Antifreeze in the hot core of Orion First detection of ethylene glycol in Orion-KL

• Published in: Astronomy and astrophysics (Berlin) Vol. 576; p. A129
• Main Authors: Brouillet, N, Despois, D, Lu, X-H, Baudry, A, Cernicharo, J, Bockelee-Morvan, D, Crovisier, J, Biver, N
• Format: Journal Article
• Language: English
• Published: EDP Sciences 01.04.2015
• Subjects: Astronomy; Astrophysics; Comets; Confusion; Continuums; Cosmology and Extra-Galactic Astrophysics; Ethylene glycol; Mantles; Orion nebula; Sciences of the Universe; Spatial resolution; Astrochemistry–ISM:molecules–Radiolines:ISM–ISM:individualobjects:Orion-KL–Comets:general
• ISSN: 0004-6361; 1432-0746; 1432-0756
• DOI: 10.1051/0004-6361/201424588

Ices are present in comets and in the mantles of interstellar grains. Their chemical composition has been indirectly derived by observing molecules released in the gas phase, when comets approach the sun and when ice mantles are sublimated or destroyed, e.g. in the hot cores present in high-mass, star-forming regions. It is important to measure the molecular abundances in various hot cores to see if the observed differences between the interstellar medium and the comets are general. We focus here on the analysis of ethylene glycol in the nearest and best studied hot core-like region, Orion-KL. We use ALMA interferometric data because high spatial resolution observations allow us to reduce the line confusion problem with respect to single-dish observations since different molecules are expected to exhibit different spatial distributions. We have detected the aGg' conformer of ethylene glycol in Orion-KL. The emission is compact and peaks towards the hot core close to the main continuum peak, about 2" to the southwest; this distribution is notably different from other O-bearing species.