Superior Mesenteric Artery Dissection after Extracorporeal Shockwave Lithotripsy

Directory of Open Access Journals (Sweden)

Christos Bakoyiannis

2012-01-01

Full Text Available The use of shockwave lithotripsy is currently the mainstay of treatment in renal calculosis. Several complications including vessel injuries have been implied to extracorporeal shockwave lithotripsy. We report an isolated dissection of the superior mesenteric artery in a 60-year-old male presenting with abdominal pain which occurred three days after extracorporeal shockwave lithotripsy. The patient was treated conservatively and the abdominal pain subsided 24 hours later. The patient's history, the course of his disease, and the timing may suggest a correlation between the dissection and the ESWL.

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

International Nuclear Information System (INIS)

Janka, H.T.

1996-01-01

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

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.

Extracorporeal shockwave for chronic patellar tendinopathy.

Science.gov (United States)

Wang, Ching-Jen; Ko, Jih-Yang; Chan, Yi-Sheng; Weng, Lin-Hsiu; Hsu, Shan-Lin

2007-06-01

Chronic patellar tendinopathy is an overuse syndrome with pathologic changes similar to tendinopathies of the shoulder, elbow, and heel. Extracorporeal shockwave was shown effective in many tendinopathies. Extracorporeal shockwave therapy may be more effective than conservative treatment for chronic patellar tendinopathy. Randomized controlled clinical trial; Level of evidence, 2. This study consisted of 27 patients (30 knees) in the study group and 23 patients (24 knees) in the control group. In the study group, patients were treated with 1500 impulses of extracorporeal shockwave at 14 KV (equivalent to 0.18 mJ/mm(2) energy flux density) to the affected knee at a single session. Patients in the control group were treated with conservative treatments including nonsteroidal anti-inflammatory drugs, physiotherapy, exercise program, and the use of a knee strap. The evaluation parameters included pain score, Victorian Institute of Sports Assessment score, and ultrasonographic examination at 1, 3, 6, and 12 months and then once a year. At the 2- to 3-year follow-up, the overall results for the study group were 43% excellent, 47% good, 10% fair, and none poor. For the control group, the results were none excellent, 50% good, 25% fair, and 25% poor. The mean Victorian Institute of Sports Assessment scores were 42.57 +/- 10.22 and 39.25 +/- 10.85, respectively, before treatment (P = .129) and 92.0 +/- 10.17 and 41.04 +/- 10.96, respectively, after treatment (P Extracorporeal shockwave therapy appeared to be more effective and safer than traditional conservative treatments in the management of patients with chronic patellar tendinopathy.

Can low-intensity extracorporeal shockwave therapy improve erectile dysfunction?

DEFF Research Database (Denmark)

Olsen, Anne B; Persiani, Marie; Boie, Sidsel

2015-01-01

OBJECTIVE: The aim of this study was to investigate whether low-intensity extracorporeal shockwave therapy (LI-ESWT) can be used as a treatment for men with erectile dysfunction of organic origin. MATERIALS AND METHODS: This prospective, randomized, blinded, placebo-controlled study included 112 ...... are needed. KEYWORDS: Erectile dysfunction; extracorporeal shockwave; penis...

Shockwave treatment for musculoskeletal diseases and bone consolidation: qualitative analysis of the literature

Directory of Open Access Journals (Sweden)

Paulo Kertzman

2015-02-01

Full Text Available Shockwave treatment is an option within orthopedics. The exact mechanism through which shockwaves function for treating musculoskeletal diseases is unknown. The aim of this study was to make a qualitative analysis on the effectiveness of shockwave treatment among patients with musculoskeletal pathological conditions and pseudarthrosis. Searches were conducted in the Cochrane Library, Medline and Lilacs databases. Thirty-nine studies that reported using shockwave treatment for musculoskeletal diseases were found. Their results varied greatly, as did the types of protocol used. The studies that evaluated the effectiveness of shockwave treatment for lateral epicondylitis, shoulder tendinopathy, knee osteoarthrosis, femoral head osteonecrosis and trochanteric bursitis reported inconsistent results for most of their patients. Those that evaluated patients with calcifying tendinopathy, plantar fasciitis, Achilles tendinopathy, patellar tendinopathy and pseudarthrosis showed benefits. Shockwave treatment is a safe and non-invasive method for chronic cases in which conventional techniques have been unsatisfactory and should be used in association with other treatment methods for tendinopathy. Further quality studies are needed.

Time Resolved Shadowgraph Images of Silicon during Laser Ablation: Shockwaves and Particle Generation

International Nuclear Information System (INIS)

Liu, C Y; Mao, X L; Greif, R; Russo, R E

2007-01-01

Time resolved shadowgraph images were recorded of shockwaves and particle ejection from silicon during laser ablation. Particle ejection and expansion were correlated to an internal shockwave resonating between the shockwave front and the target surface. The number of particles ablated increased with laser energy and was related to the crater volume

Time Resolved Shadowgraph Images of Silicon during Laser Ablation:Shockwaves and Particle Generation

Energy Technology Data Exchange (ETDEWEB)

Liu, C.Y.; Mao, X.L.; Greif, R.; Russo, R.E.

2006-05-06

Time resolved shadowgraph images were recorded of shockwaves and particle ejection from silicon during laser ablation. Particle ejection and expansion were correlated to an internal shockwave resonating between the shockwave front and the target surface. The number of particles ablated increased with laser energy and was related to the crater volume.

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.

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.

[Renal hematomas after extracorporeal shock-wave lithotripsy (ESWL)].

Science.gov (United States)

Pastor Navarro, Héctor; Carrión López, Pedro; Martínez Ruiz, Jesús; Pastor Guzmán, José Ma; Martínez Martín, Mariano; Virseda Rodríguez, Julio A

2009-03-01

The use of fragmentation due to shock- waves as a treatment of urinary stone was one of the most important therapeutics findings in the history of urology. It's the first election treatment for most of the calculus at renal and urethral location due to the fact that it is a low invasive treatment and it has a few number of complications, but this method also has a few negative side effects, it can caused a more or less important traumatic lesion at the organs which crosses the shock-waves, including the kidney where it can caused a small contusion or renal hematoma with different resolution and treatment. We reviewed 4815 extracorporeal shock-wave lithotripsy that we performed in our department in which we found six cases with subcapsular and perirenal hematoma which we followed up and treated. After the urological complications (pain, obstruction and infection) the renal and perirenal hematic collections are the most frequent adverse effects of shock-waves used in lithotripsy, these are related to the power of energy used and patient age. Between the years 1992-2007 we performed 4.815 extracorporeal shock-wave lithotripsy finding seven cases of severe hematoma, less then 1%. Treatment of these complications is usually not aggressive though sometimes it is necessary to perform surgical drainage and even nephrectomy.

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.

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)

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

Causality violation, gravitational shockwaves and UV completion

Energy Technology Data Exchange (ETDEWEB)

Hollowood, Timothy J.; Shore, Graham M. [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

2016-03-18

The effective actions describing the low-energy dynamics of QFTs involving gravity generically exhibit causality violations. These may take the form of superluminal propagation or Shapiro time advances and allow the construction of “time machines”, i.e. spacetimes admitting closed non-spacelike curves. Here, we discuss critically whether such causality violations may be used as a criterion to identify unphysical effective actions or whether, and how, causality problems may be resolved by embedding the action in a fundamental, UV complete QFT. We study in detail the case of photon scattering in an Aichelburg-Sexl gravitational shockwave background and calculate the phase shifts in QED for all energies, demonstrating their smooth interpolation from the causality-violating effective action values at low-energy to their manifestly causal high-energy limits. At low energies, these phase shifts may be interpreted as backwards-in-time coordinate jumps as the photon encounters the shock wavefront, and we illustrate how the resulting causality problems emerge and are resolved in a two-shockwave time machine scenario. The implications of our results for ultra-high (Planck) energy scattering, in which graviton exchange is modelled by the shockwave background, are highlighted.

[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.

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

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.

Uniformity of cylindrical imploding underwater shockwaves at very small radii

Science.gov (United States)

Yanuka, D.; Rososhek, A.; Bland, S. N.; Krasik, Ya. E.

2017-11-01

We compare the convergent shockwaves generated from underwater, cylindrical arrays of copper wire exploded by multiple kilo-ampere current pulses on nanosecond and microsecond scales. In both cases, the pulsed power devices used for the experiments had the same stored energy (˜500 J) and the wire mass was adjusted to optimize energy transfer to the shockwave. Laser backlit framing images of the shock front were achieved down to the radius of 30 μm. It was found that even in the case of initial azimuthal non-symmetry, the shock wave self-repairs in the final stages of its motion, leading to a highly uniform implosion. In both these and previous experiments, interference fringes have been observed in streak and framing images as the shockwave approached the axis. We have been able to accurately model the origin of the fringes, which is due to the propagation of the laser beam diffracting off the uniform converging shock front. The dynamics of the shockwave and its uniformity at small radii indicate that even with only 500 J stored energies, this technique should produce pressures above 1010 Pa on the axis, with temperatures and densities ideal for warm dense matter research.

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.

BLACK HOLE FORMATION IN FAILING CORE-COLLAPSE SUPERNOVAE

International Nuclear Information System (INIS)

O'Connor, Evan; Ott, Christian D.

2011-01-01

We present results of a systematic study of failing core-collapse supernovae and the formation of stellar-mass black holes (BHs). Using our open-source general-relativistic 1.5D code GR1D equipped with a three-species neutrino leakage/heating scheme and over 100 presupernova models, we study the effects of the choice of nuclear equation of state (EOS), zero-age main sequence (ZAMS) mass and metallicity, rotation, and mass-loss prescription on BH formation. We find that the outcome, for a given EOS, can be estimated, to first order, by a single parameter, the compactness of the stellar core at bounce. By comparing protoneutron star (PNS) structure at the onset of gravitational instability with solutions of the Tolman-Oppenheimer-Volkof equations, we find that thermal pressure support in the outer PNS core is responsible for raising the maximum PNS mass by up to 25% above the cold NS value. By artificially increasing neutrino heating, we find the critical neutrino heating efficiency required for exploding a given progenitor structure and connect these findings with ZAMS conditions, establishing, albeit approximately, for the first time based on actual collapse simulations, the mapping between ZAMS parameters and the outcome of core collapse. We also study the effect of progenitor rotation and find that the dimensionless spin of nascent BHs may be robustly limited below a* = Jc/GM 2 = 1 by the appearance of nonaxisymmetric rotational instabilities.

Shockwave-Based Automated Vehicle Longitudinal Control Algorithm for Nonrecurrent Congestion Mitigation

Directory of Open Access Journals (Sweden)

Liuhui Zhao

2017-01-01

Full Text Available A shockwave-based speed harmonization algorithm for the longitudinal movement of automated vehicles is presented in this paper. In the advent of Connected/Automated Vehicle (C/AV environment, the proposed algorithm can be applied to capture instantaneous shockwaves constructed from vehicular speed profiles shared by individual equipped vehicles. With a continuous wavelet transform (CWT method, the algorithm detects abnormal speed drops in real-time and optimizes speed to prevent the shockwave propagating to the upstream traffic. A traffic simulation model is calibrated to evaluate the applicability and efficiency of the proposed algorithm. Based on 100% C/AV market penetration, the simulation results show that the CWT-based algorithm accurately detects abnormal speed drops. With the improved accuracy of abnormal speed drop detection, the simulation results also demonstrate that the congestion can be mitigated by reducing travel time and delay up to approximately 9% and 18%, respectively. It is also found that the shockwave caused by nonrecurrent congestion is quickly dissipated even with low market penetration.

Supernova Driving. IV. The star-formation rate of molecular clouds

DEFF Research Database (Denmark)

Padoan, Paolo; Haugbølle, Troels; Nordlund, Åke

2017-01-01

We compute the star-formation rate (SFR) in molecular clouds (MCs) that originate ab initio in a new, higher-resolution simulation of supernova-driven turbulence. Because of the large number of well-resolved clouds with self-consistent boundary and initial conditions, we obtain a large range...... of cloud physical parameters with realistic statistical distributions, which is an unprecedented sample of star-forming regions to test SFR models and to interpret observational surveys. We confirm the dependence of the SFR per free-fall time, SFRff, on the virial parameter, αvir, found in previous...... MCs and in clouds near the Galactic center. Although not explicitly modeled by the theory, the scatter is consistent with the physical assumptions of our revised model and may also result in part from a lack of statistical equilibrium of the turbulence, due to the transient nature of MCs....

Extracorporeal shockwave therapy: A systematic review of its use in fracture management

Directory of Open Access Journals (Sweden)

Petrisor B

2009-01-01

Full Text Available Extracorporeal shockwave therapy is increasingly used as an adjuvant therapy in the management of nonunions, delayed unions and more recently fresh fractures. This is in an effort to increase union rates or obtain unions when fractures have proven recalcitrant to healing. In this report we have systematically reviewed the English language literature to attempt to determine the potential clinical efficacy of extracorporeal shockwave therapy in fracture management. Of 32 potentially eligible studies identified, 10 were included that assessed the extracorporeal shockwave therapy use for healing nonunions or delayed unions, and one trial was included that assessed its use for acute high-energy fractures. From the included, studies′ overall union rates were in favor of extracorporeal shockwave therapy (72% union rate overall for nonunions or delayed unions, and a 46% relative risk reduction in nonunions when it is used for acute high-energy fractures. However, the methodologic quality of included studies was weak and any clinical inferences made from these data should be interpreted with caution. Further research in this area in the form of a large-scale randomized trial is necessary to better answer the question of the effectiveness of extracorporeal shockwave therapy on union rates for both nonunions and acute fractures.

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.

Interacting supernovae and supernova impostors

Science.gov (United States)

Tartaglia, Leonardo

2016-02-01

Massive stars are thought to end their lives with spectacular explosions triggered by the gravitational collapse of their cores. Interacting supernovae are generally attributed to supernova explosions occurring in dense circumstellar media, generated through mass-loss which characterisie the late phases of the life of their progenitors. In the last two decades, several observational evidences revealed that mass-loss in massive stars may be related to violent eruptions involving their outer layers, such as the luminous blue variables. Giant eruptions of extragalactic luminous blue variables, similar to that observed in Eta Car in the 19th century, are usually labelled 'SN impostors', since they mimic the behaviour of genuine SNe, but are not the final act of the life of the progenitor stars. The mechanisms producing these outbursts are still not understood, although the increasing number of observed cases triggered the efforts of the astronomical community to find possible theoretical interpretations. More recently, a number of observational evidences suggested that also lower-mass stars can experience pre-supernova outbursts, hence becoming supernova impostors. Even more interestingly, there is growing evidence of a connection among massive stars, their outbursts and interacting supernovae. All of this inspired this research, which has been focused in particular on the characterisation of supernova impostors and the observational criteria that may allow us to safely discriminate them from interacting supernovae. Moreover, the discovery of peculiar transients, motivated us to explore the lowest range of stellar masses that may experience violent outbursts. Finally, the quest for the link among massive stars, their giant eruptions and interacting supernovae, led us to study the interacting supernova LSQ13zm, which possibly exploded a very short time after an LBV-like major outburst.

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.

COMPARISON BETWEEN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AT 120 AND 60 SHOCKWAVES PER MINUTE FOR TREATMENT OF URINARY STONES.

Science.gov (United States)

Kashima, Soki; Horikawa, Yohei; Obara, Takashi; Muto, Yumina; Koizumi, Atsushi; Honma, Naoko; Akihama, Susumu; Shimoda, Naotake

2016-01-01

(Purpose) It has recently been suggested that a slow delivery rate of shockwaves by extracorporeal shock wave lithotripsy (SWL) improved treatment outcomes for urinary stones. We retrospectively analyzed the treatment outcomes of different shockwave delivery rates at 120 and 60 shockwaves per minute. (Patients and method) A total of 88 patients were treated at a fast delivery rate of 120 shockwaves per minute between July 2010 and April 2012, and 139 patients were treated at a slow delivery rate of 60 shockwaves per minute between May 2012 and May 2014 (n=227) using a Sonolith ® Praktis lithotripter. The treatment outcome of stone-free rate (SFR) after one SWL session was assessed at four weeks. (Result) SWL at 60 shockwaves per minute resulted in a significantly higher SFR compared with SWL at 120 shockwaves per minute (39.8% and 59.0%, respectively, p=0.0047), particularly for upper ureter (U1) stones (53.1% and 72.0%, respectively, p=0.028). Multivariate analysis showed that younger age, stone sizes of 10 mm or less, U1 stones, and slow delivery rate were significant predictors of a stone-free outcome. There were fewer adverse events after the delivery rate of 60 shockwaves per minute (p=0.058). (Conclusion) Our study suggests that SWL at 60 shockwaves per minute should be recommended to successfully treat urinary stones using the Sonolith ® Praktis lithotripter.

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...

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

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.

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.

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.

Epicardial shock-wave therapy improves ventricular function in a porcine model of ischaemic heart disease.

Science.gov (United States)

Holfeld, Johannes; Zimpfer, Daniel; Albrecht-Schgoer, Karin; Stojadinovic, Alexander; Paulus, Patrick; Dumfarth, Julia; Thomas, Anita; Lobenwein, Daniela; Tepeköylü, Can; Rosenhek, Raphael; Schaden, Wolfgang; Kirchmair, Rudolf; Aharinejad, Seyedhossein; Grimm, Michael

2016-12-01

Previously we have shown that epicardial shock-wave therapy improves left ventricular ejection fraction (LVEF) in a rat model of myocardial infarction. In the present experiments we aimed to address the safety and efficacy of epicardial shock-wave therapy in a preclinical large animal model and to further evaluate mechanisms of action of this novel therapy. Four weeks after left anterior descending (LAD) artery ligation in pigs, the animals underwent re-thoracotomy with (shock-wave group, n = 6) or without (control group, n = 5) epicardial shock waves (300 impulses at 0.38 mJ/mm 2 ) applied to the infarcted anterior wall. Efficacy endpoints were improvement of LVEF and induction of angiogenesis 6 weeks after shock-wave therapy. Safety endpoints were haemodynamic stability during treatment and myocardial damage. Four weeks after LAD ligation, LVEF decreased in both the shock-wave (43 ± 3%, p wave animals 6 weeks after treatment (62 ± 9%, p = 0.006); no improvement was observed in controls (41 ± 4%, p = 0.36), yielding a significant difference. Quantitative histology revealed significant angiogenesis 6 weeks after treatment (controls 2 ± 0.4 arterioles/high-power field vs treatment group 9 ± 3; p = 0.004). No acute or chronic adverse effects were observed. As a potential mechanism of action in vitro experiments showed stimulation of VEGF receptors after shock-wave treatment in human coronary artery endothelial cells. Epicardial shock-wave treatment in a large animal model of ischaemic heart failure exerted a positive effect on LVEF improvement and did not show any adverse effects. Angiogenesis was induced by stimulation of VEGF receptors. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

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.

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)

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

Frequency of stone clearance after extracorporeal shockwave ...

African Journals Online (AJOL)

Objective: To determine the rate of stone clearance after extracorporeal shockwave lithotripsy (ESWL) for renal stones in adult patients with renal insufficiency. Subjects and methods: This is a cross-sectional descriptive study of 117 adult patients who underwent ESWL. The indications for ESWL were determined by the ...

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.

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

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study.

Science.gov (United States)

Thijs, Karin M; Zwerver, Johannes; Backx, Frank J G; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H

2017-03-01

To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. Randomized controlled trial. Sports medicine departments of a university hospital and a general hospital in the Netherlands. Fifty-two physically active male and female participants with a clinical diagnosis of PT (mean age: 28.6 years; range, 18-45) were randomly allocated to the ESWT (n = 22) or sham shockwave (n = 30). Extracorporeal shockwave therapy and sham shockwave were applied in 3 sessions at 1-week intervals with a piezoelectric device. All participants were instructed to perform eccentric exercises (3 sets of 15 repetitions twice a day) for 3 months on a decline board at home. The Victorian Institute of Sport Assessment-Patella (VISA-P) scores (primary), pain scores during functional knee loading tests, and Likert score (secondary) were registered at baseline and at 6, 12, and 24 weeks after the start with the ESWT or sham-shockwave treatment. No significant differences for the primary and secondary outcome measures were found between the groups. In the ESWT/eccentric group, the VISA-P increased from 54.5 ± 15.4 to 70.9 ± 17.8, whereas the VISA-P in the sham-shockwave/eccentric group increased from 58.9 ± 14.6 to 78.2 ± 15.8 (between-group change in VISA-P at 24 weeks -4.8; 95% confidence interval, -12.7 to 3.0, P = 0.150). This study showed no additional effect of 3 sessions ESWT in participants with PT treated with eccentric exercises. The results should be interpreted with caution because of small sample size and considerable loss to follow-up, particularly in the ESWT group.

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.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy : A Double-Blinded Randomized Study

NARCIS (Netherlands)

Thijs, Karin M; Zwerver, Johannes; Backx, Frank J G; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy : A Double-Blinded Randomized Study

NARCIS (Netherlands)

Thijs, Karin M.; Zwerver, Johannes; Backx, Frank J. G.; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H.

2017-01-01

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial.

Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

Energy Technology Data Exchange (ETDEWEB)

D' Andrea, Chris B. [Univ. of Pennsylvania, Philadelphia, PA (United States); et al.

2011-12-20

We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

Supernova feedback in numerical simulations of galaxy formation: separating physics from numerics

Science.gov (United States)

Smith, Matthew C.; Sijacki, Debora; Shen, Sijing

2018-04-01

While feedback from massive stars exploding as supernovae (SNe) is thought to be one of the key ingredients regulating galaxy formation, theoretically it is still unclear how the available energy couples to the interstellar medium and how galactic scale outflows are launched. We present a novel implementation of six sub-grid SN feedback schemes in the moving-mesh code AREPO, including injections of thermal and/or kinetic energy, two parametrizations of delayed cooling feedback and a `mechanical' feedback scheme that injects the correct amount of momentum depending on the relevant scale of the SN remnant resolved. All schemes make use of individually time-resolved SN events. Adopting isolated disk galaxy setups at different resolutions, with the highest resolution runs reasonably resolving the Sedov-Taylor phase of the SN, we aim to find a physically motivated scheme with as few tunable parameters as possible. As expected, simple injections of energy overcool at all but the highest resolution. Our delayed cooling schemes result in overstrong feedback, destroying the disk. The mechanical feedback scheme is efficient at suppressing star formation, agrees well with the Kennicutt-Schmidt relation and leads to converged star formation rates and galaxy morphologies with increasing resolution without fine tuning any parameters. However, we find it difficult to produce outflows with high enough mass loading factors at all but the highest resolution, indicating either that we have oversimplified the evolution of unresolved SN remnants, require other stellar feedback processes to be included, require a better star formation prescription or most likely some combination of these issues.

