J/ApJ/743/24 Solar models with accretion. I. (Serenelli+, 2011)
Solar models with accretion.
I. Application to the solar abundance problem.
Serenelli A.M., Haxton W.C., Pena-Garay C.
<Astrophys. J., 743, 24 (2011)>
=2011ApJ...743...24S 2011ApJ...743...24S
ADC_Keywords: Sun ; Models
Keywords: accretion, accretion disks - neutrinos - Sun: abundances -
Sun: helioseismology - Sun: interior
Abstract:
We generate new standard solar models using newly analyzed nuclear
fusion cross sections and present results for helioseismic quantities
and solar neutrino fluxes. The status of the solar abundance problem
is discussed. We investigate whether nonstandard solar models with
accretion from the protoplanetary disk might alleviate this problem.
We examine a broad range of models, analyzing metal-enriched and
metal-depleted accretion and three scenarios for the timing of
accretion. Only partial solutions are found. For metal-rich accreted
material (Zac≳0.018) there exist combinations of accreted mass and
metallicity that bring the depth of the convective zone into agreement
with the helioseismic value. For the surface helium abundance, the
helioseismic value is reproduced if metal-poor or metal-free accretion
is assumed (Zac≲0.09). In both cases a few percent of the solar
mass must be accreted. Precise values depend on when accretion takes
place. We do not find a simultaneous solution to both problems but
speculate that changing the hydrogen-to-helium mass ratio in the
accreted material may lead to more satisfactory solutions. We also
show that, with current data, solar neutrinos are already a very
competitive source of information about the solar core and can help
constraining possible accretion histories. Even without helioseismic
constraints, solar neutrinos rule out the possibility that more than
0.02M☉ from the protoplanetary disk were accreted after the Sun
settled on the main sequence. Finally, we discuss how measurements of
neutrinos from the CN cycle could shed light on the interaction
between the early Sun and its protoplanetary disk.
Description:
The new standard solar model (SSM) calculations presented here were
done with GARSTEC (Weiss & Schlattl 2008Ap&SS.316...99W 2008Ap&SS.316...99W), including
the updates and modifications in the input physics described in
Serenelli et al. (2009ApJ...705L.123S 2009ApJ...705L.123S). The new models, in addition,
adopt the nuclear reaction rates that were recently recommended in
SFII (Solar Fusion II; Adelberger et al. 2011RvMP...83..195A 2011RvMP...83..195A).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 150 291 Main properties of solar models including accretion
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Model Model (E1 to L95) (1)
6- 7 I2 Myr tauacc Time when accretion begins (5, 15 or 30)
9- 15 E7.2 Msun Macc Accreted mass
17- 22 F6.4 --- Zacc [0/1] Metallicity of accreted matter
24- 29 F6.4 --- Yacc [0/1] Helium mass fraction of accreted matter
31- 36 F6.4 --- Zini [0/1] Initial metallicity
38- 43 F6.4 --- Yini [0/1] Initial helium mass fraction
45- 50 F6.4 --- aMLT Mixing Length Parameter αMLT
52- 57 F6.4 --- Zs [0/1] Final surface metallicity
59- 64 F6.4 --- Ys [0/1] Final surface helium mass fraction
66- 71 F6.4 Rsun Rcz Depth of convective envelope
73- 78 F6.4 --- <dc/c> Average rms of relative sound speed difference
<δc/c>
80- 85 F6.4 --- Zc [0/1] Central metallicity Zc
87- 92 F6.4 --- Yc [0/1] Central helium mass fraction Yc
94- 98 F5.2 MK Tc Central temperature Tc
100-104 F5.1 g/cm3 rho.c Central density ρc
106-110 F5.3 10+10/cm2/s pp neutrino flux from pp reaction
112-116 F5.3 10+8/cm2/s pep neutrino flux from pep reaction
118-122 F5.3 10+9/cm2/s Be7 neutrino flux from 7Be
124-129 F6.3 10+8/cm2/s B8 neutrino flux from 8B
131-136 F6.3 10+8/cm2/s N13 neutrino flux from 13N
138-143 F6.3 10+8/cm2/s O15 neutrino flux from 15O
145-150 F6.2 --- chi2 Global χ2 for neutrino fluxes
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Note (1): Selected models (table 4; see paper for AGSS09 values):
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Solar GS98 Early accr. Interm. accr. Late accr.
E10 E100 I10 I98 L4 L78 L56
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Mac --- --- 0.0600 0.0600 0.0600 0.0360 0.0067 0.0360 0.0180
Zac --- --- 0.0000 0.0300 0.0000 0.0300 0.0000 0.0180 0.0093
Yac --- --- 0.2710 0.2523 0.2850 0.2374 0.2838 0.2205 0.2837
Zini --- 0.0187 0.0169 0.0128 0.0196 0.0111 0.0180 0.0093 0.0185
Yini --- 0.2724 0.2664 0.2568 0.2794 0.2421 0.2787 0.2224 0.2810
aMLT --- 2.161 2.106 2.210 2.021 2.289 2.111 2.266 2.097
Zs 0.0168 0.0170 0.0134 0.0135 0.0132 0.0137 0.0132 0.0141 0.0131
Ys 0.2485 0.2429 0.2352 0.2274 0.2459 0.2147 0.2477 0.1952 0.2498
RCZ 0.713 0.712 0.727 0.719 0.734 0.713 0.726 0.716 0.727
<dc/c> --- 0.0009 0.0053 0.0018 0.0083 0.0025 0.0030 0.0068 0.0035
Zc --- 0.0200 0.0181 0.0137 0.0210 0.0074 0.0193 0.0099 0.0199
Yc --- 0.6333 0.6230 0.6158 0.6337 0.5681 0.6366 0.5769 0.6388
Tc --- 15.62 15.57 15.39 15.74 14.87 15.71 14.99 15.75
rhoc --- 151.4 148.3 151.6 148.5 146.3 151.4 144.6 151.5
pp 6.05 5.98 6.01 6.07 5.93 6.10 5.94 6.17 5.93
pep 1.46 1.44 1.44 1.51 1.39 1.52 1.42 1.55 1.41
7Be 4.82 5.00 4.76 4.33 5.22 3.85 5.18 3.30 5.27
8B 5.00 5.58 5.09 4.06 6.19 3.21 6.01 2.36 6.25
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Notes: Mac in solar units, RCZ in R☉, Tc in 106K, and rhoc
in g/cm3. Neutrino fluxes are given in units of 1010(pp),
109(7Be), 108(pep), 106(8B).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 26-Apr-2013