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

Sewiło, Marta; Indebetouw, Remy; Charnley, Steven B.; Zahorecz, Sarolta; Oliveira, Joana M.; Van Loon, Jacco Th.; Ward, Jacob L.; Rosie Chen, C.-H.; Wiseman, Jennifer; Fukui, Yasuo; Kawamura, Akiko; Meixner, Margaret; Onishi, Toshikazu; Schilke, Peter

Abstract

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 (${T}_{\mathrm{rot}}\sim 130$ K) and total column densities (${N}_{\mathrm{rot}}\sim {10}^{16}$ 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.

Citation

Sewiło, M., Indebetouw, R., Charnley, S. B., Zahorecz, S., Oliveira, J. M., Van Loon, J. T., …Schilke, P. (2018). The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud. Astrophysical Journal Letters, 853(2), L19 -?. https://doi.org/10.3847/2041-8213/aaa079

• Journal Article Type: Article
• Acceptance Date: Dec 8, 2017
• Publication Date: Jan 30, 2018
• Journal: Astrophysical Journal Letters
• Print ISSN: 2041-8205
• Electronic ISSN: 2041-8213
• Publisher: American Astronomical Society
• Peer Reviewed: Not Peer Reviewed
• Volume: 853
• Issue: 2
• Article Number: L19
• Pages: L19 -?
• DOI: https://doi.org/10.3847/2041-8213/aaa079
• Keywords: astrochemistry, galaxies, star formation, Magellanic Clouds, stars, protostars
• Publisher URL: http://doi.org/10.3847/2041-8213/aaa079