Neutron stars and cosmic-ray production

1968 ◽  
Vol 46 (10) ◽  
pp. S472-S475 ◽  
Author(s):  
D. B. Melrose ◽  
A. G. W. Cameron

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.

1971 ◽  
Vol 46 ◽  
pp. 394-406
Author(s):  
F. Pacini

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.


1971 ◽  
Vol 46 ◽  
pp. 65-67
Author(s):  
G. G. Fazio ◽  
H. F. Helmken ◽  
G. H. Rieke ◽  
T. C. Weekes

The detection of Čerenkov light emitted by cosmic-ray air showers was used to search for cosmic gamma rays from the Crab Nebula. By use of the 10-m optical reflector at Mt. Hopkins, Arizona, the Crab Nebula was observed during the winter of 1969–1970 for approximately 112 hours, which was a significant increase in exposure time over previous experiments. Above a gamma-ray energy of 2.2 × 1011 eV, no significant flux was detected, resulting in an upper limit to the flux of 8.1 × 10-11 photon/cm2 sec. In the synchrotron-Compton-scattering model of gamma-ray production in the Crab Nebula, this limit on the flux indicates the average magnetic field in the nebula must be greater than 3 × 10-4 G.


1967 ◽  
Vol 45 (9) ◽  
pp. 2823-2831 ◽  
Author(s):  
Carl J. Hansen ◽  
Sachiko Tsuruta

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.


2009 ◽  
Vol 692 (1) ◽  
pp. 61-72 ◽  
Author(s):  
M. Amenomori ◽  
X. J. Bi ◽  
D. Chen ◽  
S. W. Cui ◽  
Danzengluobu ◽  
...  

1965 ◽  
Vol 23 ◽  
pp. 195-225
Author(s):  
R. J. Gould ◽  
G. R. Burbidge

This review concentrates primarily on the problem of interpreting the recent X-ray and γ-ray observations of celestial sources. The expected fluxes of hard radiation from various processes are estimated (when possible) and are compared with the observations. We compute the synchrotron, bremsstrahlung, and (inverse) Compton spectra originating from relativistic electrons produced (via meson production) in the galaxy and intergalactic medium by cosmic ray nuclear collisions; the spectra from π°-decay are also computed. Neutron stars, stellar coronae, and supernova remnants are reviewed as possible X-ray sources. Special consideration is given to the processes in the Crab Nebula. Extragalactic objects as discrete sources of energetic photons are considered on the basis of energy requirements; special emphasis is given to the strong radio sources and the possibility of the emission of hard radiation during their formation. The problem of the detection of cosmic neutrinos is reviewed.As yet, no definite process can be identified with any of the observed fluxes of hard radiation, although a number of relevant conclusions can be drawn on the basis of the available preliminary observational results. In particular, some cosmogonical theories can be tested.


1987 ◽  
Vol 125 ◽  
pp. 281-303
Author(s):  
Ken'ichi Nomoto

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.


1986 ◽  
Vol 64 (4) ◽  
pp. 474-478 ◽  
Author(s):  
Eric D. Feigelson

The evidence for jets emanating from neutron stars is reviewed. Isolated radio pulsars do not appear to produce collimated outflows. A few supernova remnants, notably the Crab nebula, exhibit jetlike protrusions at their outer boundaries. These are probably "blowouts" of the plasma in the remnant rather than true jets from a neutron star. However, several cases of degenerate stars in X-ray binary systems do make jets. SS433 has twin precessing jets moving outward at v ~ 0.26c, and Sco X-1 has radio lobes with v ~ 0.0001c. Cyg X-3 appears to eject synchrotron plasmoids at high velocities. Other X-ray binaries associated with variable radio sources are discussed; some are interesting candidates for collimated outflow. G109.1-1.0 is an X-ray binary in a supernova remnant that may have radio or X-ray jets. It is not clear in all these cases, however, that the compact object is a neutron star and not a black hole or white dwarf.A tentative conclusion is reached that isolated neutron stars do not produce jets, but degenerate stars in accreting binary systems can. This suggests that the presence of an accretion disk, rather than the characteristics of an isolated pulsar's dipole magnetosphere, is critical in making collimated outflows.


2019 ◽  
Vol 489 (1) ◽  
pp. 108-115 ◽  
Author(s):  
P Cristofari ◽  
P Blasi

ABSTRACT Diffusive shock acceleration is considered as the main mechanism for particle energization in supernova remnants, as well as in other classes of sources. The existence of some remnants that show a bilateral morphology in the X-rays and gamma-rays suggests that this process occurs with an efficiency that depends upon the inclination angle between the shock normal and the large-scale magnetic field in which the shock propagates. This interpretation is additionally supported by recent particle-in-cell simulations that show how ions are not injected if the shock is more oblique than ∼45°. These shocks provide an excellent test bench for the process of reacceleration at the same shock: non-thermal seed particles that are reached by the shock front are automatically injected and accelerated. This process was recently discussed as a possible reason for some anomalous behaviour of the spectra of secondary cosmic ray nuclei. Here, we discuss how gamma-ray observations of selected supernova remnants can provide us with precious information about this process and lead us to a better assessment of particle diffusive shock reacceleration for other observables in cosmic ray physics.


2019 ◽  
Vol 2 (4) ◽  

The formation of C14 from nitrogen by collision with a gamma ray or high energy particle in our high atmosphere is a widely accepted theory. The new yet to be recognized supernova, SN, and nova impact theory, SNIT, proposes debris streams of high energy particles from exploding stars impact our planet and cause global warming, sunspot, and other extraordinary events. Some of the recorded C14 data must match the calculated impact times of exploding star debris streams and a similar result occurs for sunspots. The new calculated supernova impact times in conjunction with two temperature plots from Dr Loehle and NOAA prove our current episode of global warming is caused by the Crab nebula or SN 1054 and is waning. The accuracy of the SNIT impact times are shown for the first time due to exact C14 data. Supernova explosions within 700 light years are very dangerous to mankind.


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