Overall properties of the Gaia DR1 reference frame

Abstract

We compare quasar positions of the auxiliary quasar solution with ICRF2 sources using different samples and evaluate the influence on the {\it Gaia} DR1 reference frame owing to the Galactic aberration effect over the J2000.0-J20015.0 period. Then we estimate the global rotation between TGAS with {\it Tycho}-2 proper motion systems to investigate the property of the {\it Gaia} DR1 reference frame. Finally, the Galactic kinematics analysis using the K-M giant proper motions is performed to understand the property of {\it Gaia} DR1 reference frame. The positional comparison between the auxiliary quasar solution and ICRF2 shows negligible orientation and validates the declination bias of $\sim$$-0.1$\mas~in {\it Gaia} quasar positions with respect to ICRF2. Galactic aberration effect is thought to cause an offset $\sim$$0.01$\mas~of the $Z$ axis direction of {\it Gaia} DR1 reference frame. The global rotation between TGAS and {\it Tycho}-2 proper motion systems, obtained by different samples, shows a much smaller value than the claimed value $0.24$\masyr. For the Galactic kinematics analysis of the TGAS K-M giants, we find possible non-zero Galactic rotation components beyond the classical Oort constants: the rigid part ${\omega }_{Y_G}=-0.38\pm 0.15$\masyr~and the differential part ${\omega }_{Y_G}^{\prime }=-0.29\pm 0.19$\masyr~around the $Y_G$ axis of Galactic coordinates, which indicates possible residual rotation in {\it Gaia} DR1 reference frame or problems in the current Galactic kinematical model.

6 pages, 1 figure. Accepted for publication in A&A

References in corpus (6)

• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• Gaia Data Release 1: The reference frame and the optical properties of ICRF sources
• Distance Dependent Offsets between Parallaxes for Nearby Stars and Gaia DR1 Parallaxes
• Connecting VLBI and Gaia celestial reference frames

Cited by in corpus (2)

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