摘要
利用紫金山天文台青海站的 １３．７ ｍ毫米波望远镜，对 Ｏｒｉｏｎ Ａ分子云中的 ＯＭＣ－３区域，进行了较高分辨率的１３ＣＯ（Ｊ＝１－０）和Ｃ１８Ｏ（Ｊ＝１－０）分子辐射的成图观测．给出了该分子云中１３ＣＯ和 Ｃ１８Ｏ云核分布的整体结构和平均物理参数．观测发现，该分子云的１３ＣＯ和 Ｃ１８Ｏ的云核中心分别与最年轻的天体－Ｃｌａｓｓ ０类源 ＭＭＳＩ， ＭＭＳ４，ＭＭＳ６和ＭＭＳ７，ＭＭＳ８；ＭＭＳ９成协．此外，通过分析ＯＭＣ－３整个区域的速度场结构，发现沿 Ｃ１８Ｏ和１３ＣＯ云核方向从南到北有一个～ １．７ｋｍ／ｓ的速度场梯度，而分子云的红、蓝移团块则分别趋于云的北部和南部．并对ＯＭＣ－３区的恒星形成特征进行了讨论．
CO (J = 1 - 0) and C18O (J = 1 - 0) emissions of the OMC-3 in the Orion A molecular cloud were mapped with the 13.7 m millimeter wave telescope of Purple Mountain Observatory using a higher spatial resolution. The overall structure of the cloud and the average physical parameters of all the 13CO (J = 1 - 0) and C18O (J = 1 - 0) cores are derived. We find that the cores are well associated with the youngest objects - class 0 sources: MMS1, MMS4, MMS6 with the 13CO core centers and MMS7, MMSS, MMS9 with the C18O core centers. The velocity structure is also analyzed for the whole OMC-3 region. There is a ~ 1.7 km/s velocity gradient from south to north connecting the 13CO (J = 1 - 0) and C18O (J = 1 - 0) cores. And the redshifted clumps are consistently to the north, and the blushifted clumps, to the south of OMC-3. Star formation in the region is also discussed.
基金
国家自然科学基金
中国科学院射电天文联合实验室资助
