Characterisation of the MALT90 Survey and the Mopra Telescope at 90 GHz

Author(s)

J. B. Foster, J. M. Rathborne, P. Sanhueza, C. Claysmith, J. S. Whitaker, J. M. Jackson, J. L. Mascoop, M. Wienen, S. L. Breen, F. Herpin, A. Duarte-Cabral, T. Csengeri, Y. Contreras, B. Indermuehle, P. J. Barnes, A. J. Walsh, M. R. Cunningham, T. R. Britton, M. A. Voronkov, J. S. Urquhart, J. Alves, C. H. Jordan, T. Hill, S. Hoq, K. J. Brooks, S. N. Longmore

Abstract

We characterise the Millimetre Astronomy Legacy Team 90 GHz Survey

(MALT90) and the Mopra telescope at 90 GHz. We combine repeated

position-switched observations of the source G300.968+01.145 with a map

of the same source in order to estimate the pointing reliability of the

position-switched observations and, by extension, the MALT90 survey; we

estimate our pointing uncertainty to be 8 arcsec. We model the two

strongest sources of systematic gain variability as functions of

elevation and time-of-day and quantify the remaining absolute flux

uncertainty. Corrections based on these two variables reduce the scatter

in repeated observations from 12%-25% down to 10%-17%. We find no

evidence for intrinsic source variability in G300.968+01.145. For

certain applications, the corrections described herein will be integral

for improving the absolute flux calibration of MALT90 maps and other

observations using the Mopra telescope at 90 GHz.

Organisation(s)

Department of Astrophysics

External organisation(s)

European Southern Observatory (Germany), Yale University, Boston University, Max-Planck-Institut für Radioastronomie, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Université Bordeaux, University of Florida, Gainesville, Curtin University, University of New South Wales, Macquarie University, Université Paris VII - Paris-Diderot, Joint ALMA Observatory, Liverpool John Moores University (LJMU), University of Tasmania

Journal

Publications of the Astronomical Society of Australia

Volume

No. of pages

DOI

https://doi.org/10.1017/pasa.2013.18

Publication date

07-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

Keywords

Portal url

https://ucris.univie.ac.at/portal/en/publications/characterisation-of-the-malt90-survey-and-the-mopra-telescope-at-90-ghz(7931eb99-8147-4cef-bd6f-3d53d6d065e3).html