The class of radio sources known as Compact Symmetric Objects (CSOs) is of
particular interest in the study of the evolution of radio galaxies. CSOs are
thought to be young (probably ~10^4 years), and a very high fraction of them
exhibit HI absorption toward the central parsecs. The HI, which is thought to
be part of a circumnuclear torus of accreting gas, can be observed using the
VLBA with high enough angular resolution to map the velocity field of the gas.
This velocity field provides new information on the accretion process in the
central engines of these young sources.
We have identified 9 new CSOs from radio continuum observations for the VLBA
Calibrator Survey, increasing the number of known CSOs by almost 50%.Comment: 5 pages, 2 figures, for "Lifecycles of Radio Galaxies", eds. J.
Biretta et al., New Astronomy Review
