scholarly journals Transfer of Energy to the Crab Nebula Following the Spin-Up of the Pulsar

1971 ◽  
Vol 46 ◽  
pp. 296-307 ◽  
Author(s):  
D. B. Melrose
Keyword(s):  
Energy Flux ◽  
Central Region ◽  
Crab Nebula ◽  
Point Of View ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
X Ray ◽  
Enhanced Activity ◽  
The Crab Nebula

Observed enhanced activity in the central region of the Crab Nebula following the spin-up of the pulsar is discussed from the point of view of the transfer of energy to relativistic electrons. It is argued that a rapid deposition of energy associated with the spin-up of the pulsar causes a radial energy flux which becomes a flux in hydromagnetic activity at about the regions where enhanced synchrotron emission is observed. It is shown that such hydromagnetic activity is rapidly damped by the relativistic electrons with energy being transferred to the relativistic electrons. This acceleration can account for the short synchrotron halflifetimes observed. The model predicts highly enhanced X-ray emission from the central region of the Nebula following a spin-up.

scholarly journals A Model for the Spatial Distribution of Relativistic Electrons in the Crab Nebula

2000 ◽  
Vol 195 ◽  
pp. 371-372
Author(s):  
E. Amato
Keyword(s):  
Spatial Distribution ◽  
Good Description ◽  
Crab Nebula ◽  
Particle Diffusion ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
Constant Intensity ◽  
X Ray ◽  
Field Lines ◽  
The Crab Nebula

A model for the spatial distribution of relativistic electrons in the Crab Nebula is proposed. Particles injected in the vicinity of the pulsar propagate in a magnetic field of time-dependent but spatially constant intensity. A good description of the nebular synchrotron emission, from radio to X-ray frequencies, is obtained if particle diffusion with respect to the azimuthal field lines is taken into account.

scholarly journals Properties of Nonthermal Emission in Plerions

2000 ◽  
Vol 195 ◽  
pp. 189-197
Author(s):  
R. Bandiera
Keyword(s):  
Supernova Remnants ◽  
Crab Nebula ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
Low Frequencies ◽  
X Ray ◽  
Spatially Resolved ◽  
Spectral Break ◽  
History Of ◽  
The Crab Nebula

The synchrotron emission observed in plerions depends on the characteristics of the magnetic fields and relativistic electrons in these supernova remnants. Therefore, an analysis of the spectral and spatial properties of this emission, combined with models for the evolution and structure of plerions, would allow one to investigate the evolution of the synchrotron nebula, the structure of the magnetic field, and the distribution of the relativistic electrons, as well as to put constraints on the history of the energy input from the associated neutron star.The identification of a new class of plerionic remnants, with spectral properties different from the Crab Nebula, has been proposed. The spectra of these objects typically show a sharp spectral break at very low frequencies (below 50 GHz), with a steep spectrum right beyond the break. In order to model the properties of their emission, a nonstandard evolution of the pulsar output seems to be required.X-ray observations of the synchrotron emission from the Crab Nebula are shown. They are compared with previous data, and their implications on the structure of the Crab are discussed. Recent millimetric data of this object are also presented. A spatially resolved analysis, based on radio, millimetric, and X-ray data, will be carried out also for other plerions.

scholarly journals The Crab Nebula and other Anomalous Astrophysical Arthropods

1998 ◽  
Vol 11 (1) ◽  
pp. 366-366
Author(s):  
Virginia Trimble
Keyword(s):  
Magnetic Field ◽  
Kinetic Energy ◽  
Stellar Evolution ◽  
Crab Nebula ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
Balloon Flight ◽  
X Ray ◽  
Slowing Down ◽  
The Crab Nebula

1. Supernovae and Their Remnants The Crab Nebula is expanding and its pulsar is slowing down, both on time scales that indicate some very interesting real-time stellar evolution must have occurred about 1000 years ago, as indeed we know from Chinese and other ancient records. The Crab was, in fact, the first SNR to be confidently identified as such and to have its expansion rate measured and the first pulsar to have its first and second time derivatives measured. Among the interesting related details are (a) the current expansion is a bit faster than the average since the 1054 explosion, indicating outward pressure from the relativistic electrons and magnetic field responsible for the synchrotron emission, (b) some of the central synchrotron emission features wiggle and oscillate around at much larger speeds than the expansion but in a non-secular way, (c) the braking index of the pulsar is about 2.5 rather than 3.0 (as predicted for a pure magnetic dipole emitter), (d) energy is conserved (it wasn’t obviously so before 1968), in that the pulsar is losing rotational kinetic energy fast enough to keep up the supply of optical and X-ray emitting electrons, and (e) glitches in the slowing of the pulsar (for which data go back to a 1964 balloon flight) indicate complex coupling of crust to interior, presumably a magnetic one.

