scholarly journals Lithium, beryllium, and boron production in core-collapse supernovae

2009 ◽  
Vol 5 (S268) ◽  
pp. 463-468
Author(s):  
Ko Nakamura ◽  
Takashi Yoshida ◽  
Toshikazu Shigeyama ◽  
Toshitaka Kajino
Keyword(s):  
Massive Star ◽  
Massive Stars ◽  
Circumstellar Matter ◽  
High Energy ◽  
Core Collapse ◽  
Light Elements ◽  
Speed Of Light ◽  
Large Numbers ◽  
Very High Energy ◽  
Very High

AbstractType Ic supernova (SN Ic) is the gravitational collapse of a massive star without H and He layers. It propels several solar masses of material to the typical velocity of 10,000 km/s, a very small fraction of the ejecta nearly to the speed of light. We investigate SNe Ic as production sites for the light elements Li, Be, and B, via the neutrino-process and spallations. As massive stars collapse, neutrinos are emitted in large numbers from the central remnants. Some of the neutrinos interact with nuclei in the exploding materials and mainly 7Li and 11B are produced. Subsequently, the ejected materials with very high energy impinge on the interstellar/circumstellar matter and spall into light elements. We find that the ν-process in the current SN Ic model produces a significant amount of 11B, consistent with observations if combined with B isotopes from the following spallation production.

scholarly journals Recent Results from the CANGAROO Project

1996 ◽  
Vol 160 ◽  
pp. 363-364
Author(s):  
S.A. Dazeley ◽  
P.G. Edwards ◽  
J.R. Patterson ◽  
G.P. Rowell ◽  
M. Sinnott ◽  
...  
Keyword(s):  
Gamma Rays ◽  
South Australia ◽  
Cosmic Ray ◽  
High Energy ◽  
Relativistic Electrons ◽  
Large Numbers ◽  
Inverse Compton ◽  
Very High Energy ◽  
Large Telescopes ◽  
Very High

TheCollaboration ofAustralia andNippon for aGAmmaRayObservatory in theOutback operates two large telescopes at Woomera (South Australia), which detect the Čerenkov light images produced in the atmosphere by electronpositron cascades initiated by very high energy (~1 TeV or 1012eV) gamma rays. These gamma rays arise from a different mechanism than at EGRET energies: inverse Compton (IC) emission from relativistic electrons.The spoke-like images are recorded by a multi-pixel camera which facilitates the rejection of the large numbers of oblique and ragged cosmic ray images. A field of view ~3.5° is required. The Australian team operates a triple 4 m diameter mirror telescope, BIGRAT, with a 37 photomultiplier tube camera and energy threshold 600 GeV. The Japanese operate a single, highly accurate 3.8 m diameter f/1 telescope and high resolution 256 photomultipler tube camera. In 1998 a new 7 m telescope is planned for Woomera with a design threshold ~;200GeV.

GRAVITATIONAL COLLAPSE OF MASSIVE STARS AS A PROBE INTO HOT DENSE MATTER

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2443-2450 ◽  
Author(s):  
SHOICHI YAMADA
Keyword(s):  
Equation Of State ◽  
Gravitational Collapse ◽  
Nuclear Physics ◽  
Massive Stars ◽  
Dense Matter ◽  
High Energy ◽  
Compact Objects ◽  
Core Collapse ◽  
Accretion Shock ◽  
Very High

Nuclear physics is an indispensable input for the investigation of high energy astrophysical phenomena involving compact objects. In this paper I take a gravitational collapse of massive stars as an example and show how the macroscopic dynamics is influenced by the properties of nuclei and nuclear matter. I will discuss two topics that are rather independent of each other. The first one is the interplay of neutrino-nuclei inelastic scatterings and the standing accretion shock instability in the core of core collapse supernovae and the second is concerning the neutrino emissions from black hole formations and their dependence on the equation of state at very high densities. In the latter, I will also demonstrate that future astronomical observations might provide us with valuable information on the equation of state of hot dense matter.

scholarly journals H.E.S.S. ToO program on nearby core-collapse Supernovae : search for very-high energy gamma-ray emission towards the SN candidate AT2019krl in M74

2021 ◽  
Author(s):  
Nukri Komin ◽  
Hassan Abdalla ◽  
Felix Aharonian ◽  
Faical Ait-Benkhali ◽  
Oguzhan Anguener ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Core Collapse ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Gamma Ray Emission ◽  
Very High

scholarly journals Radiation hydrodynamical simulations of eruptive mass loss from progenitors of Type Ibn/IIn supernovae

