Astronomy and Astrophysics – Astronomy
Scientific paper
Nov 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998apj...507..281c&link_type=abstract
The Astrophysical Journal, Volume 507, Issue 1, pp. 281-286.
Astronomy and Astrophysics
Astronomy
62
Stars: Circumstellar Matter, Ism: Dust, Extinction, Ism: Individual: Alphanumeric: Crl 618, Ism: Molecules, Line: Profiles, Stars: Agb And Post-Agb
Scientific paper
A new 2.8-3.8 μm spectrum of the carbon-rich protoplanetary nebula CRL 618 confirms the previous detection of a circumstellar 3.4 μm absorption feature in this object (Lequeux & Jourdain de Muizon). The high resolution and high signal-to-noise ratio of our spectrum allow us to derive the detailed profile of this absorption feature, which is very similar to that observed in the spectrum of the Galactic center and also resembles the strong 3.4 μm emission feature in some post-asymptotic giant branch stars. A weak 3.3 μm unidentified infrared band, marginally detected in the CRL 618 spectrum of Lequeux & Jourdain de Muizon, is present in our spectrum. The existence of the 3.4 μm feature implies the presence of relatively short-chained, aliphatic hydrocarbon materials (-CH_2-/-CH_3 ~= 2-2.5) in the circumstellar environment around CRL 618. It also implies that the carriers of the interstellar 3.4 μm feature are produced at least in part in circumstellar material, and it calls into question whether any are produced by the processing of interstellar ices in dense interstellar clouds, as has been previously proposed. Other features in the spectrum are recombination lines of hydrogen, rotational and vibration-rotation lines of molecular hydrogen, and a broad absorption probably due to a blend of HCN and C_2H_2 bands.
Chiar Jean E.
Geballe Thomas Ronald
Pendleton Yvonne J.
Tielens Alexander G. G. M.
No associations
LandOfFree
Near-Infrared Spectroscopy of the Proto-Planetary Nebula CRL 618 and the Origin of the Hydrocarbon Dust Component in the Interstellar Medium does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Near-Infrared Spectroscopy of the Proto-Planetary Nebula CRL 618 and the Origin of the Hydrocarbon Dust Component in the Interstellar Medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Near-Infrared Spectroscopy of the Proto-Planetary Nebula CRL 618 and the Origin of the Hydrocarbon Dust Component in the Interstellar Medium will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1074640