4 DENSE MOLECULAR CORES IN THE TAURUS-MOLECULAR-CLOUD (TMC) - AMMONIAAND CYANODIACETYLENE OBSERVATIONS

Trying to obtain a more complete picture of star forming regions in th e 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 10(4) to 19.9 10(4) cm(-3 ) and kinetic temperatures between 7.9 and 9.9 K. The masses range fro m 0.2 and 1.0 M., placing the cores with the lowest M values at the lo wer edge of the mass distribution for ammonia cores in the TMC. Turbul ent, thermal and gravitational energies have been estimated. A compari son between these energy terms and considerations related to thermal a nd turbulent line broadening indicate that these cores are close to gr avitational equilibrium. Moreover, we report detections of the J=9-8 t ransition of HC5N towards the ammonia peak positions of these four mol ecular cores. The HC5N column densities are between 1.6 10(12) and 9.2 10(12) cm(-2), in agreement with values derived for other molecular c ores located in the TMC.