A multi-transition molecular line study of infrared dark cloud G331.71+00.59

TL;DR

This study uses multi-transition molecular line data from the MALT90 survey to analyze the structure, star formation activity, and evolutionary stages of the infrared dark cloud G331.71+00.59, revealing embedded cores and outflow/inflow dynamics.

Contribution

First multi-transition molecular line analysis of IRDC G331.71+00.59, identifying cores, star formation activity, and evolutionary stages using archival data.

Findings

Identified two molecular cores with star formation signatures.

Detected outflow and inflow activities indicating YSO evolution.

Supported the evolutionary sequence from IRDC to hot cores.

Abstract

Using archive data from the Millimeter Astronomy Legacy Team Survey at 90 GHz (MALT90), carried out using the Mopra 22-m telescope, we made the first multi-transition molecular line study of infrared dark cloud (IRDC) MSXDC G331.71+00.59. Two molecular cores were found embedded in this IRDC. Each of these cores is associated with a known extended green object (EGO), indicating places of massive star formation. The HCO+ (1-0) and HNC (1-0) transitions show prominent blue or red asymmetric structures, suggesting outflow and inflow activities of young stellar objects (YSOs). Other detected molecular lines include H13CO+ (1-0), C2H (1-0), HC3N (10-9), HNCO(404-303) and SiO (2-1), which are typical of hot cores and outflows. We regard the two EGOs as evolving from the IRDC to hot cores. Using public GLIMPS data, we investigate the spectral energy distribution of EGO G331.71+0.60. Our results support this EGO being a massive YSO driving the outflow. G331.71+0.58 may be at an earlier evolutionary stage.