scholarly journals Relativistic Quantum Response of a Strongly Magnetised Plasma. II. Ultrarelativistic Pair Plasma

1992 ◽  
Vol 45 (2) ◽  
pp. 165 ◽  
Author(s):  
WEP Padden
Keyword(s):  
Linear Response ◽  
Gamma Ray ◽  
Cyclotron Frequency ◽  
Relativistic Quantum ◽  
Numerical Schemes ◽  
Radio Pulsars ◽  
Pair Plasma ◽  
Analytic Expressions ◽  
Plasma Dispersion ◽  
Wave Properties

Approximate analytic expressions are derived for the linear response 4-tensor of a strongly magnetised, ultrarelativistic thermal pair plasma. The response is obtained in terms of relativistic plasma dispersion functions known as Dnestrovskii functions. These functions allow for a relatively simple study of wave properties of the pair plasma without requiring complicated numerical schemes. The results obtained are valid in general for frequencies below the electron cyclotron frequency. It is believed that the results could be of importance in some models of radio pulsars and gamma-ray bursters.

scholarly journals Relativistic Quantum Response of a Strongly Magnetised Plasma. I. Mildly Relativistic Electron Gas

1992 ◽  
Vol 45 (2) ◽  
pp. 131 ◽  
Author(s):  
WEP Padden
Keyword(s):  
Relativistic Electron ◽  
Cyclotron Frequency ◽  
Relativistic Quantum ◽  
Quantum Plasma ◽  
Plasma Dynamics ◽  
X Ray ◽  
Analytic Expressions ◽  
Graphical Technique ◽  
Plasma Dispersion ◽  
Wave Properties

Approximate analytic expressions are derived for the linear response 4-tensor of a strongly magnestised, mildly relativistic electron plasma. The results are obtained within the framework of quantum plasma dynamics, thus the response contains relativistic and quantum effects that are essential in a super-strong magnetic field. The response is obtained in terms of relativistic plasma dispersion functions known as Shkarofsky functions. These functions allow the wave properties of the plasma to be studied without resorting to complicated numerical schemes. The response derived is valid for radiation with frequency up to about the cyclotron frequency and is of use in the theory of spectra formation in X-ray pulsars. In addition, a simple graphical technique is introduced that allows one to visually locate the roots of the resonant denominator occurring in the response, as well as determine the conditions under which both roots are valid and contribute to absorption.

Comment on ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’

2014 ◽  
Vol 80 (3) ◽  
pp. 513-516
Author(s):  
Frank Verheest
Keyword(s):  
Shock Wave ◽  
Solitary Wave ◽  
Solitary Waves ◽  
Plasma Phys ◽  
Theoretical Underpinning ◽  
Pair Plasma ◽  
Electrons And Positrons ◽  
Small Dissipation ◽  
Pseudopotential Approach ◽  
Wave Properties

In a recent paper ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’, Malekolkalami and Mohammadi investigate nonlinear electrostatic solitary waves in a plasma comprising adiabatic electrons and positrons, and a stationary ion background. The paper contains two parts: First, the solitary wave properties are discussed through a pseudopotential approach, and then the influence of a small dissipation is intuitively sketched without theoretical underpinning. Small dissipation is claimed to lead to a shock wave whose wavelength is determined by linear oscillator analysis. Unfortunately, there are errors and inconsistencies in both the parts, and their combination is incoherent.

Preliminary investigation fo the non-linear response of image intensifiers used for gamma-ray imaging

2013 ◽  
Author(s):  
David Fastje ◽  
H. Bradford Barber ◽  
Vaibhav Bora ◽  
Daniel Lemieux ◽  
Brian Miller ◽  
...  
Keyword(s):  
Linear Response ◽  
Gamma Ray ◽  
Preliminary Investigation ◽  
Non Linear ◽  
Gamma Ray Imaging ◽  
Image Intensifiers

scholarly journals Modes of Energy Loss from Isolated Magnetized Neutron Star

1987 ◽  
Vol 125 ◽  
pp. 450-450
Author(s):  
S. Shibata
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Gamma Ray ◽  
Rotational Energy ◽  
Pair Creation ◽  
Dipole Radiation ◽  
Pair Plasma ◽  
Electron Positron ◽  
Closed Current ◽  
Electron Positron Pair

