The chemical composition
of the Sun
Nicolas Grevesse
Centre Spatial de Liège and Institut d‘Astrophysique et de
Géophysique, Université de Liège, Belgium
Martin Asplund
Max-Planck-Institut für Astrophysik (MPA)
Garching, Germany
Jacques Sauval
Observatoire Royal de Belgique, Bruxelles, Belgium
Former Solar Abundance Tables
Anders and Grevesse 1989
Grevesse and Noels 1993
Grevesse and Sauval 1998
Changes from 1980 to 2000 : mostly Atomic Data
Line formation in solar granulation
[Fe,Si,C,N,O,Na--Ca,(Fe[Fe,Si,C,N,O,Na
Ca,(Fe-Group),…]
* 1D models
3D model
* LTE
NLTE
Abundances
* All indicators (atoms + molecules)
* Best lines +atomic & molecular data
Solar abundances:
Martin Asplund (MPA-Garching)
Carlos Allende Prieto (MSSL-UK)
Nicolas Grevesse (Liège)
David Lambert (Austin)
Jacques Sauval (Brussels)
Patrick Scott (Stockholm)
3D stellar modelling:
Mats Carlsson (Oslo)
Remo Collet (Uppsala)
Åke Nordlund (Copenhagen)
Bob Stein (Michigan State)
Regner Trampedach (ANU)
New Results
M. Asplund, N. Grevesse, A.J. Sauval, in Cosmic abundances
as records of stellar evolution and nucleosynthesis, Eds T.G.
BarnesIII & F.N. Bash, ASP Conf. Ser. 336, 2005, p.25-38
(65th birthday D.L. Lambert)
N. Grevesse, M. Asplund, A.J. Sauval, in Elements stratification
in stars, 40 years of atomic diffusion, Eds G. Alecian, O. Richard
& S. Vauclair, EAS Pub. Ser. 17, 2005, p.21-32
(65th birthday G. Michaud)
N. Grevesse, M. Asplund, A.J. Sauval, in Space Science Reviews,
130, 105-114, 2007
(80th birthday J. Geiss)
3D solar atmosphere models
Ingredients:
• Radiative-hydrodynamical
• Time-dependent
• 3-dimensional
• Simplified radiative transfer
• LTE
Essentially parameter free
3D successes !
• Topology and convective motions
•…
For the first time, line profiles
are perfectly reproduced
• But
computing time !
Observations : All line profiles show …
• Widths much larger than thermal widths
MICROTURBULENCE
• λcenter blueshifted (2 mA 100 m/s at 600 nm)
• Asymmetries (C shapes : ~ 300 m/s i.e. 6 mA)
Averaged line profiles
1D vs Sun
3D vs Sun
Shift!
No micro- and macroturbulence needed in 3D!
Line asymmetries
The asymmetries and shifts of spectral
lines are very well reproduced
Observations
3D model
Balance 1D1D-3D
Various ways to test models
Q : Does the model reproduce …
Test
•
•
•
•
•
•
•
•
•
Ic=F(λ
λ)
C/L var.
Granulation
Widths of lines
Shifts of lines
Asymmetries
≠ indicators
Dependence I,EEx
High freq oscillations
1D
3D
~Yes
~Yes
No
Yes
No
No
No
No
No
~
~
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Oxygen diagnostics
Discordant results in 1D: log O~8.6-8.9
Excellent agreement in 3D: log O=8.66+/-0.05
O isotopic abundances: 16O/18O=480+/-30
Lines
HolwegerMüller
3D
[O I]
8.76+/-0.02
8.68+/-0.01
-0.08
OI
8.64+/-0.08
8.64+/-0.02
0.00
OH, dv=0
8.82+/-0.01
8.65+/-0.02
-0.17
OH, dv=1
8.87+/-0.03
8.61+/-0.03
-0.26
OH, dv=2
8.80+/-0.06
8.57+/-0.06
-0.23
Difference
*If LTE (O I): log O=8.82+/-0.10 (Δ=-0.18 dex)!!!
