The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A

Abstract

We present the first census of the interstellar Complex Organic Molecules\n(iCOMs) in the low-mass Class I protostar SVS13-A, obtained by analysing data\nfrom the IRAM-30m Large Project ASAI (Astrochemical Surveys At IRAM). They\nconsist of an high-sensitivity unbiased spectral survey at the 1mm, 2mm and 3mm\nIRAM bands. We detected five iCOMs: acetaldehyde (CH$_3$CHO), methyl formate\n(HCOOCH$_3$), dimethyl ether (CH$_3$OCH$_3$), ethanol (CH$_3$CH$_2$OH) and\nformamide (NH$_2$CHO). In addition we searched for other iCOMs and ketene\n(H$_2$CCO), formic acid (HCOOH) and methoxy (CH$_3$O), whose only ketene was\ndetected. The numerous detected lines, from 5 to 37 depending on the species,\ncover a large upper level energy range, between 15 and 254 K. This allowed us\nto carry out a rotational diagram analysis and derive rotational temperatures\nbetween 35 and 110 K, and column densities between $3\\times 10^{15}$ and\n$1\\times 10^{17}$ cm$^{-2}$ on the 0."3 size previously determined by\ninterferometric observations of glycolaldehyde. These new observations clearly\ndemonstrate the presence of a rich chemistry in the hot corino towards SVS13-A.\nThe measured iCOMs abundances were compared to other Class 0 and I hot corinos,\nas well as comets, previously published in the literature. We find evidence\nthat (i) SVS13-A is as chemically rich as younger Class 0 protostars, and (ii)\nthe iCOMs relative abundances do not substantially evolve during the\nprotostellar phase.\n