heiles meeting, sep 04 where is the atomic carbon in ophiuchus di li paul goldsmith gary melnick and...
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Heiles meeting, Sep 04
Where is the Atomic Carbon in Ophiuchus
Di Li
Paul Goldsmith
Gary Melnick
and SWAS team
Heiles meeting, Sep 04
Heiles meeting, Sep 04
JCMT 850 Micron
Heiles meeting, Sep 04
Telescopes
Heiles meeting, Sep 04
Mapping Parameters
FCRAO• 44” resolution at 2.6mm
• Beam sampling
SWAS• 4.2’ resolution at 0.6mm
• Nyquist Sampling
Line RMS V t_int Spectra
CO 2.5K 0.4 km/ s 15s 28840
13CO 0.7 0.1 30 26384
C18O 0.5 0.1 60 7631
CI 0.3 0.6 80 1271
Heiles meeting, Sep 04
CO Raw Data
Heiles meeting, Sep 04
Temperature Structure
Heiles meeting, Sep 04
Dust Radiative Transfer
Heiles meeting, Sep 04
UV, Opacity, and Temperature
Schematic Model of Orion
Heiles meeting, Sep 04
Column Density
• Optically Thin Tracer• CI and C18O 1-0
• Modest Optical Depth• 13CO
uTkE
utotal gZeNN Bu /)]/([ Tx and LTE will give thecorrection factor, Z.
dVTAhc
kN R
ul
Bu 3
28
hTk
e
e
RBTk
h
Tk
h
xB
xB
)1/(1
)1/(1ln
)1(
1ln
163
02
3
xBTkh
ul
u
eA
VN
Heiles meeting, Sep 04
Heiles meeting, Sep 04
Opacity Effects
Heiles meeting, Sep 04
The “Norm” of CI and CO in Ophiuchus
Heiles meeting, Sep 04
13CO Column Density
Heiles meeting, Sep 04
Cloud Structures: the Rho Oph Clouds
Heiles meeting, Sep 04
Turbulence
Heiles meeting, Sep 04
Opacity Correction
2ln
})]1/(2ln[
ln{0
0
e
Heiles meeting, Sep 04
Clump and Inter-Clump Structure
Heiles meeting, Sep 04
3D Model Fit
Model; Vmic=0.2 km/s; f_b = 0.35
n(H2)
Cm-3
[CI]/
[H2]
[13CO]/
[H2]
VmacKm/s
Clump 4x104 1x10-6 2x10-6 0.72
Inter-clump
2x103 10-4 10-6 1.5
Clump 5x103 0.57
Inter-clump
1.5x103
r = 0.5 pc
off
se
t
Heiles meeting, Sep 04
Fit to the Center Position
Heiles meeting, Sep 04
Fitting Results to the Center Position
Heiles meeting, Sep 04
The Fit to the Offset Position
Heiles meeting, Sep 04
CI and HI in Dark Clouds
Across One Cloud From Cloud to Cloud
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.