Carbon diagnostics
Discordant results in 1D: log C~8.4-8.7
Excellent agreement in 3D: log O=8.39+/-0.05
C isotopic abundances: 12C/13C=87+/-4
HolwegerMüller
3D
Difference
8.45
8.39
-0.06
CI
8.39+/-0.03
8.36+/-0.03
-0.03
CH, dv=1
8.53+/-0.04
8.38+/-0.04
-0.15
CH, A-X
8.59+/-0.04
8.45+/-0.03
-0.14
C2, Swan
8.53+/-0.03
8.44+/-0.03
-0.09
CO, dv=1
8.60+/-0.01
8.40+/-0.01
-0.20
CO, dv=2
8.69+/-0.02
8.37+/-0.01
-0.32
Lines
[C I]
Na – Ca and Fe
Element
1D
3D
3D-1D
Na I
6.27±
±0.04
6.17±
±0.04
-0.10
Mg I
7.64±
±0.23
7.57±
±0.23
-0.07
Mg II
7.56±
±0.08
7.53±
±0.08
-0.03
Al I
6.45±
±0.06
6.37±
±0.06
-0.08
Si I
7.55±
±0.04
7.51±
±0.04
-0.04
Si II
7.46
7.45
-0.01
P I
5.37±
±0.04
5.36±
±0.04
-0.01
S I
7.17±
±0.05
7.14±
±0.05
-0.03
K I
5.20±
±0.07
5.08±
±0.07
-0.12
Ca I
6.43±
±0.04
6.30±
±0.04
-0.13
Ca II
6.34±
±0.08
6.32±
±0.08
-0.02
Fe I
7.50±
±0.05
7.44±
±0.05
-0.06
Fe II
7.47±
±0.10
7.45±
±0.10
-0.02
Heavier elements : See older tables (but -0.03 dex for Kr and Xe)
Summary
• 3D : Granulation and line profiles
• NLTE
• All indicators agree
• No dependence on I or Eexc
C,N,O
Other elements
Implications
Implications
Significantly lower solar metallicity Z
– Z=0.0194 (Anders & Grevesse 1989)
– Z=0.0122 (Asplund et al. 2005)
New solar metallicity
Element
Abundance Contribution
to Z (%)
O
8.66
43.7
C
8.39
17.6
Fe
7.45
9.4
Ne
7.84
8.3
Si
7.51
5.4
N
7.80
5.3
Mg
7.55
5.2
S
7.14
2.6
C+N+O ~ 2/3 Z
X=0.7393 Y=0.2485 Z=0.0122 Z/X=0.0165
Anders, Grevesse 1989
Grevesse, Noels 1993
Grevesse, Sauval 1998
Z=0.019 Z/X=0.027
Z=0.017 Z/X=0.024
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
– Young O,B stars in solar neighborhood
– Local interstellar medium/Orion nebula
Turck-Chièze et al. (2004)
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
FIP
FIP
Ar
Ne
SWslow
SWrapid
SEP
Quiet Cor.
Old Abund.
2.7
1.8
3.25
1.25-1.66
New Abund.
2.0
1.4
2.4
0.8-1.1
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
FIP
Solar NEON ! High or Low? LOW!!!
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surrounding
FIP
Solar NEON ! High or Low?
Alters cosmic yardstick [X/H], [X/Fe]… WARNING!
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
Solar NEON ! High or Low?
FIP
Alters cosmic yardstick [X/H], [X/Fe], …
Agreement with meteorites !
Photospheric vs meteoritic
Very good agreement with
C1 carbonaceous
chondrites in general
Volatiles
Exceptions:
Cl, Ga, Rb, Ag, In, W, Au
Mean difference otherwise:
-0.01+/-0.06 dex
Note: change in meteoritic scale
by -0.04 dex due to 3D analysis
of Si
Solar
depletion
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
Solar NEON ! High or Low?
FIP
Alters cosmic yardstick [X/H], [X/Fe], …
Agreement with meteorites !
Diffusion Protosolar abundances
∆ (Proto-Now) = 0.05 dex ZProto=0.0132 (Z/X)Proto=0.0185
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
Solar NEON ! High or Low?
FIP
Alters cosmic yardstick [X/H], [X/Fe], …
Agreement with meteorites !
Protosolar abundances Diffusion !
Isotopes(exercise of futility-B.Gutafsson-65th…)
13C, 18O, (17O)
from IR CO
Sun ≡ Earth
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
Solar NEON ! High or Low?
FIP
Alters cosmic yardstick [X/H], [X/Fe], …
Agreement with meteorites !
Protosolar abundances Diffusion !
Isotopes
(Large) impacts in stellar structure and evolution
… (Giant planets, TTauri, Herbig Ae/Be, Gas/Dust ratio in dense clouds,Beat
Cepheids, …)
Implications
Significantly lower solar metallicity Z=0.0122
Makes Sun normal compared with surroundings
Solar NEON ! High or Low?
FIP
Alters cosmic yardstick [X/H], [X/Fe], …
Agreement with meteorites !
Protosolar abundances Diffusion !
Isotopes
Changes stellar structure and evolution
… (Giant planets, TTauri, Herbig Ae/Be, Gas/Dust ratio in dense clouds, …)
But Problems Standard Models - Helioseismology
Helioseismology
Rcz/R =0.713±0.001
Y = 0.248±0.005
(He depends on EOS)
Sound speed – Precision 10-4
The Paradise ...
Rcz/R =0.713±0.001
Ys = 0.248±0.005
Ys=0.246
Rcz/R=0.714
A. Miglio, J. Montalban, A. Noels
Troubles in Paradise ...
with new abundances
Rcz/R =0.713±0.001
Ys = 0.248±0.005
Ys=0.243
Rcz/R=0.727
Ys=0.246
Rcz/R=0.714
A. Miglio, J. Montalban, A. Noels
cz
O
Opacity inside the Sun
C
Ne
Fe
N
Solutions?
