Observations of 12CO data and models for the dark cloud L183

Abstract

We present here the first observations of the 12CO J =3-*2 and new J =2-*1 transitions for the dark cloud L183.Theoretical modelling was carried out to fit the observed antenna temperatures and some of the results obtained are included.

Spectroscopic study of ‘CO’ and its isotopic mm/submillimeter lines from dark cloud Lynds 183

“…Similarly from the other observed CO transitions and corresponding models, we could observe a kinetic temperature difference of ∼ 7 K throughout the envelope of the cloud. Our observed and modelled radiation temperature (7.5 K) agrees well with the predicted radiation temperature values for 12 CO(1 ---0) lines, as reported (7.5 K in Vedi et al 1985) in some (mostly southern) part of the cloud. A typical example at offset position (−7, −7) is shown in Fig.…”

“…From the figure it is clear that the radiation temperature values change significantly in the northern part (−7, 7) of the cloud from the predicted value suggesting a steep north to south temperature gradient within the cloud envelope. In case of 12 CO(3 ---2), we could find the radiation temperature almost matches with their predicted value of ∼ 4.1 K (Vedi et al 1985) at the central part (0, 0) and shows (in Fig. 5) the temperature gradient from the north to the central part of the cloud.…”

“…We have compared our results with the observations (Vedi et al 1985) of 12 CO J = 3 ---2 and new J = 1 ---0 transitions for the dark cloud L183. Vedi et al predicted the radiation temperature for the two transitions as T R (3 ---2) = 4.1 K and T R (1 ---0) = 7.5 K, respectively.…”