A FAST Survey of HINSA in PGCCs Guided by HC3N
  Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we
search for HI narrow-line self-absorption (HINSA) features in twelve Planck
Galactic cold clumps (PGCCs), one starless core L1521B and four star forming
sources. Eight of the 12 PGCCs have emission of J=2-1 of cyanoacetylene (HC3N).
With an improved HINSA extraction method more robust for weaker and blended
features with high velocity resolution, the detection rates of HINSA in PGCCCs
are high, at 92% overall (11/12) and 87% (7/8) among sources with HC3N J=2-1
emissions. Combining the data of molecular spectra and Planck continuum maps,
we studied the morphologies, abundances and excitations of HI, CO and HC3N in
PGCCs. The distribution of HINSA is similar to that of CO emission. HINSA tends
to be not detected in regions associated with warm dust and background ionizing
radiation, as well as regions associated with stellar objects. The abundances
of HI in PGCCs are approximately 3E-4, and vary within a factor of ~3. The
non-thermal velocity dispersions traced by C18O J=1-0 and HINSA are consistent
with each other (0.1-0.4 km/s), larger than those of HC3N (~0.1 km/s). Carbon
chain molecule abundant PGCCs provide a good sample to study HINSA.
