Mass loss and rotational CO emission from Asymptotic Giant Branch stars

Details Mass loss and rotational CO emission from Asymptotic Giant Branch stars Mass loss and rotational CO emission from Asymptotic Giant Branch stars

2003-05-12

arxiv.org/abs/astro-ph/0305207v1

Astron.Astrophys. 407 (2003) 609-630

Astronomy and Astrophysics

Astrophysics

accepted for publication by A&A

Scientific paper

10.1051/0004-6361:20030701

We present submillimeter observations of rotational transitions of carbon monoxide from J = 2 -> 1 up to 7 -> 6 for a sample of Asymptotic Giant Branch stars and red supergiants. It is the first time that the high transitions J = 6 -> 5 and 7 -> 6 are included in such a study. With line radiative transfer calculations, we aim to determine the mass-loss history of these stars by fitting the CO line intensities. We find that the observed line intensities of the high transitions, including the J = 4 -> 3 transition, are significantly lower than the predicted values. We conclude that the physical structure of the outflow of Asymptotic Giant Branch stars is more complex than previously thought. In order to understand the observed line intensities and profiles, a physical structure with a variable mass-loss rate and/or a gradient in stochastic gas velocity is required. A case study of the AGB star WX Psc is performed. We find that the CO line strengths may be explained by variations in mass-loss on time scales similar to those observed in the separated arc-like structures observed around post-AGB stars. In addition, a gradient in the stochastic velocity may play a role. Until this has been sorted out fully, any mass loss determinations based upon single CO lines will remain suspect.

Affiliated with

Also associated with

No associations

Rating

Mass loss and rotational CO emission from Asymptotic Giant Branch stars 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 Mass loss and rotational CO emission from Asymptotic Giant Branch stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mass loss and rotational CO emission from Asymptotic Giant Branch stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-90775