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Nuclear Theory for Chemical Evolution of Galaxies
Yong-Zhong QianUniversity of Minnesota
JINA GCE Workshop “Building Virtual Galaxies”
April 30, 2010
(based on review by Janka et al. 2007 in Physics Reports)
Friday, April 30, 2010
Stellar input for chemical evolution of galaxies
stellar evolution nucleosynthesis
end states
Type Ia & core-collapse SNe
star formation
nucleosynthesisenergy injection, mixing
gas return
Friday, April 30, 2010
Nuclear theory input for chemical evolution
nuclear reaction rates for:
hydrostatic & explosive burning
r-process, s-process, p-process, rp-process
nuclear equation of state
weak interaction rates
nuclear theory input for core-collapse SNe:
Friday, April 30, 2010
weak rates during pre-SN evolution & core collapse
mass, Ye, entropy of “Fe” core
mass of inner core
Friday, April 30, 2010
nuclear equation of state (EOS)radius of inner core at bounce
initial shock energylater neutrino luminosity
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nuclear EoS & neutrino processesneutrino luminosity & spectraexplosion & nucleosynthesis
Friday, April 30, 2010
e-capture & beta-decay rates for pre-SN evolution Langanke & Martinez-Pinedo (LMP 2000)
B(G
T+)
d!/d"
[mb/
(sr 5
0 ke
V)]
51V(d,2He)51Ti Elab=171 MeV #cm<1˚
Shell-Model Calculation
Ex [MeV]
Ex [MeV]
2.14
MeV
3.62
MeV 4.
88 M
eV
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smaller, non-systematic
differences for beta-decay
comparison withFuller, Fowler, & Newman
(FFN 1980, ’82, ’85)for late stages ofpre-SN evolution
1 4 7 10T9
10-4
10-3
10-2
10-1
10-4
10-3
10-2
10-1
100
! ec (s
"1)
10-15
10-12
10-9
10-6
10-3
LMPFFN
1 4 7 10T9
10-6
10-4
10-2
100
10-6
10-5
10-4
10-3
10-2
10-1
10-3
10-2
10-1
100
#7=10.7
56Fe 56Ni
#7=4.32
#7=4.32
55Co 59Co
#7=33
54Mn
#7=10.7 #7=33
60Co
further constraints onshell model calculations
from FRIB?
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10 15 20 25 30 35 40Star Mass (M!)
0.005
0.010
0.015
0.020
!Y e
0.420
0.425
0.430
0.435
0.440
0.445
0.450
Y e
WWLMP
10 15 20 25 30 35 40Star Mass (M!)
-0.2
-0.1
0.0
0.1
!M
Fe (M
!)
1.4
1.6
1.8
2.0
MFe
(M!)
WWLMP
10 15 20 25 30 35 40Star Mass (M!)
-0.2
-0.1
0.0
0.1
!S
(kB)
0.6
0.7
0.8
0.9
1.0
1.1
1.2
cent
ral e
ntro
py /
bary
on (k B
)
WWLMP
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10 100 1000DENSITY [109 g/cm3]
0
10
20
30
40EN
ERG
Y [M
eV]
temperatureQ (proton)Q (nuclei)chem. potential
beta-decay
e-capture
detailed GTstrength
distributionneeded
centroid & totalGT strength
mostly needed
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e capture during core collapse
nuclear statistical equilibrium (NSE) has many nucleiwith significant abundances
reduction of Ye depends on the product of nuclearabundance & the corresponding e-capture rate
decreasing Ye changes NSE composition to favormore n-rich nuclei
when Z<40 & N>40 nuclei have significant abundances,more sophisticated shell model calculations needed,
but computational capability forces alternative:Random Phase Approximation (RPA)
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Independent ParticleShell Model gives noGT strength for e capture on nuclei
with Z<40 & N>40
but finite temperature& residual interaction
lead to unblocking
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-15 -10 -5 0
Q (MeV)
10-2
10-1
100
101
102
103
104
105
!e
c (
s-1
)
"11Ye=0.07, T=0.93
"11Ye=0.62, T=1.32
"11Ye=4.05, T=2.08
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10-4
10-3
10-2
10-1
100
101
102
103
104r ec
(s-1
)
5 10 15 20 25 30 35 40
µe (MeV)
0
10
20
30
!E" e#
(MeV
)
protonheavy
0.3
0.4
0.5
Y e (Ele
ctro
n Fr
actio
n)
1
2
3
Entro
py p
er b
aryo
n
0 0.2 0.4 0.6 0.8 1−8
−6
−4
−2
0
Velo
city
(104 k
m/s
)
Enclosed Mass
Bruenn prescriptionLMP+hybrid rates
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nuclear EoS, neutrino emission & interaction processes
time
Nuclear theory input for supernova neutrino emission
Qian & Woosley 1996
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40 45 50 55 60 65 70 75 80 85 90Mass Number A
100
101
102
103
104Y i/Yi,!
0.5 0.52 0.54 0.56 0.58 0.6Ye
102
103
104
105
106
107
108
Y i/Yi,!
74Se
78Kr
84Sr96Ru
94Mo98Ru
102Pd
92Mo
106Cd108Cd
!p-process
!̄e + p! n + e+
without neutrinos,nuclear flow ends at
64Ge
(n, p) & (p, !)lead to heavier nuclei
Frohlich et al. 2004, ’06Pruet et al. 2005
Friday, April 30, 2010
Nuclear theory input for the r-process
possible role of neutrino-induced n emission
n-induced fission cross sections & yields
during the r-process, assuming (n, !) ! (!, n) equilibrium
neutron separation energy, beta-decay ratesboth depend on nuclear masses
macro-microscopic (e.g., FRDM) vs. ab initio (e.g., RMF) mass models
possible role of fission cycling
during freeze-out
n capture cross sections, beta-delayed n emission
Friday, April 30, 2010