CALCULATION OF SHOCK-WAVE PULSE EFFECT ON OUTSTRETCHED SPINE

Directory of Open Access Journals (Sweden)

G. A. Esman

2011-01-01

Full Text Available Combined effects of a shock-wave pulse method and mechanotherapy on a spine is considered as an alternative to conservative and operative methods.Methodology for spinal disease treatment while applying a shock-wave therapy is characterized by the following specific features. Firstly, it is necessary to limit a penetration depth of shock pulses in a biological object in order to exclude damage to a spinal cord. Secondly, it is necessary to limit an energy flux density:Imax≤ 0,280 J∕m2and  pressure in focus:PFmax≤ 0,040 MPа,in order to exclude traumatizing of spinal tissue and only stimulate blood  circulation and metabolic processes in them.Where an acceptable value of the force acting on the inter-vertebral disc while a shock wave is passing is determined by the following formula: F max = PFmaxS = PFmax πr02 = 0,040 ∙106 ∙3,14 ∙(8∙10-32 = 9 N, where r0 – a focal spot radius, mm.Mechanotherapy is applied in combination with the shock-wave therapy and it presupposes the following: an outstretching force acts created in a longitudinal direction of the spine and it is directed across a vertebral column, whose value usually ranges from 50 to 500 N.   

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.

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.

Lateral epicondylitis: This is still a main indication for extracorporeal shockwave therapy.

Science.gov (United States)

Thiele, S; Thiele, R; Gerdesmeyer, L

2015-12-01

Extracorporeal shockwave therapy (ESWT) is used in a number of indications in the medical field. A number of tendinopathies show good and excellent results due to evidence based medicine. The treatment of lateral epicondylitis is known to show conflicting results. This overview of the published RCT's on ESWT for lateral epicondylitis tries to show the reasons for this conflicting data-base and point out, why we think that this is still a main indication for extracorporeal shockwave therapy. Copyright © 2015. Published by Elsevier Ltd.

International shock-wave database project : report of the requirements workshop.

Energy Technology Data Exchange (ETDEWEB)

Aidun, John Bahram (Institute of Problems of chemical Physics of Russian Academy of Sciences); Lomonosov, Igor V. (Institute of Problems of chemical Physics of Russian Academy of Sciences); Levashov, Pavel R. (Joint Institute for High Temperatures of Russian Academy of Sciences)

2012-03-01

We report on the requirements workshop for a new project, the International Shock-Wave database (ISWdb), which was held October 31 - November 2, 2011, at GSI, Darmstadt, Germany. Participants considered the idea of this database, its structure, technical requirements, content, and principles of operation. This report presents the consensus conclusions from the workshop, key discussion points, and the goals and plan for near-term and intermediate-term development of the ISWdb. The main points of consensus from the workshop were: (1) This international database is of interest and of practical use for the shock-wave and high pressure physics communities; (2) Intermediate state information and off-Hugoniot information is important and should be included in ISWdb; (3) Other relevant high pressure and auxiliary data should be included to the database, in the future; (4) Information on the ISWdb needs to be communicated, broadly, to the research community; and (5) Operating structure will consist of an Advisory Board, subject-matter expert Moderators to vet submitted data, and the database Project Team. This brief report is intended to inform the shock-wave research community and interested funding agencies about the project, as its success, ultimately, depends on both of these groups finding sufficient value in the database to use it, contribute to it, and support it.

Lupus Loop: a possible case of star formation induced by a supernova event

Energy Technology Data Exchange (ETDEWEB)

Arnal, M; Dubner, G

1986-02-01

Expanding shock waves like those arising from supernova remnants and strong stellar winds are usually proposed as a triggering mechanism for star formation, through the interaction between the expanding shock wave and dense surrounding clouds. Neutral hydrogen observations at 21cm carried out towards the Lupus Loop SNR (Colomb and Dubner 1982) have clearly shown the existence of two concentration cold shells around the radio-remnant, the outer one probably formed by the stellar wind of an early-type star (probable SN progenitor.), whilst the inner one is likely to be associated with the supernova event itself. Because a statistically significant excess of early-type stars is noticed in the outskirts of the expanding shells, a UBV-photometric study of nearly 150 stars earlier than A5 has been carried out using the Lowell 0.6m telescope of CTIO. The ultimate goal of this investigation is to establish whether or not a genetic link between the expanding shells and the early-type stars can exist. The following preliminary results were obtained: (1) a real grouping of early-type stars does exist projected against the south-eastern border of the outer cold shell, where the HI column density contours show the steepest gradient; (2) assuming that all the member stars are main sequence ones, and using the mean evolution deviation curve method, a distance of (870 +/- 80) pc is derived for the group. The obtained results favor the existence of a physical relationship between the outer expanding shell and the early-type stars grouping. 1 reference.

THE AGES OF TYPE Ia SUPERNOVA PROGENITORS

International Nuclear Information System (INIS)

Brandt, Timothy D.; Aubourg, Eric; Strauss, Michael A.; Tojeiro, Rita; Heavens, Alan; Jimenez, Raul

2010-01-01

Using light curves and host galaxy spectra of 101 Type Ia supernovae (SNe Ia) with redshift z ∼ 2.4 Gyr. We find that each channel contributes roughly half of the Type Ia rate in our reference sample. We also construct the average spectra of high-stretch and low-stretch SN Ia host galaxies, and find that the difference of these spectra looks like a main-sequence B star with nebular emission lines indicative of star formation. This supports our finding that there are two populations of SNe Ia, and indicates that the progenitors of high-stretch supernovae are at the least associated with very recent star formation in the last few tens of Myr. Our results provide valuable constraints for models of Type Ia progenitors and may help improve the calibration of SNe Ia as standard candles.

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...

STAR FORMATION ASSOCIATED WITH THE SUPERNOVA REMNANT IC443

International Nuclear Information System (INIS)

Xu Jinlong; Wang Junjie; Miller, Martin

2011-01-01

We have performed submillimeter and millimeter observations in CO lines toward supernova remnant (SNR) IC443. The CO molecular shell coincides well with the partial shell of the SNR detected in radio continuum observations. Broad emission lines and three 1720 MHz OH masers were detected in the CO molecular shell. The present observations have provided further evidence in support of the interaction between the SNR and the adjoining molecular clouds (MCs). The total mass of the MCs is 9.26 x 10 3 M sun . The integrated CO line intensity ratio (R I CO(3-2) /I CO(2-1) ) for the whole MC is between 0.79 and 3.40. The average value is 1.58, which is much higher than previous measurements of individual Galactic MCs. Higher line ratios imply that shocks have driven into the MCs. We conclude that high R I CO(3-2) /I CO(2-1) is identified as a good signature of the SNR-MC interacting system. Based on the IRAS Point Source Catalog and the Two Micron All Sky Survey near-infrared database, 12 protostellar object and 1666 young stellar object (YSO) candidates (including 154 classical T Tauri stars and 419 Herbig Ae/Be stars) are selected. In the interacting regions, the significant enhancement of the number of protostellar objects and YSOs indicates the presence of some recently formed stars. After comparing the characteristic timescales of star formation with the age of IC443, we conclude that the protostellar objects and YSO candidates are not triggered by IC443. For the age of the stellar winds shell, we have performed our calculation on the basis of a stellar wind shell expansion model. The results and analysis suggest that the formation of these stars may be triggered by the stellar winds of the IC443 progenitor.

Mesoscale simulations of shockwave energy dissipation via chemical reactions.

Science.gov (United States)

Antillon, Edwin; Strachan, Alejandro

2015-02-28

We use a particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level to study the response of materials that undergo volume-reducing chemical reactions under shockwave-loading conditions. We find that such chemical reactions can attenuate the shockwave and characterize how the parameters of the chemical model affect this behavior. The simulations show that the magnitude of the volume collapse and velocity at which the chemistry propagates are critical to weaken the shock, whereas the energetics in the reactions play only a minor role. Shock loading results in transient states where the material is away from local equilibrium and, interestingly, chemical reactions can nucleate under such non-equilibrium states. Thus, the timescales for equilibration between the various degrees of freedom in the material affect the shock-induced chemistry and its ability to attenuate the propagating shock.

Secondary sound classification for the assessment of focus positioning in shock-wave lithotripsy

OpenAIRE

Grennberg, Anders; Almquist, Lars-Olof; Holmner, Nils-Gunnar; Olsson, Lennart

1993-01-01

A problem encountered when using acoustic shock-waves for kidney stone disintegration is that the positioning of the focus relative to a stone, for the best possible fragmenting effect, is crtitical. The standard methods for focus positioning are ultrasound or x-ray imaging. These methods are, however, not always sufficient and a better indication of a well positioned focus would be valuable. The secondary sound emitted as a result of each shock-wave has been found to contain valuable informa...

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.

Simulating Supernova Light Curves

Energy Technology Data Exchange (ETDEWEB)

Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-05

This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

Simulating Supernova Light Curves

International Nuclear Information System (INIS)

Even, Wesley Paul; Dolence, Joshua C.

2016-01-01

This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth's atmosphere.

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

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.

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.)

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.

Cavitation cluster dynamics in shock-wave lithotripsy: Part I

NARCIS (Netherlands)

Arora, M.; Junge, L.; Junge, L.; Ohl, C.D.

2005-01-01

The spatiotemporal dynamics of cavitation bubble growth and collapse in shock-wave lithotripsy in a free field was studied experimentally. The lithotripter was equipped with two independently triggerable layers of piezoceramics. The front and back layers generated positive pressure amplitudes of 30

Radio Supernovae: Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor Stars

Science.gov (United States)

2009-02-24

years initiated by K. W. Weiler, N. Panagia, and R. A. Sramek. The VLA observing programs have detected dozens of new radio SNe. After discovery , the...analysis of the recent VLA data appears to support this discovery , reporting an inversion of the spectral index at higher 6 Figure 4 Left, the VLA light...formation of pulsar wind-nebula in other SN observations where VLBI measurements are not feasible. 3 The Future of Radio Supernovae Current observing

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...

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

The TOPSHOCK study : Effectiveness of radial shockwave therapy compared to focused shockwave therapy for treating patellar tendinopath - Design of a randomised controlled trial

NARCIS (Netherlands)

van der Worp, H.; Zwerver, J.; van den Akker-Scheek, I.; Diercks, R.L.

2011-01-01

Background: Patellar tendinopathy is a chronic overuse injury of the patellar tendon that is especially prevalent in people who are involved in jumping activities. Extracorporeal Shockwave Therapy is a relatively new treatment modality for tendinopathies. It seems to be a safe and promising part of

Matching Supernovae to Galaxies

Science.gov (United States)

Kohler, Susanna

2016-12-01

One of the major challenges for modern supernova surveys is identifying the galaxy that hosted each explosion. Is there an accurate and efficient way to do this that avoids investing significant human resources?Why Identify Hosts?One problem in host galaxy identification. Here, the supernova lies between two galaxies but though the centroid of the galaxy on the right is closer in angular separation, this may be a distant background galaxy that is not actually near the supernova. [Gupta et al. 2016]Supernovae are a critical tool for making cosmological predictions that help us to understand our universe. But supernova cosmology relies on accurately identifying the properties of the supernovae including their redshifts. Since spectroscopic followup of supernova detections often isnt possible, we rely on observations of the supernova host galaxies to obtain redshifts.But how do we identify which galaxy hosted a supernova? This seems like a simple problem, but there are many complicating factors a seemingly nearby galaxy could be a distant background galaxy, for instance, or a supernovas host could be too faint to spot.The authors algorithm takes into account confusion, a measure of how likely the supernova is to be mismatched. In these illustrations of low (left) and high (right) confusion, the supernova is represented by a blue star, and the green circles represent possible host galaxies. [Gupta et al. 2016]Turning to AutomationBefore the era of large supernovae surveys, searching for host galaxies was done primarily by visual inspection. But current projects like the Dark Energy Surveys Supernova Program is finding supernovae by the thousands, and the upcoming Large Synoptic Survey Telescope will likely discover hundreds of thousands. Visual inspection will not be possible in the face of this volume of data so an accurate and efficient automated method is clearly needed!To this end, a team of scientists led by Ravi Gupta (Argonne National Laboratory) has recently

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

Heat, mass and force flows in supersonic shockwave interaction

Science.gov (United States)

Dixon, John Michael

There is no cost effective way to deliver a payload to space and, with rising fuel prices, currently the price to travel commercially is also becoming more prohibitive to the public. During supersonic flight, compressive shock waves form around the craft which could be harnessed to deliver an additional lift on the craft. Using a series of hanging plates below a lifting wing design, the total lift generated can be increased above conventional values, while still maintaining a similar lift-to-drag ratio. Here, we study some of the flows involved in supersonic shockwave interaction. This analysis uses ANSYS Fluent Computational Fluid Dynamics package as the modeler. Our findings conclude an increase of up to 30% lift on the modeled craft while maintaining the lift-to-drag profile of the unmodified lifting wing. The increase in lift when utilizing the shockwave interaction could increase transport weight and reduce fuel cost for space and commercial flight, as well as mitigating negative effects associated with supersonic travel.

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).

No difference in effectiveness between focused and radial shockwave therapy for treating patellar tendinopathy : A randomized controlled trial

NARCIS (Netherlands)

van der Worp, H.; Zwerver, J.; Hamstra, M.; van den Akker-Scheek, I.; Diercks, R. L.

The aim of the study was to compare the effectiveness of focused shockwave therapy (FSWT) and radial shockwave therapy (RSWT) for treating patellar tendinopathy. Patients were randomized into two groups. One group received three sessions of FSWT, and the other group received three sessions of RSWT.

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.

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)

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study

OpenAIRE

Thijs, Karin M.; Zwerver, Johannes; Backx, Frank J. G.; Steeneken, Victor; Rayer, Stephan; Groenenboom, Petra; Moen, Maarten H.

2017-01-01

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial. SETTING: Sports medicine departments of a university hospital and a general hospital in the Netherlands. PARTICIPANTS: Fifty-two physically active male and female participants with a clinical diagnosis ...

THE SUPERNOVA TRIGGERED FORMATION AND ENRICHMENT OF OUR SOLAR SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Gritschneder, M.; Lin, D. N. C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian, 100871 Beijing (China); Murray, S. D. [Lawrence Livermore National Laboratory, University of California, Livermore, CA 94550 (United States); Yin, Q.-Z. [Department of Geology, University of California, Davis, CA 95616 (United States); Gong, M.-N., E-mail: gritschneder@pku.edu.cn [Department of Physics, Tsinghua University, Hai Dian, 100084 Beijing (China)

2012-01-20

We investigate the enrichment of the pre-solar cloud core with short-lived radionuclides, especially {sup 26}Al. The homogeneity and the surprisingly small spread in the ratio {sup 26}Al/{sup 27}Al observed in the overwhelming majority of calcium-aluminium-rich inclusions in a vast variety of primitive chondritic meteorites places strong constraints on the formation of the solar system. Freshly synthesized radioactive {sup 26}Al has to be included and well mixed within 20 kyr. After discussing various scenarios including X-winds, asymptotic giant branch stars, and Wolf-Rayet stars, we come to the conclusion that triggering the collapse of a cold cloud core by a nearby supernova (SN) is the most promising scenario. We then narrow down the vast parameter space by considering the pre-explosion survivability of such a clump as well as the cross-section necessary for sufficient enrichment. We employ numerical simulations to address the mixing of the radioactively enriched SN gas with the pre-existing gas and the forced collapse within 20 kyr. We show that a cold clump of 10 M{sub Sun} at a distance of 5 pc can be sufficiently enriched in {sup 26}Al and triggered into collapse fast enough-within 18 kyr after encountering the SN shock-for a range of different metallicities and progenitor masses, even if the enriched material is assumed to be distributed homogeneously in the entire SN bubble. In summary, we envision an environment for the birthplace of the solar system 4.567 Gyr ago similar to the situation of the pillars in M16 nowadays, where molecular cloud cores adjacent to an H II region will be hit by an SN explosion in the future. We show that the triggered collapse and formation of the solar system as well as the required enrichment with radioactive {sup 26}Al are possible in this scenario.

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.

Management of retained encrusted urethral catheter with extracorporeal shockwave lithotripsy

Directory of Open Access Journals (Sweden)

Sameh Anwar Kunzman

2002-01-01

Full Text Available We report a case of non-deflating heavily encrusted Foley catheter successfully removed by extracorporeal shockwave lithotripsy (ESWL. To our knowledge this is the first case of using ESWL to remove encrusted foley catheter retained in the bladder.

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

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.

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.

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

Potential for supernova-induced chemical enrichment of protoglobular cluster clouds

International Nuclear Information System (INIS)

Dopita, M.A.; Smith, G.H.; Dominion Astrophysical Observatory, Victoria, Canada)

1986-01-01

This paper seeks to explain the large internal abundance variations that are seen in the globular cluster Omega Cen in terms of supernova-induced chemical enrichment that occurred when the cluster was still largely in a gaseous phase and star formation was continuing. Using a simple power-law density model of this protoglobular gas cloud, the conditions under which this can occur have been established analytically. Clouds less massive than about 100,000 solar masses are completely disrupted by supernova explosions in their adiabatic phase. In clouds of greater mass, supernova explosions occurring near the tidal radius tend to lose their hot gas and metals to the intercloud medium. For explosions occurring closer to the mass center the ejecta must be slowed below the escape velocity, and this can only occur in clouds more massive than about 3 x 10 to the 6th solar masses. If this condition is met, then the slow isothermal momentum-conserving shocks generated by the supernova explosions may eventually induce secondary star formation. For such shocks converging on the mass center, it is found that a cloud mass of at least 10 to the 7th solar masses is required for this process to be efficient. From the observed properties of Omega Cen, a primordial mass of order 10 to the 8th solar masses is estimated, which emphasizes the unusual character of this object. 39 references

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.

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.

Impacto ambiental de los remanentes de supernova

Science.gov (United States)

Dubner, G. M.

2015-08-01

The explosion of a supernovae (SN) represents the sudden injection of about ergs of thermal and mechanical energy in a small region of space, causing the formation of powerful shock waves that propagate through the interstellar medium at speeds of several thousands of km/s. These waves sweep, compress and heat the interstellar material that they encounter, forming the supernova remnants. Their evolution over thousands of years change forever, irreversibly, not only the physical but also the chemical properties of a vast region of space that can span hundreds of parsecs. This contribution briefly analyzes the impact of these explosions, discussing the relevance of some phenomena usually associated with SNe and their remnants in the light of recent theoretical and observational results.

Interaction of Supernova Blast Waves with Wind-Driven Shells: Formation of "Jets", "Bullets", "Ears", Etc.

Science.gov (United States)

Gvaramadze, V. V.

Most of middle-aged supernova remnants (SNRs) have a distorted and complicated appearance which cannot be explained in the framework of the Sedov-Taylor model. We consider three typical examples of such SNRs (Vela SNR, MSH15-52, G309.2-00.6) and show that their structure could be explained as a result of interaction of a supernova (SN) blast wave with the ambient medium preprocessed by the action of the SN progenitor's wind and ionized emission.

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)

Changes of articular cartilage and subchondral bone after extracorporeal shockwave therapy in osteoarthritis of the knee.

Science.gov (United States)

Wang, Ching-Jen; Cheng, Jai-Hong; Chou, Wen-Yi; Hsu, Shan-Ling; Chen, Jen-Hung; Huang, Chien-Yiu

2017-01-01

We assessed the pathological changes of articular cartilage and subchondral bone on different locations of the knee after extracorporeal shockwave therapy (ESWT) in early osteoarthritis (OA). Rat knees under OA model by anterior cruciate ligament transaction (ACLT) and medial meniscectomy (MM) to induce OA changes. Among ESWT groups, ESWT were applied to medial (M) femur (F) and tibia (T) condyles was better than medial tibia condyle, medial femur condyle as well as medial and lateral (L) tibia condyles in gross osteoarthritic areas (posteophyte formation and subchondral sclerotic bone (psubchondral bone repair in all ESWT groups compared to OA group (p T(M+L) > F(M) in OA rat knees.

Mapping the Supernova-Rich Fireworks Galaxy NGC 6946

Science.gov (United States)

Patton, Locke; Levesque, Emily

2018-01-01

Supernovae (SNe) are the spectacularly violent deaths of evolved young massive stars, which expel a shock wave into the intergalactic medium that in turn can spark star formation and disperse heavy elements into their host galaxy. While a SN event can be classified by its spectral signature, determining the nature of a SN progenitor depends upon chance photometry taken prior to the event. By turning to the study of SN host environments and their surrounding interstellar medium within the unique and rare population of galaxies that have hosted three or more SN events within the last century, we are granted the opportunity to study the locations and environmental properties of stellar populations prone to supernova progenitor production. Using moderate-resolution optical slit spectra taken with the Apache Point Observatory 3.5m DIS spectrograph, our goal is to map metallicity, ionization parameter, and star formation rates using emission line diagnostic ratios across each SN-rich galaxy. Dubbed the “Fireworks Galaxy” at a distance of 5.6 ± 1.5 Mpc, NGC 6946 is of particular interest as it has uniquely produced ten core-collapse supernovae (CCSNe) and several other massive star transients within the last century. We present spatially-resolved metallicity and star formation rate (SFR) maps of NGC 6946, tracing fifty-five slit orientations which span the face of the galaxy and cover all CCSN host sites. Future work will include both stellar population synthesis modelling to determine stellar populations, ages, and SFR histories in NGC 6946 and a further expansion of this analysis to the other SN-rich host galaxies in our sample.

The effects of extracorporeal shockwave on acute high-energy long bone fractures of the lower extremity.

Science.gov (United States)

Wang, Ching-Jen; Liu, Hao-Chen; Fu, Te-Hu

2007-02-01

High-energy long bone fractures of the lower extremity are at risk of poor fracture healing and high rate of non-union. Extracorporeal shockwave was shown effective to heal non-union of long bone fracture. However, the effect of shockwave on acute fractures is unknown. The purpose of this study was to investigate the effects of shockwave on acute high-energy fractures of the lower extremity. Between January and October 2004, 56 patients with 59 acute high-energy fractures were enrolled in this study. Patients were randomly divided into two groups with 28 patients with 28 fractures in the study group and 28 patients with 31 fractures in the control group. Both groups showed similar age, gender, type of fracture and follow-up time. Patients in the study group received open reduction and internal fixation and shockwave treatment immediately after surgery on odd-numbered days of the week, whereas, patients in the control group received open reduction and internal fixation without shockwave treatment on even-numbered days of the week. Postoperative managements were similarly performed in both groups including crutch walking with non-weight bearing on the affected limb until fracture healing shown on radiographs. The evaluation parameters included clinical assessments of pain score and weight bearing status of the affected leg and serial radiographs at 3, 6 and 12 months. The primary end-point is the rate of non-union at 12 months, and the secondary end point is the rate of fracture healing at 3, 6 and 12 months. At 12 months, the rate of non-union was 11% for the study group versus 20% for the control group (P fracture healing was noted in the study group than the control group at 3, 6 and 12 months (P fracture healing and decreasing the rate of non-union in acute high-energy fractures of the lower extremity.

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.

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.

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.

Astronomy. ASASSN-15lh: A highly super-luminous supernova.

Science.gov (United States)

Dong, Subo; Shappee, B J; Prieto, J L; Jha, S W; Stanek, K Z; Holoien, T W-S; Kochanek, C S; Thompson, T A; Morrell, N; Thompson, I B; Basu, U; Beacom, J F; Bersier, D; Brimacombe, J; Brown, J S; Bufano, F; Chen, Ping; Conseil, E; Danilet, A B; Falco, E; Grupe, D; Kiyota, S; Masi, G; Nicholls, B; Olivares E, F; Pignata, G; Pojmanski, G; Simonian, G V; Szczygiel, D M; Woźniak, P R

2016-01-15

We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine. Copyright © 2016, American Association for the Advancement of Science.

