The ALMA-PILS survey: Inventory of complex organic molecules towards
  IRAS 16293-2422 A
  Complex organic molecules (COM) are detected in many sources in the warm
inner regions of envelopes surrounding deeply embedded protostars. Exactly how
these COM form remains an open question. This study aims to constrain the
formation of complex organic molecules through comparisons of their abundances
towards the Class 0 protostellar binary IRAS 16293-2422 (IRAS16293). We
utilised observations from the ALMA Protostellar Interferometric Line Survey of
IRAS16293. The species identification and the rotational temperature and column
density estimation were derived by fitting the extracted spectra towards
IRAS16293 A and IRAS16293 B with synthetic spectra. The majority of the work in
this paper pertains to the analysis of IRAS16293 A for a comparison with the
results from the other binary component, which have already been published. We
detect 15 different COM, as well as 16 isotopologues towards the most luminous
companion protostar IRAS16293 A. Tentative detections of an additional 11
isotopologues are reported. We also searched for and report on the first
detections of CH3OCH2OH and t-C2H5OCH3 towards IRAS16293 B and the follow-up
detection of CH2DCHO and CH3CDO. Twenty-four lines of CHD2OH are also
identified. The comparison between the two protostars of the binary system
shows significant differences in abundance for some of the species, which are
partially correlated to their spatial distribution. The spatial distribution is
consistent with the sublimation temperature of the species; those with higher
expected sublimation temperatures are located in the most compact region of the
hot corino towards IRAS16293 A. This spatial differentiation is not resolved in
IRAS16293 B and will require observations at a higher angular resolution. In
parallel, the list of identified CHD2OH lines shows the need of accurate
spectroscopic data including their line strength.
