Study of the filamentary infrared dark cloud G192.76+00.10 in the S254-S258 OB complex

TL;DR

This study provides a detailed high-resolution analysis of the filamentary infrared dark cloud G192.76+00.10, revealing its structure, temperature, kinematics, and signs of gravitational instability and possible collapse within the S254-S258 OB complex.

Contribution

It offers new insights into the physical conditions, fragmentation, and dynamics of the filamentary cloud using multiple molecular tracers and high-resolution observations.

Findings

Gas temperature ranges from 10 to 35 K.

Dense clumps have masses between 30 and 160 solar masses.

Evidence suggests longitudinal collapse of the filament.

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 (NH$_3$), 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 NH$_3 $ $(J,K) = (1,1), (2,2)$ and $^{12}$CO(2--1) lines and the $^{13}$CO(1--0), $^{13}$CO(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 $N(\mathrm{H}_2)$ reaches the value 5.1 10$^{22}$ cm$^{-2}$. The width of the filament is of order 1 pc. The masses of the dense clumps range from $ \sim 30 $ M$_\odot$ to $ \sim 160 $ M$_\odot$. They appear to be gravitationally unstable. The molecular emission shows a gas dynamical coherence along the filament. The velocity pattern may indicate longitudinal collapse.