Extracorporeal shockwave therapy for patellar tendinopathy : a review of the literature

NARCIS (Netherlands)

van Leeuwen, M. T.; Zwerver, J.; van den Akker-Scheek, I.

Background and purpose: Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment;

Investigation of supersonic jets shock-wave structure

Science.gov (United States)

Zapryagaev, V. I.; Gubanov, D. A.; Kavun, I. N.; Kiselev, N. P.; Kundasev, S. G.; Pivovarov, A. A.

2017-10-01

The paper presents an experimental studies overview of the free supersonic jet flow structure Ma = 1.0, Npr = 5, exhausting from a convergent profiled nozzle into a ambient space. Also was observed the jets in the presence of artificial streamwise vortices created by chevrons and microjets located on the nozzle exit. The technique of experimental investigation, schlieren-photographs and schemes of supersonic jets, and Pitot pressure distributions, are presented. A significant effect of vortex generators on the shock-wave structure of the flow is shown.

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 .

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.;

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)

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.

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.

Extracorporeal shockwave therapy in the treatment of chronic diabetic foot ulcers

DEFF Research Database (Denmark)

Jeppesen, S M; Yderstraede, K B; Rasmussen, B S B

2016-01-01

OBJECTIVE: To investigate the efficacy of extracorporeal shockwave therapy (ESWT) on healing chronic diabetic foot ulcers (DFU). METHOD: Patients with chronic DFUs were randomised (1:1) to receive a series of six ESWT treatments over 3 weeks in combination with standard care or standard care alone...

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 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.

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

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

Supernova Driving. IV. The Star-formation Rate of Molecular Clouds

Science.gov (United States)

Padoan, Paolo; Haugbølle, Troels; Nordlund, Åke; Frimann, Søren

2017-05-01

We compute the star-formation rate (SFR) in molecular clouds (MCs) that originate ab initio in a new, higher-resolution simulation of supernova-driven turbulence. Because of the large number of well-resolved clouds with self-consistent boundary and initial conditions, we obtain a large range of cloud physical parameters with realistic statistical distributions, which is an unprecedented sample of star-forming regions to test SFR models and to interpret observational surveys. We confirm the dependence of the SFR per free-fall time, SFRff, on the virial parameter, α vir, found in previous simulations, and compare a revised version of our turbulent fragmentation model with the numerical results. The dependences on Mach number, { M }, gas to magnetic pressure ratio, β, and compressive to solenoidal power ratio, χ at fixed α vir are not well constrained, because of random scatter due to time and cloud-to-cloud variations in SFRff. We find that SFRff in MCs can take any value in the range of 0 ≤ SFRff ≲ 0.2, and its probability distribution peaks at a value of SFRff ≈ 0.025, consistent with observations. The values of SFRff and the scatter in the SFRff-α vir relation are consistent with recent measurements in nearby MCs and in clouds near the Galactic center. Although not explicitly modeled by the theory, the scatter is consistent with the physical assumptions of our revised model and may also result in part from a lack of statistical equilibrium of the turbulence, due to the transient nature of MCs.

Plantar fascia-specific stretching versus radial shock-wave therapy as initial treatment of plantar fasciopathy.

Science.gov (United States)

Rompe, Jan D; Cacchio, Angelo; Weil, Lowell; Furia, John P; Haist, Joachim; Reiners, Volker; Schmitz, Christoph; Maffulli, Nicola

2010-11-03

Whether plantar fascia-specific stretching or shock-wave therapy is effective as an initial treatment for proximal plantar fasciopathy remains unclear. The aim of this study was to test the null hypothesis of no difference in the effectiveness of these two forms of treatment for patients who had unilateral plantar fasciopathy for a maximum duration of six weeks and which had not been treated previously. One hundred and two patients with acute plantar fasciopathy were randomly assigned to perform an eight-week plantar fascia-specific stretching program (Group I, n = 54) or to receive repetitive low-energy radial shock-wave therapy without local anesthesia, administered weekly for three weeks (Group II, n = 48). All patients completed the seven-item pain subscale of the validated Foot Function Index and a patient-relevant outcome questionnaire. Patients were evaluated at baseline and at two, four, and fifteen months after baseline. The primary outcome measures were a mean change in the Foot Function Index sum score at two months after baseline, a mean change in item 2 (pain during the first few steps of walking in the morning) on this index, and satisfaction with treatment. No difference in mean age, sex, weight, or duration of symptoms was found between the groups at baseline. At two months after baseline, the Foot Function Index sum score showed significantly greater changes for the patients managed with plantar fascia-specific stretching than for those managed with shock-wave therapy (p plantar fascia is superior to repetitive low-energy radial shock-wave therapy for the treatment of acute symptoms of proximal plantar fasciopathy.

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...

[Extracorporeal shock-wave lithotripsy of gallstones].

Science.gov (United States)

Freund, H R; Lebensart, P D; Muggia-Sullam, M; Durst, A L

1989-08-01

We performed 16 extracorporeal shock-wave lithotripsies (ESWL) to fragment gallstones in 11 women and 2 men, aged 19 to 57 (mean 41 +/- 10) years, during the past 10 months. Criteria for selection included a history of biliary colic, not more than 3 stones with a total diameter of not more than 30 mm, and a functioning gallbladder. 210 patients were examined, of whom 98 were referred for additional screening by combined ultrasonography and oral cholecystography. This resulted in rejection of another 71 patients due to multiple stones (38%), nonfunctioning gallbladder (22%), calcified stones (12%), stones not visualized in the prone position (9%), excessively large stones (3%) and other reasons (16%). Only 27 patients fulfilled all the criteria. Under epidural or general anesthesia (11 and 2 patients, respectively), we administered 1200-3500 (mean 2250 +/- 750) shock waves at 20-24 KV with the Tripter X1 (Direx, Israel-USA). This is an ultrasound-guided, modular portable, shock-wave generator utilizing underwater high energy spark discharge. Chenodeoxycholic or ursodeoxycholic acid, 10 mg/kg/day, was started 1 week prior to ESWL and continued for 3 months after disappearance of fragments and debris. We encountered skin petechiae in all patients, transient hematuria in 8, mild biliary colic in 1 and a small liver hematoma in 1. To date, 3 patients are free of stones, while in 7 only sludge and tiny fragments are present which we expect to disappear as a result of the litholytic therapy. 3 patients had fragments larger than 5 mm and required a second ESWL. Thus ESWL, which was indicated in only 13% of screened patients, proved to be safe and can be expected to be successful in 75% of selected candidates.

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

Liver fibrosis after extracorporeal shock-wave lithotripsy of gallbladder stones - A case report

NARCIS (Netherlands)

P.W. Plaisier; J.F. Hamming (Jaap); R.L. van der Hul (René); R. den Toom (Rene); H.A. Bruining (Hajo)

1994-01-01

textabstractWe encountered significant liver fibrosis in a healthy young patient undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Twelve months prior to cholecystectomy the patient underwent multiple extracorporeal shock-wave lithotripsy (ESWL) sessions with adjuvant oral

Radiation effects on the laser ablative shockwaves from aluminum under atmospheric conditions

International Nuclear Information System (INIS)

Sai Shiva, S.; Leela, C.H.; Prem Kiran, P.; Sijoy, C.D.; Chaturvedi, Shashank

2015-01-01

The evolution of laser ablative shockwaves (LASW) from Aluminum under atmospheric pressures is numerically modeled using a one-dimensional, three-temperature (electron, ion and thermal radiation temperatures), non-equilibrium, radiation hydrodynamic (RHD) model. The governing RHD equations in Lagrangian form are solved by using an implicit scheme. Similarly, the energy relaxation between the electrons and ions and the electrons and thermal radiation are determined implicitly. Apart from these, the energy equation takes into account the flux-limited electron thermal heat flux. The RHD equations are closed by using a two temperature QEOS model for the Al. The MULTI-fs code is modified to incorporate the nanosecond laser absorption model via the photoionization (PI) and the inverse bremsstrahlung (IB) processes. The spatio-temporal evolution of the laser ablative shockwaves generated by focusing a second harmonic (532 nm, 7ns) of Nd:YAG laser on to Aluminum target under atmospheric pressures in air is captured using a shadowgraphy technique. These measurements are made from 200 ns to 10 μs after the laser pulse with a temporal resolution of 1.5 ns. We report the details of the RHD model and compare the simulated and experimental results for input laser energies in the range of 25 - 175 mJ per pulse. The evolution of the plasma parameters like electron density, charge states and the shockwaves launched into the ambient atmosphere due to expanding plasma plume are compared. The role of thermal radiation on the evolution of LASW from Al is discussed. (author)

EXTRACORPOREAL SHOCKWAVE THERAPY FOR POST BURN CARPAL TUNNEL SYNDROME

OpenAIRE

Hesham Galal Mahran; Ashraf Hassan Mohammed; Shimaa Nabil Aboelazm

2015-01-01

Background: Carpal tunnel syndrome is considered the most common compression neuropathy of the upper extremity. It may lead to work disability and functional impairment. Burns are associated with swelling and eschar which forms a tight band constricting the circulation distally. Purpose: To investigate the effect of shockwave therapy on the carpal tunnel syndrome post burn. Subjects: Thirty male and female patients selected with manifestation of carpal tunnel syndrome post burn evaluated by e...

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.

Diagnostic imaging for preparation of extracorporeal shockwave lithotripsy of gallbladder stones

International Nuclear Information System (INIS)

Brandstetter, K.; Golder, W.; Neuhaus, H.

1991-01-01

Extracorporeal shockwave lithotripsy can be applied as a non-invasive treatment of patients with predominantly cholesterol-type gallstones. As for this treatment, gall bladder contractility and patency of the ductus cysticus must be guaranteed, CT and sonography are applied to check these conditions, and also to determine the size and number of gallstones. (DG) [de

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 CHEMISTRY OF POPULATION III SUPERNOVA EJECTA. I. FORMATION OF MOLECULES IN THE EARLY UNIVERSE

International Nuclear Information System (INIS)

Cherchneff, Isabelle; Dwek, Eli

2009-01-01

We study the formation and destruction of molecules in the ejecta of Population III supernovae (SNe) using a chemical kinetic approach to follow the evolution of molecular abundances from day 100 to day 1000 after explosion. The chemical species included in the study range from simple diatomic molecules to more complex dust precursor species. All relevant molecule formation and destruction processes that are unique to the SN environment are considered. Our work focuses on zero-metallicity progenitors with masses of 20, 170, and 270 M sun , and we study the effect of different levels of heavy element mixing and the inward diffusion of hydrogen and helium on the ejecta chemistry. We show that the ejecta chemistry does not reach a steady state within the relevant timespan (∼3 yr) for molecule formation, thus invalidating previous results relying on this assumption. The primary species formed in the harsh SN environment are O 2 , CO, SiS, and SO. The SiO, formed as early as 200 days after explosion, is rapidly depleted by the formation of silica molecular precursors in the ejecta. The rapid conversion of CO to C 2 and its thermal fractionation at temperatures above 5000 K allow for the formation of carbon chains in the oxygen-rich zone of the unmixed models, providing an important pathway for the formation of carbon dust in hot environments where the C/O ratio is less than 1. We show that the fully mixed ejecta of a 170 M sun progenitor synthesizes 11.3 M sun of molecules, whereas 20 M sun and 270 M sun progenitors produce 0.78 M sun and 3.2 M sun of molecules, respectively. The admixing of 10% of hydrogen into the fully mixed ejecta of the 170 M sun progenitor increases its molecular yield to ∼47 M sun . The unmixed ejecta of a 170 M sun progenitor SN without hydrogen penetration synthesizes ∼37 M sun of molecules, whereas its 20 M sun counterpart produces ∼1.2 M sun . This smaller efficiency at forming molecules is due to the large fraction of He + in the

Laser-induced shockwave propagation from ablation in a cavity

International Nuclear Information System (INIS)

Zeng Xianzhong; Mao Xianglei; Mao, Samuel S.; Wen, S.-B.; Greif, Ralph; Russo, Richard E.

2006-01-01

The propagation of laser-induced shockwaves from ablation inside of cavities was determined from time-resolved shadowgraph images. The temperature and electron number density of the laser-induced plasma was determined from spectroscopic measurements. These properties were compared to those for laser ablation on the flat surface under the same energy and background gas condition. A theoretical model was proposed to determine the amount of energy and vaporized mass stored in the vapor plume based on these measurements

Bacterial sepsis after extracorporeal shock-wave lithotripsy (ESWL) of calyceal diverticular stone.

Science.gov (United States)

Oh, Mi Mi; Kim, Jin Wook; Kim, Jong Wook; Chae, Ji Yun; Yoon, Cheol Yong; Park, Hong Seok; Park, Min Gu; Moon, Du Geon

2013-02-01

Most calyceal diverticula are asymptomatic but symptoms occur when there is urinary stasis leading to infection and calculi. Septic shock after ESWL of calyceal stone occurs rarely. A 24-year-old woman had septic shock due to after extracorporeal shock-wave lithotripsy (ESWL) of asymptomatic calyceal diverticular stone.

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

Research in nuclear astrophysics: stellar collapse and supernovae. Progress report

International Nuclear Information System (INIS)

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

1984-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics is examined. The chief emphasis of our program is on stellar collapse, supernovae and neutron star formation. Central to these topics are the parallel development of the equation of state of hot, dense matter and a novel type of hydrodynamical code. The LLPR compressible liquid drop model forms the basis for the former, and we propose to further refine it by including curvature corrections to the surface energy and by considering other nuclear force parameters which are in better agreement with experimentally determined quantities. The development of the equation of state has another bonus - it can be used to analyze intermediate energy heavy ion collisions, which, in turn, may illuminate the nucleon-nucleon force. The hydrodynamical code includes detailed neutrino transport and a fast, but accurate, approximation to the complete LLPR equation of state, which is necessary for numerical use. We propose to model not only the stellar collapse leading up to a supernova, but also the quasi-static deleptonization and cooling stages of the nascent neutron star. Our detailed studies of the role of neutrinos in stellar collapse and neutron star formation concentrate on their detectability and signatures - after all, neutrinos are the only direct method of observationally checking supernova theory. Complementary studies include modelling both mass accretion in the nuclei of galaxies (which is probably responsible for the quasar phenomenon) and investigations of galaxy clustering and the large scale structure of the universe

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.)

Impact of extracorporeal shockwave therapy on tooth mobility in adult orthodontic patients: a randomized single-center placebo-controlled clinical trial.

Science.gov (United States)

Falkensammer, Frank; Rausch-Fan, Xiaohui; Schaden, Wolfgang; Kivaranovic, Danijel; Freudenthaler, Josef

2015-03-01

This RCT investigated the effect of non-invasive extracorporeal shockwaves on tooth mobility in orthodontic patients after active treatment. Seventy-two adult patients were included in the study. Immediately after active orthodontic treatment, patients were assigned to a treatment or a placebo group based on block randomization. The orthodontic patients were required to be otherwise healthy. The region of interest was the anterior portion of the mandible. The treatment group received a single shockwave treatment with 1000 impulses while the placebo group was treated with an acoustic sham. Tooth mobility was evaluated over a period of 6 months using a Periotest and manual testing. Pocket probing depths, bleeding on probing and the irregularity index were also assessed. Tooth mobility reduced significantly over 6 months in both groups, but shockwaves achieved significantly more rapid reduction on manual testing. Probing depth was significantly reduced while the irregularity index remained stable. Bleeding on probing was significantly reduced in the treatment group. No anti-inflammatory effect could be derived due to possible initial group differences. The mobility of teeth aligned by orthodontic treatment reduces over time. Shockwave treatment appeared to reduce tooth mobility more rapidly. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

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.

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.

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

Shock Dynamics in Stellar Outbursts. I. Shock Formation

Energy Technology Data Exchange (ETDEWEB)

Ro, Stephen; Matzner, Christopher D., E-mail: ro@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

2017-05-20

Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensional motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.

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

Working mechanism of extracorporeal shockwave therapy in non-urological disciplines

Science.gov (United States)

Schaden, Wolfgang

2005-04-01

For 32 years of extracorporeal shockwave lithotripsy (ESWL) only the mechanical strength of shockwaves were of clinical interest. For use in orthopaedics, the absence of dangerous long term effects (malignant degeneration, etc.) is the only important message. The mechanical model tries to explain the effect of shock waves by the provocation of microleasions in the tissue stimulating repairing processes. First doubts on this mechanical model came up when Schaden (2001) could show, that less energy is more efficient in the treatment of non-unions. Due to the basic research of the last years knowledge increased about the microbiological effects. Under the influence of shock waves the change of permeability of cell membranes and the liberation of free radicals was reported. Also the production of nitric oxide (NO) and different growth factors like vascular endothelial growth factor (VEGF), bone morphogenetic proteins (BMP), transforming growth factor-beta 1 (TGF-b1), insulin-like growth factor-I (IGF-I) etc. was observed. The biological model tries to explain the effect of shock waves by stimulating the ingrowth of blood vessels and liberation of growth factors. Under the influence of shock waves, biological tissues seem to be able to produce important substances to initiate healing processes.

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

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.

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

Acoustic sensing of renal stone fragmentation in extracorporeal shockwave lithotripsy

OpenAIRE

Fedele, Fiammetta

2008-01-01

This thesis describes the research carried out by the author on the exploitation of acoustic emissions detected during extracorporeal shockwave lithotripsy (a non-invasive procedure for the treatment of urinary stones) to develop a new diagnostic system. The work formed part of a research project on lithotripsy undertaken by the University of Southampton in collaboration with Guy's and St Thomas' NHS Foundation Trust (London) and a UK based company, Precision Acoustics Ltd (Dorche...

Generation of cylindrically convergent shockwaves in water on the MACH facility

Science.gov (United States)

Bland, Simon; Krasik, Ya. E.; Yanuka, D.; Gardner, R.; MacDonald, J.; Virozub, A.; Efimov, S.; Gleizer, S.; Chaturvedi, N.

2017-06-01

We report on the first experiments utilizing MACH facility at Imperial College London to explode copper wire arrays in water, generating extremely symmetric, cylindrical convergent shockwaves. The experiments were carried out with 10mm diameter arrays consisting of 60 × 130 μm wires, and currents >500 kA were achieved despite the high inductance load. Laser backlit framing images and streak photography of the implosion showed a highly uniform, stable shockwave that travelled towards the axis at velocities up to 7.5 kms-1. For the first time, imaging of the shock front has been carried at radii 1 Mbar are produced within 10 μm of the axis, with water densities 3 gcm-3 and temperatures of many 1000 s of Kelvin. The results represent a significant step in the application of the technique to drive different material samples, and calculations of scaling the technique to larger pulsed power facilities are presented. This work was supported by the Institute of Shock Physics, funded by AWE Aldermaston, and the NNSA under DOE Cooperative Agreement Nos. DE-F03-02NA00057 and DE-SC-0001063.

Evolution of supernova remnants. III. Thermal waves

International Nuclear Information System (INIS)

Chevalier, R.A.

1975-01-01

The effect of heat conduction on the evolution of supernova remnants is investigated. A thermal wave, or electron conduction front, can travel more rapidly than a shock wave during the first thousand years of the remnant's evolution. A self-similar solution describing this phase has been found by Barenblatt. Numerical computations verify the solution and give the evolution past the thermal wave phase. While shell formation is not impeded, the interior density and temperature profiles are smoothed by the action of conduction

A very energetic supernova associated with the gamma-ray burst of 29 March 2003.

Science.gov (United States)

Hjorth, Jens; Sollerman, Jesper; Møller, Palle; Fynbo, Johan P U; Woosley, Stan E; Kouveliotou, Chryssa; Tanvir, Nial R; Greiner, Jochen; Andersen, Michael I; Castro-Tirado, Alberto J; Castro Cerón, José María; Fruchter, Andrew S; Gorosabel, Javier; Jakobsson, Páll; Kaper, Lex; Klose, Sylvio; Masetti, Nicola; Pedersen, Holger; Pedersen, Kristian; Pian, Elena; Palazzi, Eliana; Rhoads, James E; Rol, Evert; van den Heuvel, Edward P J; Vreeswijk, Paul M; Watson, Darach; Wijers, Ralph A M J

2003-06-19

Over the past five years evidence has mounted that long-duration (>2 s) gamma-ray bursts (GRBs)-the most luminous of all astronomical explosions-signal the collapse of massive stars in our Universe. This evidence was originally based on the probable association of one unusual GRB with a supernova, but now includes the association of GRBs with regions of massive star formation in distant galaxies, the appearance of supernova-like 'bumps' in the optical afterglow light curves of several bursts and lines of freshly synthesized elements in the spectra of a few X-ray afterglows. These observations support, but do not yet conclusively demonstrate, the idea that long-duration GRBs are associated with the deaths of massive stars, presumably arising from core collapse. Here we report evidence that a very energetic supernova (a hypernova) was temporally and spatially coincident with a GRB at redshift z = 0.1685. The timing of the supernova indicates that it exploded within a few days of the GRB, strongly suggesting that core-collapse events can give rise to GRBs, thereby favouring the 'collapsar' model.

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.

Dynamics in a one-dimensional ferrogel model: relaxation, pairing, shock-wave propagation.

Science.gov (United States)

Goh, Segun; Menzel, Andreas M; Löwen, Hartmut

2018-05-23

Ferrogels are smart soft materials, consisting of a polymeric network and embedded magnetic particles. Novel phenomena, such as the variation of the overall mechanical properties by external magnetic fields, emerge consequently. However, the dynamic behavior of ferrogels remains largely unveiled. In this paper, we consider a one-dimensional chain consisting of magnetic dipoles and elastic springs between them as a simple model for ferrogels. The model is evaluated by corresponding simulations. To probe the dynamics theoretically, we investigate a continuum limit of the energy governing the system and the corresponding equation of motion. We provide general classification scenarios for the dynamics, elucidating the touching/detachment dynamics of the magnetic particles along the chain. In particular, it is verified in certain cases that the long-time relaxation corresponds to solutions of shock-wave propagation, while formations of particle pairs underlie the initial stage of the dynamics. We expect that these results will provide insight into the understanding of the dynamics of more realistic models with randomness in parameters and time-dependent magnetic fields.

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

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.

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

Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies

OpenAIRE

Leloudas, G.; Schulze, S.; Kruehler, T.; Gorosabel, J.; Christensen, L.; Mehner, A.; Postigo, A. de Ugarte; Amorin, R.; Thoene, C. C.; Anderson, J. P.; Bauer, F. E.; Gallazzi, A.; Helminiak, K. G.; Hjorth, J.; Ibar, E.

2014-01-01

Superluminous supernovae (SLSNe) are very bright explosions that were only discovered recently and that show a preference for occurring in faint dwarf galaxies. Understanding why stellar evolution yields different types of stellar explosions in these environments is fundamental in order to both uncover the elusive progenitors of SLSNe and to study star formation in dwarf galaxies. In this paper, we present the first results of our project to study SUperluminous Supernova Host galaxIES, focusi...

Acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy

Science.gov (United States)

Lottati, Itzhak; Eidelman, Shmuel

1993-07-01

Simulations of acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy (ESWL) are presented. The simulations are done on a structured/unstructured grid with a modified Tait equation of state for water. The Euler equations are solved by applying a second-order Godunov method. The computed results compare very well with the experimental results.

