ALMA Observations of Molecular Complexity in the Large Magellanic Cloud: Probing the Star-forming Region N 160

Abstract Hot cores are small (≲0.1 pc), dense (≥10 6 cm −3 ), and hot (>100 K) regions around massive protostars and are one of the main production sites of complex organic molecules (COMs, ≥6 atoms, including carbon). The Large Magellanic Cloud (LMC) is an ideal place to study hot core and COM formation in an environment that is different from our Galaxy, though prior to this study there have only been nine detections of extragalactic hot cores (seven in the LMC and two in the Small Magellanic Cloud, SMC). Here, we report 1.2 mm continuum and molecular line observations with the Atacama Large Millimeter/submillimeter Array in the star-forming region N 160, which we named N 160A–mm. We identify six 1.2 mm continuum sources, four of which are associated with methanol (CH 3 OH) emission. Another COM, methyl cyanide (CH 3 CN) is associated with the brightest source, N 160A–mm A, the most chemically rich source in the field. Using the XCLASS software, we perform spectral modeling to estimate rotational temperatures and total column densities of detected molecular species for four sources. Based on the temperature exceeding 100 K, its small size, and high H 2 number density, we identify N 160A–mm A as a hot core. We compare the molecular abundances of this newly detected hot core with those previously detected in the LMC and SMC, as well as with a sample of Galactic hot cores, and discuss the complex nature of N 160A–mm A.