1 / 15

Satoshi Yamamoto and Nobuyuki Kuboi Department of Physics

Submillimeter-wave CI Line Survey in Molecular Clouds. Satoshi Yamamoto and Nobuyuki Kuboi Department of Physics The University of Tokyo. Why Atomic Carbon?. The fourth abundant element after H, He, and O Two fine structure lines at submm band

helenparsons
Download Presentation

Satoshi Yamamoto and Nobuyuki Kuboi Department of Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Submillimeter-wave CI Line Survey in Molecular Clouds Satoshi Yamamoto and Nobuyuki Kuboi Department of Physics The University of Tokyo

  2. Why Atomic Carbon? • The fourth abundant element after H, He, and O • Two fine structure lines at submm band 3P1-3P0 492 GHz, 3P2-3P1 809 GHz • Low ionization potential HII region PDR MC C+ C CO Tracer of an interface between PDR and MC →Formation and Evolution of Molecular Clouds

  3. [CI] Observations with Mt. Fuji Submillimeter-wave Telescope • [CI] 3P1-3P0 (492 GHz) Large-scale Mapping (> 50 deg2) GMC: Orion A, Orion B, M17, W51, DR15, DR21, W3, W44 etc. Dark Cloud: Taurus, NGC1333, rho Oph, L134 , Bright Rimmed Clouds, etc. Translucent Cloud: G216-2.5, MBM12, Draco • [CI] 3P2-3P1 (809 GHz) Mapping toward representative sources Orion A, Orion B, DR21, NGC1333 etc.

  4. Taurus Dark Cloud • Distance ～140 pc • Active formation site of low-mass stars (Extensive studies with molecular lines) • No OB stars associated • No SNR associated 　　　　　　　　　　　↓ Spontaneous formation and evolution of molecular clouds

  5. Dense Cores CI rich cloud CI/13CO(1-0) Integrated Intensity Ratio CI Integrated Intensity Translucent Cloud

  6. TMC-1 Hirahara et al. 1992 Late Early

  7. CI Rich Cloud in HCL2 • High C/CO ratio > 0.8 Av > 6 H2 density ～ 5 x 103 cm-3 No enhancement in IRAS color Early stage of chemical evolution? • Interface between translucent part and dense part • Consistent with chemical evolution scheme in the TMC-1 ridge →Formation site of molecular cloud cores

  8. CI Peak Av=6, C/CO=0.6 CI/C18O(1-0) Integrated Intensity Ratio CI/13CO(1-0) Integrated Intensity Ratio CI Integrated Intensity

  9. CI Peak of L1495 Early Stage of Chemical Evolution?

  10. CI/13CO(1-0) Integrated Intensity Ratio No translucent part Is associated. CI/C18O(1-0) Integrated Intensity Ratio Relatively low C/CO ratio (0.2)

  11. B18 is more evolved than HCL2 and L1495 ? A lack of translucent part in B18

  12. Summary • CI/13CO(1-0) intensity ratio is a good indicator of a translucent part of a molecular cloud. • HCL2 and L1495 regions contain an interface between a translucent part and a dense part. >>> Formation site of molecular cloud cores? • B18 does not contain a clear interface. >>> More evolved than HCL2 and L1495 • CI line >>>Unique probe of cloud core formation and evolution

  13. Diffuse part is not Associated.

More Related