Sulphur-Bearing and Complex Organic Molecules in an Infrared Cold Core

Bibliographic Details
Title: Sulphur-Bearing and Complex Organic Molecules in an Infrared Cold Core
Authors: Beaklini, Pedro P. B., Mendoza, Edgar, Canelo, Carla M., Aleman, Isabel, Merello, Manuel, Kong, Shuo, Navarete, Felipe, Janot-Pacheco, Eduardo, Abraham, Zulema, Lépine, Jacques R. D., de Almeida, Amaury A., Friaça, Amâncio C. S.
Publication Year: 2019
Collection: Astrophysics
Subject Terms: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
More Details: Since the start of ALMA observatory operation, new and important chemistry of infrared cold core was revealed. Molecular transitions at millimeter range are being used to identify and to characterize these sources. We have investigated the 231 GHz ALMA archive observations of the infrared dark cloud region C9, focusing on the brighter source that we called as IRDC-C9 Main. We report the existence of two sub-structures on the continuum map of this source: a compact bright spot with high chemistry diversity that we labelled as core, and a weaker and extended one, that we labelled as tail. In the core, we have identified lines of the molecules OCS(19-18), $^{13}$CS(5-4) and CH$_{3}$CH$_{2}$CN, several lines of CH$_{3}$CHO and the k-ladder emission of $^{13}$CH$_{3}$CN.We report two different temperature regions: while the rotation diagram of CH$_{3}$CHO indicates a temperature of 25 K, the rotation diagram of $^{13}$CH$_{3}$CN indicates a warmer phase at temperature of $\sim450$K. In the tail, only the OCS(19-18) and $^{13}$CS(5-4) lines were detected. We used the $Nautilus$ and the \textsc{Radex} codes to estimate the column densities and the abundances. The existence of hot gas in the core of IRDC-C9 Main suggests the presence of a protostar, which is not present in the tail.
Comment: 13 pages, 11 figures. Accept in MNRAS
Document Type: Working Paper
DOI: 10.1093/mnras/stz3024
Access URL: http://arxiv.org/abs/1910.10805
Accession Number: edsarx.1910.10805
Database: arXiv
More Details
DOI:10.1093/mnras/stz3024