae such as SN 1993J, might affect this structure. The experiment used NIF to create a RT unstable interface subject to a high energy flux by the emergence of a blast wave into lower-density matter, in analogy to the SNR. We also preformed and with a low energy flux to compare the affect of the energy flux on the instability growth. We found that the RT growth was reduced in the experiments with a high energy flux. In analyzing the comparison with SN 1993J, we discovered that the energy fluxes produced by heat conduction appear to be larger than the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling SNRs.

The dark energy survey Y1 supernova search: Survey strategy compared to forecasts and the photometric type Is SN volumetric rate

Science.gov (United States)

Fischer, John Arthur

For 70 years, the physics community operated under the assumption that the expansion of the Universe must be slowing due to gravitational attraction. Then, in 1998, two teams of scientists used Type Ia supernovae to discover that cosmic expansion was actually acceler- ating due to a mysterious "dark energy." As a result, Type Ia supernovae have become the most cosmologically important transient events in the last 20 years, with a large amount of effort going into their discovery as well as understanding their progenitor systems. One such probe for understanding Type Ia supernovae is to use rate measurements to de- termine the time delay between star formation and supernova explosion. For the last 30 years, the discovery of individual Type Ia supernova events has been accelerating. How- ever, those discoveries were happening in time-domain surveys that probed only a portion of the redshift range where expansion was impacted by dark energy. The Dark Energy Survey (DES) is the first project in the "next generation" of time-domain surveys that will discovery thousands of Type Ia supernovae out to a redshift of 1.2 (where dark energy be- comes subdominant) and DES will have better systematic uncertainties over that redshift range than any survey to date. In order to gauge the discovery effectiveness of this survey, we will use the first season's 469 photometrically typed supernovee and compare it with simulations in order to update the full survey Type Ia projections from 3500 to 2250. We will then use 165 of the 469 supernovae out to a redshift of 0.6 to measure the supernovae rate both as a function of comoving volume and of the star formation rate as it evolves with redshift. We find the most statistically significant prompt fraction of any survey to date (with a 3.9? prompt fraction detection). We will also reinforce the already existing tension in the measurement of the delayed fraction between high (z > 1.2) and low red- shift rate measurements, where we find no

Neutrino oscillations in magnetically driven supernova explosions

Energy Technology Data Exchange (ETDEWEB)

Kawagoe, Shio; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Takiwaki, Tomoya, E-mail: shio.k@nao.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: kkotake@th.nao.ac.jp [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

2009-09-01

We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ{sub 13} (sin{sup 2} 2θ{sub 13} ∼> 10{sup −3}), we show that survival probabilities of ν-bar {sub e} and ν{sub e} seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of ν-bar {sub e} observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the ν{sub e} signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the ν-bar {sub e} and ν{sub e} signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

Neutrino oscillations in magnetically driven supernova explosions

Science.gov (United States)

Kawagoe, Shio; Takiwaki, Tomoya; Kotake, Kei

2009-09-01

We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ13 (sin2 2θ13 gtrsim 10-3), we show that survival probabilities of bar nue and νe seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of bar nue observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the νe signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the bar nue and νe signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

A cosmogonical analogy between the Big Bang and a supernova

International Nuclear Information System (INIS)

Brown, W.K.

1981-01-01

The Big Bang may be discussed most easily in analogy with an expanding spherical shell. An expanding spherical shell, in turn, is quite similar to an ejected supernova shell. In both the Big Bang and the supernova, fragmentation is postulated to occur, where each fragment of the universe becomes a galaxy, and each fragment of supernova shell becomes a solar system. By supporting the presence of shearing flow at the time of fragmentation, a model has been constructed to examine the results in both cases. It has been shown that the model produces a good description of reality on both the galactic and solar system scales. (Auth.)

Runaway companions of supernova remnants with Gaia

Science.gov (United States)

Boubert, Douglas; Fraser, Morgan; Evans, N. Wyn

2018-04-01

It is expected that most massive stars have companions and thus that some core-collapse supernovae should have a runaway companion. The precise astrometry and photometry provided by Gaia allows for the systematic discovery of these runaway companions. We combine a prior on the properties of runaway stars from binary evolution with data from TGAS and APASS to search for runaway stars within ten nearby supernova remnants. We strongly confirm the existing candidate HD 37424 in S147, propose the Be star BD+50 3188 to be associated with HB 21, and suggest tentative candidates for the Cygnus and Monoceros Loops.

VizieR Online Data Catalog: A unified supernova catalogue (Lennarz+, 2012)

Science.gov (United States)

Lennarz, D.; Altmann, D.; Wiebusch, C.

2011-11-01

A supernova catalogue containing data for 5526 extragalactic supernovae that were discovered up to 2010 December 31. It combines several catalogues that are currently available online in a consistent and traceable way. During the comparison of the catalogues inconsistent entries were identified and resolved where possible. Remaining inconsistencies are marked transparently and can be easily identified. Thus it is possible to select a high-quality sample in a most simple way. Where available, redshift-based distance estimates to the supernovae were replaced by journal-refereed distances. (1 data file).

Cosmological and supernova neutrinos

Energy Technology Data Exchange (ETDEWEB)

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GSÜ, Department of Physics, Şişli, İstanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-06-24

The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

HD271791: dynamical versus binary-supernova ejection scenario

OpenAIRE

Gvaramadze, V. V.

2009-01-01

The atmosphere of the extremely high-velocity (530-920 km/s) early B-type star HD271791 is enriched in $\\alpha$-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its surface was polluted by the nucleosynthetic products after the primary star exploded in a supernova. It was proposed that the (asymmetric) supernova explosion unbind the system and that the secondary star (HD271791) was released at its orbital velocity in the...

Earth Effects and Mass Hierarchy with Supernova Neutrinos

International Nuclear Information System (INIS)

Dasgupta, Basudeb

2009-01-01

Collective neutrino flavor transformations take place deep inside a supernova if the neutrino mass hierarchy is inverted, even for extremely small values of θ 13 . We show that the presence (or absence) of Earth matter effects in antineutrino signal is directly related to the absence (or presence) of these collective effects, when the mixing angle θ 13 is small. Thus a neutrino signal from a galactic supernova may enable us to distinguish between the hierarchies even for small values of θ 13 .

Diffuse remnants of supernova explosions of moving massive stars

Science.gov (United States)

Gvaramadze, V. V.