scholarly journals High energy cosmic photons and neutrinos

1965 ◽  
Vol 23 ◽  
pp. 195-225
Author(s):  
R. J. Gould ◽  
G. R. Burbidge
Keyword(s):  
Supernova Remnants ◽  
Crab Nebula ◽  
Meson Production ◽  
Cosmic Ray ◽  
High Energy ◽  
Relativistic Electrons ◽  
X Ray ◽  
Hard Radiation ◽  
The Galaxy ◽  
The Crab Nebula

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.

scholarly journals Supernova Remnants With Compact X-Ray Sources

1983 ◽  
Vol 101 ◽  
pp. 417-419
Author(s):  
D. H. Clark ◽  
P. G. Murdin ◽  
R. Wood ◽  
R. Gilmozzi ◽  
I. J. Danziger ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Crab Nebula ◽  
Synchrotron Emission ◽  
Thick Shell ◽  
Hollow Shell ◽  
X Ray ◽  
3 Dimensional ◽  
The Standard Model ◽  
The Face ◽  
The Crab Nebula

More than 3000 radial velocity observations across the face of the Crab Nebula are used to investigate its 3-dimensional properties. In the standard model it consists of a thick hollow shell with synchrotron emission from within. We show that the thick shell is composed of bright inner and faint outer components

scholarly journals Synchrotron Thermal Instabilities and Radio Filaments in the Lobes of Cygnus A

1989 ◽  
Vol 8 ◽  
pp. 417-422
Author(s):  
G. Bodo ◽  
A. Ferrari ◽  
S. Massaglia ◽  
E. Trussoni
Keyword(s):  
Magnetic Field ◽  
Thermal Instability ◽  
Crab Nebula ◽  
Relativistic Electrons ◽  
Synchrotron Emission ◽  
Cygnus A ◽  
The Crab Nebula ◽  
The Magnetic Field

Recent VLA observations of the lobes of Cygnus A exhibit complex “filamentary” structures, with typical scale width ~ 1 arcsec (Dreher, Carilli and Perley, 1987, Perley, 1987). The filaments appear aligned with the magnetic field, as results from polarization measures, suggesting that the field may play a fundamental role in the process of their formation.We propose a mechanism for the possible formation of these filaments based upon a thermal instability connected with synchrotron emission from relativistic electrons. This type of instability was studied by Simon and Axford (1967), who discussed it in connection with the Crab Nebula filaments, and by Eilek and Caroff (1979), who generalized the previous study for application to quasar atmospheres.

scholarly journals New Measurement of the Vertical Atmospheric Density Profile from Occultations of the Crab Nebula with X-Ray Astronomy Satellites Suzaku and Hitomi

2020 ◽  
Author(s):  
Satoru Katsuda ◽  
Hitoshi Fujiwara ◽  
Yoshitaka Ishisaki ◽  
Yoshitomo Maeda ◽  
Koji Mori ◽  
...  
Keyword(s):  
Density Profile ◽  
Crab Nebula ◽  
Atmospheric Density ◽  
X Ray ◽  
The Crab Nebula

scholarly journals Spectral Variation of Hard X-Ray Emission from the Crab Nebula with the Suzaku Hard X-Ray Detector

2013 ◽  
Vol 65 (4) ◽  
pp. 74 ◽  
Author(s):  
Tomomi Kouzu ◽  
Makoto S. Tashiro ◽  
Yukikatsu Terada ◽  
Shin’ya Yamada ◽  
Aya Bamba ◽  
...  
Keyword(s):  
Crab Nebula ◽  
Spectral Variation ◽  
X Ray ◽  
The Crab Nebula

scholarly journals The X-Ray Spectra of Cygnus XR-1 and the Crab Nebula

1968 ◽  
Vol 1 ◽  
pp. 202-205
Author(s):  
Laurence E. Peterson
Keyword(s):  
Power Law ◽  
Crab Nebula ◽  
Atmospheric Depth ◽  
Significance Level ◽  
X Ray ◽  
One Year ◽  
The Crab Nebula

In this paper we wish to present briefly the latest results which have been obtained on the hard X-ray spectra of two strong sources in the Northern skies. These observations, which have been discussed in detail previously (Peterson et al., 1967), were made from balloons launched at Palestine, Texas, to 3 gm/cm2 atmospheric depth during September 1966. The Crab Nebula and the Cygnus XR-1 were observed to have a differential number power law spectra with an index of about –2 over the 20–200 keV range. Both sources have the same intensity within about 10%. The Crab Nebula has been observed on two occasions, one year apart, and showed no change in intensity over this range at about a 5% significance level.

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