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).

Endoscopic-assisted electrohydraulic shockwave lithotripsy in standing sedated horses.

Science.gov (United States)

Röcken, Michael; Fürst, Anton; Kummer, Martin; Mosel, Gesine; Tschanz, Theo; Lischer, Christoph J

2012-07-01

To report use of transendoscopic electrohydraulic shockwave lithotripsy for fragmentation of urinary calculi in horses. Case series. Male horses (n = 21). Fragmentation of cystic calculi (median, 6 cm diameter; range, 4-11 cm diameter) was achieved by transurethral endoscopy in standing sedated horses using an electrohydraulic shockwave fiber introduced through the biopsy channel of an endoscope. The fiber was advanced until it contacted the calculus. Repeated activation of the fiber was used to disrupt the calculus into fragments calculus removal was achieved in 20 horses (95%) with mean total surgical time of 168.6 minutes (range, 45-450). In the 20 horses with single calculi, 1-6 sessions were required to completely fragment the calculus. Except for 1 horse, in which perineal urethrotomy was eventually performed for complete fragment removal, fragments calculi were excreted via the urethra. Postoperative complications included hematuria because of severe mucosal erosion (n = 2), dysuria because of a trapped urethral fragment (2), small amount of urinary debris (1). One horse was euthanatized because of bladder rupture. Complete clearance of calculi and urinary debris was confirmed endoscopically 20 (3-45) days after the last session. Telephone follow-up (mean, 18.8 months; range, 7-24 months) revealed that horses had returned to previous activity levels without recurrence of clinical signs. Transendoscopic electrohydraulic lithotripsy appears to be an effective method for fragmentation of low-density calcium carbonate cystic calculi in male horses. Copyright 2012 by The American College of Veterinary Surgeons.

Extracorporeal Shockwave Therapy Increases Growth Factor Release from Equine Platelet-Rich Plasma In Vitro

Directory of Open Access Journals (Sweden)

Kathryn A. Seabaugh

2017-12-01

Full Text Available IntroductionExtracorporeal shockwave therapy (ESWT and platelet-rich plasma (PRP are common treatments for soft tissue injuries in horses. Shockwave triggers cell specific responses to promote healing. Growth factors released from PRP also promote healing. It has been hypothesized that greater growth factor release would amplify the healing process. The combination of ESWT and PRP could promote healing in injured tendons and ligaments in the horse. The objective of this study was to determine if application of shockwaves to PRP samples increases the concentration of transforming growth factor-β1 (TGF-β1 and platelet-derived growth factor ββ (PDGF-ββ released from the platelets in vitro.Materials and methodsPRP was produced from blood drawn from six horses. The PRP from each horse was exposed to the following treatments: (1 positive control (freeze-thaw cycle, (2 untreated negative control, or shockwaves with either (3 a “standard probe” (ESWT-S with a 2 cm focal width and medium energy density or (4 a “power probe” (ESWT-P with a 1 cm focal width and high energy density. After each treatment, the samples were centrifuged, and the supernatant was harvested. The supernatant was then used for growth factor quantification via commercially available ELISA kits for TGF-β1 and PDGF-ββ.ResultsConcentrations of TGF-β1 and PDGF-ββ in PRP that underwent a freeze-thaw cycle were significantly increased compared with all other treatments. Both ESWT-S and ESWT-P resulted in significantly increased TGF-β1 concentrations, 46 and 33%, respectively, when compared with the negative control. Both ESWT-S and ESWT-P resulted in significantly increased PDGF-ββ concentrations, 219 and 190%, respectively, when compared with the negative control.DiscussionThese data indicate that the application of ESWT to PRP increases the expression of growth factors in vitro. This suggests that the combination therapy of local PRP injection followed by ESWT

PROMPT Ia SUPERNOVAE ARE SIGNIFICANTLY DELAYED

International Nuclear Information System (INIS)

Raskin, Cody; Scannapieco, Evan; Rhoads, James; Della Valle, Massimo

2009-01-01

The time delay between the formation of a population of stars and the onset of type Ia supernovae (SNe Ia) sets important limits on the masses and nature of SN Ia progenitors. Here, we use a new observational technique to measure this time delay by comparing the spatial distributions of SNe Ia to their local environments. Previous work attempted such analyses encompassing the entire host of each SN Ia, yielding inconclusive results. Our approach confines the analysis only to the relevant portions of the hosts, allowing us to show that even so-called prompt SNe Ia that trace star formation on cosmic timescales exhibit a significant delay time of 200-500 million years. This implies that either the majority of Ia companion stars have main-sequence masses less than 3 M sun , or that most SNe Ia arise from double white dwarf binaries. Our results are also consistent with a SNe Ia rate that traces the white dwarf formation rate, scaled by a fixed efficiency factor.

A meta-analysis of the effects of shockwave and high pressure processing on color and cook loss of fresh meat.

Science.gov (United States)

Ha, Minh; Dunshea, Frank R; Warner, Robyn D

2017-10-01

Meta-analysis is a statistical approach for investigating experimental differences across studies. Meta-analyses were performed to examine the effects of hydrodynamic processing (shockwave; n=12 papers) and high pressure processing (HPP; n=8 papers) on the color and cook loss of fresh meat. Shockwave did not affect color (L*, a*), whereas cook loss was increased by 0.6% relative to untreated meat. HPP resulted in an increase in lightness (L*) and a decrease in redness (a*), with the effect being greater at higher pressures (>300MPa vs pressure (high pressure (>300MPa) the cook loss was increased (-1.5% vs 3.0% respectively). The increased cook loss with shockwave and high pressure (>300MPa) processing needs to be balanced against benefits in texture if this technology is applied to meat. The reduced cook loss of meat treated at moderate pressures (<300MPa) is an advantage which would likely improve sensory traits. Copyright © 2017 Elsevier Ltd. All rights reserved.

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)

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...

On the nature of interstellar turbulence

International Nuclear Information System (INIS)

Altunin, V.I.

1981-01-01

Possible reasons of interstellar medium turbulence manifested in pulsar scintillation and radio-frequency emission scattering of extragalactic sources near by the Galaxy plane, are discussed. Sources and conditions of turbulence emergence in HII region shells, supernova, residue and in stellar wind giving observed scattering effects are considered. It is shown that in the formation of the interstellar scintillation pattern of discrete radio-frequency emission sources a certain role can be played by magnetosound turbulence, which arises due to shock-waves propagating in the interstellar medium at a velocity Vsub(sh) approximately 20-100 km/s as well as by stellar-wind inhomogeneity of OB classes stars [ru

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

Research in nuclear astrophysics: stellar collapse and supernovae: Annual performance report, December 1, 1987--November 30, 1988

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1988-01-01

This annual performance report summarizes the activity in the nuclear astrophysics research program in the Earth and Space Scienes Department at Stony Brook. The central themes in the projects that comprise this program are supernovae, neutron star formation, and the equation of state of hot, dense metter. There is a close coupling between the physics of nuclear matter and weak interactions on the one hand, and supernovae and neutron stars on the other. The properties of nuclear matter might at present best be delineated by astrophysical considerations. We have been active in researching both the nuclear physics of the equation of state and the astrophysics of stellar collapse, neutrino emission, and neutron star formation. 11 refs

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.

Regulation of the X-ray luminosity of clusters of galaxies by cooling and supernova feedback.

Science.gov (United States)

Voit, G M; Bryan, G L

2001-11-22

Clusters of galaxies are thought to contain about ten times as much dark matter as baryonic matter. The dark component therefore dominates the gravitational potential of a cluster, and the baryons confined by this potential radiate X-rays with a luminosity that depends mainly on the gas density in the cluster's core. Predictions of the X-rays' properties based on models of cluster formation do not, however, agree with the observations. If the models ignore the condensation of cooling gas into stars and feedback from the associated supernovae, they overestimate the X-ray luminosity because the density of the core gas is too high. An early episode of uniformly distributed supernova feedback could rectify this by heating the uncondensed gas and therefore making it harder to compress into the core, but such a process seems to require an implausibly large number of supernovae. Here we show how radiative cooling of intergalactic gas and subsequent supernova heating conspire to eliminate highly compressible low-entropy gas from the intracluster medium. This brings the core entropy and X-ray luminosities of clusters into agreement with the observations, in a way that depends little on the efficiency of supernova heating in the early Universe.

Ab Initio Simulations of a Supernova-driven Galactic Dynamo in an Isolated Disk Galaxy

Energy Technology Data Exchange (ETDEWEB)

Butsky, Iryna [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Zrake, Jonathan; Kim, Ji-hoon; Yang, Hung-I; Abel, Tom [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Menlo Park, CA 94025 (United States)

2017-07-10

We study the magnetic field evolution of an isolated spiral galaxy, using isolated Milky Way–mass galaxy formation simulations and a novel prescription for magnetohydrodynamic (MHD) supernova feedback. Our main result is that a galactic dynamo can be seeded and driven by supernova explosions, resulting in magnetic fields whose strength and morphology are consistent with observations. In our model, supernovae supply thermal energy and a low-level magnetic field along with their ejecta. The thermal expansion drives turbulence, which serves a dual role by efficiently mixing the magnetic field into the interstellar medium and amplifying it by means of a turbulent dynamo. The computational prescription for MHD supernova feedback has been implemented within the publicly available ENZO code and is fully described in this paper. This improves upon ENZO 's existing modules for hydrodynamic feedback from stars and active galaxies. We find that the field attains microgauss levels over gigayear timescales throughout the disk. The field also develops a large-scale structure, which appears to be correlated with the disk’s spiral arm density structure. We find that seeding of the galactic dynamo by supernova ejecta predicts a persistent correlation between gas metallicity and magnetic field strength. We also generate all-sky maps of the Faraday rotation measure from the simulation-predicted magnetic field, and we present a direct comparison with observations.

Extracorporeal shockwave therapy for patellar tendinopathy: a review of the literature.

Science.gov (United States)

van Leeuwen, M T; Zwerver, J; van den Akker-Scheek, I

2009-03-01

Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment; and to identify topics for further research. A computerised search of the Medline and Embase databases was conducted on 1 August 2007, to identify studies dealing with the effectiveness of ESWT for patellar tendinopathy. Seven articles describing the effectiveness of ESWT on patellar tendinopathy, all published after 2000, were included. These studies included a total of 283 patients (298 tendons), 204 of whom (215 tendons) were assigned to ESWT treatment. The treatment results were positive but most studies had methodological deficiencies, small numbers and/or short follow-up periods. Method of application and shockwave generation, energy level, number and frequency of treatments, use of (local) anaesthesia and method of localisation were variable. ESWT seems to be a safe and promising treatment for patellar tendinopathy with a positive effect on pain and function. Based on current knowledge it is impossible to recommend a specific treatment protocol. Further basic and clinical research into the working mechanism and effectiveness of ESWT for patellar tendinopathy are necessary.

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.

SDSS-II SUPERNOVA SURVEY: AN ANALYSIS OF THE LARGEST SAMPLE OF TYPE IA SUPERNOVAE AND CORRELATIONS WITH HOST-GALAXY SPECTRAL PROPERTIES

International Nuclear Information System (INIS)

Wolf, Rachel C.; Gupta, Ravi R.; Sako, Masao; Fischer, John A.; March, Marisa C.; Fischer, Johanna-Laina; D’Andrea, Chris B.; Smith, Mathew; Kessler, Rick; Scolnic, Daniel M.; Jha, Saurabh W.; Campbell, Heather; Nichol, Robert C.; Olmstead, Matthew D.; Richmond, Michael; Schneider, Donald P.

2016-01-01

Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HRs). Our sample consists of 345 photometrically classified or spectroscopically confirmed SNe Ia discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric host-galaxy properties from the SDSS-SNS data release such as host stellar mass and star formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6 σ significance of a nonzero linear slope. We also recover correlations between HR and host-galaxy gas-phase metallicity and specific star formation rate as they are reported in the literature. With our large data set, we examine correlations between HR and multiple host-galaxy properties simultaneously and find no evidence of a significant correlation. We also independently analyze our spectroscopically confirmed and photometrically classified SNe Ia and comment on the significance of similar combined data sets for future surveys.

Extracorporeal shockwave therapy for patellar tendinopathy: a review of the literature

OpenAIRE

van Leeuwen, M. T.; Zwerver, J.; van den Akker-Scheek, I.

2009-01-01

Background and purpose: Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment; and to identify topics for further research. Methods: A computerised search of the Medline and Embase databases was conducted on 1 August 2007, to identify studies dealing with the effectiveness of...

Neutron star formation in theoretical supernovae. Low mass stars and white dwarfs

International Nuclear Information System (INIS)

Nomoto, K.

1986-01-01

The presupernova evolution of stars that form semi-degenerate or strongly degenerate O + Ne + Mg cores is discussed. For the 10 to 13 Msub solar stars, behavior of off-center neon flashes is crucial. The 8 to 10 m/sub solar stars do not ignite neon and eventually collapse due to electron captures. Properties of supernova explosions and neutron stars expected from these low mass progenitors are compared with the Crab nebula. The conditions for which neutron stars form from accretion-induced collapse of white dwarfs in clsoe binary systems is also examined

OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

Science.gov (United States)

2002-01-01

chemical composition of this nuclear- processed material, and thereby test theories of stellar evolution. The image shows a region of the remnant 50 light-years across. The supernova explosion should have been visible from Earth's southern hemisphere around 1,000 B.C., but there are no known historical records that chronicle what would have appeared as a 'new star' in the heavens. This 'true color' picture was made by superposing images taken on 9-10 August 1994 in three of the strongest optical emission lines: singly ionized sulfur (red), doubly ionized oxygen (green), and singly ionized oxygen (blue). Photo credit: Jon A. Morse (STScI) and NASA Investigating team: William P. Blair (PI; JHU), Michael A. Dopita (MSSSO), Robert P. Kirshner (Harvard), Knox S. Long (STScI), Jon A. Morse (STScI), John C. Raymond (SAO), Ralph S. Sutherland (UC-Boulder), and P. Frank Winkler (Middlebury). Image files in GIF and JPEG format may be accessed via anonymous ftp from oposite.stsci.edu in /pubinfo: GIF: /pubinfo/GIF/N132D.GIF JPEG: /pubinfo/JPEG/N132D.jpg The same images are available via World Wide Web from links in URL http://www.stsci.edu/public.html.

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

Symptomatic gallbladder stones. Cost-effectiveness of treatment with extracorporeal shock-wave lithotripsy, conventional and laparoscopic cholecystectomy

NARCIS (Netherlands)

Go, P. M.; Stolk, M. F.; Obertop, H.; Dirksen, C.; van der Elst, D. H.; Ament, A.; van Erpecum, K. J.; van Berge Henegouwen, G. P.; Gouma, D. J.

1995-01-01

In order to strike the most favorable balance between health benefits and costs, three treatment modalities for symptomatic cholelithiasis were compared in a cost-effectiveness study: extracorporeal shock-wave lithotripsy (ESWL), conventional cholecystectomy (CC), and laparoscopic cholecystectomy

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.

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.

Supernova 1987A in the Large Magellanic Cloud

Science.gov (United States)

Kafatos, Minas; Michalitsianos, Andrew G.

2006-11-01

and S. W. Bruenn; 23. Neutrino masses from SN 1987A J. Franklin; 24. Supernova neutrinos and their oscillations T. K. Kuo and J. T. Pantaleone; 25. Neutrinos from SN 1987A and cooling of the nascent neutron star D. Q. Lamb, F. Melia and T. J. Loredo; 26. Neutrino Energetics of SN 1987A J. M. Lattimer and A. Yahil; 27. Neutrino emission from cooling neutron stars E. S. Myra, J. M. Lattimer and A. Yahil; 28. Statistical analysis of the time structure of the neutrinos from SN 1987A P. J. Schinder and S. A. Bludman; 29. Neutrino properties from observations of SN 1987A A. Dar; 30. SN 1987A and companion C. Papaliolios, M. Karovska, P. Nisenson, and C. Standley; 31. Supernovae light echoes B. E. Schaefer; 32. A real light echo: Nova Persei 1901 J. E. Felten; 33. IR speckle- interferometry of SN 1987A A. A. Chalabaev, C. Perrier and J. M. Mariotti; 34. Infrared opportunities for Supernova 1987A E. Dwek; 35. The UV interstellar spectrum and environment of SN 1987A F. C. Bruhweiler; 36. The interstellar spectrum of SN 1987A in the ultraviolet J. C. Blades, J. M. Wheatley, N. Panagia, M. Grewing, M. Pettini and W. Wamsteker; 37. The structure and spectrum of SN 1987A J. C. Wheeler, R. P. Harkness, and Z. Barkat; 38. Supernova 1987A: constraints on the theoretical model K. Nomoto and T. Shigeyama; 39. Supernova 1987A: a model and its predictions S. E. Woosley; 40. SN 1987A: circumstellar and interstellar interaction R. A. Chevalier; 41. Theoretical models of Supernova 1987A W. D. Arnett; 42. Evolution of the stellar progenitor of Supernova 1987A J. W. Truran and A. Weiss; 43.Modelling the atmosphere of SN 1987A L. B. Lucy; 44. SN 1987A: a stripped asymptotic- branch giant in a binary system P. C. Joss, Ph. Podsiadlowski, J. J. L. Hsu and S. Rappaport; 45. Pulsar formation and the fall back mass fraction S. A. Colgate; 46. An unusual hard X-ray source in the region of SN 19

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.

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

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)

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.

Extracorporeal shockwave lithotripsy for lower pole calculi smaller than one centimeter

Directory of Open Access Journals (Sweden)

Christian Chaussy

2008-01-01

When complete stone-free status is the primary goal , follow-up examinations with new radiological technologies like spiral CT show that the stone-free rate of ESWL and endoscopically treated patients (RIRS does not differ significantly. However, in comparison to endoscopic stone removal, shockwave therapy is noninvasive, anesthesia-free and can be performed in an outpatient setup. Therefore, ESWL remains the first choice option for the treatment of lower caliceal stones up to 1 cm. The patient will definitely favour this procedure.

Profiles of the stochastic star formation process in spiral galaxies

International Nuclear Information System (INIS)

Comins, N.

1981-01-01

The formation of spiral arms in disc galaxies is generally attributed to the effects of spiral density waves. These relatively small (i.e. 5 per cent) non-axisymmetric perturbations of the interstellar medium cause spiral arms highlighted by O and B type stars to be created. In this paper another mechanism for spiral arm formation, the stochastic self-propagating star formation (SSPSF) process is examined. The SSPSF process combines the theory that shock waves from supernovae will compress the interstellar medium to create new stars, some of which will be massive enough to also supernova, with a disc galaxy's differential rotation to create spiral arms. The present work extends this process to the case where the probability of star formation from supernova shocks decreases with galactic radius. Where this work and previous investigations overlap (namely the uniform probability case), the agreement is very good, pretty spirals with various numbers of arms are generated. The decreasing probability cases, taken to vary as rsup(-j), still form spiral arms for 0 1.5 the spiral structure is essentially non-existent. (author)

Supernova 2010as: the lowest-velocity member of a family of flat-velocity type IIb supernovae

Energy Technology Data Exchange (ETDEWEB)

Folatelli, Gastón; Bersten, Melina C.; Nomoto, Ken' ichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Kuncarayakti, Hanindyo; Hamuy, Mario [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Olivares Estay, Felipe; Pignata, Giuliano [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Anderson, Joseph P. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Holmbo, Simon; Stritzinger, Maximilian [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Morrell, Nidia; Contreras, Carlos; Phillips, Mark M. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Förster, Francisco [Center for Mathematical Modelling, Universidad de Chile, Avenida Blanco Encalada 2120 Piso 7, Santiago (Chile); Prieto, José Luis [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Valenti, Stefano [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Afonso, Paulo; Altenmüller, Konrad; Elliott, Jonny, E-mail: gaston.folatelli@ipmu.jp [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, D-85740 Garching (Germany); and others

2014-09-01

We present extensive optical and near-infrared photometric and spectroscopic observations of the stripped-envelope supernova SN 2010as. Spectroscopic peculiarities such as initially weak helium features and low expansion velocities with a nearly flat evolution place this object in the small family of events previously identified as transitional Type Ib/c supernovae (SNe). There is ubiquitous evidence of hydrogen, albeit weak, in this family of SNe, indicating that they are in fact a peculiar kind of Type IIb SNe that we name 'flat-velocity' Type IIb. The flat-velocity evolution—which occurs at different levels between 6000 and 8000 km s{sup –1} for different SNe—suggests the presence of a dense shell in the ejecta. Despite the spectroscopic similarities, these objects show surprisingly diverse luminosities. We discuss the possible physical or geometrical unification picture for such diversity. Using archival Hubble Space Telescope images, we associate SN 2010as with a massive cluster and derive a progenitor age of ≈6 Myr, assuming a single star-formation burst, which is compatible with a Wolf-Rayet progenitor. Our hydrodynamical modeling, on the contrary, indicates that the pre-explosion mass was relatively low, ≈4 M {sub ☉}. The seeming contradiction between a young age and low pre-SN mass may be solved by a massive interacting binary progenitor.

SUPERNOVA SIMULATIONS AND STRATEGIES FOR THE DARK ENERGY SURVEY

Energy Technology Data Exchange (ETDEWEB)

Bernstein, J. P.; Kuhlmann, S.; Biswas, R.; Kovacs, E.; Crane, I.; Hufford, T. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Kessler, R.; Frieman, J. A. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Aldering, G.; Kim, A. G.; Nugent, P. [E. O. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); D' Andrea, C. B.; Nichol, R. C. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Finley, D. A.; Marriner, J.; Reis, R. R. R. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Jarvis, M. J. [Centre for Astrophysics, Science and Technology Research Institute, University of Hertfordshire, Hatfield, Herts AL10 9AB (United Kingdom); Mukherjee, P.; Parkinson, D. [Department of Physics and Astronomy, Pevensey 2 Building, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, 203 South 33rd Street, Philadelphia, PA 19104 (United States); and others

2012-07-10

We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30 deg{sup 2} search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 Type Ia supernovae in the redshift range 0.05 supernova with an identified host galaxy will be obtained from spectroscopic observations of the host. A supernova spectrum will be obtained for a subset of the sample, which will be utilized for control studies. In addition, we have investigated the use of combined photometric redshifts taking into account data from both the host and supernova. We have investigated and estimated the likely contamination from core-collapse supernovae based on photometric identification, and have found that a Type Ia supernova sample purity of up to 98% is obtainable given specific assumptions. Furthermore, we present systematic uncertainties due to sample purity, photometric calibration, dust extinction priors, filter-centroid shifts, and inter-calibration. We conclude by estimating the uncertainty on the cosmological parameters that will be measured from the DES supernova data.

SUPERNOVA SIMULATIONS AND STRATEGIES FOR THE DARK ENERGY SURVEY

International Nuclear Information System (INIS)

Bernstein, J. P.; Kuhlmann, S.; Biswas, R.; Kovacs, E.; Crane, I.; Hufford, T.; Kessler, R.; Frieman, J. A.; Aldering, G.; Kim, A. G.; Nugent, P.; D'Andrea, C. B.; Nichol, R. C.; Finley, D. A.; Marriner, J.; Reis, R. R. R.; Jarvis, M. J.; Mukherjee, P.; Parkinson, D.; Sako, M.

