Four New Dense Molecular Cores in the Taurus Molecular Cloud (TMC): Ammonia and Cyanodiacetylene Observations

Abstract

Trying to obtain a more complete picture of star forming regions in the Taurus Molecular Cloud, four newly discovered dense 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 of 0.06-0.09 pc, hydrogen densities of order 10000 - 100000 cm-3 and kinetic temperatures between 8 and 10 K. The masses range from 0.2 - 1.0 solar masses, 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 equilibrium. Moreover we report the detection of the J=9-8 transition of HC5N towards the four ammonia peak positions. The HC5N column densities are in agreement with values derived for other molecular cores in the TMC.