The modification of the ambient interstellar medium by the wind of massive stars (the progenitors of most of supernovae) results in that the structure and evolution of diffuse supernova remnants (SNRs) significantly deviate from those derived from standard models of SNRs based of the Sedov-Taylor solution. The stellar proper motion and the regular interstellar magnetic field affect the symmetry of the processed medium and cause the SNR to be non-spherically-symmetric. We show that taking into account these effects allows us to explain the diverse morphologies of the known SNRs (the particular attention is paid to the elongated axisymmetric SNRs and the SNRs consisting of two partially overlapping shells) and to infer the ``true" supernova explosion sites in some peculiar SNRs (therefore to search for new neutron stars associated with them).

OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

Science.gov (United States)

2002-01-01

This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact

White dwarf models of supernovae and cataclysmic variables

International Nuclear Information System (INIS)

Nomoto, K.; Hashimoto, M.

1986-01-01

If the accreting white dwarf increases its mass to the Chandrasekhar mass, it will either explode as a Type I supernova or collapse to form a neutron star. In fact, there is a good agreement between the exploding white dwarf model for Type I supernovae and observations. We describe various types of evolution of accreting white dwarfs as a function of binary parameters (i.e,. composition, mass, and age of the white dwarf, its companion star, and mass accretion rate), and discuss the conditions for the precursors of exploding or collapsing white dwarfs, and their relevance to cataclysmic variables. Particular attention is given to helium star cataclysmics which might be the precursors of some Type I supernovae or ultrashort period x-ray binaries. Finally we present new evolutionary calculations using the updated nuclear reaction rates for the formation of O+Ne+Mg white dwarfs, and discuss the composition structure and their relevance to the model for neon novae. 61 refs., 14 figs

THE CARNEGIE SUPERNOVA PROJECT: SECOND PHOTOMETRY DATA RELEASE OF LOW-REDSHIFT TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Stritzinger, Maximilian D.; Phillips, M. M.; Campillay, Abdo; Morrell, Nidia; Krzeminski, Wojtek; Roth, Miguel; Boldt, Luis N.; Burns, Chris; Freedman, Wendy L.; Madore, Barry F.; Persson, Sven E.; Contreras, Carlos; Gonzalez, Sergio; Folatelli, Gaston; Salgado, Francisco; DePoy, D. L.; Marshall, J. L.; Rheault, Jean-Philippe; Suntzeff, Nicholas B.; Hamuy, Mario

2011-01-01

The Carnegie Supernova Project (CSP) was a five-year observational survey conducted at Las Campanas Observatory that obtained, among other things, high-quality light curves of ∼100 low-redshift Type Ia supernovae (SNe Ia). Presented here is the second data release of nearby SN Ia photometry consisting of 50 objects, with a subset of 45 having near-infrared follow-up observations. Thirty-three objects have optical pre-maximum coverage with a subset of 15 beginning at least five days before maximum light. In the near-infrared, 27 objects have coverage beginning before the epoch of B-band maximum, with a subset of 13 beginning at least five days before maximum. In addition, we present results of a photometric calibration program to measure the CSP optical (uBgVri) bandpasses with an accuracy of ∼1%. Finally, we report the discovery of a second SN Ia, SN 2006ot, similar in its characteristics to the peculiar SN 2006bt.

THE CARNEGIE SUPERNOVA PROJECT: FIRST PHOTOMETRY DATA RELEASE OF LOW-REDSHIFT TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Contreras, Carlos; Phillips, M. M.; Folatelli, Gaston; Stritzinger, Maximilian; Boldt, Luis; Gonzalez, Sergio; Krzeminski, Wojtek; Morrell, Nidia; Roth, Miguel; Salgado, Francisco; Hamuy, Mario; Maureira, MarIa Jose; Suntzeff, Nicholas B.; Persson, S. E.; Burns, Christopher R.; Freedman, W. L.; Madore, Barry F.; Murphy, David; Wyatt, Pamela; Li Weidong

2010-01-01

The Carnegie Supernova Project (CSP) is a five-year survey being carried out at the Las Campanas Observatory to obtain high-quality light curves of ∼100 low-redshift Type Ia supernovae (SNe Ia) in a well-defined photometric system. Here we present the first release of photometric data that contains the optical light curves of 35 SNe Ia, and near-infrared light curves for a subset of 25 events. The data comprise 5559 optical (ugriBV) and 1043 near-infrared (Y JHK s ) data points in the natural system of the Swope telescope. Twenty-eight SNe have pre-maximum data, and for 15 of these, the observations begin at least 5 days before B maximum. This is one of the most accurate data sets of low-redshift SNe Ia published to date. When completed, the CSP data set will constitute a fundamental reference for precise determinations of cosmological parameters, and serve as a rich resource for comparison with models of SNe Ia.

Observing the Next Galactic Supernova with the NOvA Detectors

Energy Technology Data Exchange (ETDEWEB)

Vasel, Justin A. [Indiana U.; Sheshukov, Andrey [Dubna, JINR; Habig, Alec [Minnesota U., Duluth

2017-10-02

The next galactic core-collapse supernova will deliver a wealth of neutrinos which for the first time we are well-situated to measure. These explosions produce neutrinos with energies between 10 and 100 MeV over a period of tens of seconds. Galactic supernovae are relatively rare events, occurring with a frequency of just a few per century. It is therefore essential that all neutrino detectors capable of detecting these neutrinos are ready to trigger on this signal when it occurs. This poster describes a data-driven trigger which is designed to detect the neutrino signal from a galactic core-collapse supernova with the NOvA detectors. The trigger analyzes 5ms blocks of detector activity and applies background rejection algorithms to detect the signal time structure over the background. This background reduction is an essential part of the process, as the NOvA detectors are designed to detect neutrinos from Fermilab's NuMI beam which have an average energy of 2GeV--well above the average energy of supernova neutrinos.

Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

Energy Technology Data Exchange (ETDEWEB)

Volpe, C.; Welzel, J. [Institut de Physique Nuclueaire, 91 - Orsay (France)

2007-07-01

We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic {nu}{sub e} and {nu}-bar{sub e} fluxes and on the number of events for {nu}{sub e} + C{sup 12}, {nu}{sub e} + O{sup 16}, {nu}{sub e} + Ar{sup 40} and {nu}-bar{sub e} + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

The Progenitor Dependence of Core-collapse Supernovae from Three-dimensional Simulations with Progenitor Models of 12–40 M ⊙

Science.gov (United States)

Ott, Christian D.; Roberts, Luke F.; da Silva Schneider, André; Fedrow, Joseph M.; Haas, Roland; Schnetter, Erik

2018-03-01

We present a first study of the progenitor star dependence of the three-dimensional (3D) neutrino mechanism of core-collapse supernovae. We employ full 3D general-relativistic multi-group neutrino radiation-hydrodynamics and simulate the postbounce evolutions of progenitors with zero-age main sequence masses of 12, 15, 20, 27, and 40 M ⊙. All progenitors, with the exception of the 12 M ⊙ star, experience shock runaway by the end of their simulations. In most cases, a strongly asymmetric explosion will result. We find three qualitatively distinct evolutions that suggest a complex dependence of explosion dynamics on progenitor density structure, neutrino heating, and 3D flow. (1) Progenitors with massive cores, shallow density profiles, and high post-core-bounce accretion rates experience very strong neutrino heating and neutrino-driven turbulent convection, leading to early shock runaway. Accretion continues at a high rate, likely leading to black hole formation. (2) Intermediate progenitors experience neutrino-driven, turbulence-aided explosions triggered by the arrival of density discontinuities at the shock. These occur typically at the silicon/silicon–oxygen shell boundary. (3) Progenitors with small cores and density profiles without strong discontinuities experience shock recession and develop the 3D standing-accretion shock instability (SASI). Shock runaway ensues late, once declining accretion rate, SASI, and neutrino-driven convection create favorable conditions. These differences in explosion times and dynamics result in a non-monotonic relationship between progenitor and compact remnant mass.

An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova.

Science.gov (United States)

Della Valle, M; Chincarini, G; Panagia, N; Tagliaferri, G; Malesani, D; Testa, V; Fugazza, D; Campana, S; Covino, S; Mangano, V; Antonelli, L A; D'Avanzo, P; Hurley, K; Mirabel, I F; Pellizza, L J; Piranomonte, S; Stella, L

2006-12-21

Gamma-ray bursts (GRBs) are short, intense flashes of soft gamma-rays coming from the distant Universe. Long-duration GRBs (those lasting more than approximately 2 s) are believed to originate from the deaths of massive stars, mainly on the basis of a handful of solid associations between GRBs and supernovae. GRB 060614, one of the closest GRBs discovered, consisted of a 5-s hard spike followed by softer, brighter emission that lasted for approximately 100 s (refs 8, 9). Here we report deep optical observations of GRB 060614 showing no emerging supernova with absolute visual magnitude brighter than M(V) = -13.7. Any supernova associated with GRB 060614 was therefore at least 100 times fainter, at optical wavelengths, than the other supernovae associated with GRBs. This demonstrates that some long-lasting GRBs can either be associated with a very faint supernova or produced by different phenomena.

Type-Ia supernova rates to redshift 2.4 from clash: The cluster lensing and supernova survey with Hubble

International Nuclear Information System (INIS)

Graur, O.; Rodney, S. A.; Riess, A. G.; Medezinski, E.; Maoz, D.; Jha, S. W.; Holoien, T. W.-S.; McCully, C.; Patel, B.; Postman, M.; Dahlen, T.; Strolger, L.-G.; Coe, D.; Bradley, L.; Koekemoer, A.; Benítez, N.; Molino, A.; Jouvel, S.; Nonino, M.; Balestra, I.

2014-01-01

We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope (HST), we have imaged 25 galaxy-cluster fields and parallel fields of non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel fields. Of these SNe, ∼13 are classified as SN Ia candidates, including four SN Ia candidates at redshifts z > 1.2. We measure volumetric SN Ia rates to redshift 1.8 and add the first upper limit on the SN Ia rate in the range 1.8 < z < 2.4. The results are consistent with the rates measured by the HST/GOODS and Subaru Deep Field SN surveys. We model these results together with previous measurements at z < 1 from the literature. The best-fitting SN Ia delay-time distribution (DTD; the distribution of times that elapse between a short burst of star formation and subsequent SN Ia explosions) is a power law with an index of −1.00 −0.06(0.10) +0.06(0.09) (statistical) −0.08 +0.12 (systematic), where the statistical uncertainty is a result of the 68% and 95% (in parentheses) statistical uncertainties reported for the various SN Ia rates (from this work and from the literature), and the systematic uncertainty reflects the range of possible cosmic star-formation histories. We also test DTD models produced by an assortment of published binary population synthesis (BPS) simulations. The shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN Ia measurements, when the DTD models are scaled up by factors of 3-9. In contrast, all BPS single-degenerate DTDs are ruled out by the measurements at >99% significance level.

Exploring the Outer Solar System with the ESSENCE Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Becker, A.C.; /Washington U., Seattle, Astron. Dept.; Arraki, K.; /Washington U., Seattle, Astron. Dept.; Kaib, N.A.; /Washington U., Seattle, Astron. Dept.; Wood-Vasey, W.M.; /Harvard-Smithsonian Ctr. Astrophys.; Aguilera, C.; /Cerro-Tololo InterAmerican Obs.; Blackman, J.W.; /Australian Natl. U., Canberra; Blondin, S.; /Harvard-Smithsonian Ctr. Astrophys.; Challis, P.; /Harvard-Smithsonian Ctr. Astrophys.; Clocchiatti, A.; /Rio de Janeiro, Pont. U. Catol.; Covarrubias, R.; /Kyushu Sangyo U.; Damke, G.; /Cerro-Tololo InterAmerican Obs.; Davis, T.M.; /Bohr Inst. /Queensland U.; Filippenko, A.V.; /UC, Berkeley; Foley, R.J.; /UC, Berkeley; Garg, A.; /Harvard-Smithsonian Ctr. Astrophys. /Harvard U.; Garnavich, P.M.; /Notre Dame U.; Hicken, M.; /Harvard-Smithsonian Ctr. Astrophys. /Harvard U.; Jha, S.; /Harvard U. /SLAC; Kirshner, R.P.; /Harvard-Smithsonian Ctr. Astrophys.; Krisciunas, K.; /Notre Dame U. /Texas A-M; Leibundgut, B.; /Munich, Tech. U. /UC, Berkeley /NOAO, Tucson /Washington U., Seattle, Astron. Dept. /Fermilab /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Chile U., Santiago /Ohio State U. /Cerro-Tololo InterAmerican Obs. /Harvard U. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Australian Natl. U., Canberra /Australian Natl. U., Canberra /Cerro-Tololo InterAmerican Obs. /Munich, Tech. U. /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Cerro-Tololo InterAmerican Obs. /Texas A-M /Cerro-Tololo InterAmerican Obs.

