Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/research/multibeam/papers/haynesr.ps.gz Дата изменения: Wed Sep 23 09:23:44 1998 Дата индексирования: Sun Dec 23 04:55:47 2007 Кодировка: Поисковые слова: saturn's moon

Narrow Band HI System for the Parkes Telescope
Multibeam Package
Raymond Haynes, Lister Staveley-Smith
Australia Telescope National Facility,CSIRO,PO Box 76,Epping 1710,
NSW,Australia (Raymond.Haynes@atnf.csiro.au)
Ulrich Mebold,Peter Kalberla
RAIUB,University of Bonn
Keith Jones
Physics Department, University of Queensland
Graeme White, Paul Jones, Miroslav Filipovic
University of Western Sydney, Nepean
John Dickey
University of Minnesota
Anne Green
School of Physics, University of Sydney
Abstract. A narrow-band translater and lter system has been con-
structed for the Parkes Multibeam receiver. This brief note outlines the
characteristics of the system and indicates the range of new projects that
will be possible in studies of the Magellanic Clouds.
1. Introduction
In a proposal funded by the ATNF, the University of Queensland and the Uni-
versity of Bonn, the ATNF has now developed a narrow-band back-end system
for the Parkes Multi-Beam system.
The project has provided a narrow-band back-end lter and correlation-
system able to use the inner 7-beams of the multi-beam system for observations
of spectral lines over 2048 channels with a total bandwidth across each spectrum
of either 4 or 8 MHz. This will provide a spectral resolution of down to 0.4km s 1
for each of the two polarization channels on the inner 7-beams of the multi-beam
system.
This makes an important addition to the multi-beam system which can
then be used to obtain 'zero-spacing' data at Parkes on the multi-beam system
1

to complement Australia Telescope Compact Array (ATCA) data or to map
larger areas of the sky in HI with the observing speed-advantage obtained by
multi-beaming the Parkes Telescope.
2. System Characteristics
The new Parkes narrow-band HI system will provide:
1. 7 beams on the sky;
2. 14.4 arc min beam-width on each beam;
3. Ts on the sky on each beam 24K
4. 2 orthogonal polarizations per beam;
5. 14 IF channels of 4 or 8MHz bandwidth;
6. 2048 channels of spectral resolution;
7. velocity coverage is -800 to 800km s 1 (in 8 MHz bandwidth);
8. velocity resolution down to 0.4km s 1 per channel.
3. Projects
Initial projects being undertaken with the facility by the team will include: a
study of the stray-radiation problems at 21-cm wavelength with the Parkes Tele-
scope and the multi-beam system preparatory to using the facility for mapping
of HI in the Galaxy; a project to map the HI in a test region along the Galactic
Plane; and a project to survey the extended HI in the LMC region at Parkes.
In the future other feasible projects with the system will include: fully
sampled surveys of the Magellanic System (including the the LMC and SMC,
Magellanic Bridge and Stream); gas ow into the Magellanic Stream from the
Magellanic Bridge; searches for HI gas in the neighborhood of the discrete HI
clouds in the Magellanic Stream; projects related to the interaction of Magellanic
Cloud gas and HI in the halo of the Galaxy 1 ; high-velocity HI cloud 1 studies;
surveys of HI in the Galactic plane 1 ; rotation curves of larger galaxies discovered
in the HIPASS and ZOA surveys; simultaneous HI and continuum polarization
studies at 1420 MHz; HI observations of newly discovered galaxies in the Zone
of Avoidance survey 1 ; HI observations of galaxies found in the HIPASS multi-
beam survey; and 'zero-spacing' data acquisition to complement HI studies on
the ATCA.
Acknowledgments. We would like to thank the ATNF's electronics, re-
ceiver and computing sta for their support in developing the narrow-band sys-
tem for the Parkes multi-beam system.
1
this project requires a good understanding of stray-radiation eects at the Parkes Telescope
2