Preview

PDF (Whole thesis) whole_CaneHilar...pdf | Download (11MB) Available under University of Tasmania Standard License. | Preview

Abstract

This thesis presents the results and analysis of data
obtained using the Llanherne low-frequency array. Surveys of the
Galaxy at five frequencies in the range 2 to 20 MHz have been made
and the data have been assembled into maps covering the area
320° ≤ ₰ ≤ 30° 30 ° and -25° ≤ b ≤ 22 ° . The data from these maps are
combined with data from seven earlier continuum surveys to produce
galactic radio spectra in various directions.
A summary is made of most of the measurements, at frequencies
less than approximately 400 MHz, 'of the galactic background radiation
and their interpretation. Two new composite maps, at 10 and 30 MHz,
are presented. These, combined with the 85 MHz all-sky map, are
used to illustrate the variation of the galactic non-thermal radiation
across the sky, and with frequency.
The galactic spectra are interpreted in terms of a model of
the Galaxy in which synchrotron emission, and absorption in HII
regions predominate in spiral arms. However, it is proposed that
the synchrotron emission arms and the arms defined by HII regions
are not coincident. In addition to the HII absorbing gas the model
incorporates a much broader uniform absorbing HI gas which is
responsible for high latitude absorption, pulsar signal dispersion
and Faraday rotation.
For the HI gas it is found that
∫ne2Te¯1.35 dl ≈ 1.1 x 10¯7 cm¯6 K¯1 . 35 pc
For the HII gas the above quantity varies for different arms. An
average value is
∫ne2Te¯1.35 dl ≈ 2.7 x 10¯6 k¯1.35 pc

Item Type:	Thesis - PhD
Authors/Creators:	Cane, Hilary Vivien,1949-
Keywords:	Radiation
Copyright Holders:	The Author
Copyright Information:	Copyright 1977 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:	Thesis (Ph.D.)--University of Tasmania, 1978. Includes bibliographical references
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page