Open AccessDeep dredge‐up in intermediate‐mass thermally pulsing asymptotic giant branch stars
Author(s) -
Stancliffe Richard J.,
Tout Christopher A.,
Pols Onno R.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07987.x
Subject(s) - physics , astrophysics , asymptotic giant branch , metallicity , stellar evolution , stars , carbon star , luminosity , stellar structure , pulse (music) , helium , thermal , galaxy , atomic physics , thermodynamics , detector , optics
We present results of the evolution of asymptotic giant branch (AGB) stars of 3 and 5 M ⊙ with solar metallicity calculated with the Eggleton stellar evolution code ( stars ), which has a fully implicit and simultaneous method for solving for the stellar structure, convective mixing and nuclear burning. We introduce the concept of a viscous mesh in order to improve the numerical stability of the calculations. For the 5‐M ⊙ star, we evolve through 25 thermal pulses and their associated third dredge‐up events. We obtain a maximum helium luminosity of 1.7 × 10 9 L ⊙ and significantly deep dredge‐up after the second pulse. Strong hot‐bottom burning is observed after the fifth pulse. The 3‐M ⊙ model is evolved through 20 thermal pulse events, and we find third dredge‐up after the seventh pulse. During the 14th pulse, sufficient carbon has been brought to the surface to produce a carbon star. We find that dredge‐up and the transformation into a carbon star occur at significantly smaller core masses (0.584 and 0.608 M ⊙ , respectively) than in previous calculations for 3 M ⊙ .