DENSE CORES IN DARK CLOUDS .10. AMMONIA EMISSION IN THE PERSEUS MOLECULAR CLOUD COMPLEX

We present a survey for dense material around young IRAS sources in th e Perseus molecular cloud complex in the NH3 (J, K) = (1, 1) line at 1 .3 cm. NH3 emission was detected in eight, and mapped in seven, out of 10 positions chosen for study. The dense cores found typically have l ower masses and narrower line widths than cores previously studied in Perseus and are located near sources of lower luminosity. NH3 cores ar e found throughout the Perseus complex; however, much of the detected dense gas is concentrated into two filamentary '' ridges '' located in the western part. As a group, NH3 cores in Perseus have a mean line w idth of 0.6 km s-1, mean radius of 0.12 pc, mean kinetic temperature o f 13 K, and mean mass of 9 M.. These mean values are larger than the m ean values for NH, cores with associated stars in Taurus, but smaller than the mean values for cores associated with stars in Orion A. Some of the cores in Perseus are ''thermally dominated,'' with thermal and nonthermal line widths similar to most Taurus cores, while others are ''nonthermally dominated'' and are more similar to the cores in Orion A. We conclude that the Perseus complex is intermediate in its star-fo rming potential between the predominantly low-mass star-producing regi ons like Taurus and the regions capable of the producing high-mass sta rs such as Orion A.