NON-LTE DETERMINATION OF THE SILICON ABUNDANCE USING A THREE-DIMENSIONAL HYDRODYNAMICAL MODEL OF THE SOLAR PHOTOSPHERE

作者：Shchukina N^*; Sukhorukov A; Trujillo Bueno J

来源：Astrophysical Journal, 2012, 755(2): 176.

DOI：10.1088/0004-637X/755/2/176

• convection
• hydrodynamics
• line: formation
• radiative transfer
• Sun: abundances
• Sun: atmosphere
• Sun: photosphere

Confrontations of spectroscopic observations with local thermodynamic equilibrium (LTE) spectral syntheses in a three-dimensional (3D) hydrodynamical model of the solar photosphere led to a downward revision of the photospheric and meteoritic silicon abundances. Here we derive the photospheric silicon abundance taking into account non-LTE (NLTE) effects in the same 3D model. We show that the above-mentioned downward revision of the silicon abundance is caused by using the LTE approximation in the context of 3D modeling, an experimental scale of oscillator strengths, and a small number of Si I lines. We demonstrate that no revision of the solar silicon abundance is required if NLTE effects are taken into account and one uses a %26quot;solar%26quot; oscillator strength scale and an extended list of Si I lines. The NLTE abundance value we find by fitting the equivalent widths of 65 Si I lines is A(Si)(NLTE) = 7.549 +/- 0.016. This value agrees well with the silicon abundance that had been recommended earlier by Grevesse %26 Sauval and Lodders for the solar photosphere and CI chondrite meteorites.

• 出版日期2012-8-20