Galactic Aberration in VLBI Analysis:

D. S. Macmillan , A. L. Fey , J. M. Gipson , David Gordon , Christopher S. Jacobs , H. Krásná , Sébastien Lambert (1) , Chopo Ma , Z. Malkin , O. A. Titov , Guangli Wang , Minghui Xu , Norbert Zacharias

1 Observatoire de Paris

The IVS Working Group on Galactic Aberration (WG8) was established to investigate issues related to incorporating the effect of galactic aberration in IVS analysis. Secular aberration drift is caused by the acceleration of the Solar System barycenter. It is mainly due to the rotation of the barycenter about the center of the Milky Way galaxy. Studies made by working group members have shown that aberration can be estimated from VLBI geodetic data. The VLBI estimates of the aberration amplitude are in the range 5.1 to 6.4 ?as/yr. These estimates are close to independent estimates of 4.8 to 5.4 ?as/yr that were derived from astrometric measurements of proper motions and parallaxes of masers in the Milky Way galaxy. For the recommended aberration constant, a geodetic value 5.8 ?as/yr based on data until May 2018 was chosen by the Working Group in order to be consistent with geodetic VLBI applications, specifically for the generation of the ICRF3 solution. In this paper, we discuss the investigation of the Working Group and its findings.

Domaines: Astrophysique [astro-ph]

D. S. Macmillan, A. L. Fey, J. M. Gipson, David Gordon, Christopher S. Jacobs, et al.. Galactic Aberration in VLBI Analysis:. International VLBI Service for Geodesy and Astrometry 2018 General Meeting Proceedings: "Global Geodesy and the Role of VGOS - Fundamental to Sustainable Development, Jun 2018, Longyearbyen, Norway, Norway. pp.163. ⟨hal-03804304⟩