First clear detection of the CCS Zeeman splitting toward the pre-stellar
  core, Taurus Molecular Cloud-1
  We report a first clear detection of the Zeeman splitting of a CCS emission
line at 45 GHz toward a nearby prestellar dense filament, Taurus Molecular
Cloud-1. We observed HC$_3$N non-Zeeman line simultaneously as the CCS line,
and did not detect any significant splitting of HC$_3$N line. Thus, we conclude
that our detection of the CCS Zeeman splitting is robust. The derived
\textcolor{black}{line-of-sight} magnetic field strength is about 117 $\pm$ 21
$\mu$G, which corresponds to the normalized mass-to-magnetic flux ratio of 2.2
if we adopt the inclination angle of 45$^\circ$. Thus, we conclude that the
TMC-1 filament is magnetically supercritical. Recent radiative transfer
calculations of CCS and HC$_3$N lines along the line of sight suggest that the
filament is collapsing with a speed of $\sim$ 0.6 km s$^{-1}$, which is
comparable to three times the isothermal sound speed. This infall velocity
appears to be consistent with the evolution of a gravitationally-infalling
core.
