2017MNRAS.469L..73L

We report on a systematic search for oxygen-bearing complex organic molecules (COMs) in the solar-like protostellar shock region L1157-B1, as part of the IRAM Large Program 'Astrochemical Surveys At IRAM'. Several COMs are unambiguously detected, some for the first time, such as ketene H₂CCO, dimethyl ether (CH₃OCH₃) and glycolaldehyde (HCOCH₂OH), and others firmly confirmed, such as formic acid (HCOOH) and ethanol (C₂H₅OH). Thanks to the high sensitivity of the observations and full coverage of the 1, 2 and 3 mm wavelength bands, we detected numerous (∼10-125) lines from each of the detected species. Based on a simple rotational diagram analysis, we derive the excitation conditions and the column densities of the detected COMs. Combining our new results with those previously obtained towards other protostellar objects, we found a good correlation between ethanol, methanol and glycolaldehyde. We discuss the implications of these results on the possible formation routes of ethanol and glycolaldehyde.