Herschel-SPIRE FTS spectroscopy of the carbon-rich objects AFGL 2688, AFGL 618, and NGC 7027
R. Wesson
(1)
,
José Cernicharo
(2)
,
Michael J. Barlow
(1)
,
Mikako Matsuura
(1)
,
Leen Decin
(3)
,
M. A. T. Groenewegen
(4)
,
Edward T. Polehampton
(5)
,
Marcelino Agúndez
(6)
,
Mathieu Cohen
(7)
,
Fabien Daniel
(2)
,
K. M. Exter
(3)
,
Walter K. Gear
(8)
,
H. L. Gomez
(8)
,
Peter C. Hargrave
(8)
,
P. Imhof
(9)
,
Robert J. Ivison
(10)
,
Sarah J. Leeks
(5)
,
Tanya L. Lim
(5)
,
Goran Olofsson
(11)
,
Giorgio Savini
(1)
,
B. Sibthorpe
(10)
,
Bruce Swinyard
(5)
,
T. Ueta
(12)
,
D. K. Witherick
(1)
,
J. A. Yates
(1)
1
UCL -
University College of London [London]
2 CAB - Centro de Astrobiología, Consejo Superior de Investigaciones Científicas (CSIC)/Instituto Nacional de Técnica Aeroespacial (INTA)
3 Instituut voor Sterrenkunde, Katholieke Universiteit Leuven
4 ROB - Royal Observatory of Belgium = Observatoire Royal de Belgique
5 Space Science and Technology Department, Rutherford Appleton Laboratory
6 LUTH (UMR_8102) - Laboratoire Univers et Théories
7 Radio Astronomy Laboratory, University of California, Berkeley
8 Cardiff University
9 BSS - Blue Sky Spectroscopy
10 UKATC - UK Astronomy Technology Centre, Royal Observatory Edinburgh
11 Stockholm University
12 Department of Physics and Astronomy, University of Denver
2 CAB - Centro de Astrobiología, Consejo Superior de Investigaciones Científicas (CSIC)/Instituto Nacional de Técnica Aeroespacial (INTA)
3 Instituut voor Sterrenkunde, Katholieke Universiteit Leuven
4 ROB - Royal Observatory of Belgium = Observatoire Royal de Belgique
5 Space Science and Technology Department, Rutherford Appleton Laboratory
6 LUTH (UMR_8102) - Laboratoire Univers et Théories
7 Radio Astronomy Laboratory, University of California, Berkeley
8 Cardiff University
9 BSS - Blue Sky Spectroscopy
10 UKATC - UK Astronomy Technology Centre, Royal Observatory Edinburgh
11 Stockholm University
12 Department of Physics and Astronomy, University of Denver
Résumé
We present far-infrared and submillimetre spectra of three carbon-rich evolved objects, AFGL 2688, AFGL 618 and NGC 7027. The spectra were obtained with the SPIRE Fourier-transform spectrometer on board the Herschel Space Observatory, and cover wavelengths from 195-670 mum, a region of the electromagnetic spectrum hitherto difficult to study in detail. The far infrared spectra of these objects are rich and complex, and we measure over 150 lines in each object. Lines due to 18 different species are detected. We determine physical conditions from observations of the rotational lines of several molecules, and present initial large velocity gradient models for AFGL 618. We detect water in AFGL 2688 for the first time, and confirm its presence in AFGL 618 in both ortho and para forms. In addition, we report the detection of the J = 1-0 line of CH+ in NGC 7027.