A mapping study of massive cores with (CO)-C-13 J=1-0 line

作者：Esimbek Jarken^*; Wu Yuefang; Wang Yang

来源：New Astronomy, 2008, 13(3): 144-156.

DOI：10.1016/j.newast.2007.08.002

• Stars : formation
• ISM : clouds
• ISM : structure
• ISM : kinematics and dynamics

Using 13.7 m telescope of Qinghai station of Purple Mountain Observatory (PMO) at Delingha, 27 sources were observed with (CO)-C-12 J = 1-0 and mapped with (CO)-C-13 J = 1-0 lines. Midcourse Space Experiment (MSX) images and IRAS point source catalogue (PSC) were used to identify stellar objects embedded in the detected cores. Forty-one (CO)-C-13 cores were obtained. The sizes of these cores is from 0.4 pc to 7 pc. Their average excitation temperatures and masses are 23.4 K and 3.1 x 10(4)M(circle dot), which shows that these cores are massive and relatively cold. The line widths are much wider than those of low-mass cores. The correlation between line widths and core sizes is weak. According to the radio, IRAS and MSX data, there are three kinds of cores in the entire sample: group A has 21 cores whose T-ex and Delta V are 15.5 K and 3.2 km/s on the average. The cores in group A are not associated with infrared sources. Group B contains 17 cores, of which five are associated with IRAS sources, the remaining 12 are associated with MSX sources. All the 17 cores are not associated with UC HII regions. Group C contains three cores which are associated with UC HII regions. All these physical parameters indicate that there could be an evolutionary development from group A to group C. The bolometric luminosities of groups B and C are also investigated. The reason for the displacement of the cores and the infrared sources in group A was discussed.

• 出版日期2008-4
• 单位北京大学