The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud


Atacama Large Millimeter/submillimeter Array

We report the first extragalactic detection of the complex organic molecules (COMs) dimethyl ether (CH3OCH3) and methyl formate (CH3OCHO) with the Atacama Large Millimeter/submillimeter Array (ALMA).

These COMs together with their parent species methanol (CH3OH), were detected toward two 1.3 mm continuum sources in the N 113 star-forming region in the low-metallicity Large Magellanic Cloud (LMC). Rotational temperatures (Trot∼130 K) and total column densities (Nrot∼1016 cm−2) have been calculated for each source based on multiple transitions of CH3OH. We present the ALMA molecular emission maps for COMs and measured abundances for all detected species.

The physical and chemical properties of two sources with COMs detection, and the association with H2O and OH maser emission indicate that they are hot cores. The fractional abundances of COMs scaled by a factor of 2.5 to account for the lower metallicity in the LMC are comparable to those found at the lower end of the range in Galactic hot cores. Our results have important implications for studies of organic chemistry at higher redshift.

Marta Sewilo, Remy Indebetouw, Steven B. Charnley, Sarolta Zahorecz, Joana M. Oliveira, Jacco Th. van Loon, Jacob L. Ward, C.-H. Rosie Chen, Jennifer Wiseman, Yasuo Fukui, Akiko Kawamura, Margaret Meixner, Toshikazu Onishi, Peter Schilke
(Submitted on 31 Jan 2018)

Comments: 10 pages, 4 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Journal reference: 2018, ApJ Letters, 853, 2
DOI: 10.3847/2041-8213/aaa079
Cite as: arXiv:1801.10275 [astro-ph.GA] (or arXiv:1801.10275v1 [astro-ph.GA] for this version)
Submission history
From: Marta Sewiło
[v1] Wed, 31 Jan 2018 02:04:51 GMT (775kb,D)

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