1. Heiles meeting, Sep 04 Where is the Atomic Carbon in Ophiuchus Di Li Paul Goldsmith Gary Melnick and SWAS team

2. Heiles meeting, Sep 04

3. JCMT 850 Micron

4. Heiles meeting, Sep 04 Telescopes

5. Heiles meeting, Sep 04 Mapping Parameters FCRAO 44” resolution at 2.6mm Beam sampling SWAS 4.2’ resolution at 0.6mm Nyquist Sampling

6. Heiles meeting, Sep 04 CO Raw Data

7. Heiles meeting, Sep 04 Temperature Structure

8. Heiles meeting, Sep 04 Dust Radiative Transfer

9. Heiles meeting, Sep 04 UV, Opacity, and Temperature Schematic Model of Orion

10. Heiles meeting, Sep 04 Column Density Optically Thin Tracer CI and C18O 1-0 Modest Optical Depth 13CO T x and LTE will give the correction factor, Z.

11. Heiles meeting, Sep 04

12. Opacity Effects

13. Heiles meeting, Sep 04 The “Norm” of CI and CO in Ophiuchus

14. Heiles meeting, Sep 04 13 CO Column Density

15. Heiles meeting, Sep 04 Cloud Structures: the Rho Oph Clouds

16. Heiles meeting, Sep 04 Turbulence

17. Heiles meeting, Sep 04 Opacity Correction

18. Heiles meeting, Sep 04 Clump and Inter-Clump Structure

19. Heiles meeting, Sep 04 3D Model Fit Model; V mic =0.2 km/s; f_b = 0.35 n(H 2 ) Cm -3 [CI]/ [H 2 ] [ 13 CO]/ [H 2 ] V mac Km/s Clump 4x10 4 1x10 -6 2x10 -6 0.72 Inter- clump 2x10 3 10 -4 10 -6 1.5 Clump 5x10 3 0.57 Inter- clump 1.5x10 3 r = 0.5 pc offset

20. Heiles meeting, Sep 04 Fit to the Center Position

21. Heiles meeting, Sep 04 Fitting Results to the Center Position

22. Heiles meeting, Sep 04 The Fit to the Offset Position

23. Heiles meeting, Sep 04 CI and HI in Dark Clouds Across One Cloud From Cloud to Cloud

24. Heiles meeting, Sep 04 Summary Ophiuchus Clouds are low mass star forming clouds in enhanced UV fields. The distribution and abundance of CI cannot be explained by UV field alone. The statistics of CO, CI, and HINSA turbulence suggest different origin of atomic CI and cold atomic hydrogen in molecular clouds. Clump-Interclump structure is a straightforward model to provide good fit to both CO and CI spectra through 3d radiative transfer. GALFA, combined with large scale millimeter surveys, would provide a unprecedented opportunity to study the distribution, kinematics, and correlation between atomic hydrogen and molecules in nearby star forming clouds. Particularly, whether UV is import in regulating HINSA abundance.