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Cosmic x-ray surveys.


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Francey, R J 1970 , 'Cosmic x-ray surveys.', PhD thesis, University of Tasmania.

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PDF (Whole thesis)
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Available under University of Tasmania Standard License.

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Chapters 1 to 3 are devoted solely to review of the
X-ray sky, the environmental limitations on an experiment,
and the techniques of X-ray detection. These are necessary
for the design of proportional counters for a series of
rocket surveys of the X-ray sky. Particular attention is
given to the reduction of background noise, and significant
improvements in the performance of laboratory tested
detectors is achieved and discussed in Chapter 4. Chapter
4. also describes a wide range of calibration techniques
developed and used on the rocket payloads. Because of the
desirability of recording design detail, it is included in
Chapters 1-4, contained in Volume 1. The first volume is
used freely as a source of reference in Volume 2, the
analysis section of the thesis.
Results from three early rocket flights were available
for analysis. Preliminary results, published at the time of
these flights are included in Chapter 5. These are
(i) the discovery of an intense X-ray source in Centaurus
on 4. April 1967 (flight i)
(2) a measure of the decrease in intensity and steepening
of X-ray spectrum of the source, Cen XR-2, by 20 April
1967 (flight II) and complete disappearance by I
December 1967 (flight III). (The variability made Cen
XR-2 unique among X-ray sources at the time.)
(3) a possible source in Cetus, significant in view of
its large separation from the galactic disc (flight
ii, III).
In Chapter 6, flight II data has been reanalysed in
detail and in the light of more recent evidence. Two
significant findings are
(i) An accurate and unambiguous location of Cen XR-2 in
galactic longitude. The new position excludes a
number of objects (hard X-ray, optical, radio), whose
properties have been employed in constructing models
for the source.
(2) An established variability of X-ray sources in the
Cygnus and nearby regions.
The properties of the variation in Cen XR-2 and a
similar newly discovered variable allow some restrictions
to be placed on source models.
With future low noise surveys in mind, the
possibility of galactic structure in the diffuse X-ray
background is investigated in Chapter 7. Remarkable
similarities in the spectra of low frequency radio, X-ray
and extraterrestrial electron spectra are displayed, and
can be interpreted in terms of galactic phenomena with
some reservations.. The radio data are used to predict
possible X-ray anisotropies.
Finally, in Chapter 8 attention is given to the
possibility of ground based surveys of X-ray stars.
Extensive new information on the electron production rates
in the ionospheric fl-region are compiled and it is shown
that the reported detection of a cosmic X-ray effect has
implications on the chemistry of the ionosphere.

Item Type: Thesis - PhD
Authors/Creators:Francey, R J
Keywords: X-ray astronomy
Copyright Holders: The Author
Copyright Information:

Copyright 1970 the Author - The University is continuing to endeavour to trace the copyright
owner(s) and in the meantime this item has been reproduced here in good faith. We
would be pleased to hear from the copyright owner(s).

Additional Information:

Bibliography: p. 329-342. Thesis (Ph.D.) - University of Tasmania, 1970

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