2011-11-10

We report the discovery and orbital determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging data set. Two additional objects discovered in a similar search of the SDSS-II Supernova Survey database were recovered in this effort. ESSENCE repeatedly observed fields far from the solar system ecliptic (-21{sup o} < {beta} < -5{sup o}), reaching limiting magnitudes per observation of I {approx} 23.1 and R {approx} 23.7. We examine several of the newly detected objects in detail, including 2003 UC{sub 414}, which orbits entirely between Uranus and Neptune and lies very close to a dynamical region that would make it stable for the lifetime of the solar system. 2003 SS{sub 422} and 2007 TA{sub 418} have high eccentricities and large perihelia, making them candidate members of an outer class of TNOs. We also report a new member of the 'extended' or 'detached' scattered disk, 2004 VN{sub 112}, and verify the stability of its orbit using numerical simulations. This object would have been visible to ESSENCE for only {approx}2% of its orbit, suggesting a vast number of similar objects across the sky. We emphasize that off-ecliptic surveys are optimal for uncovering the diversity of such objects, which in turn will constrain the history of gravitational influences that shaped our early solar system.

NEW HYPERON EQUATIONS OF STATE FOR SUPERNOVAE AND NEUTRON STARS IN DENSITY-DEPENDENT HADRON FIELD THEORY

Energy Technology Data Exchange (ETDEWEB)

Banik, Sarmistha [BITS Pilani, Hyderabad Campus, Hyderabad-500078 (India); Hempel, Matthias [Departement Physik, Universität Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Bandyopadhyay, Debades [Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)

2014-10-01

We develop new hyperon equation of state (EoS) tables for core-collapse supernova simulations and neutron stars. These EoS tables are based on a density-dependent relativistic hadron field theory where baryon-baryon interaction is mediated by mesons, using the parameter set DD2 for nucleons. Furthermore, light and heavy nuclei along with interacting nucleons are treated in the nuclear statistical equilibrium model of Hempel and Schaffner-Bielich which includes excluded volume effects. Of all possible hyperons, we consider only the contribution of Λs. We have developed two variants of hyperonic EoS tables: in the npΛφ case the repulsive hyperon-hyperon interaction mediated by the strange φ meson is taken into account, and in the npΛ case it is not. The EoS tables for the two cases encompass a wide range of densities (10{sup –12} to ∼1 fm{sup –3}), temperatures (0.1 to 158.48 MeV), and proton fractions (0.01 to 0.60). The effects of Λ hyperons on thermodynamic quantities such as free energy per baryon, pressure, or entropy per baryon are investigated and found to be significant at higher densities. The cold, β-equilibrated EoS (with the crust included self-consistently) results in a 2.1 M {sub ☉} maximum mass neutron star for the npΛφ case, whereas that for the npΛ case is 1.95 M {sub ☉}. The npΛφ EoS represents the first supernova EoS table involving hyperons that is directly compatible with the recently measured 2 M {sub ☉} neutron stars.

A relativistic type Ibc supernova without a detected gamma-ray burst.

Science.gov (United States)

Soderberg, A M; Chakraborti, S; Pignata, G; Chevalier, R A; Chandra, P; Ray, A; Wieringa, M H; Copete, A; Chaplin, V; Connaughton, V; Barthelmy, S D; Bietenholz, M F; Chugai, N; Stritzinger, M D; Hamuy, M; Fransson, C; Fox, O; Levesque, E M; Grindlay, J E; Challis, P; Foley, R J; Kirshner, R P; Milne, P A; Torres, M A P

2010-01-28

Long duration gamma-ray bursts (GRBs) mark the explosive death of some massive stars and are a rare sub-class of type Ibc supernovae. They are distinguished by the production of an energetic and collimated relativistic outflow powered by a central engine (an accreting black hole or neutron star). Observationally, this outflow is manifested in the pulse of gamma-rays and a long-lived radio afterglow. Until now, central-engine-driven supernovae have been discovered exclusively through their gamma-ray emission, yet it is expected that a larger population goes undetected because of limited satellite sensitivity or beaming of the collimated emission away from our line of sight. In this framework, the recovery of undetected GRBs may be possible through radio searches for type Ibc supernovae with relativistic outflows. Here we report the discovery of luminous radio emission from the seemingly ordinary type Ibc SN 2009bb, which requires a substantial relativistic outflow powered by a central engine. A comparison with our radio survey of type Ibc supernovae reveals that the fraction harbouring central engines is low, about one per cent, measured independently from, but consistent with, the inferred rate of nearby GRBs. Independently, a second mildly relativistic supernova has been reported.

A relativistic type Ibc supernova without a detected γ-ray burst

Science.gov (United States)

Soderberg, A. M.; Chakraborti, S.; Pignata, G.; Chevalier, R. A.; Chandra, P.; Ray, A.; Wieringa, M. H.; Copete, A.; Chaplin, V.; Connaughton, V.; Barthelmy, S. D.; Bietenholz, M. F.; Chugai, N.; Stritzinger, M. D.; Hamuy, M.; Fransson, C.; Fox, O.; Levesque, E. M.; Grindlay, J. E.; Challis, P.; Foley, R. J.; Kirshner, R. P.; Milne, P. A.; Torres, M. A. P.

2010-01-01

Long duration γ-ray bursts (GRBs) mark the explosive death of some massive stars and are a rare sub-class of type Ibc supernovae. They are distinguished by the production of an energetic and collimated relativistic outflow powered by a central engine (an accreting black hole or neutron star). Observationally, this outflow is manifested in the pulse of γ-rays and a long-lived radio afterglow. Until now, central-engine-driven supernovae have been discovered exclusively through their γ-ray emission, yet it is expected that a larger population goes undetected because of limited satellite sensitivity or beaming of the collimated emission away from our line of sight. In this framework, the recovery of undetected GRBs may be possible through radio searches for type Ibc supernovae with relativistic outflows. Here we report the discovery of luminous radio emission from the seemingly ordinary type Ibc SN 2009bb, which requires a substantial relativistic outflow powered by a central engine. A comparison with our radio survey of type Ibc supernovae reveals that the fraction harbouring central engines is low, about one per cent, measured independently from, but consistent with, the inferred rate of nearby GRBs. Independently, a second mildly relativistic supernova has been reported.

