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Astron. Astrophys. 324, 203-210 (1997)
Four dense molecular cores in the Taurus Molecular Cloud (TMC)
Ammonia and cyanodiacetylene observations
C. Codella 1,
R. Welser 1,
C. Henkel 1,
P.J. Benson 2 and
P.C. Myers 3
1 Max-Planck-Institut für Radioastronomie, Auf dem
Hügel 69, D-53121 Bonn, Germany
2 Whitin Observatory Wellesley, Wellesley, Massachusetts
02181, USA
3 Harvard-Smithsonian Center for Astrophysics, 60 Garden
Street, Cambridge, MA 02138, USA
Received 12 July 1996 / Accepted 7 January 1997
Abstract
Trying to obtain a more complete picture of star forming regions in
the Taurus molecular cloud, four dense molecular cores (L1521D,
L1521F, L1524, L1507A) are identified and mapped through the ammonia
(J,K) = (1,1) and (2,2) rotational inversion lines. These cores have
sizes from 0.06 to 0.09 pc, hydrogen densities from
0.6 104 to 19.9 104 cm-3
and kinetic temperatures between 7.9 and 9.9 K. The masses range from
0.2 and 1.0 ![[FORMULA]](img1.gif)
, placing the cores with the lowest
M values at the lower edge of the mass distribution for ammonia
cores in the TMC. Turbulent, thermal and gravitational energies have
been estimated. A comparison between these energy terms and
considerations related to thermal and turbulent line broadening
indicate that these cores are close to gravitational equilibrium.
Moreover, we report detections of the J=9-8 transition of
HC5 N towards the ammonia peak positions of these four
molecular cores. The HC5 N column densities are between 1.6
1012 and 9.2 1012 cm-2, in agreement
with values derived for other molecular cores located in the TMC.
Key words: ISM:
clouds 
ISM: molecules
radio lines:
ISM
ISM: individual objects: TMC
Send offprint requests to: C. Henkel
Contents
- 1. Introduction
- 2. Selection criteria
- 3. Observations
- 4. Results
- 5. Discussion
- 6. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 1997
Online publication: May 26, 1998
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