New detected CO (1-0) emission from planetary nebulae

作     者：孙锦 孙艳春 

作者机构：Department of Astronomy Beijing Normal University Beijing China 

出 版 物：《Science China Mathematics》 (中国科学：数学（英文版）)

年 卷 期：2000年第43卷第2期

页      面：217-224页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 0701[理学-数学] 

基　　金：We would like to thank the operators and staff of the 13.7m telescope of Purple Mountain Observatory at the Qinghai Station for their support.This work was supported by the National Natural Science Foundation of China(Grant No.19873003)and United Laborat 

主　　题：planetary nebulae CO emission molecular envelope stellar evolution. 

摘      要：We report the results of CO(1-0 (J = 1 -0) observations for 20 selected planetary nebulae (PNe), using the 13.7 m radio telescope of Purple Mountain Observatory at the Qinghai Station. Due to weak CO(1-0) emission, long integrated time observations have been carried out for most of sampled PNe. Among these PNe, nine are first detections in CO(1-0) named NGC6445, M1-59, M4-9, M2-51, M4-18, He2-459, Sh2-71, K3-31, M2-52, and one is the first possible detection named V-V1-8, a probably misclassified PN. NGC6445, Ml-59, M4-9 and M2-51 have been detected in CO(2-1) (J = 2-1). Although having been observed in previous CO surveys, Sh2-71 and M4-18 were not detected in CO; M2-52, K3-31, He2-459 are the first detected PNe in CO emission and V-V1-8 is given with a first completed spectrum detected in CO(1-0). Comparing these data with other previous observational ones, we discuss the relationships between CO(1-0) emission and evolution of PNe: While the nebular radii increase, the CO(1-0) line integrated