In search of Mahutonga: a possible supernova recorded in Maori astronomical traditions?

Science.gov (United States)

Green, David A.; Orchiston, Wayne

Maori astronomical traditions refer to Mahutonga, which can be interpreted as a possible record of a southern supernova (SN) in or near Crux. A search for any known "young" supernova remnants in this region does not reveal any obvious candidate to associate with this possible supernova. Relaxing the positional constraint somewhat, the SN of A.D. 185 near a Centauri is nearby. If this is associated with Mahutonga, then the Maori term must be a relic of an earlier Proto-Polynesian record.

Analysis of the 5-year final dataset of the Supernova Legacy Survey project

International Nuclear Information System (INIS)

Fourmanoit, N.

2010-01-01

The Supernova Legacy Survey (SNLS) is a program that aims at discovering and photometrically following hundreds of Type Ia supernovae (SNe Ia). Its goal is to measure the expansion history of the Universe in order to constrain the nature of the dark energy, namely its equation of state w DE . The survey completed its data taking during summer 2008 after 5 years of program. This thesis work consists in the analysis of these 5 years of SNLS data and the photometry of the 419 Type Ia supernovae discovered and spectroscopically identified. For each supernova, the light-curves are produced in the g M r M i M z M bands, calibrated and fitted with a spectrophotometric model. A new photometric method which does not make use of any pixel re-sampling has also been implemented and tested. This method preserves the pixels statistical properties, and produces this way more accurate flux measurement statistical uncertainties, that can be propagated to cosmological measurements. Both photometry results were checked and compared using calibration stars and supernovae, proving that the accuracy of the new method flux measurement uncertainty is indeed better, and that the photometric accuracy and stability of both techniques are similar. A sample of supernovae with unprecedented statistics and quality is now available for cosmological analysis. With the complement of an external nearby supernovae sample, a measurement within 5% of the dark energy equation of state of dark energy is thus for the first time within reach. (author)

RADIO POLARIMETRY SIGNATURES OF STRONG MAGNETIC TURBULENCE IN SUPERNOVA REMNANTS

International Nuclear Information System (INIS)

Stroman, Wendy; Pohl, Martin

2009-01-01

We discuss the emission and transport of polarized radio-band synchrotron radiation near the forward shocks of young shell-type supernova remnants, for which X-ray data indicate a strong amplification of turbulent magnetic field. Modeling the magnetic turbulence through the superposition of waves, we calculate the degree of polarization and the magnetic polarization direction which is at 90 deg. to the conventional electric polarization direction. We find that isotropic strong turbulence will produce weakly polarized radio emission even in the absence of internal Faraday rotation. If anisotropy is imposed on the magnetic-field structure, the degree of polarization can be significantly increased, provided internal Faraday rotation is inefficient. Both for shock compression and a mixture with a homogeneous field, the increase in polarization degree goes along with a fairly precise alignment of the magnetic-polarization angle with the direction of the dominant magnetic-field component, implying tangential magnetic polarization at the rims in the case of shock compression. We compare our model with high-resolution radio polarimetry data of Tycho's remnant. Using the absence of internal Faraday rotation we find a soft limit for the amplitude of magnetic turbulence, δB ∼ 0 . An alternative viable scenario involves anisotropic turbulence with stronger amplitudes in the radial direction, as was observed in recent Magnetohydrodynamics simulations of shocks propagating through a medium with significant density fluctuations.

The effect of weak lensing on distance estimates from supernovae

Energy Technology Data Exchange (ETDEWEB)

Smith, Mathew; Maartens, Roy [Department of Physics, University of the Western Cape, Cape Town 7535 (South Africa); Bacon, David J.; Nichol, Robert C.; Campbell, Heather; D' Andrea, Chris B. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Clarkson, Chris [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Bassett, Bruce A. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Cinabro, David [Wayne State University, Department of Physics and Astronomy, Detroit, MI 48202 (United States); Finley, David A.; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Galbany, Lluis [CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Olmstead, Matthew D. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Shapiro, Charles [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, La Canada Flintridge, CA 91109 (United States); Sollerman, Jesper, E-mail: matsmith2@gmail.com [The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)

2014-01-01

Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7σ). Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied. When these other correlations are taken into account, the lensing signal is detected at 1.4σ. We show, for the first time, that distance estimates from supernovae can be improved when lensing is incorporated, by including a new parameter in the SALT2 methodology for determining distance moduli. The recovered value of the new parameter is consistent with the lensing prediction. Using cosmic microwave background data from WMAP7, H {sub 0} data from Hubble Space Telescope and Sloan Digital Sky Survey (SDSS) Baryon acoustic oscillations measurements, we find the best-fit value of the new lensing parameter and show that the central values and uncertainties on Ω {sub m} and w are unaffected. The lensing of supernovae, while only seen at marginal significance in this low-redshift sample, will be of vital importance for the next generation of surveys, such as DES and LSST, which will be systematics-dominated.

Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Dilday, Benjamin; /Rutgers U., Piscataway /Chicago U. /KICP, Chicago; Smith, Mathew; /Cape Town U., Dept. Math. /Portsmouth U.; Bassett, Bruce; /Cape Town U., Dept. Math. /South African Astron. Observ.; Becker, Andrew; /Washington U., Seattle, Astron. Dept.; Bender, Ralf; /Munich, Tech. U. /Munich U. Observ.; Castander, Francisco; /Barcelona, IEEC; Cinabro, David; /Wayne State U.; Filippenko, Alexei V.; /UC, Berkeley; Frieman, Joshua A.; /Chicago U. /Fermilab; Galbany, Lluis; /Barcelona, IFAE; Garnavich, Peter M.; /Notre Dame U. /Stockholm U., OKC /Stockholm U.

2010-01-01

We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z {approx}< 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04{sub -0.95}{sup +1.61}% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of r{sub V} = (2.69{sub -0.30-0.01}{sup +0.34+0.21}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} at a mean redshift of {approx} 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, r{sub V} (z) = A{sub p} x ((1+z)/(1+z{sub 0})){sup {nu}}, over the redshift range 0.0 < z < 0.3 with z{sub 0} = 0.21, results in A{sub p} = (3.43{sub -0.15}{sup +0.15}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} and {nu} = 2.04{sub -0.89}{sup +0.90}.