2012-01-01

We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30 deg 2 search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 Type Ia supernovae in the redshift range 0.05 < z < 1.2 and (2) that the increased red efficiency of the DES camera will significantly improve high-redshift color measurements. The redshift of each supernova with an identified host galaxy will be obtained from spectroscopic observations of the host. A supernova spectrum will be obtained for a subset of the sample, which will be utilized for control studies. In addition, we have investigated the use of combined photometric redshifts taking into account data from both the host and supernova. We have investigated and estimated the likely contamination from core-collapse supernovae based on photometric identification, and have found that a Type Ia supernova sample purity of up to 98% is obtainable given specific assumptions. Furthermore, we present systematic uncertainties due to sample purity, photometric calibration, dust extinction priors, filter-centroid shifts, and inter-calibration. We conclude by estimating the uncertainty on the cosmological parameters that will be measured from the DES supernova data.

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.

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

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 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

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

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

High temperature science: future needs and anticipated development in high-density shock-wave research

International Nuclear Information System (INIS)

Ross, M.; Ahrens, T.J.; Nellis, W.J.

1979-01-01

Shock-wave experiments on condensed matter currently achieve pressures up to 5 Mbar, and temperatures over 20,000 0 K. In this report we survey a number of experimental methods that, in the next decade, may increase the conditions by an order of magnitude. These advanced experiments will allow us to investigate a new range of physics problems

On the O/Fe versus Fe/H relationship and the progenitors of type I supernovae

International Nuclear Information System (INIS)

Abia, C.; Canal, R.; Isern, J.

1991-01-01

The new observational O/Fe versus Fe/H abundance relationship for halo stars is studied in terms of several models of chemical evolution for the solar neighborhood. Nucleosynthesis products from type I (both Ia and Ib) and Type II SNs are taken into account. The behavior of the O/Fe ratio for halo and disk stars is well reproduced by assuming (1) a lower iron production in SN II than in previous theoretical prescriptions, (2) the coalescence by gravitational wave radiation of two CO white dwarfs as the scenario for type Ia supernovae, and (3) stars in the Wolf-Rayet stage as progenitors of type Ib supernovae. Nevertheless, the best agreement with the observations is obtained by adopting an IMF favoring massive star formation only at very early epochs in the life of the Galaxy. Model predictions from other plausible scenarios for the origin of type I supernovae are also discussed. 41 refs

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

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.

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.

A SYSTEMATIC STUDY OF THE THERMAL AND NONTHERMAL EMISSION IN THE SUPERNOVA REMNANT RCW 86 WITH SUZAKU

International Nuclear Information System (INIS)

Tsubone, Yoshio; Sawada, Makoto; Bamba, Aya; Katsuda, Satoru; Vink, Jacco

2017-01-01

Diffusive shock acceleration by the shockwaves in supernova remnants (SNRs) is widely accepted as the dominant source for Galactic cosmic rays. However, it is unknown what determines the maximum energy of accelerated particles. The surrounding environment could be one of the key parameters. The SNR RCW 86 shows both thermal and nonthermal X-ray emission with different spatial morphologies. These emission originate from the shock-heated plasma and accelerated electrons respectively, and their intensities reflect their density distributions. Thus, the remnant provides a suitable laboratory to test possible association between the acceleration efficiency and the environment. In this paper, we present results of spatially resolved spectroscopy of the entire remnant with Suzaku . The spacially resolved spectra are well reproduced with a combination of a power-law for synchrotron emission and a two-component optically thin thermal plasma, corresponding to the shocked interstellar medium (ISM) with kT of 0.3–0.6 keV and Fe-dominated ejecta. It is discovered that the photon index of the nonthermal component becomes smaller when decreasing the emission measure of the shocked ISM, where the shock speed has remained high. This result implies that the maximum energy of accelerated electrons in RCW 86 is higher in the low-density and higher shock speed regions.

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...

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)

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

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

On type Ia supernovae and the formation of single low-mass white dwarfs

OpenAIRE

Justham, Stephen; Wolf, Christian; Podsiadlowski, Philipp; Han, Zhanwen

2008-01-01

There is still considerable debate over the progenitors of type Ia supernovae (SNe Ia). Likewise, it is not agreed how single white dwarfs with masses less than ~0.5 Msun can be formed in the field, even though they are known to exist. We consider whether single low-mass white dwarfs (LMWDs) could have been formed in binary systems where their companions have exploded as a SN Ia. In this model, the observed single LMWDs are the remnants of giant-branch donor stars whose envelopes have been st...

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

Effect of Low-Energy Linear Shockwave Therapy on Erectile Dysfunction

DEFF Research Database (Denmark)

Fojecki, Grzegorz L; Thiessen, Stefan; Osther, Palle Jørn Sloth

2017-01-01

INTRODUCTION: Previous studies have shown that focal low-energy extracorporeal shockwave therapy (Li-ESWT) can have a positive effect in men with erectile dysfunction (ED). Linear Li-ESWT (LLi-ESWT) for ED has not been previously assessed in a randomized trial. AIM: To evaluate the treatment...... MEASURES: The primary outcome measurement was an increase of at least five points on the IIEF-EF score. The secondary outcome measurement was an increased EHS score to at least 3 in men with a score no higher than 2 at baseline. Data were analyzed by linear and logistic regression. RESULTS: Mean IIEF...

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.

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

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.

Extracorporeal shockwave therapy versus exercise program in patients with low back pain: short-term results of a randomised controlled trial.

Science.gov (United States)

Notarnicola, A; Maccagnano, G; Gallone, M F; Mastromauro, L; Rifino, F; Pesce, V; Covelli, I; Moretti, B

2018-01-01

The physiotherapy treatment of low back pain (LBP) with physical stimulation offers different possibilities of application. Until now, the physical therapies used in LBP are laser therapy, ultrasonotherapy and currents. We conducted a clinical trial in order to verify whether shockwave therapy, which is very effective in treating tendinopathies and fracture consolidation delays, leads to clinical and electromyographic improvement in patients affected by LBP. We randomized thirty patients affected by LBP treated with shock waves (shockwave group) or a standard protocol characterized by rehabilitative exercises (control group). At one and three months, the patients treated with shockwave therapy showed clinical improvement measured by VAS scales (p=0.002; p= 0.02), and disability evaluated with Roland scales (p=0.002; p=0.002) and Oswestry (p=0.002; p=0.002). At three months, the patients treated with shock waves, showed a significant improvement in terms of values of amplitude of the sensory nerve conduction velocity (SNCV) of the plantar medialis nerve (left: p=0.007; right: p=0.04), the motor nerve muscular conduction (MNCV) of the deep peroneal nerve (left: p=0.28; right: p=0.01) and recruitment of motor units of finger brevis extensor (left: p = 0.02; right: p=0.006). In the control group, there was a trend to increase the clinical and electromyographic results without statistical significance. The preliminary results suggest a good applicability of shockwave therapy in the treatment of LBP, in accordance with the antiinflammatory, antalgic, decontracting effects and remodeling of the nerve fiber damage verified in previous studies conducted on other pathological models. Future research will allow us to verify the integration of this therapy into a rehabilitation protocol combined with other physical therapies.

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)

EVOLUTION IN THE VOLUMETRIC TYPE Ia SUPERNOVA RATE FROM THE SUPERNOVA LEGACY SURVEY

Energy Technology Data Exchange (ETDEWEB)

Perrett, K.; Gonzalez-Gaitan, S.; Carlberg, R. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Sullivan, M.; Hook, I. M. [Department of Physics (Astrophysics), University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom); Conley, A. [Center for Astrophysics and Space Astronomy, University of Colorado, 593 UCB, Boulder, CO 80309-0593 (United States); Fouchez, D. [CPPM, CNRS-IN2P3 and University Aix Marseille II, Case 907, 13288 Marseille cedex 9 (France); Ripoche, P. [Lawrence Berkeley National Laboratory, Mail Stop 50-232, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Neill, J. D. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125 (United States); Astier, P.; Balland, C.; Guy, J.; Hardin, D.; Pain, R.; Regnault, N. [LPNHE, Universite Pierre et Marie Curie Paris 6, Universite Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75005 Paris (France); Balam, D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Basa, S. [Laboratoire d' Astrophysique de Marseille, Pole de l' Etoile Site de Chateau-Gombert, 38, rue Frederic Joliot-Curie, 13388 Marseille cedex 13 (France); Howell, D. A. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Dr., Suite 102, Goleta, CA 93117 (United States); Palanque-Delabrouille, N. [DSM/IRFU/SPP, CEA-Saclay, F-91191 Gif-sur-Yvette (France); Pritchet, C., E-mail: perrett@astro.utoronto.ca, E-mail: sullivan@astro.ox.ac.uk [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Stn CSC, Victoria, BC, V8W 3P6 (Canada); and others

2012-08-15

We present a measurement of the volumetric Type Ia supernova (SN Ia) rate (SNR{sub Ia}) as a function of redshift for the first four years of data from the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). This analysis includes 286 spectroscopically confirmed and more than 400 additional photometrically identified SNe Ia within the redshift range 0.1 {<=} z {<=} 1.1. The volumetric SNR{sub Ia} evolution is consistent with a rise to z {approx} 1.0 that follows a power law of the form (1+z){sup {alpha}}, with {alpha} = 2.11 {+-} 0.28. This evolutionary trend in the SNLS rates is slightly shallower than that of the cosmic star formation history (SFH) over the same redshift range. We combine the SNLS rate measurements with those from other surveys that complement the SNLS redshift range, and fit various simple SN Ia delay-time distribution (DTD) models to the combined data. A simple power-law model for the DTD (i.e., {proportional_to}t{sup -{beta}}) yields values from {beta} = 0.98 {+-} 0.05 to {beta} = 1.15 {+-} 0.08 depending on the parameterization of the cosmic SFH. A two-component model, where SNR{sub Ia} is dependent on stellar mass (M{sub stellar}) and star formation rate (SFR) as SNR{sub Ia}(z) = A Multiplication-Sign M{sub stellar}(z) + B Multiplication-Sign SFR(z), yields the coefficients A = (1.9 {+-} 0.1) Multiplication-Sign 10{sup -14} SNe yr{sup -1} M{sup -1}{sub Sun} and B = (3.3 {+-} 0.2) Multiplication-Sign 10{sup -4} SNe yr{sup -1} (M{sub Sun} yr{sup -1}){sup -1}. More general two-component models also fit the data well, but single Gaussian or exponential DTDs provide significantly poorer matches. Finally, we split the SNLS sample into two populations by the light-curve width (stretch), and show that the general behavior in the rates of faster-declining SNe Ia (0.8 {<=} s < 1.0) is similar, within our measurement errors, to that of the slower objects (1.0 {<=} s < 1.3) out to z {approx} 0.8.

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

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 radiation-hydrodynamics. General relativistic versus multidimensional supernova simulations

International Nuclear Information System (INIS)

Liebendoerfer, Matthias; Fischer, Tobias; Hempel, Matthias

2010-01-01

Recently, simulations of the collapse of massive stars showed that selected models of the QCD phase transitions to deconfined quarks during the early postbounce phase can trigger the supernova explosion that has been searched for over many years in spherically symmetric supernova models. Using sophisticated general relativistic Boltzmann neutrino transport, it was found that a characteristic neutrino signature is emitted that permits to falsify or identify this scenario in the next Galactic supernova event. On the other hand, more refined observations of past supernovae and progressing theoretical research in different supernova groups demonstrated that the effects of multidimensional fluid instabilities cannot be neglected in global models of the explosions of massive stars. We point to different efforts where neutrino transport and general relativistic effects are combined with multidimensional fluid instabilities in supernovae. With those, it will be possible to explore the gravitational wave emission as a potential second characteristic observable of the presence of quark matter in new-born neutron stars. (author)

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.

Healing of Achilles tendon partial tear following focused shockwave: a case report and literature review

Directory of Open Access Journals (Sweden)

Hsu YC

2017-05-01

Full Text Available Yu-Chun Hsu,1,* Wei-Ting Wu,2,* Ke-Vin Chang,2–4 Der-Sheng Han,2–4 Li-Wei Chou5–7 1Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, 2Department of Physical Medicine and Rehabilitation and Community and Geriatric Research Center, National Taiwan University Hospital, Bei-Hu Branch, 3National Taiwan University College of Medicine, 4Community and Geriatric Research Center, National Taiwan University Hospital, Bei-Hu Branch, Taipei, 5Department of Physical Medicine and Rehabilitation, China Medical University Hospital, 6Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, 7Department of Rehabilitation, Asia University Hospital, Taichung, Taiwan *These authors contributed equally to this work Abstract: Achilles tendinopathy is a common cause of posterior heel pain and can progress to partial tendon tear without adequate treatment. Effects of traditional treatments vary, and many recent reports focus on the use of extracorporeal shockwave therapy (ESWT for Achilles tendinopathy but not for Achilles tendon partial tear. Here, we report the case of a 64-year-old female suffering from severe left heel pain for half a year. All treatment and rehabilitation were less effective until ESWT was applied. Each course of focused shockwave therapy included 2500 shots with energy flux density from 0.142 mJ/mm2 to 0.341 mJ/mm2. The visual analog scale decreased from nine to one degree. High-resolution musculoskeletal ultrasonography was performed before and 1 month after the treatment, which revealed healing of the torn region and decrease in inflammation. ESWT had shown to be an alternative treatment for Achilles tendon partial tear under safety procedure and ultrasound observation. Keywords: focused shockwave, Achilles tendon, partial tear, ultrasonography

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

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.

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.

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.

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 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)

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.

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)

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.

The impact of magnetic fields on the chemical evolution of the supernova-driven ISM

Czech Academy of Sciences Publication Activity Database

Pardi, A.; Girichidis, P.; Naab, T.; Walch, S.; Peters, T.; Heitsch, F.; Glover, S.C.O.; Klessen, R.S.; Wünsch, Richard; Gatto, A.

2017-01-01

Roč. 465, č. 4 (2017), s. 4611-4633 ISSN 0035-8711 R&D Projects: GA ČR GA15-06012S Institutional support: RVO:67985815 Keywords : turbulent interstellar-medium * molecular cloud formation * ISM: supernova remnants Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 4.961, year: 2016

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.

Evaluation of the contact switch materials in high voltage power supply for generate of underwater shockwave by electrical discharge

Directory of Open Access Journals (Sweden)

K Higa

2016-10-01

Full Text Available We have developed the high voltage power-supply unit by Cockcroft-Walton circuit for ingenerate high pressure due to underwater shockwave by electrical discharge. This high voltage power supply has the problem of the metal contact switch operation that contact switch stop by melting and bonding due to electrical spark. We have studied the evaluation of materials of contact switch for the reducing electrical energy loss and the problem of contact switch operation. In this research, measurement of discharge voltage and high pressure due to underwater shockwave was carried out using the contact switch made of different materials as brass plate, brass-carbon plate-brass and carbon block. The contact switch made of carbon is effective to reduce energy loss and problem of contactor switch operation.

EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY (ESWL PADA BATU GINJAL

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Anak Agung Sri Satyawati

2014-09-01

Full Text Available Latar Belakang. Extracorporeal shockwave lithotripsy (ESWL merupakan pilihan terapi yang paling cost effective pada kasus kasus batu ginjal, namun sayangnya modalitas terapi ini belum banyak dipilih karena dianggap mahal dan kurangnya informasi mengenai keuntungan penggunaannya. Kasus. Perempuan usia 65 tahun mengeluh nyeri pinggang yang dirasakan mendadak dan semakin memberat  sejak 2 bulan sebelum masuk rumah sakit, disertai mual dan penurunan nafsu makan. Berdasarkan pemeriksaan foto polos abdomen dan USG Urologi  didapatkan kesan adanya batu renal dekstra ukuran 16mm x 18mm, dengan hidronefrosis derajat I renal dekstra. Kemudian dilakukan tindakan ESWL. Hasil. Setelah dilakukan tindakan ESWL berupa penghantaran gelombang kejut pada permukaan ginjal  kanan selama 20-30 menit, keluar pecahan pecahan kecil batu kalsium. Berdasarkan pemeriksaan radiografi post ESWL tidak ditemukan gambaran radioopak pada kaliks ginjal, ureter maupun kandung kemih. Kesimpulan. Batu kalsium dengan ukuran 16mm x 18mm pada renal dekstra berhasil dikeluarkan total tanpa adanya komplikasi.

Light-Like Shockwaves in Scalar-Tensor Theories

Directory of Open Access Journals (Sweden)

Bence Racskó

2018-02-01

Full Text Available Both electromagnetic shock-waves and gravitational waves propagate with the speed of light. If they carry significant energy-momentum, this will change the properties of the space-time they propagate through. This can be described in terms of the junction conditions between space-time regions separated by a singular, null hypersurface. We derived generic junction conditions for Brans-Dicke theory in the Jordan frame, exploring a formalism based on a transverse vector, rather than normal, which can be applied to any type of hypersurfaces. In the particular case of a non-null hypersurface we obtain a generalised Lanczos equation, in which the jump of the extrinsic curvature is sourced by both the distributional energy-momentum tensor and by the jump in the transverse derivative of the scalar. In the case of null hypersurfaces, the distributional source is decomposed into surface density, current and pressure. The latter, however, ought to vanish by virtue of the scalar junction condition.

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.

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.

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

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).

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...

Low-Intensity Extracorporeal Shockwave Therapy in Sexual Medicine

DEFF Research Database (Denmark)

Fode, Mikkel; Lowenstein, Lior; Reisman, Yacov

2017-01-01

INTRODUCTION: Low-intensity extracorporeal shockwave therapy (LI-ESWT) has emerged as a treatment option for male sexual dysfunction. However, results have been contradictory. AIM: To investigate the knowledge, practice patterns, and attitudes regarding LI-ESWT among experts in sexual medicine....... METHODS: A study-specific questionnaire was handed out at the 18th Congress for the European Society for Sexual Medicine. Participants were queried on their knowledge about LI-ESWT and about their use of the equipment. MAIN OUTCOME MEASURES: Descriptive data on the knowledge of LI-ESWT and perception...... of treatment effects. RESULTS: One hundred ninety-two questionnaires were available for analysis. Most respondents were physicians (79.7%) and most of these specialized in urology (58.9%). Overall, 144 of 192 (75%) reported that they were familiar with LI-ESWT in sexual medicine. Twenty-seven (14.1%) had...

Spleen injury following left extracorporeal shockwave lithotripsy (ESWL).

Science.gov (United States)

Marinkovic, Serge P; Marinkovic, Christina M; Xie, Donghua

2015-02-18

A splenic rupture associated with extracorporeal shockwave lithotripsy (ESWL) is exceedingly rare. We report a case of stage 3 splenic laceration, hemoperitoneum and subsequent splenic rupture following an ESWL for a left mid polar renal calculus. During the ESWL, although the patient's pain was controlled the gentleman was very nervous and had to be repositioned eight individual times. Approximately 6 hours after the ESWL, the patient phoned the urologist complaining of severe left flank pain unlike any previous episode of renal colic. A computerized tomography (CT) scan demonstrated a stage 3 splenic injury with hemoperitoneum. The patient decompensated and an emergent splenectomy was then performed and the patient experienced an uneventful recovery. Splenic injury likely results from unintentional movement during the sound wave administration for the stone fragmentation procedure. Utilizing noise cancelling headphones during ESWL may preclude the potential pitfalls of patient nervousness.

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.

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.

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.

Nucleosynthesis and hydrodynamic instabilities in core collapse supernovae

International Nuclear Information System (INIS)

Kifonidis, K.

2001-01-01

Hydrodynamic instabilities are of crucial importance for the explosion of massive stars as core collapse supernovae, for the synthesis of the heavy elements, and for their injection into the interstellar medium. The processes hereby involved are studied by means of two-dimensional hydrodynamic simulations which follow all phases from shock revival to shock breakout through the photosphere of a massive star. The computed distributions of radioactive elements are compared to observational data of SN 1987 A and other supernovae. While we find good agreement of our models with observations of Type Ib supernovae, the high velocities of iron group elements observed in SN 1987 A cannot be reproduced. Possible reasons for this discrepancy are discussed. Hydrodynamic instabilities are of crucial importance for the explosion of massive stars as core collapse supernovae, for the synthesis of the heavy elements, and for their injection into the interstellar medium. The processes hereby involved are studied by means of two-dimensional hydrodynamic simulations which follow all phases from shock revival to shock breakout through the photosphere of a massive star. The computed distributions of radioactive elements are compared to observational data of SN 1987 A and other supernovae. While we find good agreement of our models with observations of Type Ib supernovae, the high velocities of iron group elements observed in SN 1987 A cannot be reproduced. Possible reasons for this discrepancy are discussed

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

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 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.

Three-phase Interstellar Medium in Galaxies Resolving Evolution with Star Formation and Supernova Feedback (TIGRESS): Algorithms, Fiducial Model, and Convergence

Science.gov (United States)

Kim, Chang-Goo; Ostriker, Eve C.

2017-09-01

We introduce TIGRESS, a novel framework for multi-physics numerical simulations of the star-forming interstellar medium (ISM) implemented in the Athena MHD code. The algorithms of TIGRESS are designed to spatially and temporally resolve key physical features, including: (1) the gravitational collapse and ongoing accretion of gas that leads to star formation in clusters; (2) the explosions of supernovae (SNe), both near their progenitor birth sites and from runaway OB stars, with time delays relative to star formation determined by population synthesis; (3) explicit evolution of SN remnants prior to the onset of cooling, which leads to the creation of the hot ISM; (4) photoelectric heating of the warm and cold phases of the ISM that tracks the time-dependent ambient FUV field from the young cluster population; (5) large-scale galactic differential rotation, which leads to epicyclic motion and shears out overdense structures, limiting large-scale gravitational collapse; (6) accurate evolution of magnetic fields, which can be important for vertical support of the ISM disk as well as angular momentum transport. We present tests of the newly implemented physics modules, and demonstrate application of TIGRESS in a fiducial model representing the solar neighborhood environment. We use a resolution study to demonstrate convergence and evaluate the minimum resolution {{Δ }}x required to correctly recover several ISM properties, including the star formation rate, wind mass-loss rate, disk scale height, turbulent and Alfvénic velocity dispersions, and volume fractions of warm and hot phases. For the solar neighborhood model, all these ISM properties are converged at {{Δ }}x≤slant 8 {pc}.

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.)

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

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.

Extracorporeal shockwave therapy versus placebo for the treatment of chronic proximal plantar fasciitis: results of a randomized, placebo-controlled, double-blinded, multicenter intervention trial.

