PoS - Proceedings of Science
Volume 399 - European VLBI Network Mini-Symposium and Users' Meeting 2021 (EVN2021) - VLBI Techniques and Arrays
The impact of new estimates of models of stellar motion from VLBI on the alignment of the optically bright Gaia frame to ICRF3
S. Lunz*, J. Anderson, M. Xu, R. Heinkelmann, O. Titov, J.F. Lestrade, M.C. Johnson, F. Shu, W. Chen, A. Melnikov, J. McCallum, Y. Lopez, A. Mikhailov, P. de Vicente Abad and H. Schuh
Full text: pdf
Pre-published on: March 10, 2022
Published on: May 24, 2022
Abstract
The reference frame determined by Gaia EDR3, Gaia-CRF3, is aligned to the International Celestial Reference System by referring to counterparts in its latest realization, the third International Celestial Reference Frame (ICRF3), which is calculated from very long baseline interferometry (VLBI) observations of extragalactic objects at radio frequencies.
The objects in ICRF3, although bright at radio frequencies, are mostly faint at optical frequencies.
The non-rotation of the optically bright Gaia frame to ICRF3 has to be tested separately because the Gaia dataset is known to be magnitude-dependent in terms of astrometric calibration. This can be done by identifying additional counterparts besides objects in ICRF3.
Suitable counterparts are radio stars observed by VLBI relative to extragalactic objects in ICRF3 using phase-referencing.
We discuss the rotational differences, i.e., orientation and spin, between the optically bright Gaia EDR3 and models of stellar motion from VLBI. In particular, we show the effects of improved models of stellar motion, for which we extended the time series from literature or archives with new VLBI results.
DOI: https://doi.org/10.22323/1.399.0032
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.