Bibcode
Orozco Suárez, D.; Bellot Rubio, L. R.; Vögler, A.; Del Toro Iniesta, J. C.
Bibliographical reference
Astronomy and Astrophysics, Volume 518, id.A2
Advertised on:
7
2010
Journal
Citations
26
Refereed citations
25
Description
Context. The physical conditions of the solar photosphere change on very
small spatial scales both horizontally and vertically. Such a complexity
may pose a serious obstacle to the accurate determination of solar
magnetic fields. Aims: We examine the applicability of
Milne-Eddington (ME) inversions to high spatial resolution observations
of the quiet Sun. Our aim is to understand the connection between the ME
inferences and the actual stratifications of the atmospheric parameters.
Methods: We use magnetoconvection simulations of the solar
surface to synthesize asymmetric Stokes profiles such as those observed
in the quiet Sun. We then invert the profiles with the ME approximation.
We perform an empirical analysis of the heights of formation of ME
measurements and analyze the uncertainties brought about by the ME
approximation. We also investigate the quality of the fits and their
relationship with the model stratifications. Results: The
atmospheric parameters derived from ME inversions of high-spatial
resolution profiles are reasonably accurate and can be used for
statistical analyses of solar magnetic fields, even if the fit is not
always good. We also show that the ME inferences cannot be assigned to a
specific atmospheric layer: different parameters sample different ranges
of optical depths, and even the same parameter may trace different
layers depending on the physical conditions of the atmosphere. Despite
this variability, ME inversions tend to probe deeper layers in granules
than in intergranular lanes.
Figure 10 and appendix are only available in electronic form at http://www.aanda.org