Implications of the Galactic aberration for CRF Virtual Observatory Resource

Authors
  1. Malkin Z.
  2. Published by
    CDS
Abstract

During the last few years, much attention has been paid to the astrometric implications of the galactic aberration in proper motions (GA). This effect causes systematic errors in astrometric measurements at a {mu}as level. Some authors consider it so serious that it requires redefinition of the Celestial Reference Frame (CRF). We argue that such attention to the GA is exaggerated too much. It is just a small astrometric correction that must be taken into account during highly accurate astrometric and geodetic data processing. The accuracy of this correction depends on the accuracy of the Galactic rotation parameters and, for most applications, on the accuracy of the rotation matrix between Galactic and equatorial systems. Our analysis has shown that our current knowledge of these two factors is sufficient to compute the correction of the GA with an accuracy better than 10 per cent. The remaining effect at the level of a few tenths {mu}as/yr is negligible nowadays. Another consequence of introducing the GA correction is the necessity to return to classical astrometric modelling of the extragalactic radio source position - derived by very-long-baseline interferometry (VLBI) - by the linear trend model. Changing the current paradigm of the VLBI-derived CRF, based on the assumption of zero motion of radio sources, to classical one leads to bias in the radio source positions of up to several tens of {mu}as for a catalogue at epoch J2000.0.

Keywords
  1. Interferometry
  2. Very long baseline interferometry
  3. Astrometry
Bibliographic source Bibcode
2014MNRAS.445..845M
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/445/845
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/445/845

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/445/845
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/445/845
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/445/845
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/445/845/icrf2a?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/445/845/icrf2a?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/445/845/icrf2a?

History

2016-06-07T10:21:03Z
Resource record created
2016-06-07T09:29:30Z
Updated
2016-06-07T10:21:03Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr