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On the peculiarities of manifestation of kG magnetic elements in observations of the Sun with low spatial resolution

Published online by Cambridge University Press:  24 July 2015

Mikhail L. Demidov
Affiliation:
Institute of Solar-Terrestrial Physics SB RAS, 664033, Irkutsk, P.O. Box 291, Russia email: demid@iszf.irk.ru
Renat M. Veretsky
Affiliation:
Institute of Solar-Terrestrial Physics SB RAS, 664033, Irkutsk, P.O. Box 291, Russia email: demid@iszf.irk.ru
Alexander V. Kiselev
Affiliation:
Institute of Solar-Terrestrial Physics SB RAS, 664033, Irkutsk, P.O. Box 291, Russia email: demid@iszf.irk.ru
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Abstract

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On the agenda of modern astrophysics is the exploration of not only disk-integrated stellar magnetic fields but surface mapping of them. However, it is hardly possible to expect that spatial resolution better than some dozens or hundreds pixels over stellar disk will be achieved for this goal in the foreseeable future. Among other reasons this fact makes very important observations of the average and large-scale magnetic fields of the Sun, which can be naturally used for testing polarimetric measurements on other stars, especially on solar-type stars. In this study we explore different aspects of observations of solar magnetic fields (SMF) with low spatial resolution, including Sun-as-a-star observations, which are characterized by extremely low magnetic flux densities. Comparison of disk-integrated and spatially resolved Stokes observations of the Sun allow us to demonstrate how Stokes V profiles depend on the distribution of large-scale magnetic fields in the disk center. It is shown that center-to-limb variations of magnetic strength ratios (MSR) and area asymetries, most likely could be interpreted as the manifestation of kG magnetic flux tubes. We have made cross-calibration of the full-disk magnetograms obtained by space-borned SDO/HMI and by the ground-based STOP telescope, and pretty good agreement is found. Finally, the absence of significant systematic time variations of MSRs with solar cycle is demonstrated.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2015 

References

Bünte, M, Solanki, S. K. & Steiner, O 1993, A&A 268, 736 Google Scholar
Demidov, M. L. & Veretsky, R. M. 2003, in: Pevtsov, A. A. & Uitenbroek, H. (eds.), Current Theoretical Models and High Resolution Solar Observations: Preparing for ATST, ASP Conf. Series 286 (San Francisco: ASP), p. 133 Google Scholar
Demidov, M. L., Zhigalov, V. V., Peshcherov, V. S., & Grigoryev, V. M. 2002, Solar Phys. 209, 217 Google Scholar
Demidov, M. L., Golubeva, E. M., Balthasar, H., Staude, J., & Grigoryev, V. M. 2008, Solar Phys. 250, 279 Google Scholar
Frutiger, C., Solanki, S. K., & Gandorfer, A. 2003, in: Trujillo Bueno, J. and Sánchez Almeida, J. (eds.), Solar Polarization 3, ASP Conf. Series 307 (San Francisco: ASP), p. 344 Google Scholar
Grossmann-Doerth, U., Schüssler, M., & Solanki, S. K. 1988, A&A 206, L37 Google Scholar
Grossmann-Doerth, U., Keller, C. U., & Schüssler, M. 1996, A&A 315, 610 Google Scholar
Grossmann-Doerth, U., Schüssler, M., Sigwarth, M., & Steiner, O. 2000, A&A 357, 351 Google Scholar
Marsden, S. C., Petit, P., Jeffers, S. V., et al. 2014, MNRAS 444, 3517 Google Scholar
Petit, P., Dintrans, B., & Solanki, S. K., et al. 2008, MNRAS 388, 80 Google Scholar
Solanki, S. K. 1986, A&A 168, 311 Google Scholar
Stenflo, J. O. 1973, Solar Phys. 32, 41 Google Scholar
Stenflo, J. O. & Harvey, J. W. 1985, Solar Phys. 95, 99 Google Scholar
Stenflo, J. O., Demidov, M. L., Bianda, M., & Ramelli, R. 2013, A&A 556, A113 Google Scholar