scholarly journals Radio Observations of the Crab Nebula Pulsar

1971 ◽  
Vol 46 ◽  
pp. 73-83
Author(s):  
F. D. Drake
Keyword(s):  
Multipath Propagation ◽  
Crab Nebula ◽  
Crab Pulsar ◽  
Great Intensity ◽  
Radio Observations ◽  
Radiated Power ◽  
Propagation Effects ◽  
The Crab Nebula

The radio properties of the Crab Nebula pulsar are reviewed. The pulsar lies at the centre of the Crab Nebula and has a period of 33 msec. Its increase in period with time releases an amount of energy which is equal in magnitude to the total radiated power. Instabilities in the period of the Crab pulsar have been discovered with timescales ranging from days to months. The length of the pulse increases at longer wavelengths due apparently to multipath propagation effects. A characteristic of the Crab pulsar is the great intensity of the occasional pulse.

scholarly journals The Magnetic Field of the Crab as Revealed by New, High Resolution, Multi-Band Radio Images

1990 ◽  
Vol 140 ◽  
pp. 79-80
Author(s):  
M. F. Bietenholz ◽  
P. P. Kronberg
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Crab Nebula ◽  
Radio Observations ◽  
Field Orientation ◽  
Magnetic Field Orientation ◽  
The Crab Nebula ◽  
The Magnetic Field ◽  
Made In ◽  
Multi Band

We present and describe recent radio observations of the Crab Nebula, which allow us to determine the magnetic field orientation and depolarization at unprecedented resolution. The observations were made in 1987-1988 using all four configurations of the VLA, at 1410,1515,4625, and 4885 MHz. The resulting maps were all convolved with a clean beam of 1.8″ × 2.0″, elongated in P.A. 80°, and the residuals added back in.

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.

Radio Observations of the Crab Nebula during a Lunar Occultation

Nature ◽  
1964 ◽  
Vol 203 (4941) ◽  
pp. 171-173 ◽  
Author(s):  
B. H. ANDREW ◽  
N. J. B. A. BRANSON ◽  
D. WILLS
Keyword(s):  
Crab Nebula ◽  
Radio Observations ◽  
Lunar Occultation ◽  
The Crab Nebula

scholarly journals Faraday Rotation of the Crab Pulsar Radiation

1971 ◽  
Vol 46 ◽  
pp. 118-118
Author(s):  
R. N. Manchester
Keyword(s):  
Faraday Rotation ◽  
Radio Astronomy ◽  
Crab Nebula ◽  
Position Angle ◽  
Crab Pulsar ◽  
Astronomy Observatory ◽  
Pulsar Radiation ◽  
Rotation Measure ◽  
The Mean ◽  
The Crab Nebula

During April, 1970, the 300-ft telescope of the National Radio Astronomy Observatory was used to determine the mean polarisation of the Crab Nebula pulsar radiation at several frequencies around 400 MHz. The position angle of the highly polarised precursor measured at each frequency, corrected for ionospheric Faraday rotation and plotted against inverse frequency squared is shown in Figure 1. The observed variation of the position angle with frequency is consistent with Faraday rotation of the plane of polarisation with a rotation measure of −40.5 ± 4.5 rad/m2. This value is of the same sign but larger than the rotation measure for the nebular radiation in the vicinity of the pulsar.

scholarly journals Optical Observations of the Crab Pulsar, and Searches for other Optical Pulsars

1971 ◽  
Vol 46 ◽  
pp. 87-90
Author(s):  
Jerome Kristian
Keyword(s):  
Optical Properties ◽  
Light Curve ◽  
Total Energy ◽  
Crab Nebula ◽  
Optical Observations ◽  
Crab Pulsar ◽  
Time Variations ◽  
Optical Wavelengths ◽  
High Degree ◽  
The Crab Nebula

The optical properties of the Crab nebula pulsar are reviewed. The Crab nebula pulsar has a high degree of constancy at optical wavelengths. No time variations over short or long periods have been detected; the light curve is nearly the same in all colors. The intensity and color of the pulsar are V = 16.5, B − V = +0.5, U − B = −0.45 and V − R = −0.75. There is no precursor as found at radio wavelengths and the main pulse contains 65 per cent of the total energy. No lines have been detected.Searches for other pulsars have been unsuccessful.

The Crab pulsar echoes

2000 ◽  
Vol 177 ◽  
pp. 499-502 ◽  
Author(s):  
F. Graham Smith ◽  
A.G. Lyne
Keyword(s):  
Electron Density ◽  
Continuous Monitoring ◽  
Crab Nebula ◽  
Outer Part ◽  
Dispersion Measure ◽  
Crab Pulsar ◽  
The Past ◽  
The Crab Nebula

AbstractObservations over an eight month period from July 1997 to March 1998 show echoes following the radio pulses, and unusual changes in dispersion measure. We interpret this remarkable and complex event as refraction and dispersion in an ionised shell in the outer part of the Crab Nebula. The shell is remarkably compact; it has a electron density of about 103– 104cm−3and a thickness of about 3 × 1011m. Similar events have been noticed on several other occasions during the continuous monitoring of the Crab pulsar over the past 25 years.

scholarly journals The Crab Pulsar and Nebula as Seen in Gamma-Rays

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 448
Author(s):  
Elena Amato ◽  
Barbara Olmi
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Crab Pulsar ◽  
Gamma Ray Astronomy ◽  
Very High Energy ◽  
Energy Gamma ◽  
The Crab Nebula ◽  
The Impact ◽  
Very High

Slightly more than 30 years ago, Whipple detection of the Crab Nebula was the start of Very High Energy gamma-ray astronomy. Since then, gamma-ray observations of this source have continued to provide new surprises and challenges to theories, with the detection of fast variability, pulsed emission up to unexpectedly high energy, and the very recent detection of photons with energy exceeding 1 PeV. In this article, we review the impact of gamma-ray observations on our understanding of this extraordinary accelerator.

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