Science.gov (United States)

Malay, D Scot; Pressman, Martin M; Assili, Amir; Kline, Jason T; York, Shane; Buren, Ben; Heyman, Eugene R; Borowsky, Pam; LeMay, Carley

2006-01-01

Extracorporeal shockwave therapy (ESWT) has demonstrated efficacy in the treatment of recalcitrant proximal plantar fasciitis. The objective of this investigation was to compare the outcomes of participants treated with a new ESWT device with those treated with placebo. A total of 172 volunteer participants were randomized in a 2:1 active-to-placebo ratio in this prospective, double-blind, multicenter trial conducted between October 2003 and December 2004. ESWT (n=115) or placebo control (n=57) was administered on a single occasion without local or systemic anesthesia or sedation, after which follow-up was undertaken. The primary outcomes were the blind assessor's objective, and the participant's subjective assessments of heel pain during the first 3 months of follow-up. Participants were also followed up to 1 year to identify any adverse outcomes that may have been related to the shockwave device. On the visual analog scale, the blind assessor's objective assessment of heel pain displayed a mean reduction of 2.51 in the shockwave group and 1.57 in the placebo group; this difference was statistically significant (P=.045). On the visual analog scale, the participant's self-assessment of heel pain displayed a mean reduction of 3.39 in the shockwave group and 1.78 in the placebo group; this difference was statistically significant (P<.001). No serious adverse events were observed at any time. It was concluded that ESWT was both efficacious and safe for participants with chronic proximal plantar fasciitis that had been unresponsive to exhaustive conservative treatment.

Research in nuclear astrophysics: stellar collapse and supernovae. Progress report

International Nuclear Information System (INIS)

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

1986-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics is examined. The chief emphasis of our program is on stellar collapse, supernovae and neutron star formation. Central to these topics are the parallel development of both an equation of state of hot, dense matter and a novel type of hydrodynamical code. The LLPR compressible liquid drop model is the basis of the former. We are refining it to include both curvature corrections to the surface energy nuclear force parameters which are in better agreement with recently determined experimental quantities. Our study of the equation of state has the added bonus that our results can be used to analyze intermediate energy heavy ion collisions, which, in turn, may illuminate the nucleon-nucleon force. The hydrodynamical code includes a fast, but accurate, approximation to the complete LLPR equation of state. We model not only the stellar collapse leading up to a supernova, but also the quasi-static deleptonization and cooling stages of the nascent neutron star. Our detailed studies of the role of neutrinos in stellar collapse and neutron star formation concentrate on their detectability and signatures. Complementary studies include modelling both mass accretion in the nuclei of galaxies and investigating both galaxy clustering and the large scale structure of the universe. These studies are intended to shed light on the early history of the universe, in which both nuclear and elementary particle physics play a crucial role

Low-intensity extracorporeal shockwave therapy in the treatment of postprostatectomy erectile dysfunction

DEFF Research Database (Denmark)

Frey, Anders; Sønksen, Jens; Fode, Mikkel

2016-01-01

OBJECTIVE: The objective was to investigate the effect and feasibility of low-intensity extracorporeal shockwave therapy (LI-ESWT) as a treatment for erectile dysfunction (ED) after bilateral nerve-sparing radical prostatectomy (RP). MATERIALS AND METHODS: Patients who had undergone robot......-assisted bilateral nerve-sparing RP more than a year before entering this pilot study, had no preoperative ED and were suffering from mild to severe postoperative ED were invited to participate. Six treatments were given over a 6 week period, using the Duolith® SD1 T-Top machine. The effect of the treatment...

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

Uniform Contribution of Supernova Explosions to the Chemical Enrichment of Abell 3112 out to R{sub 200}

Energy Technology Data Exchange (ETDEWEB)

Ezer, Cemile; Ercan, E. Nihal [Department of Physics, Boğaziçi University, Istanbul (Turkey); Bulbul, Esra; Bautz, Mark W.; McDonald, Mike; Miller, Eric D. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Smith, Randall K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Loewenstein, Mike, E-mail: cemile.ezer@boun.edu.tr [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

2017-02-10

The spatial distribution of the metals residing in the intra-cluster medium (ICM) of galaxy clusters records all the information on a cluster’s nucleosynthesis and chemical enrichment history. We present measurements from a total of 1.2 Ms Suzaku XIS and 72 ks Chandra observations of the cool-core galaxy cluster Abell 3112 out to its virial radius (∼1470 kpc). We find that the ratio of the observed supernova type Ia explosions to the total supernova explosions has a uniform distribution at a level of 12%–16% out to the cluster’s virial radius. The observed fraction of type Ia supernova explosions is in agreement with the corresponding fraction found in our Galaxy and the chemical enrichment of our Galaxy. The non-varying supernova enrichment suggests that the ICM in cluster outskirts was enriched by metals at an early stage before the cluster itself was formed during a period of intense star formation activity. Additionally, we find that the 2D delayed detonation model CDDT produce significantly worse fits to the X-ray spectra compared to simple 1D W7 models. This is due to the relative overestimate of Si, and the underestimate of Mg in these models with respect to the measured abundances.

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

Resolving the Formation of Protogalaxies. 3; Feedback from the First Stars

Science.gov (United States)

Wise, John H.; Abel, Tom

2008-01-01

The first stars form in dark matter halos of masses 106 M as suggested by an increasing number of numerical simulations. Radiation feedback from these stars expels most of the gas from the shallow potential well of their surrounding dark matter halos.We use cosmological adaptive mesh refinement simulations that include self-consistent Population III star formation and feedback to examine the properties of assembling early dwarf galaxies. Accurate radiative transport is modeled with adaptive ray tracing. We include supernova explosions and follow the metal enrichment of the intergalactic medium. The calculations focus on the formation of several dwarf galaxies and their progenitors. In these halos, baryon fractions in 10(exp 8) Stelar Mass halos decrease by a factor of 2 with stellar feedback and by a factor of 3 with supernova explosions.We find that radiation feedback and supernova explosions increase gaseous spin parameters up to a factor of 4 and vary with time. Stellar feedback, supernova explosions, and H2 cooling create a complex, multiphase interstellar medium whose densities and temperatures can span up to 6 orders of magnitude at a given radius. The pair-instability supernovae of Population III stars alone enrich the halos with virial temperatures of 10(exp 4) K to approximately 10(exp -3) of solar metallicity.We find that 40% of the heavy elements resides in the intergalactic medium (IGM) at the end of our calculations. The highest metallicity gas exists in supernova remnants and very dilute regions of the IGM.

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.

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

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

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.

Shock-Wave Acceleration of Protons on OMEGA EP

Science.gov (United States)

Haberberger, D.; Froula, D. H.; Pak, A.; Link, A.; Patel, P.; Fiuza, F.; Tochitsky, S.; Joshi, C.

2015-11-01

Recent experimental results using shock-wave acceleration (SWA) driven by a CO2 laser in a H2 gas-jet plasma have shown the possibility of producing proton beams with energy spreads emission from a UV ablated material. The desired characteristics optimal for SWA are met: (a) peak plasma density is overcritical for the 1- μm main pulse and (b) the plasma profile exponentially decays over a long scale length on the rear side. Results will be shown using a 4 ω probe to experimentally characterize the plasma density profile. Scaling from simulations of the SWA mechanism shows that ion energies in the range of 100 MeV/amu are achievable with a focused a0 of 5 from the OMEGA EP Laser System. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

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 ...

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.

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

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.

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.

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...

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

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

Type-Ia Supernova Rates to Redshift 2.4 from Clash: The Cluster Lensing and Supernova Survey with Hubble

Science.gov (United States)

Graur, O.; Rodney, S. A.; Maoz, D.; Riess, A. G.; Jha, S. W.; Postman, M.; Dahlen, T.; Holoien, T. W.-S.; McCully, C.; Patel, B.;

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

Evolution of r-process elements in the hot supernova bubble

International Nuclear Information System (INIS)

Mathews, G.J.; Wilson, J.R.; Woosley, S.E.

1993-02-01

We review some of the recent arguments as to why the r-process is thought to be associated with supernovae and how the high-temperature, high-entropy inner region of a core-collapse supernova is an ideal r-process site. We present preliminary extensions of our earlier work on the formation of the high-entropy ''bubble'' that describe more accurately its late-time evolution and the ejection of the neutrino-energized wind from the surface of the nascent neutron star. This site leads naturally to a distribution of temperature, density, neutron excess, and entropy for material ejected at different times in the wind as required by Solar abundances. We present simple analytic expressions which approximate these distributions. This site also predicts an amount of reprocess material ejected per event in agreement with simple galactic evolution arguments. However, it is not yet clear whether the entropy in this model is high enough (or the electron fraction is low enough) to produce an optimum fit to the Solar r-process abundance curve and additional mechanisms may be required to increase the entropy per baryon. We conclude with a discussion of nuclear measurements which would help to probe this r-process environment

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.

Hot interstellar tunnels. I. Simulation of interacting supernova remnants

International Nuclear Information System (INIS)

Smith, B.W.

1977-01-01

Reexamining a suggestion of Cox and Smith, we find that intersecting supernova remnants can indeed generate and maintain hot interstellar regions with napproximately-less-than10 -2 cm -3 and Tapprox.10 6 K. These regions are likely to occupy at least 30% of the volume of a spiral arm near the midplane of the gaseous disk if the local supernova rate there is greater than 1.5 x 10 -7 Myr -1 pc -3 . Their presence in the interstellar medium is supported by observations of the soft X-ray background. The theory required to build a numerical simulation of interacting supernova remnants is developed. The hot cavities within a population of remnants will become connected for a variety of assumed conditions in the outer shells of old remnants. Extensive hot cavity regions or tunnels are built and enlarged by supernovae occurring in relatively dense gas which produce connections, but tunnels are kept hot primarily by supernovae occurring within the tunnels. The latter supernovae initiate fast shock waves which apparently reheat tunnels faster than they are destroyed by thermal conduction in a galactic magnetic field or by radiative cooling. However, the dispersal of these rejuvenating shocks over a wide volume is inhibited by motions of cooler interstellar gas in the interval between shocks. These motions disrupt the contiguity of the component cavities of a tunnel and may cause its death.The Monte Carlo simulations indicate that a quasi-equilibrium is reached within 10 7 years of the first supernova in a spiral arm. This equilibrium is characterized by a constant average filling fraction for cavities in the interstellar volume. Aspects of the equilibrium are discussed for a range of supernova rates. Two predictions of Cox and Smith are not confirmed within this range: critical growth of hot regions to encompass the entire medium, and the efficient quenching of a remnant's expansion by interaction with other cavities

Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. I. 60Fe transport to the solar system by turbulent mixing of ejecta from nearby supernovae into a locally homogeneous interstellar medium

Science.gov (United States)

Schulreich, M. M.; Breitschwerdt, D.; Feige, J.; Dettbarn, C.

2017-08-01

Context. The discovery of radionuclides like 60Fe with half-lives of million years in deep-sea crusts and sediments offers the unique possibility to date and locate nearby supernovae. Aims: We want to quantitatively establish that the 60Fe enhancement is the result of several supernovae which are also responsible for the formation of the Local Bubble, our Galactic habitat. Methods: We performed three-dimensional hydrodynamic adaptive mesh refinement simulations (with resolutions down to subparsec scale) of the Local Bubble and the neighbouring Loop I superbubble in different homogeneous, self-gravitating environments. For setting up the Local and Loop I superbubble, we took into account the time sequence and locations of the generating core-collapse supernova explosions, which were derived from the mass spectrum of the perished members of certain stellar moving groups. The release of 60Fe and its subsequent turbulent mixing process inside the superbubble cavities was followed via passive scalars, where the yields of the decaying radioisotope were adjusted according to recent stellar evolution calculations. Results: The models are able to reproduce both the timing and the intensity of the 60Fe excess observed with rather high precision, provided that the external density does not exceed 0.3 cm-3 on average. Thus the two best-fit models presented here were obtained with background media mimicking the classical warm ionised and warm neutral medium. We also found that 60Fe (which is condensed onto dust grains) can be delivered to Earth via two physical mechanisms: either through individual fast-paced supernova blast waves, which cross the Earth's orbit sometimes even twice as a result of reflection from the Local Bubble's outer shell, or, alternatively, through the supershell of the Local Bubble itself, injecting the 60Fe content of all previous supernovae at once, but over a longer time range.

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.

No effect of extracorporeal shockwave therapy on patellar tendinopathy in jumping athletes during the competitive season : A randomized clinical trial

NARCIS (Netherlands)

Zwerver, Johannes; Hartgens, Fred; Verhagen, Evert; van der Worp, Henk; van den Akker-Scheek, Inge; Diercks, Ronald

Background: Patellar tendinopathy is a common overuse injury among jumping athletes. No evidence-based treatment guidelines exist. Extracorporeal shockwave therapy (ESWT) appears to be a promising treatment but its effectiveness has not been studied in athletes with patellar tendinopathy who have

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

THE TYPE Ia SUPERNOVA RATE IN RADIO AND INFRARED GALAXIES FROM THE CANADA-FRANCE-HAWAII TELESCOPE SUPERNOVA LEGACY SURVEY

International Nuclear Information System (INIS)

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

2010-01-01

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, Very Large Array 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ∼1-5 times the rate in all early-type galaxies, and that any enhancement is always ∼<2σ. Rates in these subsets are consistent with predictions of the two-component 'A+B' SN Ia rate model. Since infrared properties of radio SN Ia hosts indicate dust-obscured star formation, we incorporate infrared star formation rates into the 'A+B' model. We also show the properties of SNe Ia in radio and infrared galaxies suggest the hosts contain dust and support a continuum of delay time distributions (DTDs) for SNe Ia, although other DTDs cannot be ruled out based on our data.

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

Core-Collapse Supernova Progenitors In The Era Of Untargeted Transient Searches

Science.gov (United States)

Sanders, Nathan Edward

2014-04-01

Core-collapse supernovae (SNe) are the highly energetic explosions of massive stars (≳ 8 M⊙) that are pervasive in their influence throughout astrophysics. They are the phenomenon with primary responsibility for enriching the universe with many of the heavy elements (like carbon and oxygen) that are needed for life, provide a critical feedback pressure which helps to shape the galaxies that host them, and are the likely formation mechanism for stellar mass black holes. In the past decade, the study of these explosions has been revolutionized by the advent of wide field, untargeted transient searches like Pan-STARRS1 (PS1). These new searches permit the discovery of SNe at unprecedented rates, and absent of many of the selection effects that have enforced biases on past, targeted transient searches. This thesis presents a broad survey of core-collapse SN phenomenology exhibited in the discoveries of untargeted searches, and statistically quantifies population properties of these explosions that link them to distinct classes of progenitor stars. Through studies of the host galaxy and explosion properties of extreme PS1-discovered events, and controlled samples of specific classes of core-collapse objects, we constrain the effect of progenitor star chemical composition (metallicity) on their eventual death states. We provide a new observational, photometric tool which lowers the cost of precisely and accurately measuring the metallicities of distant galaxies and supernova host environments. Moreover, we develop and apply a novel, multi-level Bayesian model for optical transient light curves which we apply to simultaneously interpret more than 20,000 PS1 images. This study illustrates how population-level modeling of data from large photometric surveys can yield improved physical inference on their progenitor stars through comparison to physical models. In the coming era, as next-generation facilities like the Large Synoptic Survey Telescope come online, the

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.)

The Carnegie Supernova Project I. Methods to estimate host-galaxy reddening of stripped-envelope supernovae

Science.gov (United States)

Stritzinger, M. D.; Taddia, F.; Burns, C. R.; Phillips, M. M.; Bersten, M.; Contreras, C.; Folatelli, G.; Holmbo, S.; Hsiao, E. Y.; Hoeflich, P.; Leloudas, G.; Morrell, N.; Sollerman, J.; Suntzeff, N. B.

2018-02-01

We aim to improve upon contemporary methods to estimate host-galaxy reddening of stripped-envelope (SE) supernovae (SNe). To this end the Carnegie Supernova Project (CSP-I) SE SN photometry data release, consisting of nearly three dozen objects, is used to identify a minimally reddened sub-sample for each traditionally defined spectroscopic sub-type (i.e., SNe IIb, SNe Ib, SNe Ic). Inspection of the optical and near-infrared (NIR) colors and color evolution of the minimally reddened sub-samples reveals a high degree of homogeneity, particularly between 0 d to +20 d relative to B-band maximum. This motivated the construction of intrinsic color-curve templates, which when compared to the colors of reddened SE SNe, yields an entire suite of optical and NIR color excess measurements. Comparison of optical/optical vs. optical/NIR color excess measurements indicates the majority of the CSP-I SE SNe suffer relatively low amounts of reddening (i.e., E(B-V)host 0.20 mag) objects with the Fitzpatrick (1999, PASP, 111, 63) reddening law model provides robust estimates of the host visual-extinction AVhost and RVhost. In the case of the SE SNe with relatively low amounts of reddening, a preferred value of RVhost is adopted for each sub-type, resulting in estimates of AVhost through Fitzpatrick (1999) reddening law model fits to the observed color excess measurements. Our analysis suggests SE SNe reside in galaxies characterized by a range of dust properties. We also find evidence that SNe Ic are more likely to occur in regions characterized by larger RVhost values compared to SNe IIb/Ib and they also tend to suffer more extinction. The later finding is consistent with work in the literature suggesting SNe Ic tend to occur in regions of on-going star formation. Based on observations collected at Las Campanas Observatory.

Spallation reactions in shock waves at supernova explosions and related problems

Energy Technology Data Exchange (ETDEWEB)

Ustinova, G. K., E-mail: ustinova@dubna.net.ru [RAS, V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry (Russian Federation)

2013-05-15

The isotopic anomalies of some extinct radionuclides testify to the outburst of a nearby supernova just before the collapse of the protosolar nebula, and to the fact that the supernova was Sn Ia, i.e. the carbon-detonation supernova. A key role of spallation reactions in the formation of isotopic anomalies in the primordial matter of the Solar System is revealed. It is conditioned by the diffusive acceleration of particles in the explosive shock waves, which leads to the amplification of rigidity of the energy spectrum of particles and its enrichment with heavier ions. The quantitative calculations of such isotopic anomalies of many elements are presented. It is well-grounded that the anomalous Xe-HL in meteoritic nanodiamonds was formed simultaneously with nanodiamonds themselves during the shock wave propagation at the Sn Ia explosion. The possible effects of shock wave fractionation of noble gases in the atmosphere of planets are considered. The origin of light elements Li, Be and B in spallation reactions, predicted by Fowler in the middle of the last century, is argued. All the investigated isotopic anomalies give the evidence for the extremely high magnetohydrodynamics (MHD) conditions at the initial stage of free expansion of the explosive shock wave from Sn Ia, which can be essential in solution of the problem of origin of cosmic rays. The specific iron-enriched matter of Sn Ia and its MHD-separation in turbulent processes must be taking into account in the models of origin of the Solar System.

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.

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...

Chandra Maps Vital Elements From Supernova

Science.gov (United States)

1999-12-01

composition of the various knots and filaments of stellar material visible in Cas A. Not only could the astronomers determine the composition of many knots in the remnant from the Chandra data, they were also able to infer where in the exploding star the knots had originated. For example, the most compact and brightest knots were composed mostly of silicon and sulfur, with little or no iron. This pointed to an origin deep in the star's interior where the temperatures had reached three billion degrees during the collapse and resulting supernova. Elsewhere, they found fainter features that contained significant amounts of iron as well as some silicon and sulfur. This material was produced even deeper in the star, where the temperatures during the explosion had reached higher values of four to five billion degrees. When Hughes and his collaborators compared where the compact silicon-rich knots and fainter iron-rich features were located in Cas A, they discovered that the iron-rich features from deepest in the star were near the outer edge of the remnant. This meant that they had been flung the furthest by the explosion that created Cas A. Even now this material appears to be streaming away from the site of the explosion with greater speed than the rest of the remnant. By studying the Cas A Chandra data further, astronomers hope to identify which of the several processes proposed by theoretical studies is likely to be the correct mechanism for explaining supernova explosions, both in terms of the dynamics and elements they produce. "In addition to understanding how iron and the other elements are produced in stars, we also want to learn how it gets out of stars and into the interstellar medium. This is why the study of supernovas and supernova remnants is so important," said Hughes. "Once released from stars, newly-created elements can then participate in the formation of new stars and planets in a great cycle that has gone on numerous times already. It is remarkable to realize

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

The Transition of a Type IIL Supernova into a Supernova Remnant: Late-time Observations of SN 2013by

Energy Technology Data Exchange (ETDEWEB)

Black, C. S.; Fesen, R. A. [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Milisavljevic, D.; Patnaude, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Margutti, R. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Parker, S. [Parkdale Observatory, 225 Warren Road, RDl Oxford, Canterbury 7495 (New Zealand)

2017-10-10

We present early-time Swift and Chandra X-ray data along with late-time optical and near-infrared observations of SN 2013by, a Type IIL supernova (SN) that occurred in the nearby spiral galaxy ESO 138−G10 ( D ∼ 14.8 Mpc). Optical and NIR photometry and spectroscopy follow the late-time evolution of the SN from days +89 to +457 post maximum brightness. The optical spectra and X-ray light curves are consistent with the picture of an SN having prolonged interaction with circumstellar material (CSM) that accelerates the transition from SN to supernova remnant (SNR). Specifically, we find SN 2013by’s H α profile exhibits significant broadening (∼10,000 km s{sup −1}) on day +457, the likely consequence of high-velocity, H-rich material being excited by a reverse shock. A relatively flat X-ray light curve is observed that cannot be modeled using Inverse Compton scattering processes alone, but requires an additional energy source most likely originating from the SN-CSM interaction. In addition, we see the first overtone of CO emission near 2.3 μ m on day +152, signaling the formation of molecules and dust in the SN ejecta and is the first time CO has been detected in a Type IIL SN. We compare SN 2013by with Type IIP SNe, whose spectra show the rarely observed SN-to-SNR transition in varying degrees and conclude that Type IIL SNe may enter the remnant phase at earlier epochs than their Type IIP counterparts.

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.

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

Detecting First Supernovae with JWST

Science.gov (United States)

Regos, Eniko; FLARE

2018-01-01

We have applied for a JWST ERS First Transients Survey, FLARE to answer empirically how the Universe made its first stars. To quest the epoch of reionization we target what happened to these first stars by observing the most luminous events, supernovae. These transients provide direct constraints on star formation rates and the initial mass function.These very rare events can be reached by JWST at 27 mag AB in 2 micron and 4.4 micron over a field of 0.1 square degree visited multiple times each year.The survey may detect massive Pop III SNe at redshifts up to 10, pinpointing the redshift of first stars, a key scientific goal of JWST.We explore all models of star formation history (derived from UV luminosity densities and IR data), DTD, top heavy IMF of early, low metallicity stars, and normalizations to data of SN Ia, II rates (SNLS, CLASH, CANDELS, SDSS, SVISS), as well as SLSN (ROTSE, SNLS) to estimate the expected SN rates as function of redshift.Population synthesis of double degenerate and single degenerate scenarios of SN Ia shows that the shape of the DTD is rather insensitive to the assumptions (common envelope prescription and metallicities, or retention efficiency of accreted H to white dwarf core and mass transfer rate).Indeed GOODS High z SN Ia rates imply substantial delay in their progenitor model, and Hubble Higher z SN search constrains delay time distribution models as well.SLSN (I, II /H/ and extreme rare pulsational pair instability) are magnetars (ULGRB) in high local star formation rate, faint, low metallicity galaxies.

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...

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.

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 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.

The Importance of Electron Captures in Core-Collapse Supernovae

International Nuclear Information System (INIS)

Langanke, K.; Sampaio, J.M.; Martinez-Pinedo, G.

2004-01-01

Nuclear physics plays an essential role in the dynamics of a type II supernova (a collapsing star). Recent advances in nuclear many-body theory allow now to reliably calculate the stellar weak-interaction processes involving nuclei. The most important process is the electron capture on finite nuclei with mass numbers A > 55. It is found that the respective capture rates, derived from modern many-body models, differ noticeably from previous, more phenomenological estimates. This leads to significant changes in the stellar trajectory during the supernova explosion, as has been found in state-of-the-art supernova simulations. (author)

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.