LIGHT CURVES OF CORE-COLLAPSE SUPERNOVAE WITH SUBSTANTIAL MASS LOSS USING THE NEW OPEN-SOURCE SUPERNOVA EXPLOSION CODE (SNEC)

International Nuclear Information System (INIS)

Morozova, Viktoriya; Renzo, Mathieu; Ott, Christian D.; Clausen, Drew; Couch, Sean M.; Ellis, Justin; Roberts, Luke F.; Piro, Anthony L.

2015-01-01

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 blackbody emission. As a first application of SNEC, we consider the explosions of a grid of 15 M ⊙ (at zero-age main sequence, ZAMS) stars whose hydrogen envelopes are stripped to different extents and at different points in their evolution. The resulting light curves exhibit plateaus with durations of ∼20–100 days if ≳1.5–2 M ⊙ of hydrogen-rich material is left and no plateau if less hydrogen-rich material is left. If these shorter plateau lengths are not seen for SNe IIP in nature, it suggests that, at least for ZAMS masses ≲20 M ⊙ , hydrogen mass loss occurs as an all or nothing process. This perhaps points to the important role binary interactions play in generating the observed mass-stripped supernovae (i.e., Type Ib/c events). These light curves are also unlike what is typically seen for SNe IIL, arguing that simply varying the amount of mass loss cannot explain these events. The most stripped models begin to show double-peaked light curves similar to what is often seen for SNe IIb, confirming previous work that these supernovae can come from progenitors that have a small amount of hydrogen and a radius of ∼500 R ⊙

LIGHT CURVES OF CORE-COLLAPSE SUPERNOVAE WITH SUBSTANTIAL MASS LOSS USING THE NEW OPEN-SOURCE SUPERNOVA EXPLOSION CODE (SNEC)

Energy Technology Data Exchange (ETDEWEB)

Morozova, Viktoriya; Renzo, Mathieu; Ott, Christian D.; Clausen, Drew; Couch, Sean M.; Ellis, Justin; Roberts, Luke F. [TAPIR, Walter Burke Institute for Theoretical Physics, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Piro, Anthony L., E-mail: morozvs@tapir.caltech.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2015-11-20

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 blackbody emission. As a first application of SNEC, we consider the explosions of a grid of 15 M{sub ⊙} (at zero-age main sequence, ZAMS) stars whose hydrogen envelopes are stripped to different extents and at different points in their evolution. The resulting light curves exhibit plateaus with durations of ∼20–100 days if ≳1.5–2 M{sub ⊙} of hydrogen-rich material is left and no plateau if less hydrogen-rich material is left. If these shorter plateau lengths are not seen for SNe IIP in nature, it suggests that, at least for ZAMS masses ≲20 M{sub ⊙}, hydrogen mass loss occurs as an all or nothing process. This perhaps points to the important role binary interactions play in generating the observed mass-stripped supernovae (i.e., Type Ib/c events). These light curves are also unlike what is typically seen for SNe IIL, arguing that simply varying the amount of mass loss cannot explain these events. The most stripped models begin to show double-peaked light curves similar to what is often seen for SNe IIb, confirming previous work that these supernovae can come from progenitors that have a small amount of hydrogen and a radius of ∼500 R{sub ⊙}.

Fitting oscillating string gas cosmology to supernova data

International Nuclear Information System (INIS)

Ferrer, Francesc; Multamaeki, Tuomas; Raesaenen, Syksy

2009-01-01

In string gas cosmology, extra dimensions are stabilised by a gas of strings. In the matter-dominated era, competition between matter pushing the extra dimensions to expand and the string gas pulling them back can lead to oscillations of the extra dimensions and acceleration in the visible dimensions. We fit this model to supernova data, taking into account the Big Bang Nucleosynthesis constraint on the energy density of the string gas. The fit to the Union set of supernova data is acceptable, but the fit to the ESSENCE data is poor.

r-Process nucleosynthesis from three-dimensional jet-driven core-collapse supernovae with magnetic misalignments

Science.gov (United States)

Halevi, Goni; Mösta, Philipp

2018-06-01

We investigate r-process nucleosynthesis in three-dimensional general relativistic magnetohydrodynamic simulations of jet-driven supernovae resulting from rapidly rotating, strongly magnetized core-collapse. We explore the effect of misaligning the pre-collapse magnetic field with respect to the rotation axis by performing four simulations: one aligned model and models with 15°, 30°, and 45° misalignments. The simulations we present employ a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to post-bounce neutrino emission and absorption. We track the thermodynamic properties of the ejected material with Lagrangian tracer particles and analyse its composition with the nuclear reaction network SKYNET. By using different neutrino luminosities in post-processing the tracer data with SKYNET, we constrain the impact of uncertainties in neutrino luminosities. We find that, for the aligned model considered here, the use of an approximate leakage scheme results in neutrino luminosity uncertainties corresponding to a factor of 100-1000 uncertainty in the abundance of third peak r-process elements. Our results show that for misalignments of 30° or less, r-process elements are robustly produced as long as neutrino luminosities are reasonably low (≲ 5 × 1052 erg s-1). For a more extreme misalignment of 45°, we find the production of r-process elements beyond the second peak significantly reduced. We conclude that robust r-process nucleosynthesis in magnetorotational supernovae requires a progenitor stellar core with a large poloidal magnetic field component that is at least moderately (within ˜30°) aligned with the rotation axis.

On Neutron Star/Supernova Remnant Association

Science.gov (United States)

Gvaramadze, V. V.

It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1706-44, PSR B1757-24, SGR 0526-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possible NS/SNR associations could be enlarged. An observational test is discussed, which could provide a determination of the true birth-places of NSs associated with middle-aged SNRs, and thereby provide more reliable estimates of their transverse velocities.

Identifying the neutrino mass hierarchy with supernova neutrinos

International Nuclear Information System (INIS)

Tomas, Ricard

2006-01-01

We review how a high-statistics observation of the neutrino signal from a future galactic core-collapse supernova (SN) may be used to discriminate between different neutrino mixing scenarios. We discuss two complementary methods that allow for the positive identification of the mass hierarchy without knowledge of the emitted neutrino fluxes, provided that the 13-mixing angle is large, sin 2 θ 13 -5 . These two approaches are the observation of modulations in the neutrino spectra by Earth matter effects or by the passage of shock waves through the SN envelope. If the value of the 13-mixing angle is unknown, using additionally the information encoded in the prompt neutronization ν e burst-a robust feature found in all modern SN simulations-can be sufficient to fix both the neutrino hierarchy and to decide whether θ 13 is 'small' or 'large'

Constraints on the electron-neutrino mass from the supernova data

International Nuclear Information System (INIS)

Abbott, L.F.; Walker, T.P.

