2021A&A...651A..53G -
Astronomy and Astrophysics, volume 651A53-53 (2021/7-1)
Water and methanol ice in L 1544.
GOTO M., VASYUNIN A.I., GIULIANO B.M., JIMENEZ-SERRA I., CASELLI P., ROMAN-ZUNIGA C.G. and ALVES J.
Abstract (from CDS):
Context. Methanol and complex organic molecules have been found in cold starless cores, where a standard warm-up scenario would not work because of the absence of heat sources. A recent chemical model attributed the presence of methanol and large organics to the efficient chemical desorption and a class of neutral-neutral reactions that proceed fast at low temperatures in the gas phase.
Aims. The model calls for a high abundance of methanol ice at the edge of the CO freeze-out zone in cold cloud cores.
Methods. We performed medium-resolution spectroscopy toward three field stars behind the starless core L 1544 at 3µm to constrain the methanol ice abundance and compare it with the model predictions.
Results. One of the field stars shows a methanol ice abundance of 11% with respect to water ice. This is higher than the typical methanol abundance previously found in cold cloud cores (4%), but is 4.5 times lower than predicted. The reason for the disagreement between the observations and the model calculations is not yet understood.
Abstract Copyright:
© ESO 2021
Journal keyword(s):
astrochemistry - dust, extinction - ISM: clouds - evolution - ISM: individual objects: L 1544 - infrared: ISM
Simbad objects:
8
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