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Astron. Astrophys. 359, 755-758 (2000)

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Line formation in solar granulation

III. The photospheric Si and meteoritic Fe abundances

M. Asplund

NORDITA, Blegdamsvej 17, 2100 Copenhagen O, Denmark

Received 24 January 2000 / Accepted 4 May 2000


Using realistic hydrodynamical simulations of the solar surface convection as 3D, time-dependent, inhomogeneous model atmospheres, the solar photospheric Si abundance has been determined to be log [FORMULA]. This constitutes a difference of 0.04 dex compared with previous estimates based on the 1D Holweger-Müller (1974) model, of which half is attributable to the adopted model atmosphere and the remaining part to the improved quantum mechanical broadening treatment. As a consequence, all meteoritic abundances should be adjusted downwards by the same amount. In particular the meteoritic Fe abundance will be log [FORMULA], in good agreement with the recently determined photospheric Fe abundance (Asplund et al. 2000b). The existing uncertainties unfortunately prevent an observational confirmation of the postulated effects of elemental migration of metals in the Sun.

Key words: convection – hydrodynamics – line: formation – Sun: abundances – Sun: granulation – Sun: photosphere

Present address: Uppsala Astronomical Observatory, Box 515, 751 20 Uppsala, Sweden (martin@astro.uu.se)

© European Southern Observatory (ESO) 2000

Online publication: July 7, 2000