Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-17T15:09:42.715Z Has data issue: false hasContentIssue false

Models for Source Structure Corrections

Published online by Cambridge University Press:  12 April 2016

P. Charlot*
Affiliation:
Observatoire de Bordeaux - CNRS/UMR 5804, 2 rue de l’Observatoire, BP 89, 33270 Floirac, France

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

At the milliarcsecond scale, most of the extragalactic radio sources exhibit spatially-extended intrinsic structures which are variable in both time and frequency. Such radio structures set limits on the accuracy of source positions determined with the Very Long Baseline Interferometry (VLBI) technique unless their effects in the astrometric data can be accounted for. We review the modeling scheme for calculating source structure corrections and discuss the magnitude and impact of these effects for the sources that are part of the International Celestial Reference Frame (ICRF). Results obtained by applying source structure corrections to actual VLBI observations on the time-varying source 4C39.25 (0923 + 392) are also presented.

Type
Section 1. Celestial Reference System and Frame
Copyright
Copyright © US Naval Observatory 2000

References

Alberdi, A., Marcaide, J.M., Marscher, A.P., Zhang, Y.F., Elósegui, P., Gómez, J.L., Shaffer, D.B., 1993, Astrophys. J., 402, 160.Google Scholar
Charlot, P., 1990, Astron. J., 99, 1309.Google Scholar
Charlot, P., 1994, in VLBI Technology: Progress and Future Observational Possibilities, eds. Sasao, T, Manabe, S, Kameya, O., & Inoue, M, Tokyo: Terra Scientific Publishing Company, 287.Google Scholar
Charlot, P. & Sovers, O.J., 2000 (in preparation).Google Scholar
Eubanks, T.M., 1997, 23rd Meeting of the IAU, Joint Discussion 7.Google Scholar
Fey, A.L. & Charlot, P., 1997, Astrophys. J. Sup., 111, 95.Google Scholar
Fey, A.L. & Charlot, P., 2000, Astrophys. J. Sup., (in press).Google Scholar
Fey, A.L., Eubanks, T.M., & Kingham, K. A., 1997, Astron. J., 114, 2284.Google Scholar
Guirado, J.C., Marcaide, J.M., Alberdi, A., Elósegui, P., Ratner, M.I., Shapiro, I.I., Kilger, R., Mantovani, F., Venturi, T., Rius, A., Ros, E., Trigilio, C., Whitney, A.R., 1995, Astron. J. 110, 2586.Google Scholar
Ma, C., Arias, E.F., Eubanks, T.M., Fey, A.L., Gontier, A.-M., Jacobs, C.S., Sovers, O.J., Archinal, B.A., Charlot, P., 1998, Astron. J., 116, 516.Google Scholar
Shaffer, D.B., Marscher, A.P., Marcaide, J., Romney, J.D., 1987, Astrophys. J., 314, LI.Google Scholar
Sovers, O.J., & Jacobs, C.S., 1996, Observation Model and Parameter Partials for the JPL VLBI parameter Estimation Software “MODEST”, Jet Propulsion laboratory Publ. 83-89, Rev. 6, Pasadena, CA.Google Scholar