The ISO LWS grating spectrum of NGC 7027.
Walker, H. J.; Omont, A.; Ade, P. A. R.; Burgdorf, M.; Serra, G.; Griffin, M. J.; Barlow, M. J.; Caux, E.; Cohen, M.; Liu, X. -W.; Cox, P.; Swinyard, B. M.; Molinari, S.; di Giorgio, A.; Lim, T.; Baluteau, J. P.; Sidher, S.; Lorenzetti, D.; Nisini, B.; Fischer, J.; Texier, D.; Smith, H. A.; Unger, S. J.; Saraceno, P.; Clegg, P. E.; Armand, C.; Furniss, I.; Glencross, W. M.; Gry, C.; King, K. J.; Orfei, R.; Nguyen-Q-Rieu; Trams, N.; Emery, R. J.; Greenhouse, M. A.; Joubert, M.; Pequignot, D.; Skinner, C. J.; Towlson, W. A.; Price, M.; Davis, G. R.; Truong-Bach
Abstract
We present a high signal-to-noise ISO Long Wavelength Spectrometer (LWS) grating spectrum of the planetary nebula NGC 7027 from 43-194μm. In total 40 emission lines have been detected, with 30 identified. From the ionized region, we observe fine-structure lines from [N II], [N III] and [O III]. The [O I] and [C II] fine-structure lines from the photodissociation region are the strongest features observed in this spectral region. Amongst the molecular lines, 11 pure rotation CO lines from J=14-13 up to J=24-23 have been detected. The most striking result, however, is the detection in this carbon-rich nebula of the o-H_2_O 179.53μm and the OH 119.3μm fundamental lines. Astrophysical implications are briefly discussed.