2014A&A...567A..53K

This paper presents the richness of submillimeter spectral features in the high-mass star forming region AFGL 2591. As part of the Chemical Herschel Survey of Star Forming Regions (CHESS) key programme, AFGL 2591 was observed by the Herschel (HIFI) instrument. The spectral survey covered a frequency range from 480 to 1240GHz as well as single lines from 1267 to 1901GHz (i.e. CO, HCl, NH₃, OH, and [CII]). Rotational and population diagram methods were used to calculate column densities, excitation temperatures, and the emission extents of the observed molecules associated with AFGL 2591. The analysis was supplemented with several lines from ground-based JCMT spectra. From the HIFI spectral survey analysis a total of 32 species were identified (including isotopologues). Although the lines are mostly quite weak (∫T_mbdV∼ few Kkm/s), 268 emission and 16 absorption lines were found (excluding blends). Molecular column densities range from 6x10¹¹ to 1x10¹⁹/cm2 and excitation temperatures from 19 to 175K. Cold (e.g. HCN, H₂S, and NH₃ with temperatures below 70 K) and warm species (e.g. CH₃OH, SO₂) in the protostellar envelope can be distinguished.