Bibcode
Beck, C.; Mikurda, K.; Bellot Rubio, L. R.; Schlichenmaier, R.; Sütterlin, P.
Referencia bibliográfica
"Modern solar facilities - advanced solar science, Proceedings of a Workshop held at Göttingen September 27-29, 2006 ISBN 978-3-938616-84-0 382 pages, many illustrations, soft-bound, Price: 23.- Euros Published by Universitätsverlag Göttingen (http://univerlag.uni-goettingen.de The online edition (PDF, 12 MB) is available free of charge at: http://webdoc.sub.gwdg.de/univerlag/2007/solar_science_book.pdf, p.165"
Advertised on:
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2007
Número de citas
1
Número de citas referidas
1
Descripción
Bright points (BPs) visible in the G band at 430 nm are commonly used as
tracers of magnetic fields, indicating the location of kG flux
concentrations. To study the actual magnetic properties of G-band BPs,
we took observations in 2003 and 2005, employing simultaneously a
speckle setup in the G band and vector spectropolarimetry to derive the
magnetic field vector. From the analysis of the co-aligned polarimetric
data we find that the BPs show a broad range of field strengths,
magnetic fluxes, and field inclinations. Many G-band BPs are not
co-spatial with the central part of the nearby flux concentrations. Even
at the small heliocentric angle of only 12°, the BPs appear
projected on adjacent granules, whereas the magnetic field is
concentrated in the intergranular lanes. Our findings support the view
that the G-band BPs are a result of the "hot wall effect". The downward
shift of the optical depth scale in the presence of magnetic fields
allows to see deeper and hotter layers in the hot granules next to the
field concentrations, where CH dissociates. Thus, information drawn from
imaging observations of BPs has limited use to investigate the actual
magnetic field structure, when the BPs are not co-spatial with the
central part of the flux concentrations.