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Astron. Astrophys. 351, 701-706 (1999)
Is the FIP effect present inside solar photospheric magnetic flux tubes?
V.A. Sheminova 1 and
S.K. Solanki 2,3
1 Main Astronomical Observatory of Ukrainian NAS, Goloseevo, 252650 Kiev-22, Ukraine
2 Institute of Astronomy, ETH-Zentrum, 8092 Zürich, Switzerland
3 Max-Planck-Institute of Aeronomy, 37191 Katlenburg-Lindau, Germany
Received 7 May 1999 / Accepted 8 September 1999
Abstract
The first determination of the elemental composition in the photospheric layers of solar magnetic flux tubes is described. Stokes I and V profiles of 13 elements observed in solar active region plage and in the network are analysed. The abundances are obtained for elements with high (C, O) and low (Al, Ca, Cr, Na, Ni, Sc, Si, Ti, Y, Zn) first ionization potential (FIP) in order to investigate to what extent the abundance anomalies observed in the upper solar atmosphere (FIP-effect) are already present in the photospheric layers of flux tubes, which are the source of much of the gas in the upper atmosphere. Various sources of error are considered and the uncertainties introduced by them are estimated. There are hints of a weak FIP-effect in the flux tubes, corresponding to an overabundance of a factor of 1.1-1.2 of the low-FIP elements relative to high-FIP elements, as compared to the quiet photosphere. However, our data set a firm upper limit of 1.3-1.6 on this factor, which is well below the enhancement seen in many parts of the upper solar atmosphere.
Key words: Sun:
abundances 
line: formation
Sun:
photosphere
Sun: magnetic fields
Send offprint requests to: S.K. Solanki (solanki@astro.phys.ethz.ch)
This article contains no SIMBAD objects.
Contents
- 1. Introduction
- 2. Observational data and selected spectral lines
- 3. Analysis technique, calculations and results
- 4. Uncertainties in the analysis
- 5. Discussion and conclusion
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999
Online publication: November 3, 1999
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