VizieR Online Data Catalog: VLBA astrometry combined with Gaia DR1 epoch (Darling+, 2018)

We measure proper motions from astrometric time series using VLBA data only and VLBA data combined with a single Gaia epoch.

The VLBA astrometric catalog is described and characterized in detail in Truebenbach & Darling (2017, J/ApJS/233/3). In summary, the catalog contains 713 objects with mean astrometric uncertainties of 24μas/yr. These were obtained from long-term astrometric monitoring programs as well as new observations. The time baselines spanned by the new and archival data cover the range 6.4-27.2 years (1.2x10^-9Hz to 5.0x10^-9Hz).

The first Gaia data release (DR1) catalog (2016, I/337) contains a single-epoch (2015.0) position for 2191 AGN in the International Celestial Reference Frame (ICRF2) catalog. 577 of these are VLBA sources in the Truebenbach & Darling (2017, J/ApJS/233/3) catalog, and we use them to measure proper motions from the VLBA-Gaia time series. Median uncertainties in the Gaia astrometry of these objects are 518μas and 459μas in RA and DEC, respectively.

(2 data files).