Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-12-11
Astronomy and Astrophysics
Astrophysics
16 pages, 5 figures, accepted for publication in ApJ
Scientific paper
10.1086/527669
We report high angular-resolution VLA observations of cyanopolyyne molecules HC$_3$N and HC$_5$N from the carbon rich circumstellar envelope of IRC+10216. The observed low-lying rotational transitions trace a much more extended emitting region than seen in previous observations at higher frequency transitions. We resolve the hollow quasi-spherical distribution of the molecular emissions into a number of clumpy shells. These molecular shells coincide spatially with dust arcs seen in deep optical images of the IRC+10216 envelope, allowing us to study for the first time the kinematics of these features. We find that the molecular and dust shells represent the same density enhancements in the envelope separated in time by $\sim$120 to $\sim$360 yrs. From the angular size and velocity spread of the shells, we estimate that each shell typically covers about 10% of the stellar surface at the time of ejection. The distribution of the shells seems to be random in space. The good spatial correspondance between HC$_3$N and HC$_5$N emissions is in qualitative agreement with a recent chemical model that takes into account the presence of density-enhanced shells. The broad spatial distribution of the cyanopolyyne molecules, however, would necessitate further study on their formation.
Dinh-V-Trung
Lim Jeremy
No associations
LandOfFree
Molecular shells in IRC+10216: Evidence for non-isotropic and episodic mass loss enhancement 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 Molecular shells in IRC+10216: Evidence for non-isotropic and episodic mass loss enhancement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molecular shells in IRC+10216: Evidence for non-isotropic and episodic mass loss enhancement will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-474380