Molecular Spectral Lines In Filamentary Infrared Dark Clouds

Lu, Xing

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https://hdl.handle.net/2142/50877 Copy

Description

Title

Molecular Spectral Lines In Filamentary Infrared Dark Clouds

Author(s)

Lu, Xing

Contributor(s)

• Liu, Hauyu Baobab
• Zhang, Qizhou

Issue Date

2014-06-17

Keyword(s)

Mini-symposium: Astronomical Molecular Spectroscopy in the Age of ALMA

Abstract

Many infrared dark clouds (IRDCs) in our Galaxy have filamentary structures, and some of them present converging filaments to a central hub, known as hub-filament systems (HFSs). These filaments could play a crucial role in feeding gas to the star forming regions at the hub. We analyzed NH$_3$ (J,K)=(1,1) and (2,2) spectral lines data obtained with the Very Large Array (VLA) towards five filamentary IRDCs, and derived the gas temperature based on the line ratios. Furthermore, with the Submillimeter Array (SMA) in the compact and sub-compact configurations, we obtained dust emission and spectra lines at 1.3 mm towards these sources. We found filamentary structures in both dust continuum and spectral line emission, with a characteristic width of 0.1 pc and length of 1 pc. The dust emission is consistent with the infrared extinction features, indicating the existence of dense and cold gas, while massive dust cores are usually associated with the hubs. Complex organic molecules including CH$_3$OH are found towards the dust cores. In particular, optically-thin intermediate density gas tracers, such as C$^{18}$O, reveal a possible trend of gas infall along filaments towards hubs. This is consistent with the scenario that dense gas is accreted onto dense cores through filaments and form high-mass star clusters.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/50877

DOI

https://doi.org/10.15278/isms.2014.TF11

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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