Defining Source Selection and Celestial Reference Frame Stability

Cesar Gattano (1, 2) , Sébastien Lambert (1, 2)

1 SYRTE - Systèmes de Référence Temps Espace
2 Systèmes de référence célestes

The celestial reference frames are conceptu- ally materialized by point-like sources with no motion on the sky. But with the accuracy of our observations increasing, to fulfill those conditions becomes more and more difficult. In this study, we first present the danger of taking into account unstable sources in the set of defining sources of a celestial reference frame. Then, based on a previous study where we classified radio sources observed by Very Long Baseline Inter- ferometry with respect to their position stability us- ing a statistical tool called Allan Variance (see “Source Characterization by the Allan Variance”, this volume), we constructed several celestial reference frames by choosing sets of defining sources using the new classi- fication. We studied the stability of the frames in three ways: (1) statistically and temporally, (2) inspired by Lambert [6], and (3) using Earth precession-nutation as a stability indicator, as it was not done before.

Domaines: Astrophysique [astro-ph]

Cesar Gattano, Sébastien Lambert. Defining Source Selection and Celestial Reference Frame Stability. IVS 2016 General Meeting Proceedings, Mar 2016, Johannesburg, South Africa. pp.292. ⟨hal-03743363⟩