CH3OCH3 in Orion-KL: a striking similarity with HCOOCH3

摘要: Context. Orion-KL is a remarkable, nearby star-forming region where recent explosive event has generated shocks that could have released complex molecules from the grain mantles. Aims. A comparison of distribution different will help in understanding their formation and constraining chemical models. Methods. We used several data sets Plateau de Bure Interferometer to map dimethyl ether emission with arcsec spatial resolutions energy levels (from Eup = 18 330 K) compare our previous methyl formate maps. Results. Our show remarkable similarity between (CH3OCH3) (HCOOCH3) distributions even on small scale (1.8 �� × 0.8 or ∼500 AU). This long suspected similarity, seen both observational theoretical arguments, demonstrated unprecedented confidence, correlation coefficient maps ∼0.8. Conclusions. common precursor simplest explanation correlation. Comparisons laboratory work models suggest major role surface chemistry release, probably little processing, mantle by shocks. In this case CH3O radical produced methanol ice would be (whereas ethanol, C2H5OH, CH2OH). The alternative gas phase scheme, protonated CH3OH + produce through reactions HCOOH CH3OH, also compatible data. observations cannot yet definitely allow choice processes, but tight HCOOCH3 CH3OCH3 strongly contrasts behavior we observe for ethanol formic acid. provides very significant constraint