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Characterisation of the Mopra Radio Telescope at 16–50 GHz

Published online by Cambridge University Press:  02 January 2013

J. S. Urquhart ,
M. G. Hoare ,
C. R. Purcell ,
K. J. Brooks ,
M. A. Voronkov ,
B. T. Indermuehle ,
M. G. Burton ,
N. F. H. Tothill  and
P. G. Edwards
J. S. Urquhart*
Affiliation:
Australia Telescope National Facility, CSIRO Astronomy and Space Science, Sydney, NSW 2052, Australia
M. G. Hoare
Affiliation:
School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
C. R. Purcell
Affiliation:
University of Manchester, Jodrell Bank Centre for Astrophysics, Manchester, M13 9LP, UK
K. J. Brooks
Affiliation:
Australia Telescope National Facility, CSIRO Astronomy and Space Science, Sydney, NSW 2052, Australia
M. A. Voronkov
Affiliation:
Australia Telescope National Facility, CSIRO Astronomy and Space Science, Sydney, NSW 2052, Australia
B. T. Indermuehle
Affiliation:
Australia Telescope National Facility, CSIRO Astronomy and Space Science, Sydney, NSW 2052, Australia
M. G. Burton
Affiliation:
School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
N. F. H. Tothill
Affiliation:
School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
P. G. Edwards
Affiliation:
Australia Telescope National Facility, CSIRO Astronomy and Space Science, Sydney, NSW 2052, Australia
*
EEmail: James.Urquhart@csiro.au (ATNF)
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Abstract

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We present the results of a programme of scanning and mapping observations of astronomical masers and Jupiter designed to characterise the performance of the Mopra Radio Telescope at frequencies between 16 and 50 GHz using the 12-mm and 7-mm receivers. We use these observations to determine the telescope beam size, beam shape, and overall telescope beam efficiency as a function of frequency. We find that the beam size is well fit by λ/D over the frequency range with a correlation coefficient of ∼90%. We determine the telescope main beam efficiencies are between ∼48 and 64% for the 12-mm receiver and reasonably flat at ∼50% for the 7-mm receiver. Beam maps of strong H2O (22 GHz) and SiO masers (43 GHz) provide a means to examine the radial beam pattern of the telescope. At both frequencies, the radial beam pattern reveals the presence of three components: a central ‘core’, which is well fit by a Gaussian and constitutes the telescopes main beam; and inner and outer error beams. At both frequencies, the inner and outer error beams extend out to ∼2 and ∼3.4 times the full-width half maximum of the main beam, respectively. Sources with angular sizes of a factor of two or more larger than the telescope main beam will couple to the main and error beams, and therefore the power contributed by the error beams needs to be considered. From measurements of the radial beam power pattern we estimate the amount of power contained in the inner and outer error beams is of order one-fifth at 22 GHz, rising slightly to one-third at 43 GHz.

Keywords

instrumentsISM: moleculesradio sources: lines
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 27 , Issue 3 , 2010 , pp. 321 - 330
Copyright
Copyright © Astronomical Society of Australia 2010

References

Baars, J.W.M., van der Brugge, J. F., Casse, J.L., Hamaker, J.P., Sondaar, L.H., Visser, J.J. & Wellington, K.J., 1973, IEEE Proceedings, 61, 1258CrossRefGoogle Scholar
Cooper, D.N., James, G.L., Parsons, B.F. & Yabsley, D.E., 1992, J. Electrical and Electronics Eng. Australia, 12, 121Google Scholar
De Pater, I. & Massie, S.T., 1985, Icarus, 62, 143CrossRefGoogle Scholar
Dodson, R. et al. , 2008, ApJS, 175, 314CrossRefGoogle Scholar
Elmouttie, M., Haynes, R.F. & Jones, K.L., 1997, PASA, 14, 140CrossRefGoogle Scholar
Frater, R.H., Brooks, J.W. & Whiteoak, J.B., 1992, J. Electrical and Electronics Eng. Australia, 12, 103Google Scholar
Gough, R., Archer, J., Roberts, P., Moorey, G., Graves, G., Bowen, M. & Kanoniuk, H., 2004, Proc.12th European Gallium Arsenide and other Compound Semiconductors Symposium, 359Google Scholar
Greenhill, L.J. et al. , 2003, ApJ, 590, 162CrossRefGoogle Scholar
Hirabayashi, H. et al. , 2000, PASJ, 52, 955CrossRefGoogle Scholar
Kobayashi, H. et al. , 2000, PASJ, 52, 967CrossRefGoogle Scholar
Koribalski, B., Johnston, S. & Otrupcek, R., 1994, MNRAS, 270, L43CrossRefGoogle Scholar
Ladd, N., Purcell, C., Wong, T. & Robertson, S., 2005, PASA, 22, 62CrossRefGoogle Scholar
Liang, H., Dickey, J.M., Moorey, G. & Ekers, R.D., 1997, A&A, 326, 108Google Scholar
Moorey, G.G., Sinclair, M.W. & Payne, J.M., 1997, IAU Symposium, 170, 441Google Scholar
Moorey, G.G., Bolton, R.J., Bowen, M.A., Carrad, G.J., Dunning, A., Gough, R.G., Graves, G.R., Kanoniuk, H.P. & Reilly, L.J., 2008a, Proc. European Microwave Conf., 155Google Scholar
Moorey, G., Bolton, R., Bowen, M., Dunning, A., Gough, R., Kanoniuk, H., Reilly, L. & Roberts, P., 2008b, Proc. WARS, Ed. Norris, R.Google Scholar
Scott, W.K. et al. , 2004, ApJS, 155, 33CrossRefGoogle Scholar
Tarter, J.C., 1997, IAU Colloq. 161:Astronomical and Biochemical Origins and the Search for Life in the Universe, 633Google Scholar
Tingay, S.J., Murphy, D.W. & Edwards, P.G., 1998, ApJ, 500, 673CrossRefGoogle Scholar
Urquhart, J.S. et al. , 2009, A&A, 507, 795Google Scholar
Walsh, A.J., Longmore, S.N., Thorwirth, S., Urquhart, J.S. & Purcell, C.R., 2007, MNRAS, 382, L35CrossRefGoogle Scholar
Walsh, A.J., Lo, N., Burton, M.G., White, G.L., Purcell, C.R., Longmore, S.N., Phillips, C.J. & Brooks, K.J., 2008, PASA, 25, 105CrossRefGoogle Scholar
Witasse, O. et al. , 2006, JGR (Planets), 111, 7Google Scholar