CO~($J = 1-0$) Observations of a Filamentary Molecular Cloud in the
  Galactic Region Centered at $l = 150\arcdeg, b = 3.5\arcdeg$
  We present large-field (4.25~$\times$~3.75 deg$^2$) mapping observations
toward the Galactic region centered at $l = 150\arcdeg, b = 3.5\arcdeg$ in the
$J = 1-0$ emission line of CO isotopologues ($^{12}$CO, $^{13}$CO, and
C$^{18}$O), using the 13.7 m millimeter-wavelength telescope of the Purple
Mountain Observatory. Based on the $^{13}$CO observations, we reveal a
filamentary cloud in the Local Arm at a velocity range of $-$0.5 to
6.5~km~s$^{-1}$. This molecular cloud contains 1 main filament and 11
sub-filaments, showing the so-called "ridge-nest" structure. The main filament
and three sub-filaments are also detected in the C$^{18}$O line. The velocity
structures of most identified filaments display continuous distribution with
slight velocity gradients. The measured median excitation temperature, line
width, length, width, and linear mass of the filaments are $\sim$9.28~K,
0.85~km~s$^{-1}$, 7.30~pc, 0.79~pc, and 17.92~$M_\sun$~pc$^{-1}$, respectively,
assuming a distance of 400~pc. We find that the four filaments detected in the
C$^{18}$O line are thermally supercritical, and two of them are in the
virialized state, and thus tend to be gravitationally bound. We identify in
total 146 $^{13}$CO clumps in the cloud, about 77$\%$ of the clumps are
distributed along the filaments. About 56$\%$ of the virialized clumps are
found to be associated with the supercritical filaments. Three young stellar
object (YSO) candidates are also identified in the supercritical filaments,
based on the complementary infrared (IR) data. These results indicate that the
supercritical filaments, especially the virialized filaments, may contain
star-forming activities.
