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Paper: High Resolution Survey of Molecular Clouds in and Between the Galactic Spiral Arms
Volume: 317, Milky Way Surveys: The Structure and Evolution of Our Galaxy
Page: 88
Authors: Sugimoto, M.; Koda, J.; Hasegawa, T.; Sawada, T.; Handa, T.; Yamamoto, F.; Naito, S.
Abstract: We are carrying out 13CO J = 1−0 survey observations of Sagittarius arm region (l = 38°) to investigate relations between the dynamics of the Galaxy and the properties of molecular clouds. The survey is on-going, and we have already mapped a 20′ x 30′ (31 x 44 pc at 5 kpc) region. The arm components have clumpy structures. To the contrary, the inter-arm component shows clump-less structure and is distributed broadly. We investigate the correlation between the line width ΔVFWHM and the size R in each region. There are differences in the size-line width relation of clumps among these three components, i.e. the size of clumps in the near arm is smaller than that in the far arm and inter-arm. The majority of clumps is distributed above MVIR/MLTE =1 in all regions. If clumps with MVIR/MLTE > 1 are externally bound. Averages of external pressure for the near arm, far arm, and inter-arm regions are 2.4 x 105, 0.6 x 105, and 1.0 x 105K cm−3, respectively. Clump-mass spectra have the same tendency of a probability density function (pdf) in the observed region. The slope of clump-mass spectrum in the inter-arm region is steeper than that in the arm.
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