tokens: Support for this work was provided by the French space agency CNES. M.P. acknowledges funding from the European Unions Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 664931. Support for this work was also provided by NASA ( Herschel OT funding) through an award issued by JPL/Caltech. This paper makes use of Herschel /HIFI data. Herschel is an ESA space observatory with science instruments provided by European-led principal Investigator consortia and with important participation from NASA. HIFI has been designed and built by a consortium of institutes and university departments from across Europe, Canada, and the United States under the leadership of SRON Netherlands Institute for Space Research, Groningen, The Netherlands and with major contributions from Germany, France, and the U.S. Consortium members are: Canada: CSA, U. Waterloo; France: CESR, LAB, LERMA, IRAM; Germany: KOSMA, MPIfR, MPS; Ireland: NUI Maynooth; Italy: ASI, IFSI-INAF, Osservatorio Astrofisico di Arcetri-INAF; Netherlands: SRON, TUD; Poland: CAMK, CBK; Spain: Observatorio Astronómico Nacional (IGN), Centro de Astrobiología (CSIC-INTA); Sweden: Chalmers University of Technology-MC2, RSS and GARD, Onsala Space Observatory, Swedish National Space Board, Stockholm Observatory; Switzerland: ETH Zurich, FHNW; USA: Caltech, JPL, NHSC. Finally, we thank the anonymous referee for helpful comments and suggestions.
ner_tags: O O O O O O O O B-Location O O B-Organization B-Person O O O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O O O O O O B-Organization O B-Grant I-Grant I-Grant O O O O O B-Organization O O O O O B-Telescope B-Instrument O B-Telescope O O B-Organization O O O O O O O B-Location O O O O O O O O B-Organization B-Instrument O O O O O O O O O O O O O O O B-Location B-Location O O B-Location I-Location O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location I-Location I-Location O O O O O B-Location B-Location O O B-Location O O O B-Location B-Organization B-Organization I-Organization B-Location B-Organization B-Organization B-Organization B-Telescope B-Location B-Organization B-Organization B-Organization B-Location B-Organization I-Organization B-Location B-Organization B-Organization B-Observatory I-Observatory I-Observatory I-Observatory B-Location B-Organization B-Organization B-Location B-Organization B-Organization B-Location B-Observatory I-Observatory I-Observatory B-Observatory B-Organization I-Organization I-Organization B-Organization B-Location B-Organization I-Organization I-Organization I-Organization B-Organization O B-Organization B-Observatory I-Observatory I-Observatory B-Organization I-Organization I-Organization I-Organization B-Observatory I-Observatory B-Location B-Organization I-Organization B-Organization B-Location B-Organization B-Organization B-Organization O O O O O O O O O O O