|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'928
Articles rated: 2609
25 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Interferometric imaging of the sulfur-bearing molecules H2S, SO and CS in comet C/1995 O1 (Hale-Bopp) | | J. Boissier
; D. Bockelée-Morvan
; N. Biver
; J. Crovisier
; D. Despois
; B.G. Marsden
; R. Moreno
; | | Date: |
24 Sep 2007 | | Abstract: | We present observations of rotational lines of H2S, SO and CS performed in
comet C/1995 O1 (Hale-Bopp) in March 1997 with the Plateau de Bure
interferometer (IRAM). The observations provide informations on the spatial and
velocity distributions of these molecules. They can be used to constrain their
photodissociation rate and their origin. We use a radiative transfer code which
allows us to compute synthetic line profiles and interferometric maps, to be
compared to the observations. Both single-dish spectra and interferometric
spectral maps show a day/night asymmetry in the outgassing. From the analysis
of the spectral maps, including the astrometry, we show that SO and CS present
in addition a jet-like structure that may be the gaseous counterpart of the
dust high-latitude jet observed in optical images. A CS rotating jet is also
observed. Using the astrometry provided by continuum radio maps obtained in
parallel, we conclude that there is no need to invoke of nongravitational
forces acting on this comet, and provide an updated orbit. The radial extension
of H2S is found to be consistent with direct release from the nucleus. SO
displays an extended radial distribution. Assuming that SO2 is the parent of
SO, the photodissociation rate of SO is measured to be 1.5 E-4 s-1 at 1 AU from
the Sun. This is lower than most laboratory-based estimates and may suggest
that SO is not solely produced by SO2 photolysis. From the observations of
J(2-1) and J(5-4) CS lines, we deduce a CS photodissociation rate of 1 to 5 E-5
s-1. The photodissociation rate of CS2, the likely parent of CS, cannot be
constrained due to insufficient resolution, but our data are consistent with
published values. These observations illustrate the cometary science that will
be performed with the future ALMA interferometer. | | Source: | arXiv, 0709.3792 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER