Study of the filamentary infrared dark cloud G192.76+00.10 in the S254-S258 OB complex
Abstract
We present results of a high resolution study of the filamentary infrared dark cloud G192.76+00.10 in the S254-S258 OB complex in several molecular species tracing different physical conditions. These include three isotopologues of carbon monoxide (CO), ammonia (NH3), carbon monosulfide (CS). The aim of this work is to study the general structure and kinematics of the filamentary cloud, its fragmentation and physical parameters. The gas temperature is derived from the NH3 (J,K) = (1,1), (2,2) and 12CO(2--1) lines and the 13CO(1--0), 13CO(2--1) emission is used to investigate the overall gas distribution and kinematics. Several dense clumps are identified from the CS(2--1) data. Values of the gas temperature lie in the ranges 10-35 K, column density N(H2) reaches the value 5.1 1022 cm-2. The width of the filament is of order 1 pc. The masses of the dense clumps range from 30 M to 160 M. They appear to be gravitationally unstable. The molecular emission shows a gas dynamical coherence along the filament. The velocity pattern may indicate longitudinal collapse.