CO(J=1-0) Observations of a Filamentary Molecular Cloud in the Galactic Region Centered at l=150 degrees, b=3 degrees.5

2017 
We present large-field (4.25 x 3.75 deg(2)) mapping observations toward the Galactic region centered at l = 150 degrees, b = 3 degrees.5 in the J = 1-0 emission line of CO isotopologues ((CO)-C-12, (CO)-C-13, and (CO)-O-18), using the 13.7 m millimeter-wavelength telescope of the Purple Mountain Observatory. Based on the (CO)-C-13 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 (CO)-O-18 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 similar to 9.28 K, 0.85 km s(-1), 7.30 pc, 0.79 pc, and 17.92 M-circle dot pc(-1), respectively, assuming a distance of 400 pc. We find that the four filaments detected in the (CO)-O-18 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 (CO)-C-13 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 candidates are also identified in the supercritical filaments, based on the complementary infrared data. These results indicate that the supercritical filaments, especially the virialized filaments, may contain star-forming activities.
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