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

[Extracorporeal shockwave lithotripsy (ESWL) for salivary gland stones: a retrospective study of 1571 patients].

Science.gov (United States)

Guerre, A; Katz, P

2011-04-01

The fragmentation of salivary stones by extracorporeal shockwave lithotripsy (ESWL) has been described since the 1990s. We wanted to assess its effectiveness through a retrospective study. We reviewed the files of 1571 patients (801 women and 770 men, from 6 to 85 years of age) treated by ESWL between 1995 and 2010 for 1031 submandibular (65.6%) and 540 parotid gland sialolithiasis (34.4%). The treatment consisted in one or several sessions of ESWL distributed over 3 to 24 months. Three thousand to 6000 shockwaves were delivered by session, if there was no hemostatic disorder or infection. Ultrasound control examinations were performed regularly and systematically. An average of six sessions was necessary. All the lithiases were fragmented, 1056 (67.2%) totally and 515 (32.8%) partially with residual fragments from 1 to 6mm in size. After treatment, 1446 patients (92%) were asymptomatic and 125 (8%) continued to present salivary symptoms, without residual fragments on ultrasound examination in 82% of the cases. The main adverse reaction was infection (628 patients, 40%) resolved thanks to antibiotic treatment or extraction of fragments under local anesthesia. Developed for 20 years, LEC is an excellent alternative to conventional surgery as long as indications are respected. It seems very effective, but its drawbacks are the length of management and the difficulty of ultrasound localization of calculi, which requires an experienced operator. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

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.

Evidence for supernova injection into the solar nebula and the decoupling of r-process nucleosynthesis.

Science.gov (United States)

Brennecka, Gregory A; Borg, Lars E; Wadhwa, Meenakshi

2013-10-22

The isotopic composition of our Solar System reflects the blending of materials derived from numerous past nucleosynthetic events, each characterized by a distinct isotopic signature. We show that the isotopic compositions of elements spanning a large mass range in the earliest formed solids in our Solar System, calcium-aluminum-rich inclusions (CAIs), are uniform, and yet distinct from the average Solar System composition. Relative to younger objects in the Solar System, CAIs contain positive r-process anomalies in isotopes A 140. This fundamental difference in the isotopic character of CAIs around mass 140 necessitates (i) the existence of multiple sources for r-process nucleosynthesis and (ii) the injection of supernova material into a reservoir untapped by CAIs. A scenario of late supernova injection into the protoplanetary disk is consistent with formation of our Solar System in an active star-forming region of the galaxy.

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.

Apolipoprotein E4 genotype and gallbladder motility influence speed of gallstone clearance and risk of recurrence after extracorporeal shock-wave lithotripsy

NARCIS (Netherlands)

Portincasa, P.; van Erpecum, K. J.; van de Meeberg, P. C.; Dallinga-Thie, G. M.; de Bruin, T. W.; van Berge-Henegouwen, G. P.

1996-01-01

Extracorporeal shock-wave lithotripsy (ESWL) is an effective treatment in selected gallstone patients, but stone recurrence is a major drawback, Factors potentially influencing gallstone clearance and recurrence were studied in 84 patients in whom stone dissolution was diagnosed after ESWL plus bile

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.)

New Evidence Links Stellar Remains to Oldest Recorded Supernova

Science.gov (United States)

2006-09-01

Recent observations have uncovered evidence that helps to confirm the identification of the remains of one of the earliest stellar explosions recorded by humans. The new study shows that the supernova remnant RCW 86 is much younger than previously thought. As such, the formation of the remnant appears to coincide with a supernova observed by Chinese astronomers in 185 A.D. The study used data from NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory, "There have been previous suggestions that RCW 86 is the remains of the supernova from 185 A.D.," said Jacco Vink of University of Utrecht, the Netherlands, and lead author of the study. "These new X-ray data greatly strengthen the case." When a massive star runs out of fuel, it collapses on itself, creating a supernova that can outshine an entire galaxy. The intense explosion hurls the outer layers of the star into space and produces powerful shock waves. The remains of the star and the material it encounters are heated to millions of degrees and can emit intense X-ray radiation for thousands of years. Animation of a Massive Star Explosion Animation of a Massive Star Explosion In their stellar forensic work, Vink and colleagues studied the debris in RCW 86 to estimate when its progenitor star originally exploded. They calculated how quickly the shocked, or energized, shell is moving in RCW 86, by studying one part of the remnant. They combined this expansion velocity with the size of the remnant and a basic understanding of how supernovas expand to estimate the age of RCW 86. "Our new calculations tell us the remnant is about 2,000 years old," said Aya Bamba, a coauthor from the Institute of Physical and Chemical Research (RIKEN), Japan. "Previously astronomers had estimated an age of 10,000 years." The younger age for RCW 86 may explain an astronomical event observed almost 2000 years ago. In 185 AD, Chinese astronomers (and possibly the Romans) recorded the appearance of a new

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

Star formation

International Nuclear Information System (INIS)

Woodward, P.R.

1978-01-01

Theoretical models of star formation are discussed beginning with the earliest stages and ending in the formation of rotating, self-gravitating disks or rings. First a model of the implosion of very diffuse gas clouds is presented which relies upon a shock at the edge of a galactic spiral arm to drive the implosion. Second, models are presented for the formation of a second generation of massive stars in such a cloud once a first generation has formed. These models rely on the ionizing radiation from massive stars or on the supernova shocks produced when these stars explode. Finally, calculations of the gravitational collapse of rotating clouds are discussed with special focus on the question of whether rotating disks or rings are the result of such a collapse. 65 references

A Model of the Action of the Shockwave Generated by a Multichannel Discharge on the Union of Bone Tissue with Bone Cement

Czech Academy of Sciences Publication Activity Database

Zeman, J.; Hach, J.; Mikulaková, W.; Derňarová, Ľ.; Eliášová, A.; Lukeš, Petr; Balážová, L.; Beneš, J.

2016-01-01

Roč. 30, č. 3 (2016), s. 237-242 ISSN 0258-851X Institutional support: RVO:61389021 Keywords : Shockwave * bone cement extractions * surgical revision Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.953, year: 2016

The Data Release of the Sloan Digital Sky Survey-II Supernova Survey

Science.gov (United States)

Sako, Masao; Bassett, Bruce; Becker, Andrew C.; Brown, Peter J.; Campbell, Heather; Wolf, Rachel; Cinabro, David; D’Andrea, Chris B.; Dawson, Kyle S.; DeJongh, Fritz; Depoy, Darren L.; Dilday, Ben; Doi, Mamoru; Filippenko, Alexei V.; Fischer, John A.; Foley, Ryan J.; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter M.; Goobar, Ariel; Gupta, Ravi R.; Hill, Gary J.; Hayden, Brian T.; Hlozek, Renée; Holtzman, Jon A.; Hopp, Ulrich; Jha, Saurabh W.; Kessler, Richard; Kollatschny, Wolfram; Leloudas, Giorgos; Marriner, John; Marshall, Jennifer L.; Miquel, Ramon; Morokuma, Tomoki; Mosher, Jennifer; Nichol, Robert C.; Nordin, Jakob; Olmstead, Matthew D.; Östman, Linda; Prieto, Jose L.; Richmond, Michael; Romani, Roger W.; Sollerman, Jesper; Stritzinger, Max; Schneider, Donald P.; Smith, Mathew; Wheeler, J. Craig; Yasuda, Naoki; Zheng, Chen

2018-06-01

This paper describes the data release of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, and ancillary data are presented for 10,258 variable and transient sources discovered through repeat ugriz imaging of SDSS Stripe 82, a 300 deg2 area along the celestial equator. This data release is comprised of all transient sources brighter than r ≃ 22.5 mag with no history of variability prior to 2004. Dedicated spectroscopic observations were performed on a subset of 889 transients, as well as spectra for thousands of transient host galaxies using the SDSS-III BOSS spectrographs. Photometric classifications are provided for the candidates with good multi-color light curves that were not observed spectroscopically, using host galaxy redshift information when available. From these observations, 4607 transients are either spectroscopically confirmed, or likely to be, supernovae, making this the largest sample of supernova candidates ever compiled. We present a new method for SN host-galaxy identification and derive host-galaxy properties including stellar masses, star formation rates, and the average stellar population ages from our SDSS multi-band photometry. We derive SALT2 distance moduli for a total of 1364 SN Ia with spectroscopic redshifts as well as photometric redshifts for a further 624 purely photometric SN Ia candidates. Using the spectroscopically confirmed subset of the three-year SDSS-II SN Ia sample and assuming a flat ΛCDM cosmology, we determine Ω M = 0.315 ± 0.093 (statistical error only) and detect a non-zero cosmological constant at 5.7σ.

The Data Release of the Sloan Digital Sky Survey-II Supernova Survey

Energy Technology Data Exchange (ETDEWEB)

Sako, Masao; et al.

2014-01-14

This paper describes the data release of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, and ancillary data are presented for 10,258 variable and transient sources discovered through repeat ugriz imaging of SDSS Stripe 82, a 300 deg2 area along the celestial equator. This data release is comprised of all transient sources brighter than r~22.5 mag with no history of variability prior to 2004. Dedicated spectroscopic observations were performed on a subset of 889 transients, as well as spectra for thousands of transient host galaxies using the SDSS-III BOSS spectrographs. Photometric classifications are provided for the candidates with good multi-color light curves that were not observed spectroscopically. From these observations, 4607 transients are either spectroscopically confirmed, or likely to be, supernovae, making this the largest sample of supernova candidates ever compiled. We present a new method for SN host-galaxy identification and derive host-galaxy properties including stellar masses, star-formation rates, and the average stellar population ages from our SDSS multi-band photometry. We derive SALT2 distance moduli for a total of 1443 SN Ia with spectroscopic redshifts as well as photometric redshifts for a further 677 purely-photometric SN Ia candidates. Using the spectroscopically confirmed subset of the three-year SDSS-II SN Ia sample and assuming a flat Lambda-CDM cosmology, we determine Omega_M = 0.315 +/- 0.093 (statistical error only) and detect a non-zero cosmological constant at 5.7 sigmas.

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.

SN 2008jb: A 'LOST' CORE-COLLAPSE SUPERNOVA IN A STAR-FORMING DWARF GALAXY AT ∼10 Mpc

International Nuclear Information System (INIS)

Prieto, J. L.; Lee, J. C.; Drake, A. J.; Djorgovski, S. G.; McNaught, R.; Garradd, G.; Beacom, J. F.; Beshore, E.; Catelan, M.; Pojmanski, G.; Stanek, K. Z.; Szczygieł, D. M.

2012-01-01

We present the discovery and follow-up observations of SN 2008jb, a core-collapse supernova in the southern dwarf irregular galaxy ESO 302–14 (M B = –15.3 mag) at 9.6 Mpc. This nearby transient was missed by galaxy-targeted surveys and was only found in archival optical images obtained by the Catalina Real-time Transient Survey and the All-Sky Automated Survey. The well-sampled archival photometry shows that SN 2008jb was detected shortly after explosion and reached a bright optical maximum, V max ≅ 13.6 mag (M V,max ≅ –16.5). The shape of the light curve shows a plateau of ∼100 days, followed by a drop of ∼1.4 mag in the V band to a slow decline with an approximate 56 Co decay slope. The late-time light curve is consistent with 0.04 ± 0.01 M ☉ of 56 Ni synthesized in the explosion. A spectrum of the supernova obtained two years after explosion shows a broad, boxy Hα emission line, which is unusual for normal Type II-Plateau supernovae at late times. We detect the supernova in archival Spitzer and WISE images obtained 8-14 months after explosion, which show clear signs of warm (600-700 K) dust emission. The dwarf irregular host galaxy, ESO 302–14, has a low gas-phase oxygen abundance, 12 + log(O/H) = 8.2 (∼1/5 Z ☉ ), similar to those of the Small Magellanic Cloud and the hosts of long gamma-ray bursts and luminous core-collapse supernovae. This metallicity is one of the lowest among local (∼ 5 M ☉ for the star formation complex, assuming a single-age starburst. These properties are consistent with the expanding Hα supershells observed in many well-studied nearby dwarf galaxies, which are tell-tale signs of feedback from the cumulative effect of massive star winds and supernovae. The age estimated for the star-forming region where SN 2008jb exploded suggests a relatively high-mass progenitor star with an initial mass M ∼ 20 M ☉ and warrants further study. We discuss the implications of these findings in the study of core

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...

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

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.

Treatment of mid- and lower ureteric calculi: extracorporeal shock-wave lithotripsy vs laser ureteroscopy. A comparison of costs, morbidity and effectiveness

NARCIS (Netherlands)

Bierkens, A. F.; Hendrikx, A. J.; de la Rosette, J. J.; Stultiens, G. N.; Beerlage, H. P.; Arends, A. J.; Debruyne, F. M.

1998-01-01

To determine the efficacy and costs of extracorporeal shock-wave lithotripsy (ESWL) compared with ureteroscopy (URS) in the treatment of mid- and lower ureteric calculi. The records of patients treated primarily by ESWL and URS were analysed retrospectively. Treatment with ESWL included 63 patients

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.

Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction—12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study

Directory of Open Access Journals (Sweden)

Grzegorz Lukasz Fojecki, MD

2018-03-01

Fojecki GL, Tiessen S, Osther PJS. Effect of Linear Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction—12-Month Follow-Up of a Randomized, Double-Blinded, Sham-Controlled Study. Sex Med 2018;6:1–7.

Mass Extinctions and Supernova Explosions

Science.gov (United States)

Korschinek, Gunther

A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation or the direct exposure of lethal X-rays. Another indirect effect is cloud formation, induced by cosmic rays in the atmosphere which result in a drop in the Earth's temperature, causing major glaciations of the Earth. The discovery of highly intensive gamma-ray bursts (GRBs), which could be connected to SNe, initiated further discussions on possible life-threatening events in the Earth's history. The probability that GRBs hit the Earth is very low. Nevertheless, a past interaction of Earth with GRBs and/or SNe cannot be excluded and might even have been responsible for past extinction events.

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

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

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

Shock-induced hotspot formation and chemical reaction initiation in PETN containing a spherical void

International Nuclear Information System (INIS)

Shan, Tzu-Ray; Thompson, Aidan P

2014-01-01

We present results of reactive molecular dynamics simulations of hotspot formation and chemical reaction initiation in shock-induced compression of pentaerythritol tetranitrate (PETN) with the ReaxFF reactive force field. A supported shockwave is driven through a PETN crystal containing a 20 nm spherical void at a sub-threshold impact velocity of 2 km/s. Formation of a hotspot due to shock-induced void collapse is observed. During void collapse, NO 2 is the dominant species ejected from the upstream void surface. Once the ejecta collide with the downstream void surface and the hotspot develops, formation of final products such as N 2 and H 2 O is observed. The simulation provides a detailed picture of how void collapse and hotspot formation leads to initiation at sub-threshold impact velocities.

Distant Supernovae Indicate Ever-Expanding Universe

Science.gov (United States)

1998-12-01

parameters, the age of the Universe and the geometry of space can be derived. They have been the focus of a large number of astronomical programmes over the past decades. Many aspects of the currently preferred cosmological model, the Hot Big Bang , have been impressively confirmed by observations of the expansion of the Universe, the cosmic background radiation, and also the explanation of the synthesis of light elements. Still, our knowledge about the dynamical state of the Universe, as well as the early formation of structures, i.e., of galaxies and stars, is far from complete - this remains a field of active research. Possibly, the simplest way to test our present assumptions in this direction is to measure accurate distances and compare them with the expected cosmic scale. This is where the recent results contribute to our understanding of the Universe. The key role of supernovae The two research teams, both with participation from ESO [1], have concentrated on the study of rare stellar explosions, during which certain old stars undergo internal incineration. In this process, explosive nuclear fusion burns matter into the most stable atomic nucleus, iron, and releases a gigantic amount of energy. ESO PR Photo 50a/98 ESO PR Photo 50a/98 [Preview - JPEG: 800 x 648 pix - 768k] [High-Res - JPEG: 3000 x 2431 pix - 8.5Mb] ESO PR Photo 50b/98 ESO PR Photo 50b/98 [Preview - JPEG: 800 x 649 pix - 784k] [High-Res - JPEG: 3000 x 2432 pix - 8.4Mb] These photos illustrate the follow-up observations on which the new results described in this Press Release are based. Sky fields with clusters of galaxies are monitored with the 4-m telescope at Cerro Tololo Interamerican Observatory (CTIO) in Chile and spectra are obtained of suddenly appearing star-like objects that may be supernovae. Confirmed Type Ia supernovae are then monitored by ESO telescopes at La Silla and at other observatories. In PR Photo 50a/98 , a supernova at redshift z = 0.51 [2] (corresponding to a distance of about 10

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

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)

The combined effect of AGN and supernovae feedback in launching massive molecular outflows in high-redshift galaxies

Science.gov (United States)

Biernacki, Pawel; Teyssier, Romain

2018-04-01

We have recently improved our model of active galactic nucleus (AGN) by attaching the supermassive black hole (SMBH) to a massive nuclear star cluster (NSC). Here, we study the effects of this new model in massive, gas-rich galaxies with several simulations of different feedback recipes with the hydrodynamics code RAMSES. These simulations are compared to a reference simulation without any feedback, in which the cooling halo gas is quickly consumed in a burst of star formation. In the presence of strong supernovae (SN) feedback, we observe the formation of a galactic fountain that regulates star formation over a longer period, but without halting it. If only AGN feedback is considered, as soon as the SMBH reaches a critical mass, strong outflows of hot gas are launched and prevent the cooling halo gas from reaching the disc, thus efficiently halting star formation, leading to the so-called `quenching'. If both feedback mechanisms act in tandem, we observe a non-linear coupling, in the sense that the dense gas in the supernovae-powered galactic fountain is propelled by the hot outflow powered by the AGN at much larger radii than without AGN. We argue that these particular outflows are able to unbind dense gas from the galactic halo, thanks to the combined effect of SN and AGN feedback. We speculate that this mechanism occurs at the end of the fast growing phase of SMBH, and is at the origin of the dense molecular outflows observed in many massive high-redshift 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

Kiloparsec-scale Simulations of Star Formation in Disk Galaxies. IV. Regulation of Galactic Star Formation Rates by Stellar Feedback

International Nuclear Information System (INIS)

Butler, Michael J.; Tan, Jonathan C.; Teyssier, Romain; Nickerson, Sarah; Rosdahl, Joakim; Van Loo, Sven

2017-01-01

Star formation from the interstellar medium of galactic disks is a basic process controlling the evolution of galaxies. Understanding the star formation rate (SFR) in a local patch of a disk with a given gas mass is thus an important challenge for theoretical models. Here we simulate a kiloparsec region of a disk, following the evolution of self-gravitating molecular clouds down to subparsec scales, as they form stars that then inject feedback energy by dissociating and ionizing UV photons and supernova explosions. We assess the relative importance of each feedback mechanism. We find that H 2 -dissociating feedback results in the largest absolute reduction in star formation compared to the run with no feedback. Subsequently adding photoionization feedback produces a more modest reduction. Our fiducial models that combine all three feedback mechanisms yield, without fine-tuning, SFRs that are in excellent agreement with observations, with H 2 -dissociating photons playing a crucial role. Models that only include supernova feedback—a common method in galaxy evolution simulations—settle to similar SFRs, but with very different temperatures and chemical states of the gas, and with very different spatial distributions of young stars.

Kiloparsec-scale Simulations of Star Formation in Disk Galaxies. IV. Regulation of Galactic Star Formation Rates by Stellar Feedback

Energy Technology Data Exchange (ETDEWEB)

Butler, Michael J. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Tan, Jonathan C. [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States); Teyssier, Romain; Nickerson, Sarah [Institute for Computational Science, University of Zurich, 8049 Zurich (Switzerland); Rosdahl, Joakim [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Van Loo, Sven [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)

2017-06-01

Star formation from the interstellar medium of galactic disks is a basic process controlling the evolution of galaxies. Understanding the star formation rate (SFR) in a local patch of a disk with a given gas mass is thus an important challenge for theoretical models. Here we simulate a kiloparsec region of a disk, following the evolution of self-gravitating molecular clouds down to subparsec scales, as they form stars that then inject feedback energy by dissociating and ionizing UV photons and supernova explosions. We assess the relative importance of each feedback mechanism. We find that H{sub 2}-dissociating feedback results in the largest absolute reduction in star formation compared to the run with no feedback. Subsequently adding photoionization feedback produces a more modest reduction. Our fiducial models that combine all three feedback mechanisms yield, without fine-tuning, SFRs that are in excellent agreement with observations, with H{sub 2}-dissociating photons playing a crucial role. Models that only include supernova feedback—a common method in galaxy evolution simulations—settle to similar SFRs, but with very different temperatures and chemical states of the gas, and with very different spatial distributions of young stars.

THE STELLAR ANCESTRY OF SUPERNOVAE IN THE MAGELLANIC CLOUDS. I. THE MOST RECENT SUPERNOVAE IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Badenes, Carles; Harris, Jason; Zaritsky, Dennis; Prieto, Jose L.

2009-01-01

We use the star formation history (SFH) map of the Large Magellanic Cloud recently published by Harris and Zaritsky to study the sites of the eight smallest (and presumably youngest) supernova remnants (SNRs) in the Cloud: SN 1987A, N158A, N49, and N63A (core collapse remnants), 0509 - 67.5, 0519 - 69.0, N103B, and DEM L71 (Type Ia remnants). The local SFHs provide unique insights into the nature of the supernova (SN) progenitors, which we compare with the properties of the SN explosions derived from the remnants themselves and from SN light echoes. We find that all the core collapse SNe that we have studied are associated with vigorous star formation (SF) in the recent past. In the case of SN 1987A, the time of the last peak of SF (12 Myr) matches the lifetime of a star with the known mass of its blue supergiant progenitor (∼20 M sun ). More recent peaks of SF can lead to SNe with more massive progenitors, which opens the possibility of a Type Ib/c origin for SNRs N158A and N63A. Stars more massive than 21.5 M sun are very scarce around SNR N49, implying that the magnetar SGR 0526 - 66 in this SNR was either formed elsewhere or came from a progenitor with a mass well below the 30M sun threshold suggested in the literature. Three of our four Ia SNRs are associated with old, metal-poor stellar populations. This includes SNR 0509 - 67.5, which is known to have been originated by an extremely bright Type Ia event, and yet is located very far away from any sites of recent SF, in a population with a mean age of 7.9 Gyr. The Type Ia SNR N103B, on the other hand, is associated with recent SF, and might have had a relatively younger and more massive progenitor with substantial mass loss before the explosion. We discuss these results in the context of our present understanding of core collapse and Type Ia SN progenitors.

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.)

Efficacy Management of Urolithiasis: Flexible Ureteroscopy versus Extracorporeal Shockwave Lithotripsy.

