Publication Date:
2019-06-27
Description:
The hard X-ray experiment (1 - 28 keV) on ANS, observed Cygnus X-1 in November 1974, and in May 1975, putting in evidence the two dramatically different states of this object. The average intensity in November was 15 cts/sec, and the observations showed remarkable features in the X-ray light curve and in the spectrum, which were correlated with the 5.6 days period of HDE226868. The May observations showed a count rate of approximately 80-100 cts/sec, with fluctuations up to approximately 130 cts/sec, uncorrelated with the spectroscopic binary. The May X-ray spectrum was much softer than the November one, and possibly was made up of two components.
Keywords:
ASTRONOMY
Type:
NASA Goddard Space Flight Center X-ray Binaries; p 429-442
Format:
text
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