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On the estimation of a celestial reference frame in the presence of source structure

Citation

Plank, L and Shabala, SS and McCallum, JN and Krasna, H and Petrachenko, B and Rastorgueva-Foi, E and Lovell, JEJ, On the estimation of a celestial reference frame in the presence of source structure, Monthly Notices of the Royal Astronomical Society, 455, (1) pp. 343-356. ISSN 0035-8711 (2016) [Refereed Article]


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Copyright Statement

Copyright 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

DOI: doi:10.1093/mnras/stv2080

Abstract

The spatial structure of sources making up the celestial reference frame (CRF) at radio frequencies is a systematic error source in very long baseline interferometry (VLBI) measurements. Using simulations, we investigate the effects of source structure on the CRF, determined by the actual observational programme of the International VLBI Service for Geodesy and Astrometry. This is done using the source structure simulator of the Vienna VLBI Software. Applying various mock two-component source models, systematic displacements of 1080 μas in median source position offsets are found. These offsets are predominantly aligned with the direction of the jet. The simulations further show that slight changes in the source model can significantly change the estimated positions. We finally present a new parametrization of source positions in the analysis, namely along the jet direction and perpendicular to it, allowing us to significantly mitigate the effects of source structure on an estimated CRF.

Item Details

Item Type:Refereed Article
Keywords:techniques: interferometric, astrometry, reference systems, quasars: general
Research Division:Physical Sciences
Research Group:Astronomical and Space Sciences
Research Field:Cosmology and Extragalactic Astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Physical Sciences
Author:Plank, L (Dr Lucia McCallum)
Author:Shabala, SS (Dr Stas Shabala)
Author:McCallum, JN (Dr Jamie McCallum)
Author:Rastorgueva-Foi, E (Dr Elizaveta Rastorgueva-Foi)
Author:Lovell, JEJ (Dr Jim Lovell)
ID Code:105945
Year Published:2016
Web of Science® Times Cited:3
Deposited By:Mathematics and Physics
Deposited On:2016-01-20
Last Modified:2017-11-03
Downloads:344 View Download Statistics

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