TWO MOLECULAR CLOUDS WITH ANOMALOUS VELOCITIES IN THE GALACTIC ANTICENTER

Abstract

We map two molecular clouds located in the exact anticenter region emitting in the (J = 1-0) transition of 12 CO and 13 CO using the 3-mm SIS mixer receiver on the 14-m radio telescope at Taeduk Radio Astronomy Observatory. The target clouds with anomalous velocities of V LSR ~ -20 km s -1 are distinguished from other clouds in this direction. In addition, they are located in the interarm region between the Orion Arm and the Perseus Arm. Sizes of the clouds are estimated to be about 8.6 and 10.8 pc, respectively. The total mass is estimated to be about 4 x 10³ M ⊙ using CO luminosity of the clouds. Several cores are detected, but no sign of star formation is found according to the IRAS point sources. Their larger linewidths, anomalous velocities, and their location at the interarm region make these clouds more distinguished, though their physical properties are similar to the dark clouds in the solar neighborhood in terms of mass and size.