Science.gov (United States)

Tauber, Volkmar; Wohlmuth, Martin; Hochmuth, Andreas; Schimetta, Wolfgang; Schimetta, Wofgang; Krause, F Steffen

2015-01-01

To evaluate the efficacy of flexible ureterscopy (fURS) and extracorporal shockwave lithotripsy (SWL) in the treatment of urolithiasis, complemented by a subgroup analysis of lower pole calyx. Retrospective analysis of patients treated by fURS or SWL was performed by independent variables such as gender, age, nephrolith size, double-J stent (DJ stent) and stone localisation. Out of 326 patients, 165 were treated by SWL and 161 by fURS. Complete stone removal was achieved by fURS in 83.2% and by SWL in 43.0% (p auxillary DJ stent was performed more often preoperative before fURS. The subgroup analysis of lower pole calyx confirmed these evaluations. Complete stone-free removal was almost 8 times higher after fURS compared to SWL. The efficacy of fURS in treatment of urolithiasis is substantially higher than the efficacy of SWL. © 2015 S. Karger AG, Basel.

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.

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.

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 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.

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.

Radial extracorporeal shock-wave therapy in patients with chronic rotator cuff tendinitis: a prospective randomised double-blind placebo-controlled multicentre trial

NARCIS (Netherlands)

Kolk, A. van der; Yang, K.G.; Tamminga, R.; Hoeven, H. van der

2013-01-01

The aim of this study was to determine the effect of radial extracorporeal shock-wave therapy (rESWT) on patients with chronic tendinitis of the rotator cuff. This was a randomised controlled trial in which 82 patients (mean age 47 years (24 to 67)) with chronic tendinitis diagnosed clinically were

Supernova remnants in the GC region

Science.gov (United States)

Asvarov, Abdul

2016-07-01

Along with the central Black hole the processes of active star formation play very important role in the energetics of the Galactic center region. The SNe and their remnants (SNRs) are the main ingredients of the processes of star formation. SNRs are also the sources of electromagnetic radiation of all wavelengths from the optical to hard gamma rays. In the presented work we consider the physics of supernova remnants evolving in extreme environmental conditions which are typical for the region of the Galactic center. Because of the high density and strong inhomogeneity of the surrounding medium these objects remain practically invisible at almost all wavelengths. We model evolution of SNR taking into account the pressure of the surrounding medium and the gravitational field of the matter (stars, compact clouds, dark matter) inside the remnant. As it is well established, considerable portion of the kinetic energy of the SNR can be converted into the cosmic ray particles by diffusive shock acceleration mechanism. Therefore the effect of particle acceleration is also included in the model (with the effectiveness of acceleration as a free parameter). Using the observed radiation fluxes at different wavelengths we attempt to obtain limits on the parameters of the model of the Galactic Center, namely, the frequency of star birth, the average density of the matter and radiation field, etc.

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

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.)

[The results of the combined application of extracorporeal shock-wave therapy and radon baths during the rehabilitative treatment of the patients presenting with gonarthrosis].

Science.gov (United States)

Razumov, A N; Puriga, A O; Yurova, O V

2015-01-01

Osteoarthritis (OA) is one of the leading diseases of the musculoskeletal system and the main cause of arthritic joint damage. The objective of the present study was to evaluate the effectiveness of the combined application of radon baths and shock-wave therapy in the patients suffering from knee OA. The study involved 75 patients at the age of 35 to 62 years with the confirmed diagnosis of stage II and III gonarthrosis; they were divided into 3 groups. The patients of the main group received the combined treatment including extracorporeal shock-wave therapy and radon baths The patients comprising the group of comparison were given the course of radon therapy alone while those in the control group were offered the standard treatment including physiotherapy, magnetic therapy, and NSAIDs. The study has demonstrated the high effectiveness of the combined application of the radon baths and extracorporeal shock-wave therapy for the rehabilitation of the patients with deforming arthrosis of the knee that was apparent from the substantial decrease of pain syndrome, the increase of the range of motions in the knee joints, and the overall improvement of the quality of life. These beneficial changes persisted for a period of up to 6 months. The results of the present study give reason to recommend the proposed method of the remedial treatment for the wide practical application as a component in the framework of the medical rehabilitation programs.

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).

Barium from a mini r-process in supernovae

Science.gov (United States)

Heymann, D.

1983-01-01

McCulloch and Wasserburg (1978) have reported nonlinear isotopic anomalies in barium for two Ca-Al-rich inclusions of the Allende carbonaceous chondrite, known as EK-1-4-1 and C-1. In an attempt to account for these anomalies, it has been proposed that Ba from an r-process of nucleosynthesis, containing Ba-135 and Ba-137, was injected into the primeval color system but was not totally homogenized. Questions arise in connection with the relations of Xe isotopes in carbonaceous chondrites. This has prompted Heymann and Dziczkaniec (1979, 1980, 1981) to study the formation of r-Xe, r-Kr, and r-Te by the mini r-process which is thought to occur in the O, Ne-rich shells of Type II supernovae. Lee et al. (1979) have studied the formation of r-Ba, r-Nd, and r-Sm by the same process. Certain differences regarding the approaches used by Lee et al. and by Heymann and Dziczkaniec make it necessary to restudy the work of Lee et al. Attention is given to the survival probabilities of nuclear species of interest, taking into accounts the elements Cs, Ba, I, and Xe.

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 .

PRE-DISCOVERY AND FOLLOW-UP OBSERVATIONS OF THE NEARBY SN 2009nr: IMPLICATIONS FOR PROMPT TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Khan, Rubab; Stanek, K. Z.; Beacom, J. F.; Szczygiel, D. M.; Mogren, K.; Eastman, J. D.; Martini, P.; Stoll, R.; Prieto, J. L.; Pojmanski, G.; Pilecki, B.

2011-01-01

We present photometric and spectroscopic observations of the Type Ia supernova SN 2009nr in UGC 8255 (z = 0.0122). Following the discovery announcement at what turned out to be 10 days after peak, we detected it at V ≅15.7 mag in data collected by the All-Sky Automated Survey (ASAS) North telescope 2 weeks prior to the peak, and then followed it up with telescopes ranging in aperture from 10 cm to 6.5 m. Using early photometric data available only from ASAS, we find that the supernova is similar to the overluminous Type Ia SN 1991T, with a peak at M V ≅ -19.6 mag, and a slow decline rate of Δm 15 (B) ≅ 0.95 mag. The early post-maximum spectra closely resemble those of SN 1991T, while the late-time spectra are more similar to those of normal Type Ia supernovae (SNe Ia). Interestingly, SN 2009nr has a projected distance of 13.0 kpc (∼4.3 disk scale lengths) from the nucleus of the small star-forming host galaxy UGC 8255. This indicates that the progenitor of SN 2009nr is not associated with a young stellar population, calling into question the conventional association of luminous SNe Ia with the 'prompt' component directly correlated with current star formation. The pre-discovery observation of SN 2009nr using ASAS demonstrates the science utility of high-cadence all sky surveys conducted using small telescopes for the discovery of nearby (d ∼< 50 Mpc) supernovae.

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).

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.

Spherical shock-wave propagation in three-dimensional granular packings.

Science.gov (United States)

Xue, Kun; Bai, Chun-Hua

2011-02-01

We investigate numerically the spherical shock-wave propagation in an open dense granular packing perturbed by the sudden expansion of a spherical intruder in the interior of the pack, focusing on the correlation between geometrical fabrics and propagating properties. The measurements of the temporal and spatial variations in a variety of propagating properties define a consistent serrated wave substructure with characteristic length on the orders of particle diameters. Further inspection of particle packing reveals a well-defined particle layering that persists several particle diameters away from the intruder, although its dominant effects are only within one to two diameters. This interface-induced layering not only exactly coincides with the serrated wave profile, but also highlights the competition between two energy transmission mechanisms involving distinct transport speeds. The alternating dominances between these two mechanisms contribute to the nonlinear wave propagation on the particle scale. Moreover, the proliferation of intricate three-dimensional contact force networks suggests the anisotropic stress transmission, which is found to also arise from the localized packing structure in the vicinity of the intruder.

Extracorporeal shockwave therapy in a dog with chronic bicipital tenosynovitis.

Science.gov (United States)

Venzin, C; Ohlerth, S; Koch, D; Spreng, D

2004-03-01

A 15-month-old, spayed female, Bernese mountain dog was presented to the Institute of Small Animal Surgery at the University of Zurich because of chronic left forelimb lameness. The referring veterinarian diagnosed pain in the left shoulder region and had treated the dog with systemic non-steroidal anti-inflammatory drugs and restricted exercise for a two-week period. The follow-up examination revealed only minimal improvement and therefore, the dog was referred for further diagnostic evaluation. Chronic bicipital tenosynovitis and tendinitis of the infraspinatus muscle was diagnosed based on survey radiographs, arthrography, ultrasound, computed tomography (CT), and synovial fluid cytology. The dog underwent three sessions of extracorporeal shockwave therapy and substantial clinical improvement was observed. On follow-up examinations, only mild left forelimb lameness was evident following exercise, and changes in the intertubercular groove and at the supraglenoid tuberosity appeared less active on radiographs and CT. However, six months following treatment, mild degenerative joint disease was apparent.

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.

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.

LOSS Revisited. I. Unraveling Correlations between Supernova Rates and Galaxy Properties, as Measured in a Reanalysis of the Lick Observatory Supernova Search

Energy Technology Data Exchange (ETDEWEB)

Graur, Or [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Bianco, Federica B.; Huang, Shan; Modjaz, Maryam [CCPP, New York University, 4 Washington Place, New York, NY 10003 (United States); Shivvers, Isaac; Filippenko, Alexei V.; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Eldridge, J. J., E-mail: or.graur@cfa.harvard.edu [Department of Physics, University of Auckland, Private Bag 92019, Auckland (New Zealand)

2017-03-10

Most types of supernovae (SNe) have yet to be connected with their progenitor stellar systems. Here, we reanalyze the 10-year SN sample collected during 1998–2008 by the Lick Observatory Supernova Search (LOSS) in order to constrain the progenitors of SNe Ia and stripped-envelope SNe (SE SNe, i.e., SNe IIb, Ib, Ic, and broad-lined Ic). We matched the LOSS galaxy sample with spectroscopy from the Sloan Digital Sky Survey and measured SN rates as a function of galaxy stellar mass, specific star formation rate, and oxygen abundance (metallicity). We find significant correlations between the SN rates and all three galaxy properties. The SN Ia correlations are consistent with other measurements, as well as with our previous explanation of these measurements in the form of a combination of the SN Ia delay-time distribution and the correlation between galaxy mass and age. The ratio between the SE SN and SN II rates declines significantly in low-mass galaxies. This rules out single stars as SE SN progenitors, and is consistent with predictions from binary-system progenitor models. Using well-known galaxy scaling relations, any correlation between the rates and one of the galaxy properties examined here can be expressed as a correlation with the other two. These redundant correlations preclude us from establishing causality—that is, from ascertaining which of the galaxy properties (or their combination) is the physical driver for the difference between the SE SN and SN II rates. We outline several methods that have the potential to overcome this problem in future works.

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.

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

International Nuclear Information System (INIS)

Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A.; Yudin, A. V.

2011-01-01

Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

Energy Technology Data Exchange (ETDEWEB)

Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A., E-mail: trusov@itep.ru; Yudin, A. V. [Institute for Theoretical and Experimental Physics (Russian Federation)

2011-03-15

Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

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)

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 ⊙}.

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...

Modeling shockwave deformation via molecular dynamics

International Nuclear Information System (INIS)

Holian, B.L.

1987-01-01

Molecular dynamics (MD), where the equations of motion of up to thousands of interacting atoms are solved on the computer, has proven to be a powerful tool for investigating a wide variety of nonequilibrium processes from the atomistic viewpoint. Simulations of shock waves in three-dimensional (3D) solids and fluids have shown conclusively that shear-stress relaxation is achieved through atomic rearrangement. In the case of fluids, the transverse motion is viscous, and the constitutive model of Navier-Stokes hydrodynamics has been shown to be accurate - even on the time and distance scales of MD experiments. For strong shocks in solids, the plastic flow that leads to shear-stress relaxation in MD is highly localized near the shock front, involving a slippage along close-packed planes. For shocks of intermediate strength, MD calculations exhibit an elastic precursor running out in front of the steady plastic wave, where slippage similar in character to that in the very strong shocks leads to shear-stress relaxation. An interesting correlation between the maximum shear stress and the Hugoniot pressure jump is observed for both 3D and fluid shockwave calculations, which may have some utility in modeling applications. At low shock strengths, the MD simulations show only elastic compression, with no permanent transverse atomic strains. The result for perfect 3D crystals is also seen in calculations for 1D chains. It is speculated that, if it were practical, a very large MD system containing dislocations could be expected to exhibit more realistic plastic flow for weak shock waves, too

Supernova-regulated ISM. V. Space and Time Correlations

Science.gov (United States)

Hollins, J. F.; Sarson, G. R.; Shukurov, A.; Fletcher, A.; Gent, F. A.

2017-11-01

We apply correlation analysis to random fields in numerical simulations of the supernova-driven interstellar medium (ISM) with the magnetic field produced by dynamo action. We solve the magnetohydrodynamic (MHD) equations in a shearing Cartesian box representing a local region of the ISM, subject to thermal and kinetic energy injection by supernova explosions, and parameterized, optically thin radiative cooling. We consider the cold, warm, and hot phases of the ISM separately; the analysis mostly considers the warm gas, which occupies the bulk of the domain. Various physical variables have different correlation lengths in the warm phase: 40,50, and 60 {pc} for the random magnetic field, density, and velocity, respectively, in the midplane. The correlation time of the random velocity is comparable to the eddy turnover time, about {10}7 {year}, although it may be shorter in regions with a higher star formation rate. The random magnetic field is anisotropic, with the standard deviations of its components {b}x/{b}y/{b}z having approximate ratios 0.5/0.6/0.6 in the midplane. The anisotropy is attributed to the global velocity shear from galactic differential rotation and locally inhomogeneous outflow to the galactic halo. The correlation length of Faraday depth along the z axis, 120 {pc}, is greater than for electron density, 60{--}90 {pc}, and the vertical magnetic field, 60 {pc}. Such comparisons may be sensitive to the orientation of the line of sight. Uncertainties of the structure functions of synchrotron intensity rapidly increase with the scale. This feature is hidden in a power spectrum analysis, which can undermine the usefulness of power spectra for detailed studies of interstellar turbulence.

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.

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.

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.

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.)

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.

THE ABSOLUTE RATE OF LGRB FORMATION

Energy Technology Data Exchange (ETDEWEB)

Graham, J. F.; Schady, P. [Max-Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, D-85748 Garching (Germany)

2016-06-01

We estimate the long-duration gamma-ray burst (LGRB) progenitor rate using our recent work on the effects of environmental metallically on LGRB formation in concert with supernovae (SNe) statistics via an approach patterned loosely off the Drake equation. Beginning with the cosmic star formation history, we consider the expected number of broad-line Type Ic events (the SNe type associated with LGRBs) that are in low-metallicity host environments adjusted by the contribution of high-metallicity host environments at a much reduced rate. We then compare this estimate to the observed LGRB rate corrected for instrumental selection effects to provide a combined estimate of the efficiency fraction of these progenitors to produce LGRBs and the fraction of which are beamed in our direction. From this we estimate that an aligned LGRB occurs for approximately every 4000 ± 2000 low-metallically broad-lined SNe Ic. Therefore, if one assumes a semi-nominal beaming factor of 100, then only about one such supernova out of 40 produce an LGRB. Finally, we propose an off-axis LGRB search strategy of targeting only broad-line Type Ic events that occur in low-metallicity hosts for radio observation.

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.

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.

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

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

The effect of peculiar velocities on supernova cosmology

DEFF Research Database (Denmark)

Davis, Tamara Maree; Hui, Lam; Frieman, Joshua A.

2011-01-01

We analyze the effect that peculiar velocities have on the cosmological inferences we make using luminosity distance indicators, such as Type Ia supernovae. In particular we study the corrections required to account for (1) our own motion, (2) correlations in galaxy motions, and (3) a possible lo...... when future surveys aim for percent-level accuracy and we recommend our statistical approach to down-weighting peculiar velocities as a more robust option than a sharp low-redshift cut....... local under- or overdensity. For all of these effects we present a case study showing the impact on the cosmology derived by the Sloan Digital Sky Survey-II Supernova Survey (SDSS-II SN Survey). Correcting supernova (SN) redshifts for the cosmic microwave background (CMB) dipole slightly overcorrects...... nearby SNe that share some of our local motion. We show that while neglecting the CMB dipole would cause a shift in the derived equation of state of ¿w ~ 0.04 (at fixed O m ), the additional local-motion correction is currently negligible (¿w

Automated Supernova Discovery (Abstract)

Science.gov (United States)

Post, R. S.

2015-12-01

(Abstract only) We are developing a system of robotic telescopes for automatic recognition of Supernovas as well as other transient events in collaboration with the Puckett Supernova Search Team. At the SAS2014 meeting, the discovery program, SNARE, was first described. Since then, it has been continuously improved to handle searches under a wide variety of atmospheric conditions. Currently, two telescopes are used to build a reference library while searching for PSN with a partial library. Since data is taken every night without clouds, we must deal with varying atmospheric and high background illumination from the moon. Software is configured to identify a PSN, reshoot for verification with options to change the run plan to acquire photometric or spectrographic data. The telescopes are 24-inch CDK24, with Alta U230 cameras, one in CA and one in NM. Images and run plans are sent between sites so the CA telescope can search while photometry is done in NM. Our goal is to find bright PSNs with magnitude 17.5 or less which is the limit of our planned spectroscopy. We present results from our first automated PSN discoveries and plans for PSN data acquisition.

The TOPGAME-study: effectiveness of extracorporeal shockwave therapy in jumping athletes with patellar tendinopathy. Design of a randomised controlled trial

OpenAIRE

Zwerver, Johannes; Verhagen, Evert; Hartgens, Fred; van den Akker-Scheek, Inge; Diercks, Ron L.

2010-01-01

Background: Patellar tendinopathy is a major problem for many athletes, especially those involved in jumping activities. Despite its frequency and negative impact on athletic careers, no evidence-based guidelines for management of this overuse injury exist. Since functional outcomes of conservative and surgical treatments remain suboptimal, new diagnostic and therapeutic strategies have to be developed and evaluated. Extracorporeal shockwave therapy (ESWT) appears to be a promising treatment ...

The Final Stages of Massive Star Evolution and Their Supernovae

Science.gov (United States)

Heger, Alexander

In this chapter I discuss the final stages in the evolution of massive stars - stars that are massive enough to burn nuclear fuel all the way to iron group elements in their core. The core eventually collapses to form a neutron star or a black hole when electron captures and photo-disintegration reduce the pressure support to an extent that it no longer can hold up against gravity. The late burning stages of massive stars are a rich subject by themselves, and in them many of the heavy elements in the universe are first generated. The late evolution of massive stars strongly depends on their mass, and hence can be significantly effected by mass loss due to stellar winds and episodic mass loss events - a critical ingredient that we do not know as well as we would like. If the star loses all the hydrogen envelope, a Type I supernova results, if it does not, a Type II supernova is observed. Whether the star makes neutron star or a black hole, or a neutron star at first and a black hole later, and how fast they spin largely affects the energetics and asymmetry of the observed supernova explosion. Beyond photon-based astronomy, other than the sun, a supernova (SN 1987) has been the only object in the sky we ever observed in neutrinos, and supernovae may also be the first thing we will ever see in gravitational wave detectors like LIGO. I conclude this chapter reviewing the deaths of the most massive stars and of Population III stars.

Neutrino nucleosynthesis in supernovae: Shell model predictions

International Nuclear Information System (INIS)

Haxton, W.C.

1989-01-01

Almost all of the 3 · 10 53 ergs liberated in a core collapse supernova is radiated as neutrinos by the cooling neutron star. I will argue that these neutrinos interact with nuclei in the ejected shells of the supernovae to produce new elements. It appears that this nucleosynthesis mechanism is responsible for the galactic abundances of 7 Li, 11 B, 19 F, 138 La, and 180 Ta, and contributes significantly to the abundances of about 15 other light nuclei. I discuss shell model predictions for the charged and neutral current allowed and first-forbidden responses of the parent nuclei, as well as the spallation processes that produce the new elements. 18 refs., 1 fig., 1 tab

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

Novae, supernovae, and the island universe hypothesis

International Nuclear Information System (INIS)

Van Den Bergh, S.

1988-01-01

Arguments in Curtis's (1917) paper related to the island universe hypothesis and the existence of novae in spiral nebulae are considered. It is noted that the maximum magnitude versus rate-of-decline relation for novae may be the best tool presently available for the calibration of the extragalactic distance scale. Light curve observations of six novae are used to determine a distance of 18.6 + or - 3.5 MPc to the Virgo cluster. Results suggest that Type Ia supernovae cannot easily be used as standard candles, and that Type II supernovae are unsuitable as distance indicators. Factors other than precursor mass are probably responsible for determining the ultimate fate of evolving stars. 83 references

Why type 2 supernovae do not explode in irregular galaxies

International Nuclear Information System (INIS)

Shklovskij, I.S.

1984-01-01

The conclusion is drawn that reason for an absence of type 2 supernovae explosions in irregular galaxies is their peculiar chemical composition. The observed lack of stellar wind from massive hot giants is due to relatively low heavy element abundance. For this reason evolving massive stars do not form an extended dense envelopes that is a necessary condition for the type 2 supernova phenomenon

On the Origin of Hard X-ray Structures in the VELA Supernova Remnant

Science.gov (United States)

Gvaramadze, V. V.

1998-12-01

We propose an alternative explanation for the origin of two hard X-ray structures recently discovered in the central part of the Vela supernova remnant (SNR) by Willmore et al. (1992, MNRAS, 254, 139) and Markwardt & Ogelman (1995, Nature, 375, 40; 1997, ApJ, 480, L13), and interpreted as a plerion and a pulsar jet respectively. We suggest that the first structure is a dense material shed by the supernova progenitor star during the red supergiant stage, and reheated after the supernova exploded, while the "jet" is simply a dense filament in the Vela SNR's general shell, whose origin is connected with the Rayleigh-Taylor instability in the (main-sequence) wind-driven shell reaccelerated by the supernova blast wave.

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

A statistically self-consistent type Ia supernova data analysis

International Nuclear Information System (INIS)

Lago, B.L.; Calvao, M.O.; Joras, S.E.; Reis, R.R.R.; Waga, I.; Giostri, R.

2011-01-01

Full text: The type Ia supernovae are one of the main cosmological probes nowadays and are used as standardized candles in distance measurements. The standardization processes, among which SALT2 and MLCS2k2 are the most used ones, are based on empirical relations and leave room for a residual dispersion in the light curves of the supernovae. This dispersion is introduced in the chi squared used to fit the parameters of the model in the expression for the variance of the data, as an attempt to quantify our ignorance in modeling the supernovae properly. The procedure used to assign a value to this dispersion is statistically inconsistent and excludes the possibility of comparing different cosmological models. In addition, the SALT2 light curve fitter introduces parameters on the model for the variance that are also used in the model for the data. In the chi squared statistics context the minimization of such a quantity yields, in the best case scenario, a bias. An iterative method has been developed in order to perform the minimization of this chi squared but it is not well grounded, although it is used by several groups. We propose an analysis of the type Ia supernovae data that is based on the likelihood itself and makes it possible to address both inconsistencies mentioned above in a straightforward way. (author)