Seismic diagnostics of the equation of state and element abundances in the solar envelope S. V....
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Transcript of Seismic diagnostics of the equation of state and element abundances in the solar envelope S. V....
Seismic diagnostics of the equation of stateand element abundances in the solar envelope
S. V. Vorontsov1,2, V. A. Baturin3, S. V. Ayukov3, V. K. Gryaznov4
1Astronomy Unit, Queen Mary, University of London2Institute of Physics of the Earth, Moscow3Sternberg State Astronomical Institute of Lomonosov Moscow State University4Institute of Problems of Chemical Physics RAS, Chernogolovka, Russia
Conclusions
SAHA-S equation of state allows to achieve better agreement with seismic data, when compared with OPAL equation of state
All our results support the downward revision of solar metallicity.
Further work
Seismic measurement of C- and O abundances.
This will require reduction of systematic errors in frequencymeasurements, with possible extension of the degree range
p-mode frequency data sets
SOHO MDI ‘Medium-l’ program
(1) 15-years frequency averaging
(2) 5-yrs averaging, high activity
(3) First year, low solar activity
(4) as (3) but with new measurementdescribed in Vorontsov, Jefferies, Giebink,Schou, 2009, Toward Eliminating SystematicErrors in Intermediate-Degree p-ModeMeasurements, ASP Conf. Series 416, 301
Conclusions
• Despite of systematic errors, and limitations in degree range, p-mode dataallows to compare the performance of modern versions of the equation of state, and allows simultaneous measurement of solar Y and Z values
• The best agreement with seismic data is provided by the most recentSAHA-S3 equation of state
• All our results support the downward revision of solar Z value.