scholarly journals Electron-positron energy deposition rate from neutrino pair annihilation in the equatorial plane of rapidly rotating neutron and quark stars

2010 ◽  
Vol 402 (3) ◽  
pp. 1714-1728 ◽  
Author(s):  
Z. Kovács ◽  
K. S. Cheng ◽  
T. Harko
Keyword(s):  
Deposition Rate ◽  
Equatorial Plane ◽  
Energy Deposition ◽  
Positron Energy ◽  
Quark Stars ◽  
Electron Positron ◽  
Pair Annihilation ◽  
Neutrino Pair ◽  
Energy Deposition Rate

scholarly journals GENERAL RELATIVISTIC EFFECT ON THE ENERGY DEPOSITION RATE FOR NEUTRINO PAIR ANNIHILATION ABOVE THE EQUATORIAL PLANE ALONG THE SYMMETRY AXIS NEAR A ROTATING NEUTRON STAR

2013 ◽  
Vol 22 (02) ◽  
pp. 1350008 ◽  
Author(s):  
RITAM MALLICK ◽  
ABHIJIT BHATTACHARYYA ◽  
SANJAY K. GHOSH ◽  
SIBAJI RAHA
Keyword(s):  
Neutron Star ◽  
Deposition Rate ◽  
Equatorial Plane ◽  
Energy Deposition ◽  
Rotation Axis ◽  
Rotational Velocity ◽  
Pair Annihilation ◽  
Negative Effect ◽  
Neutrino Pair ◽  
Energy Deposition Rate

The estimate of the energy deposition rate (EDR) for neutrino pair annihilation has been carried out. The EDR for the neutrinos coming from the equatorial plane of a rotating neutron star is calculated along the rotation axis using the Cook–Shapiro–Teukolsky metric. The neutrino trajectories and hence the neutrinos emitted from the disk are affected by the redshift due to disk rotation and gravitation. The EDR is very sensitive to the value of the temperature and its variation along the disk. The rotation of the star has a negative effect on the EDR; it decreases with increase in rotational velocity.

GRB-SN CONNECTION: CENTRAL ENGINE OF LONG GRBs AND EXPLOSIVE NUCLEOSYNTHESIS

2011 ◽  
Vol 20 (10) ◽  
pp. 1975-1978 ◽  
Author(s):  
SHIGEHIRO NAGATAKI
Keyword(s):  
Numerical Simulations ◽  
Deposition Rate ◽  
Energy Deposition ◽  
Two Dimensional ◽  
Hydrodynamic Simulations ◽  
X Ray ◽  
Central Engine ◽  
Explosive Nucleosynthesis ◽  
General Relativistic ◽  
Energy Deposition Rate

I have developed two-dimensional general relativistic magnetohydrodynamic (GRMHD) code. I have performed numerical simulations of collapsars using these codes and realistic progenitor models. In the GRMHD simulation, it is shown that a jet is launched from the center of the progenitor. We also performed two-dimensional hydrodynamic simulations in the context of collapsar model to investigate the explosive nucleosynthesis happened there. It is found that the amount of 56 Ni is very sensitive to the energy deposition rate. This result means that the amount of synthesized 56 Ni can be little even if the total explosion energy is as large as 1052 erg. Thus, some GRBs can associate with faint supernovae. Thus we consider it is quite natural to detect no underlying supernova in some X-ray afterglows.

scholarly journals Neutrino pair annihilation ($$\nu {\bar{\nu }}\rightarrow e^-e^+$$) in the presence of quintessence surrounding a black hole

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
G. Lambiase ◽  
L. Mastrototaro
Keyword(s):  
Neutron Star ◽  
Energy Deposition ◽  
Maximum Energy ◽  
Neutrino Energy ◽  
Close Binary ◽  
Binary Neutron Star ◽  
Pair Annihilation ◽  
Sphere Radius ◽  
Effects Of Rotation ◽  
Neutrino Pair

AbstractQuintessence fields, introduced to explain the speed-up of the Universe, might affect the geometry of spacetime surrounding black holes, as compared to the standard Schwarzschild and Kerr geometries. In this framework, we study the neutrino pairs annihilation into electron-positron pairs ($$\nu {\bar{\nu }}\rightarrow e^-e^+$$ ν ν ¯ → e - e + ) near the surface of a neutron star, focusing, in particular, on the Schwarzschild-like geometry in presence of quintessence fields. The effect of the latter is to increase the photon-sphere radius ($$R_{ph}$$ R ph ), increasing in such a way the maximum energy deposition rate near to $$R_{ph}$$ R ph . The rate turns out to be several orders of magnitude greater than the rate computed in the framework of General Relativity. These results might provide a rising in the GRBs energy emitted from a close binary neutron star system and might be used to constraints the parameters of the quintessence model. Finally we theoretically study the effects of rotation on the neutrino energy deposition.

scholarly journals Electromagnetic energy deposition rate in the polar upper thermosphere derived from the EISCAT Svalbard radar and CUTLASS Finland radar observations

2007 ◽  
Vol 25 (11) ◽  
pp. 2393-2403 ◽  
Author(s):  
H. Fujiwara ◽  
R. Kataoka ◽  
M. Suzuki ◽  
S. Maeda ◽  
S. Nozawa ◽  
...  
Keyword(s):  
Electric Field ◽  
Deposition Rate ◽  
Energy Deposition ◽  
Electromagnetic Energy ◽  
Soft Particle ◽  
Small Contribution ◽  
Polar Cap ◽  
Radar Observations ◽  
Cusp Region ◽  
Energy Deposition Rate

Abstract. From simultaneous observations of the European incoherent scatter Svalbard radar (ESR) and the Cooperative UK Twin Located Auroral Sounding System (CUTLASS) Finland radar on 9 March 1999, we have derived the height distributions of the thermospheric heating rate at the F region height in association with electromagnetic energy inputs into the dayside polar cap/cusp region. The ESR and CUTLASS radar observations provide the ionospheric parameters with fine time-resolutions of a few minutes. Although the geomagnetic activity was rather moderate (Kp=3+~4), the electric field obtained from the ESR data sometimes shows values exceeding 40 mV/m. The estimated passive energy deposition rates are also larger than 150 W/kg in the upper thermosphere over the ESR site during the period of the enhanced electric field. In addition, enhancements of the Pedersen conductivity also contribute to heating the upper thermosphere, while there is only a small contribution for thermospheric heating from the direct particle heating due to soft particle precipitation in the dayside polar cap/cusp region. In the same period, the CUTLASS observations of the ion drift show the signature of poleward moving pulsed ionospheric flows with a recurrence rate of about 10–20 min. The estimated electromagnetic energy deposition rate shows the existence of the strong heat source in the dayside polar cap/cusp region of the upper thermosphere in association with the dayside magnetospheric phenomena of reconnections and flux transfer events.

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