1988-01-01

The energy versus time of arrival pattern of neutrinos from SN1987A is sensitive to a neutrino mass, m ν , of order a few eV. To disentangle constraints on m ν , from the data, a theory of supernova emission is necessary. We recall the present status of this theory and approximate its predictions in two diffusion models: One designed to reflect the present supernova lore, the other devised to pessimize, within reason, the consequent upper limits on m ν . We discuss the model dependence and statistical significance of our results, as well as the experimental uncertainties and caveats to which they are subject. We adress the question, do the supernova results supercede the present laboratory limits on m ν ? (orig.)

"Type Ia Supernovae: Tools for Studying Dark Energy" Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Woosley, Stan [Lick Observatory, San Jose, CA (United States); Kasen, Dan [Univ. of California, Berkeley, CA (United States)

2017-05-10

Final technical report for project "Type Ia Supernovae: Tools for the Study of Dark Energy" awarded jointly to scientists at the University of California, Santa Cruz and Berkeley, for computer modeling, theory and data analysis relevant to the use of Type Ia supernovae as standard candles for cosmology.

The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda,and w from the First Year Data Set

Energy Technology Data Exchange (ETDEWEB)

Astier, P.; Guy, J.; Regnault, N.; Pain, R.; Aubourg, E.; Balam,D.; Basa, S.; Carlberg, R.G.; Fabbro, S.; Fouchez, D.; Hook, I.M.; Howell, D.A.; Lafoux, H.; Neill, J.D.; Palanque-Delabrouille, N.; Perrett, K.; Pritchet, C.J.; Rich, J.; Sullivan, M.; Taillet, R.; Aldering, G.; Antilogus, P.; Arsenijevic, V.; Balland, C.; Baumont, S.; Bronder, J.; Courtois, H.; Ellis, R.S.; Filiol, M.; Goncalves, A.C.; Goobar, A.; Guide, D.; Hardin, D.; Lusset, V.; Lidman, C.; McMahon, R.; Mouchet, M.; Mourao, A.; Perlmutter, S.; Ripoche, P.; Tao, C.; Walton, N.

2005-10-14

We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.

The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda, and w from the First Year Data Set

Science.gov (United States)

Astier, P.; Guy, J.; Regnault, N.; Pain, R.; Aubourg, E.; Balam, D.; Basa, S.; Carlberg, R. G.; Fabbro, S.; Fouchez, D.; Hook, I. M.; Howell, D. A.; Lafoux, H.; Neill, J. D.; Palanque-Delabrouille, N.; Perrett, K.; Pritchet, C. J.; Rich, J.; Sullivan, M.; Taillet, R.; Aldering, G.; Antilogus, P.; Arsenijevic, V.; Balland, C.; Baumont, S.; Bronder, J.; Courtois, H.; Ellis, R. S.; Filiol, M.; Goncalves, A. C.; Goobar, A.; Guide, D.; Hardin, D.; Lusset, V.; Lidman, C.; McMahon, R.; Mouchet, M.; Mourao, A.; Perlmutter, S.; Ripoche, P.; Tao, C.; Walton, N.

2005-10-14

We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.

Discovery of 11 ASAS-SN Supernovae

Science.gov (United States)

Brimacombe, J.; Cacella, P.; Stone, G.; Fernandez, J. M.; Vallely, P.; Stanek, K. Z.; Kochanek, C. S.; Brown, J. S.; Shields, J.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W.-S.; Prieto, J. L.; Bersier, D.; Dong, Subo; Bose, S.; Chen, Ping; Stritzinger, M.; Holmbo, S.; Nicholls, B.; Post, R. S.

2018-05-01

During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from 14-cm telescopes in Hawaii, Texas, South Africa, and Chile, we discovered several new transient sources.

Three-dimensional simulations of core-collapse supernovae: from shock revival to shock breakout

Science.gov (United States)

Wongwathanarat, A.; Müller, E.; Janka, H.-Th.

2015-05-01

We present three-dimensional hydrodynamic simulations of the evolution of core-collapse supernovae (SN) from blast-wave initiation by the neutrino-driven mechanism to shock breakout from the stellar surface, using an axis-free Yin-Yang grid and considering two 15 M⊙ red supergiants (RSG) and two blue supergiants (BSG) of 15 M⊙ and 20 M⊙. We demonstrate that the metal-rich ejecta in homologous expansion still carry fingerprints of asymmetries at the beginning of the explosion, but the final metal distribution is massively affected by the detailed progenitor structure. The most extended and fastest metal fingers and clumps are correlated with the biggest and fastest-rising plumes of neutrino-heated matter, because these plumes most effectively seed the growth of Rayleigh-Taylor (RT) instabilities at the C+O/He and He/H composition-shell interfaces after the passage of the SN shock. The extent of radial mixing, global asymmetry of the metal-rich ejecta, RT-induced fragmentation of initial plumes to smaller-scale fingers, and maximum Ni and minimum H velocities depend not only on the initial asphericity and explosion energy (which determine the shock and initial Ni velocities), but also on the density profiles and widths of C+O core and He shell and on the density gradient at the He/H transition, which leads to unsteady shock propagation and the formation of reverse shocks. Both RSG explosions retain a large global metal asymmetry with pronounced clumpiness and substructure, deep penetration of Ni fingers into the H-envelope (with maximum velocities of 4000-5000 km s-1 for an explosion energy around 1.5 bethe) and efficient inward H-mixing. While the 15 M⊙ BSG shares these properties (maximum Ni speeds up to ~3500 km s-1), the 20 M⊙ BSG develops a much more roundish geometry without pronounced metal fingers (maximum Ni velocities only ~2200 km s-1) because of reverse-shock deceleration and insufficient time for strong RT growth and fragmentation at the He

The R-process: supernovae and other sources of the heaviest elements

International Nuclear Information System (INIS)

Thielemann, F.-K.; Moceli, D.; Panov, I.

