A multipole analysis of the apparent motion of reference radio sources

Abstract

In this paper, the apparent motions of quasars, which are the reference sources of the international celestial reference system (ICRS), are analyzed. Kinematic parameters from four catalogs compiled by different research groups are used. Apparent motions are expanded on a special set of vector functions on the sphere that are an irreducible representation of the rotation group O(3). The degree of the noninertiality of the barycentric reference system caused by the rotation of the solar system around the galactic center is estimated according to expansion coefficients. The direction and magnitude of the acceleration vector are calculated and compared with the alternative estimates. This method is discussed as a way to test Newton’s law on a large scale.