Alessandro Chieffi
(Istituto di Astrofisica Spaziale e Fisica Cosmica & INAF)
Email: [email protected]
25 MO
1 MO
5 MO
REMEMBER that:
The interplay between the evolution of a star and the nuclear processes occurs through the RATES and NOT the cross sections:
Rlk => Xl x Xk
x screening x <v>lk
25 MO
5 MO
1 MO
PP chain
CNO cycle
CNO cycle
14N(p,)15O
p(p,e+)d
t(H-burn)= - 0.3%
t(H-burn)= - 4%M(He) => 0.91 to 0.97 MO
M(He) => 8.3 to 8.6 MO
<v>3 x 10 is NOT appreciablex 10
t(H-burn)= - 3%
MS
TORGB
HB
10 Gyr
Z=10-4
Y=0.23
Dashed => (14N(p,)15O) / 2
13 Gyr
Solid => reference
M=0.8 MO
Y=0.23
Z=10-4
MHe = 1%
Mbol(tip) = 0.055 Mag
Red – reference
Blue – 14N(p,)15O / 2
-0.04 Mag => - 0.6 Gyr
COcore
H-rich mantle
He burning shell
He (+C) intershell
H burning shell
AGB phase
R(Hshell) ~10-5 Rstar
0.7 < M / MO < 7
Neutron production
s process nucleosynthesis
Convective envelope
He shell
H shell
t(yr)
M(MO)
Convective envelope
He shell
H shell
t(yr)
M(MO)
He conv. shell
-3 8.1 6.5
-1 8.5 7.5
Base conv. env.
H burn. shell
He burn. shell
Log(Surf. C abund.)
Log(Tmax He shell)
Log(T base conv. Env.)
He luminosity
M=3 MO Z=0.02 Y=0.284
Neutron captures on:
Fe
Kr84 – Rb – Sr – Y – Zr92
Xe132 – Cs – Ba – La – Ce – Pr – Nd144
Hg202 – Tl – Pb – Bi209
Network:
H to Si (full)
+
92 nuclei
Lo
g10
(PF
)
Element
Lo
g10
(PF
)
Stable Isotopes
Reference
3 / 23 x 2
M=3 MO - Z=0.02
14Np
Reference
3 / 23 x 2
14Np
SURFACE CARBON ABUNDANCE
The mother of all rates: 12C(,)16O
Roadmap...
1) WR stars: evolution & explosive nucleosynthesis
35
120
2) Intermediate Mass Stars: elemental yields