- Proper Motion of Components in 4C39.25 ,
J. C. Guirado, J. M. Marcaide, A. Alberdi, P. Elósegui,
M. I. Ratner, I. I. Shapiro, R. Kilger, F. Mantovani, A. Rius,
E. Ros, C. Trigilio, T. Venturi, & A. R. Whitney,
Astronomical Journal, 110:2586-2596 (1995)
- Abstract
From a series of simultaneous 8.4 and 2.3 GHz VLBI observations of the
quasar 4C 39.25 phase referenced to the radio source 0920 + 390, carried
out in
1990-1992, we have measured the proper motion of component b in 4C
39.25:
mu(alpha) = 90 +/- 43 mu as/yr, mu(delta) = 7 +/- 68 mu as/yr, where the
quoted
uncertainties account for the contribution of the statistical standard
deviation and the errors assumed for the parameters related to the
geometry of
the interferometric array, the atmosphere, and the source structure.
This
proper motion is consistent with earlier interpretations of VLBI hybrid
mapping
results, which showed an internal motion of this component with respect
to
other structural components, Our differential astrometry analyses show
component b to be the one in motion, Our results thus further constrain
models
of this quasar.
Eduardo Ros
ros@mpifr-bonn.mpg.de