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Temporal X-ray astronomy with a pinhole cameraPreliminary results from the Ariel-5 All-Sky X-Ray Monitor are presented, along with sufficient experiment details to define the experiment sensitivity. Periodic modulation of the X-ray emission is investigated from three sources with which specific periods have been associated, with the results that the 4.8 h variation from Cyg X-3 is confirmed, a long-term average 5.6 day variation from Cyg X-1 is discovered, and no detectable 0.787 day modulation of Sco X-1 is observed. Consistency of the long-term Sco X-1 emission with a 'shot-noise' model is discussed, wherein the source behavior is shown to be interpretable as about 100 'flares' per day, each with a duration of several hours. A sudden increase in the Cyg X-1 intensity by almost a factor of three on 22 April 1975 is reported, after 5 months of relative source constancy. The light curve of a bright nova-like transient source in Triangulum is presented, and compared with previously observed transient sources. Preliminary evidence for the existence of X-ray 'bursts' with duration less than 1 h is offered, with the caveat that there is not yet any supporting evidence to guarantee that the effect is truly astronomical.
Document ID
19760055452
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Holt, S. S.
(NASA Goddard Space Flight Center Greenbelt, Md., United States)
Date Acquired
August 8, 2013
Publication Date
June 1, 1976
Subject Category
Astronomy
Accession Number
76A38418
Distribution Limits
Public
Copyright
Other

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