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A STUDY OF MOLECULAR CLOUD ASSOCIATED WITH THE H II REGION Sh 156

  • KANG MEEJOO (Department of Astronomy & Space Science, Chungnam National University) ;
  • LEE YOUNGUNG (Korea Astronomy and Space Science Institute, Taeduk Radio Astronomy Observatory)
  • Published : 2005.06.01

Abstract

We have conducted observations toward the molecular cloud associated with the H II region Sh 156 in $^{13}CO$(J = 1-0), $C^{18}O$(J = 1-0), and CS(J = 2 -1) using the TRAO 14 m telescope. Combining with existing $^{12}CO$(J = 1- 0) data of the Outer Galaxy Survey, we delineated the physical properties of the cloud. We found that there is a significant sign of interaction between the H II region and the molecular gas. We estimated the masses of the molecular cloud, using three different techniques; the most plausible mass is estimated to be $1.37 {\times} 10^5 M_{\bigodot}$, using a conversion factor of $X = 1.9 {\times} 10^{20}\;cm^{-2} (K\;km\;s^{-1})^{-1}$, and this is similar to virial mass estimate. This implies that the cloud is gravitationally bound and in virial equilibrium even though it is closely associated with the H II region. In addition to existing outflow, we found several MSX and IRAS point sources associated with dense core regions. Thus, more star forming activities other than the existing H II region are also going on in this region.

Keywords

H II region;ISM: molecular lines;ISM: individual objects;Sh 156

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