3,061 research outputs found
Wilbur Norman Christiansen 1913-2007
W. N. ('Chris') Christiansen was an innovative and influential radio
astronomy pioneer. The hallmarks of his long and distinguished career in
science and engineering, spanning almost five decades, were his inventiveness
and his commitment to, and success with, large-scale projects. These projects
were the outcome of his innovative skill as physicist and engineer. Paralleling
this was his equal commitment to forging strong international links and
friendships, leading to his election as Vice-President of the International
Astronomical Union for the years 1964 to 1970, as President of the
International Union of Radio Science, URSI, from 1978 to 1981, and subsequently
as Honorary Life President in 1984, and as Foreign Secretary of the Australian
Academy of Science from 1981 to 1985. Major subsequent developments in radio
astronomy and wireless communications on the global scene stand as a legacy to
Chris's approach to his work and to the development of those who worked with
him.Comment: 16 pages, 4 figure
Bernard Yarnton Mills 1920-2011
Bernie Mills is remembered globally as an influential pioneer in the evolving
field of radio astronomy. His contributions with the 'Mills Cross' at the CSIRO
Division of Radiophysics and later at the University of Sydney's School of
Physics and the development of the Molonglo Observatory Synthesis Telescope
(MOST) were widely recognised as astronomy evolved in the years 1948-1985 and
radio astronomy changed the viewpoint of the astronomer as a host of new
objects were discovered
Optical fiber coupling method and apparatus
Systems are described for coupling a pair of optical fibers to pass light between them, which enables a coupler to be easily made, and with simple equipment, while closely controlling the characteristics of the coupler. One method includes mounting a pair of optical fibers on a block having a large hole therein, so the fibers extend across the hole while lying adjacent and parallel to one another. The fibers are immersed in an etchant to reduce the thickness of cladding around the fiber core. The fibers are joined together by applying a liquid polymer so the polymer-air interface moves along the length of the fibers to bring the fibers together in a zipper-like manner, and to progressively lay a thin coating of the polymer on the fibers
VLA observations of 6-cm excited OH
The VLA was used to determine precise positions for 4765-MHz OH maser
emission sources toward star-forming regions which had been observed about
seven months earlier with the Effelsberg 100-meter telescope. The observations
were successful for K3-50, DR21EX, W75N, and W49A. No line was detected toward
S255: this line had decreased to less than 5 per cent of the flux density
observed only seven months earlier. The time-variability of the observed
features during the past 30 years is summarised. In addition, to compare with
the Effelsberg observations, the 4750-MHz and 4660-MHz lines were observed in
W49A. These lines were found to originate primarily from an extended region
which is distinguished as an exceptional collection of compact continuum
components as well as by being the dynamical centre of the very powerful H_2 O
outflow.Comment: 11 pages, will require MN style file to process. MNRAS, accepted Oct
15, 200
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