T. Onaka 1 - M. Mizutani 1 - H. Shibai 2
1 Department of Astronomy, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan -
The Carina region (
and 
)on the Galactic Plane of about 20' x 40' has been observed with LWS01, SWS02, and
PHT-S with an interval of 3'.
Several emission lines, such as [OI]63, 146
m, [OIII]52
and 88 m, [NIII]57m, [NII]122m, and [CII]158 m
have been detected in the LWS spectra of most positions observed,
while the PHT-S observations have shown the unidentified emission bands (UEBs;
6.2, 7.7, 8.6, and 11.2 m)
as well as ionic lines, such as [ArIII]8.99m and [SIV]10.5m.
The SWS observations detected [SiII]35m at most positions and
H2 of 9.66m (J=5-3) at several positions.
The emission lines from the ionized gas are peaked in
the east part of the Carina region, but they also show an extended
spatial distribution over the entire observed area.
The observed ratio of the [OIII]52m to 88m is relatively low
(in the range of 0.5 -1.0) and fairly uniform. The ratio of [NIII]57m to
[OIII]52m also stays in a narrow range (0.3-0.5).
These results indicate the
presence of extended ionized gas of low electron
density of 200 - 300 cm-3 around the Carina region.
The far infrared continuum in the LWS spectra can be fitted fairly
well with blackbodies with constant emissivity. From this fit
we have derived the dust optical depth at 100 m, the dust temperature,
and the total far-infrared intensity.
The lines of [OI]63m and [CII]158m, and the UEBs
are peaked around the peak of the far-infrared intensity, which coincides
with the photodissociation region, the interface
between the ionized region (east) and the molecular region (west).
In addition to this peak,
[CII]158m and the UEBs show a very extended spatial
distribution, indicating that they originate also from various stages
of the interstellar medium (Onaka et al. 1996, Shibai et al. 1996).
Postscript version