与主序前星成协分子云的CO成图观测

使用美国五大学射电天文台（ＦＣＲＡＯ）的１４ｍ无线和新建立的ＱＵＡＲＲＹ接收系统对中心区ＣＯ（２－１）谱线呈现双峰特征的２个ＰＭＳ星Ｐ１１和Ｖ１５１５Ｃｙｇ进行了ＣＯ（１－０）的谱线成图观测。观测表明，无论是ＰＰ１１还是Ｖ１５１５Ｃｙｇ，其ＣＯ（１－０）谱线都在大范围内表现出双峰谱型。分析ＰＰ１１和Ｖ１５１５Ｃｙｇ红、蓝２个速度峰和峰谷速度上的等强分布可以发现，与主序前星成协且具有ＣＯ双峰谱的分子云中可能存在２种运动：一种是低速的与视线方向成某个角度的大张角的双向运动，它可能是ＰＭＳ星形成前双极外向流阶段的进一步发展（张角变大，速度变小）；另一种是起因于ＰＭＳ星风的向四外发展的膨胀的壳层运动，而在壳层内密度分布是高度团块性的，这种团块可能是新形成的ＰＭＳ星与母分子云相互作用，从而导致分子云碎裂的结果。

CO MAPPING OBSERVATIONS OF MOLECULAR CLOUD AROUND PRE-MAIN-SEQUENCE STARS

With the FCRAO antenna and new installed QUARRY system,A CO mapping and spectral observations have been made for PP11 and V1515 Cyg,both stars are pre-main-sequence(PMS) stars and show the characteristic doube-peak emission profile in the CO J=2-1 transition.The new observations confirm that CO J=1-0 spectra also show the double-peak profile obviously either in PP11 or V1515Cyg and it covers a considerable extents.Analysing the contours of integrated intensities at the red-peak,blue-peak and valley of CO(1-0) spectra for PP11 and V1515 Cyg,it is found that the characteristic double-peak profile may be caused by two molecular clouds,one is the low velocity double-direction motion at a large angle to line of sight,it may be an evolved bipolar outflow formed before PMS stage,another is an expanding shell motion due to the PMS wind.In the expanding shell the density distribution is highly dumped.It may be a fragmentary sequent from the interaction between new formed PMS star and the parent molecular cloud.