2007-01-01

Rapid neutron capture in stellar explosions is responsible for the heaviest elements in nature, up to Th, U and beyond. This nucleosynthesis process, the r-process, is unique in the sense that a combination of nuclear physics far from stability (masses, half-lives, neutron-capture and photodisintegration, neutron-induced and beta-delayed fission and last but not least neutrino-nucleus interactions) is intimately linked to ejecta from astrophysical explosions (core collapse supernovae or other neutron star related events). The astrophysics and nuclear physics involved still harbor many uncertainties, either in the extrapolation of nuclear properties far beyond present experimental explorations or in the modeling of multidimensional, general relativistic (neutrino-radiation) hydrodynamics with rotation and possibly required magnetic fields. Observational clues about the working of the r-process are mostly obtained from solar abundances and from the abundance evolution of the heaviest elements as a function of galactic age, as witnessed in old extremely metal-poor stars. They contain information whether the r-process is identical for all stellar events, how abundance features develop with galactic time and whether the frequency of r-process events is comparable to that of average core collapse supernovae - producing oxygen through titanium, as well as iron-group nuclei. The theoretical modeling of the r-process has advanced from simple approaches, where the use of static neutron densities and temperatures can aid to test the influence of nuclear properties far from stability on abundance features, to more realistic expansions with a given entropy, global neutron/proton ratio and expansion timescales, as expected from explosive astrophysical events. The direct modeling in astrophysical events such as supernovae still faces the problem whether the required conditions can be met. (author)

Colorful Investigations of Supernovae for WFIRST-AFTA

Science.gov (United States)

Foley, Ryan

Type Ia supernovae (SNe Ia) are extremely good probes of dark energy, and WFIRST-AFTA is particularly well suited to make the best SN distance measurements possible. For conservative assumptions, the WFIRST SN survey is projected to have twice the impact as its other probes. Considering that Euclid will only have a minimal SN survey, but strong programs for other dark energy probes, the WFIRST SN survey is especially unique and important. With an initial simulation of the WFIRST-AFTA survey, we have determined that the largest statistical and systematic uncertainties are related to SN color. SN distances strongly depend on the precise measurement of SN colors since we must make a dust extinction correction that depends on the observed color. The details of how the correction is applied and the possibility that the correction evolves with redshift combine with potential calibration systematics to limit the current effectiveness of the SN component of WFIRST-AFTA. Here, we propose to support two graduate students to (1) investigate how intrinsic color variations will impact WFIRST-AFTA systematic uncertainties, (2) determine improved methods for reducing the systematic uncertainties related to SN color, and (3) simulate survey strategies incorporating our results to obtain the highest dark energy figure of merit (DE-FoM).

The Influence of Host Galaxies in Type Ia Supernova Cosmology

Energy Technology Data Exchange (ETDEWEB)

Uddin, Syed A. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, Jiangshu (China); Mould, Jeremy [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, VIC (Australia); Lidman, Chris; Zhang, Bonnie R. [Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Ruhlmann-Kleider, Vanina, E-mail: saushuvo@gmail.com [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette, Paris (France)

2017-10-10

We use a sample of 1338 spectroscopically confirmed and photometrically classified Type Ia supernovae (SNe Ia) sourced from Carnegie Supernova Project, Center for Astrophysics Supernova Survey, Sloan Digital Sky Survey-II, and SuperNova Legacy Survey SN samples to examine the relationships between SNe Ia and the galaxies that host them. Our results provide confirmation with improved statistical significance that SNe Ia, after standardization, are on average more luminous in massive hosts (significance >5 σ ), and decline more rapidly in massive hosts (significance >9 σ ) and in hosts with low specific star formation rates (significance >8 σ ). We study the variation of these relationships with redshift and detect no evolution. We split SNe Ia into pairs of subsets that are based on the properties of the hosts and fit cosmological models to each subset. Including both systematic and statistical uncertainties, we do not find any significant shift in the best-fit cosmological parameters between the subsets. Among different SN Ia subsets, we find that SNe Ia in hosts with high specific star formation rates have the least intrinsic scatter ( σ {sub int} = 0.08 ± 0.01) in luminosity after standardization.

A supernova origin for dust in a high-redshift quasar.

Science.gov (United States)

Maiolino, R; Schneider, R; Oliva, E; Bianchi, S; Ferrara, A; Mannucci, F; Pedani, M; Sogorb, M Roca

2004-09-30

Interstellar dust plays a crucial role in the evolution of the Universe by assisting the formation of molecules, by triggering the formation of the first low-mass stars, and by absorbing stellar ultraviolet-optical light and subsequently re-emitting it at infrared/millimetre wavelengths. Dust is thought to be produced predominantly in the envelopes of evolved (age >1 Gyr), low-mass stars. This picture has, however, recently been brought into question by the discovery of large masses of dust in the host galaxies of quasars at redshift z > 6, when the age of the Universe was less than 1 Gyr. Theoretical studies, corroborated by observations of nearby supernova remnants, have suggested that supernovae provide a fast and efficient dust formation environment in the early Universe. Here we report infrared observations of a quasar at redshift 6.2, which are used to obtain directly its dust extinction curve. We then show that such a curve is in excellent agreement with supernova dust models. This result demonstrates a supernova origin for dust in this high-redshift quasar, from which we infer that most of the dust at high redshifts probably has the same origin.

Could a nearby supernova explosion have caused a mass extinction?

Science.gov (United States)

Ellis, J; Schramm, D N

1995-01-03

We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of gamma-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the "KT boundary." The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events.

Clustered supernovae versus the gaseous disk and halo

International Nuclear Information System (INIS)

Heiles, C.

1990-01-01

The effects of clustered supernovae on the two-dimensional porosity parameter Q(2D) and the rates M of mass injection of both hot and cold gas into the halo are reconsidered. The effects of high-absolute value z, low-density extension of the neutral gas layer are theoretically calculated and the distribution of H-alpha luminosities of extragalactic H II regions is observationally determined. These results are used to estimate the birth rate of star clusters having N supernovae as a function of N. A Galaxy-wide average of Q(2D) roughly 0.30 is obtained, corresponding to an area filling factor of 0.23. Area filling factors and mass injection rates into the halo due to breakthrough bubbles with large N are calculated for different types of galaxy. The calculations are related to the area covered by H I 'holes' and the area covered by giant H II regions. The effects of supernova clusters that are too small to produce breakthrough bubbles are discussed. 53 refs