2020 ◽  
Vol 635 ◽  
pp. A127 ◽  
Author(s):  
Naoto Kuriyama ◽  
Toshikazu Shigeyama
Keyword(s):  
Mass Loss ◽  
Massive Star ◽  
Massive Stars ◽  
Circumstellar Matter ◽  
Core Collapse ◽  
The Core ◽  
Actual Mechanism ◽  
Nuclear Burning ◽  
Hydrodynamical Simulations ◽  
Extract Information

Context. Observations suggest that some massive stars experience violent and eruptive mass loss associated with significant brightening that cannot be explained by hydrostatic stellar models. This event seemingly forms dense circumstellar matter (CSM). The mechanism of eruptive mass loss has not been fully explained. We focus on the fact that the timescale of nuclear burning gets shorter than the dynamical timescale of the envelope a few years before core collapse for some massive stars. Aims. To reveal the properties of the eruptive mass loss, we investigate its relation to the energy injection at the bottom of the envelope supplied by nuclear burning taking place inside the core. In this study, we do not specify the actual mechanism for transporting energy from the site of nuclear burning to the bottom of the envelope. Instead, we parameterize the amount of injected energy and the injection time and try to extract information on these parameters from comparisons with observations. Methods. We carried out 1D radiation hydrodynamical simulations for progenitors of red, yellow, and blue supergiants, and Wolf–Rayet stars. We calculated the evolution of the progenitors with a public stellar evolution code. Results. We obtain the light curve associated with the eruption, the amount of ejected mass, and the CSM distribution at the time of core-collapse. Conclusions. The energy injection at the bottom of the envelope of a massive star within a period shorter than the dynamical timescale of the envelope could reproduce some observed optical outbursts prior to the core-collapse and form the CSM, which can power an interaction supernova classified as Type IIn.

scholarly journals Equations of geodesic deviation and properties of tidal forces in the Kerr metric

2016 ◽  
Vol 41 ◽  
pp. 1660122
Author(s):  
A. M. Rasulova
Keyword(s):  
Kerr Black Hole ◽  
Lorentz Factor ◽  
High Energy ◽  
Radial Component ◽  
Kerr Metric ◽  
Speed Of Light ◽  
Geodesic Deviation ◽  
Tidal Forces ◽  
Very High Energy ◽  
Very High

In the paper the work of the tidal forces that arise when the relative deviation of the protons on distance of the order of the Compton wavelength near the horizon of Kerr black hole is considered. For ease of calculation the assumption is made that the proton has only a radial component of the velocity. It is shown that the work of the tidal forces at speeds close to the speed of light sharply increases with Lorentz factor and it can obtain very high energy of the Grand Unification order.

Strong interactions at very high energy

1964 ◽  
Vol 82 (1) ◽  
pp. 3-81 ◽  
Author(s):  
Evgenii L. Feinberg ◽  
Dmitrii S. Chernavskii
Keyword(s):  
High Energy ◽  
Strong Interactions ◽  
Very High Energy ◽  
Very High

scholarly journals Focused VHEE (very high energy electron) beams and dose delivery for radiotherapy applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Whitmore ◽  
R. I. Mackay ◽  
M. van Herk ◽  
J. K. Jones ◽  
R. M. Jones
Keyword(s):  
Electron Beams ◽  
Focal Point ◽  
External Beam Radiotherapy ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Dose Delivery ◽  
Entrance Dose ◽  
Very High Energy ◽  
Very High

AbstractThis paper presents the first demonstration of deeply penetrating dose delivery using focused very high energy electron (VHEE) beams using quadrupole magnets in Monte Carlo simulations. We show that the focal point is readily modified by linearly changing the quadrupole magnet strength only. We also present a weighted sum of focused electron beams to form a spread-out electron peak (SOEP) over a target region. This has a significantly reduced entrance dose compared to a proton-based spread-out Bragg peak (SOBP). Very high energy electron (VHEE) beams are an exciting prospect in external beam radiotherapy. VHEEs are less sensitive to inhomogeneities than proton and photon beams, have a deep dose reach and could potentially be used to deliver FLASH radiotherapy. The dose distributions of unfocused VHEE produce high entrance and exit doses compared to other radiotherapy modalities unless focusing is employed, and in this case the entrance dose is considerably improved over existing radiations. We have investigated both symmetric and asymmetric focusing as well as focusing with a range of beam energies.

Very high energy nucleus-nucleus collisions and multi-chain model

1981 ◽  
Vol 8 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Kisei Kinoshita ◽  
Akira Minaka ◽  
Hiroyuki Sumiyoshi
Keyword(s):  
High Energy ◽  
Chain Model ◽  
Very High Energy ◽  
Very High
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