Pulsar may be regarded as a discharge tube by electron-positron pair creation. On this viewpoint we carry out two numerical calculations. The obtained magnetic field is consistent with the flow. We find that pulsars emit their rotational energy through three modes simultaneously. The three modes are (1)relativistic acceleration and following gamma-ray emission in the closed current circuit in the magnetosphere, (2)wind of the electron-positron pair plasma, and (3)dipole radiation.

scholarly journals Common envelope episodes that lead to double neutron star formation

2020 ◽  
Vol 37 ◽  
Author(s):  
Alejandro Vigna-Gómez ◽  
Morgan MacLeod ◽  
Coenraad J. Neijssel ◽  
Floor S. Broekgaarden ◽  
Stephen Justham ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Initial Conditions ◽  
Large Fraction ◽  
Computational Modelling ◽  
Evolutionary Stage ◽  
Population Synthesis ◽  
Radio Pulsars ◽  
Common Envelope ◽  
The Common ◽  
The Moment

Abstract Close double neutron stars (DNSs) have been observed as Galactic radio pulsars, while their mergers have been detected as gamma-ray bursts and gravitational wave sources. They are believed to have experienced at least one common envelope episode (CEE) during their evolution prior to DNS formation. In the last decades, there have been numerous efforts to understand the details of the common envelope (CE) phase, but its computational modelling remains challenging. We present and discuss the properties of the donor and the binary at the onset of the Roche lobe overflow (RLOF) leading to these CEEs as predicted by rapid binary population synthesis models. These properties can be used as initial conditions for detailed simulations of the CE phase. There are three distinctive populations, classified by the evolutionary stage of the donor at the moment of the onset of the RLOF: giant donors with fully convective envelopes, cool donors with partially convective envelopes, and hot donors with radiative envelopes. We also estimate that, for standard assumptions, tides would not circularise a large fraction of these systems by the onset of RLOF. This makes the study and understanding of eccentric mass-transferring systems relevant for DNS populations.

scholarly journals EMERGENCE OF A FILAMENTARY STRUCTURE IN THE FIREBALL FROM GRB SPECTRA

2005 ◽  
Vol 14 (01) ◽  
pp. 97-105 ◽  
Author(s):  
REMO RUFFINI ◽  
CARLO LUCIANO BIANCO ◽  
SHE-SHENG XUE ◽  
PASCAL CHARDONNET ◽  
FEDERICO FRASCHETTI ◽  
...  
Keyword(s):  
Radio Emission ◽  
Gamma Ray ◽  
Surrounding Medium ◽  
Effective Area ◽  
Gamma Ray Bursts ◽  
Moving Frame ◽  
Filamentary Structure ◽  
X Ray ◽  
Spectral Changes ◽  
Analytic Expressions

It is shown that the concept of a fireball with a definite filamentary structure naturally emerges from the analysis of the spectra of Gamma-Ray Bursts (GRBs). These results, made possible by the recently obtained analytic expressions of the equitemporal surfaces in the GRB afterglow, depend crucially on the single parameter ℛ describing the effective area of the fireball emitting the X-ray and gamma-ray radiation. The X-ray and gamma-ray components of the afterglow radiation are shown to have a thermal spectrum in the co-moving frame of the fireball and originate from a stable shock front described self-consistently by the Rankine–Hugoniot equations. Precise predictions are presented on a correlation between spectral changes and intensity variations in the prompt radiation verifiable, e.g., by the Swift and future missions. The highly variable optical and radio emission depends instead on the parameters of the surrounding medium. The GRB 991216 is used as a prototype for this model.

X-ray and gamma-ray upper limits for pulsed emission from radio pulsars

1982 ◽  
Vol 260 ◽  
pp. 553 ◽  
Author(s):  
F. K. Knight ◽  
J. L. Matteson ◽  
L. E. Peterson ◽  
R. E. Rothschild
Keyword(s):  
Gamma Ray ◽  
Radio Pulsars ◽  
X Ray ◽  
Upper Limits

The gamma-ray spectra of radio pulsars

1981 ◽  
Vol 249 ◽  
pp. 698 ◽  
Author(s):  
S. Ayasli
Keyword(s):  
Gamma Ray ◽  
Radio Pulsars

Gamma-ray bursts from extragalactic radio pulsars

1992 ◽  
Vol 398 ◽  
pp. L85 ◽  
Author(s):  
Fulvio Melia ◽  
Marco Fatuzzo
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Radio Pulsars
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