Lunar occultation of the hard X-ray source in the Crab Nebula

Nature ◽  
1975 ◽  
Vol 255 (5508) ◽  
pp. 465-466 ◽  
Author(s):  
Y. FUKADA ◽  
S. HAYAKAWA ◽  
I. KASAHARA ◽  
F. MAKINO ◽  
Y. TANAKA ◽  
...  
Keyword(s):  
Crab Nebula ◽  
X Ray ◽  
Lunar Occultation ◽  
The Crab Nebula

The Crab Nebula - High energy X-ray observation of a lunar occultation

1975 ◽  
Vol 201 ◽  
pp. L15 ◽  
Author(s):  
R. Staubert ◽  
E. Kendziorra ◽  
J. Truemper ◽  
C. Reppin ◽  
J. A. Hoffman ◽  
...  
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Ray ◽  
Lunar Occultation ◽  
The Crab Nebula

High-energy X-ray observations of a lunar occultation of the Crab Nebula

1975 ◽  
Vol 197 ◽  
pp. L83 ◽  
Author(s):  
G. R. Ricker ◽  
S. G. Ryckman ◽  
J. E. Ballintine ◽  
J. P. Doty ◽  
P. M. Downey ◽  
...  
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Ray ◽  
Lunar Occultation ◽  
The Crab Nebula

Lunar Occultation of X-ray Emission from the Crab Nebula

Science ◽  
1964 ◽  
Vol 146 (3646) ◽  
pp. 912-917 ◽  
Author(s):  
S. Bowyer ◽  
E. T. Byram ◽  
T. A. Chubb ◽  
H. Friedman
Keyword(s):  
Crab Nebula ◽  
X Ray ◽  
Lunar Occultation ◽  
The Crab Nebula

scholarly journals Observational results of X-Ray astronomy

1965 ◽  
Vol 23 ◽  
pp. 227-239 ◽  
Author(s):  
Par S. Bowyer ◽  
E. T. Byram ◽  
T. A. Chubb ◽  
H. Friedman
Keyword(s):  
Galactic Plane ◽  
Crab Nebula ◽  
Angular Diameter ◽  
Radio Sources ◽  
X Rays ◽  
X Ray ◽  
Lunar Occultation ◽  
Sgr A ◽  
The Crab Nebula

Ten discrete sources of X-rays have been identified from observations made with Geiger counters aboard unstabilized Aerobee rockets. The distribution of sources is flattened toward the galactic plane. Tau XR-1 is an X-ray source within one arc minute of the center of the Crab Nebula and of angular diameter one arc minute as determined from observation of a lunar occultation. The position of the strongest source, Sco XR-1, is known to about 0.5 degree and the remaining eight sources to about 1.5 degree. Three X-ray sources, Sco XR-1, Cyg XR-1, and Cyg XR-2, are not accompanied by any known optical or radio objects at their positions. Oph XR-1 matches the position of the Kepler SN 1604 and Sgr XR-1 is within 2.3 degrees of Sgr A. The remaining five sources are not sufficiently well resolved or positioned to permit identifications with optical or radio sources. The X-ray flux from the Crab Nebula is compatible with synchrotron spectrum with index — 1.1 and the flux of 1.8 × 10-8 erg cm-2 s-1 (1.5-8 Å) fits the extrapolated optical synchrotron spectrum with the same index.

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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