Search: onr:"swepub:oai:research.chalmers.se:c62f3e4c-002a-40b5-a610-96496fc7b660" >
Herschel/HIFI deepe...
Herschel/HIFI deepens the circumstellar NH3 enigma
-
- Menten, K. M. (author)
- Max Planck Gesellschaft zur Förderung der Wissenschaften e.V. (MPG),Max Planck Society for the Advancement of Science (MPG)
-
- Wyrowski, F. (author)
- Max Planck Gesellschaft zur Förderung der Wissenschaften e.V. (MPG),Max Planck Society for the Advancement of Science (MPG)
-
Alcolea, J. (author)
-
show more...
-
- De Beck, Elvire, 1985 (author)
- Katholieke Universiteit Leuven
-
- Decin, L. (author)
- Universiteit Van Amsterdam,University of Amsterdam,Katholieke Universiteit Leuven
-
- Marston, A. P. (author)
- European Space Astronomy Centre (ESAC),Atacama Large Millimeter-submillimeter Array (ALMA)
-
Bujarrabal, V. (author)
-
- Cernicharo, J. (author)
- Centro de Astrobiologia (CAB)
-
- Dominik, C. (author)
- Radboud Universiteit,Radboud University,European Space Astronomy Centre (ESAC)
-
- Justtanont, Kay, 1965 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- de Koter, A. (author)
- European Space Astronomy Centre (ESAC)
-
- Melnick, G. J. (author)
- Harvard-Smithsonian Center for Astrophysics
-
- Neufeld, D. A. (author)
- Johns Hopkins University
-
- Olofsson, Hans, 1952 (author)
- Stockholms universitet,Institutionen för astronomi,Chalmers tekniska högskola,Chalmers University of Technology
-
- Planesas, P. (author)
- Atacama Large Millimeter-submillimeter Array (ALMA),California Institute of Technology (Caltech)
-
- Schmidt, M. (author)
- Polish Academy of Sciences
-
- Schöier, Fredrik, 1969 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Szczerba, R. (author)
- Polish Academy of Sciences
-
- Teyssier, D. (author)
- European Space Astronomy Centre (ESAC)
-
- Waters, Lbfm (author)
- Katholieke Universiteit Leuven,Universiteit Van Amsterdam,University of Amsterdam
-
- Edwards, K. (author)
- Netherlands Institute for Space Research (SRON),University of Waterloo
-
- Olberg, Michael, 1956 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Phillips, T. G. (author)
- California Institute of Technology (Caltech)
-
- Morris, P. (author)
- California Institute of Technology (Caltech)
-
- Salez, M. (author)
- LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres, France,Ecole Normale Superieure (ENS)
-
- Caux, E. (author)
- Université de Toulouse,University of Toulouse,Institut National des Sciences de l'Univers
-
show less...
-
Max Planck Gesellschaft zur Förderung der Wissenschaften eV. (MPG) Katholieke Universiteit Leuven (creator_code:org_t)
- 2010-10-01
- 2010
- English.
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521:1, s. Article Number: L7-
- Related links:
-
http://publications.... (primary) (free)
-
show more...
-
https://www.aanda.or...
-
https://doi.org/10.1...
-
https://research.cha...
-
https://urn.kb.se/re...
-
show less...
Abstract
Subject headings
Close
- Context. Circumstellar envelopes (CSEs) of a variety of evolved stars have been found to contain ammonia (NH3) in amounts that exceed predictions from conventional chemical models by many orders of magnitude. Aims. The observations reported here were performed in order to better constrain the NH3 abundance in the CSEs of four, quite diverse, oxygen-rich stars using the NH3 ortho J(K) = 1(0)-0(0) ground-state line. Methods. We used the Heterodyne Instrument for the Far Infrared aboard Herschel to observe the NH3 J(K) = 1(0)-0(0) transition near 572.5 GHz, simultaneously with the ortho-H2O J(Ka,Kc) = 1(1,0)-1(0,1) transition, toward VY CMa, OH 26.5+0.6, IRC+10420, and IK Tau. We conducted non-LTE radiative transfer modeling with the goal to derive the NH3 abundance in these objects' CSEs. For the last two stars, Very Large Array imaging of NH3 radio-wavelength inversion lines were used to provide further constraints, particularly on the spatial extent of the NH3-emitting regions. Results. We find remarkably strong NH3 emission in all of our objects with the NH3 line intensities rivaling those of the ground state H2O line. The NH3 abundances relative to H-2 are very high and range from 2 x 10(-7) to 3 x 10(-6) for the objects we have studied. Conclusions. Our observations confirm and even deepen the circumstellar NH3 enigma. While our radiative transfer modeling does not yield satisfactory fits to the observed line profiles, it does lead to abundance estimates that confirm the very high values found in earlier studies. New ways to tackle this mystery will include further Herschel observations of more NH3 lines and imaging with the Expanded Very Large Array.
Subject headings
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Keyword
- emission
- circumstellar matter
- inversion lines
- vy canis majoris
- stars: AGB and post-AGB
- mass-loss
- molecules
- stars
- irc+10216
- interstellar ammonia
- bearing
- water
- infrared observations
- supergiants
- Astronomy and astrophysics
Publication and Content Type
- art (subject category)
- ref (subject category)
Find in a library
To the university's database
- By the author/editor
-
Menten, K. M.
-
Wyrowski, F.
-
Alcolea, J.
-
De Beck, Elvire, ...
-
Decin, L.
-
Marston, A. P.
-
show more...
-
Bujarrabal, V.
-
Cernicharo, J.
-
Dominik, C.
-
Justtanont, Kay, ...
-
de Koter, A.
-
Melnick, G. J.
-
Neufeld, D. A.
-
Olofsson, Hans, ...
-
Planesas, P.
-
Schmidt, M.
-
Schöier, Fredrik ...
-
Szczerba, R.
-
Teyssier, D.
-
Waters, Lbfm
-
Edwards, K.
-
Olberg, Michael, ...
-
Phillips, T. G.
-
Morris, P.
-
Salez, M.
-
Caux, E.
-
show less...
- About the subject
-
- NATURAL SCIENCES
-
NATURAL SCIENCES
-
and Physical Science ...
-
and Astronomy Astrop ...
- Articles in the publication
-
Astronomy and As ...
- By the university
-
Chalmers University of Technology
-
Stockholm University