Application of Vector Spherical Harmonics for Kinematic Analysis of Stars from Zonal Catalogues

V.V. Vityazev, A.S. Tsvetkov

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Abstract

We solve the problem on a kinematic analysis of the three-dimensional velocity field of stars from zonal catalogues, i.e., catalogues in which the stars are presented at all right ascensions in some declination zones. We have constructed a system of vector spherical harmonics with the properties of completeness and orthogonality for a chosen declination zone. We suggest a method that allows the Ogorodnikov–Milne model parameters in the Galactic coordinate system to be estimated by analyzing the proper motions and radial velocities of stars in the equatorial coordinate system. The vector spherical harmonics are shown to have the following advantages over the standard approach based on a direct leastsquares estimation of the parameters for a specific model. First, in contrast to the standard approach, the new method can reveal all systematic components of the velocity field irrespective of a particular model. Second, it allows one to get rid of the correlation between the sought-for parameters, which presents a
Original languageUndefined
Pages (from-to)874-887
JournalAstronomy Letters
Volume37
Issue number12
DOIs
StatePublished - 2011

Keywords

  • stellar proper motions
  • spherical harmonics
  • astrometry
  • stellar kinematics

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