VIBRATING NEUTRON STARS

1967 ◽  
Vol 45 (9) ◽  
pp. 2823-2831 ◽  
Author(s):  
Carl J. Hansen ◽  
Sachiko Tsuruta
Keyword(s):  
Neutron Stars ◽  
Storage Capacity ◽  
Vibrational Energy ◽  
Crab Nebula ◽  
X Rays ◽  
Vibrational Heating ◽  
Large Spread ◽  
Vibrational Energies ◽  
The Crab Nebula ◽  
Urca Process

The time variation of some interesting properties of vibrating neutron stars is considered. The models used are based on two nuclear potentials that cover a large spread of possibilities. The modified URCA neutrino process has been assumed to be the major damping mechanism. The calculations are performed both for the case when the vibration energy is partially converted into heat through the URCA process and for the case when this conversion does not take place. It is found that the vibrational energy-storage capacity is extremely model-dependent. The vibrational energies at 1 000 years range from about 1047 to 1050 ergs, which are sufficiently large as a possible energy source for the X rays from the Crab Nebula, ft is shown also that the cooling times of neutron stars will not be significantly increased by the inclusion of the vibrational heating.

Neutron stars and cosmic-ray production

1968 ◽  
Vol 46 (10) ◽  
pp. S472-S475 ◽  
Author(s):  
D. B. Melrose ◽  
A. G. W. Cameron
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Crab Nebula ◽  
Cosmic Ray ◽  
X Rays ◽  
Strong Point ◽  
Electrons And Ions ◽  
Supernova Explosions ◽  
The Crab Nebula

Recent investigations of the properties of neutron stars and of supernova explosions indicate that neutron stars should frequently be formed as supernova remnants. It now appears unlikely that any form of internal energy storage can play an important role in the production of X rays or cosmic rays. If mass infall onto a neutron star occurs at the upper limiting value allowed by radiation stresses, instabilities are likely to make the resulting mass infall, X-ray, gamma-ray, and cosmic-ray production very intermittent. It is shown that such a model may be able to account for many features of the Crab nebula: the energy input in electrons and ions, the character of the fast-moving light ripples or wisps, and the strong point source of ~50 MHz radiation.

scholarly journals Physical Processes and Parameters in the Magnetosphere of NP 0532

1971 ◽  
Vol 46 ◽  
pp. 394-406
Author(s):  
F. Pacini
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Crab Nebula ◽  
General Relation ◽  
Energy Generation ◽  
Main Pulse ◽  
Physical Processes ◽  
X Ray ◽  
The Crab Nebula

The Crab Nebula pulsar conforms to the model of a rotating magnetised neutron star in the rate of energy generation and the exponent of the rotation law.It is suggested that the main pulse is due to electrons and the precursor to protons. Both must radiate in coherent bunches. Optical and X-ray radiation is by the synchrotron process.The wisps observed in the Nebula may represent the release of an instability storing about 1043 erg and 1047–48 particles.Finally, some considerations are made about the general relation between supernova remnants and rotating neutron stars.

scholarly journals Superfluidity in Neutron Stars

1974 ◽  
Vol 53 ◽  
pp. 151-165
Author(s):  
George Greenstein
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Crab Nebula ◽  
Crab Pulsar ◽  
X Ray ◽  
Effects Of Rotation ◽  
The Crab Nebula

We present a short Cook's tour of the possible effects of rotation coupled with superfluid properties of neutron star interiors. A suggestion is made to take advantage of forthcoming lunar occultations of the Crab Nebula in order to search for blackbody X-ray emission from the Crab pulsar.

Low-energy cosmic X-ray measurements

1969 ◽  
Vol 47 (23) ◽  
pp. 2651-2666 ◽  
Author(s):  
A. J. Baxter ◽  
B. G. Wilson ◽  
D. W. Green
Keyword(s):  
Spectral Analysis ◽  
Energy Range ◽  
Crab Nebula ◽  
Spectral Characteristics ◽  
Low Energy ◽  
Data Recovery ◽  
X Rays ◽  
X Ray ◽  
Recovery System ◽  
The Crab Nebula

An experiment is described to investigate cosmic X rays in the energy range 0.25–12 keV. The data-recovery system and methods of spectral analysis are considered. Results are presented for the energy spectrum of the diffuse X-ray component and its distribution over the northern sky down to 1.6 keV with a limited extension at 0.27 keV.In the energy range 1.6 to 12 keV, the spectrum is represented by:[Formula: see text]although separate analyses indicate a flattening below 4.5 keV to give:[Formula: see text]and[Formula: see text]At the lowest energies, the flux appears to increase more rapidly and exhibits some anisotropy in arrival directions related to the gross galactic structure. Spectral characteristics of the Crab Nebula and Cygnus X-2 have also been determined.

Sky survey of high-energy cosmic X-rays and spectral information on sources in the Crab nebula, Cygnus, and Scorpius

1968 ◽  
Vol 46 (10) ◽  
pp. S409-S413 ◽  
Author(s):  
Walter H. G. Lewin ◽  
George W. Clark ◽  
William B. Smith
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Rays ◽  
Coma Cluster ◽  
X Ray ◽  
Sky Survey ◽  
Upper Limits ◽  
Intensity Ratios ◽  
The Crab Nebula ◽  
Made In

A complete X-ray survey of the northern sky has been made in the energy range 20–100 keV. Spectra are given for Cyg X-1 and Tau X-1. Intensity ratios (Cyg X-1/Tau X-1) of 0.84 ± 0.10 and 1.30 ± 0.25 were derived in the 20–70 keV range from data obtained on July 19, 1966 and February 13, 1967, respectively. Observations on Sco X-1 and the Coma cluster show upper limits which are quite different from results reported by other groups.

scholarly journals High-energy X rays from the Crab Nebula

1966 ◽  
Vol 71 (13) ◽  
pp. 3261-3264 ◽  
Author(s):  
R. C. Haymes ◽  
W. L. Craddock
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Rays ◽  
The Crab Nebula

scholarly journals Interstellar Absorption of the Low Energy X-rays from the Crab Nebula

1973 ◽  
Vol 165 (4) ◽  
pp. 355-361 ◽  
Author(s):  
P. A. Charles ◽  
J. L. Culhane ◽  
I. R. Tuohy
Keyword(s):  
Crab Nebula ◽  
Low Energy ◽  
X Rays ◽  
Interstellar Absorption ◽  
The Crab Nebula

scholarly journals Neutron Star Formation in Theoretical Supernovae — Low Mass Stars and White Dwarfs —

1987 ◽  
Vol 125 ◽  
pp. 281-303
Author(s):  
Ken'ichi Nomoto
Keyword(s):  
Neutron Stars ◽  
White Dwarfs ◽  
Binary Systems ◽  
Crab Nebula ◽  
Close Binary ◽  
Low Mass Stars ◽  
Supernova Explosions ◽  
Low Mass ◽  
Strongly Degenerate ◽  
The Crab Nebula

The presupernova evolution of stars that form semi-degenerate or strongly degenerate O+Ne+Mg cores is discussed. For the 10–13 M⊙ stars, behavior of off-center neon flashes is crucial. The 8–10 M⊙ 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. We also examine the conditions for which neutron stars form from accretion-induced collapse of white dwarfs in close binary systems.

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