J. Bahcall, A. Antia, S. Basu, M. Pinsonneault, J. Guzik, S. Turck-Chièze,
S. Vauclair, A. Miglio, J. Montalban, A. Noels, …
Erroneous solar CNO abundances?
− Hopefully not (see O here after)
Missing opacity?
− Apparently not
Underestimated element diffusion?
− Unlikely
Internal gravity waves?
− Possibly
Underestimated solar Ne abundance?
− NO
The
terrible tragedy of
Science is the murder of
beautiful theories by ugly
facts. (W. Fowler?)
*The most interesting topics are the
ones where Theory and Observations
disagree.
*Thanks to these challenges Progress is
made in both fields*
*«The matter raised by Asplund et al
al..(2004)
2004) therefore
challenges either the opacity calculations, the nuclear
reaction rates, or the basic physics of stellar evolution,
NOT HELIOSEISMOLOGY, as some spectators have
surmised..
surmised
From seismological structure inversions, we know that
the
solar
models
are
not
accurate
by
helioseismological standards
standards.. Therefore the properties
(i..e. for example the chemical composition) inferred
(i
from these calibrations could be more contaminated by
systematic errors than by errors in the observed
frequencies»
G. Houdek and D.O. Gough 2007
65th
65
th birthday D. Gough
HT T☺PICS Solar O
(4 recent papers …)
Solar Neon?
Solar Ne abundance
We used Ne/O=0.15 (SEP, SW, Corona at ≠ T)
ANe = 7.84
0.24 dex (1.74x) smaller than older values
Such ‘low’ Ne/O solar values have been confirmed by
• Young (2005) Quiet Sun (EUV, CDS, Soho)
• Schmelz et al. (2005) Active regions (X rays)
Solar Ne abundance
New studies of solar neighborhood suggested that
solar Ne is underestimated
Drake & Testa (2005):
Cunha et al. (2006):
Ne/O
B stars
Orion
New solar
X-ray luminosity
log O
(see also Liefke and Schmitt (2006))
*The <solar model problem> solved by the abundance of Neon
in nearby stars
Solar Ne abundance
Very recent studies of solar neighborhood show
that solar Ne is NOT underestimated !
Ne/O
Drake & Testa (2005):
Robrade, Schmitt & Favata (2008)
X-ray luminosity
(see also Liefke and Schmitt (2006))
• Landi et al. 2007 High Ne from solar flares …
but possible IFIP (Ne: 21.6, O: 13.6eV)
• Bochsler 2007 Ne and O from solar wind by comparing
to He
He very variable in SW. Depending on the adopted
He, Ne and O can be high or low
ISM and OB stars: O and Ne
Good agreement with low solar O abundance
Cunha et al. (2006), Esteban et al. (2004)
OB stars
Neon?
Morel
Orion
Asplund et al.
Old solar
O I: 3D semisemi-empirical model
Socas-Navarro & Norton 2007:
Observations of Fe I lines to map T(x,y,z) over surface
⇒ 3D semi-empirical model
O I 777nm non-LTE calculations without H collisions:
log O ≈ 8.63 ± 0.08 dex
[O I]: 630nm in Sunspots
Centeno & Socas-Navarro 2008:
Ratio atomic O/Ni in small sunspot log O = 8.86 ± 0.07
BUT
•Correction for wrong gf
•Corr. for Ni abundance
•Corr. for CO
•
- 0.06 dex
- 0.06 dex
- 0.08 dex
log O = 8.66 (very uncertain!!!)
[O I]: another 3D model
Ayres 2008:
New wavelength calibration
of solar atlas and one
snapshot of a different 3D
model (CO5BOLD)
log O = 8.81 ± 0.02
If Ni I blend treated as
free parameter
Ni contribution much too
low
If Ni correct, log O = 8.74
but less good fit
O I+[O I]: another 3D analysis(1)
Caffau,Ludwig,Steffen,Ayres,Bonifacio,Cayrel,Freytag,Plez
2008
O I lines with CO5BOLD: log O = 8.77 ± 0.05
- Choice of H collisions: ∆log O ≈ +0.02 dex
- Equivalent widths:
∆log O ≈ +0.09 dex!
777.1nm
777.4nm
777.5nm
O I+[O I]: another 3D analysis(2)
New equivalent widths
8.70 (Caffau)
777.1nm
777.4nm
777.5nm
New abundances
8.69 (us)
New
New
New
Oxygen: status report
No clear consensus what the real solar O abundance is
Personal guess: log O ≈ 8.70-8.72?
Lines
HolwegerMueller
Asplund et
al. (2004)
Real Sun?
[O I]
8.76+/-0.02
8.68+/-0.01
~8.7
OI
8.64+/-0.08
8.64+/-0.02
~8.7
OH, dv=0
8.82+/-0.01
8.65+/-0.02
OH, dv=1
8.87+/-0.03
8.61+/-0.03
OH, dv=2
8.80+/-0.06
8.57+/-0.06
~8.7?
Stay tuned for a complete re-analysis of
ALL elements with NEW 3D solar model