J/A+A/512/A10 Evolution of massive AGB stars. III. (Siess, 2010)
Evolution of massive AGB stars. III. The thermally pulsing super-AGB phase.
Siess L.
<Astron. Astrophys. 512, A10 (2010)>
=2010A&A...512A..10S 2010A&A...512A..10S
ADC_Keywords: Models, evolutionary ; Clusters, globular
Keywords: stars: AGB and post-AGB - stars: evolution -
nuclear reactions, nucleosynthesis, abundances - stars: abundances
Abstract:
We present the first simulations of the full evolution of super-AGB
stars through the entire thermally pulsing AGB phase. We analyse their
structural and evolutionary properties and determine the first SAGB
yields. Stellar models of various initial masses and metallicities
were computed using standard physical assumptions which prevents the
third dredge-up. A postprocessing nucleosynthesis code was used to
compute the SAGB yields, to quantify the effect of the third dredge-up
(3DUP) and to assess the uncertainties associated with the treatment
of convection. Owing to their massive oxygen-neon core, SAGB stars
suffer weak thermal pulses, have very short interpulse periods and
develop very high temperatures at the base of their convective
envelope (up to 140x108K), leading to very efficient hot bottom
burning. SAGB stars are consequently heavy manufacturers of 4He,
13C, and 14N. They are also able to inject significant amounts of
7Li, 17O, 25Mg, and 26,27Al in the interstellar medium. The
3DUP mainly affects the CNO yields, especially in the lower
metallicity models. Our post-processing simulations also indicate that
changes in the temperature at the base of the convective envelope,
which would result from a change in the efficiency of convective
energy transport, have a dramatic impact on the yields and represent
another major source of uncertainty.
Description:
The tables contains the stellar yields of 36 nuclei from H to 37Cl for
20 super-AGB stars of various initial masses between 7.5 and
10.5M☉ and for metallicities ranging between Z=1e-4 and 0.04.
The yields are given in solar mass and were computed using the
postprocessing code considering the full coupling between the nuclear
burning and the diffusive mixing.
Table 2 provides the reference yields which do no experience third
dredge-ups. Tables 3 and 4 simulate the effect of a high (lambda=0.8)
and low (lambda=0.3) 3DUP efficiency. The intershell composition is
set to 4He:12C:16O=0.66:0.31:0.02. Tables 5 and 6 simulate the
yields which would result from an increase/decrease of the envelope
temperature (Tenv) by±10%, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 247 36 Standard yields (no 3rd dredge-up, λ=0)
table3.dat 247 36 High 3rd dredge-up efficiency yields (λ=0.8)
table4.dat 247 36 Low 3rd dredge-up efficiency yields (λ=0.3)
table5.dat 247 36 High envelope temperature yields (1.1*Tenv)
table6.dat 247 36 Low envelope temperature yields (0.9*Tenv)
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Byte-by-byte Description of file (#): table?.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- A Nucleon number
5- 6 A2 --- El Chemical Species name
8- 19 E12.4 solMass M07.5Z1e-4 Yields from 7.5Msun, Z=1e-4 for species
20- 31 E12.4 solMass M08.0Z1e-4 Yields from 8.0Msun, Z=1e-4 for species
32- 43 E12.4 solMass M08.5Z1e-4 Yields from 8.5Msun, Z=1e-4 for species
44- 55 E12.4 solMass M09.0Z1e-4 Yields from 9.0Msun, Z=1e-4 for species
56- 67 E12.4 solMass M08.0Z1e-3 Yields from 8.0Msun, Z=1e-3 for species
68- 79 E12.4 solMass M08.5Z1e-3 Yields from 8.5Msun, Z=1e-3 for species
80- 91 E12.4 solMass M09.0Z1e-3 Yields from 9.0Msun, Z=1e-3 for species
92-103 E12.4 solMass M08.5Z4e-3 Yields from 8.5Msun, Z=4e-3 for species
104-115 E12.4 solMass M09.0Z4e-3 Yields from 9.0Msun, Z=1e-3 for species
116-127 E12.4 solMass M09.5Z4e-3 Yields from 9.5Msun, Z=4e-3 for species
128-139 E12.4 solMass M10.0Z4e-3 Yields from 10.0Msun, Z=4e-3 for species
140-151 E12.4 solMass M09.0Z8e-3 Yields from 9.0Msun, Z=8e-3 for species
152-163 E12.4 solMass M09.5Z8e-3 Yields from 9.5Msun, Z=8e-3 for species
164-175 E12.4 solMass M10.0Z8e-3 Yields from 10.0Msun, Z=8e-3 for species
176-187 E12.4 solMass M09.0Z2e-2 Yields from 9.0Msun, Z=2e-2 for species
188-199 E12.4 solMass M09.5Z2e-2 Yields from 9.5Msun, Z=2e-2 for species
200-211 E12.4 solMass M10.0Z2e-2 Yields from 10.0Msun, Z=2e-2 for species
212-223 E12.4 solMass M10.5Z2e-2 Yields from 10.5Msun, Z=2e-2 for species
224-235 E12.4 solMass M09.0Z4e-2 Yields from 9.0Msun, Z=4e-2 for species
236-247 E12.4 solMass M09.5Z4e-2 Yields from 9.5Msun, Z=4e-2 for species
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Acknowledgements:
Lionel Siess, Lionel.Siess(at)astro.ulb.ac.be
References:
Siess, Paper I 2006A&A...448..717S 2006A&A...448..717S
Siess, Paper II 2007A&A...476..893S 2007A&A...476..893S
(End) Patricia Vannier [CDS] 11-Jan-2010