Free access article
A&A 405, 331-340 (2003)
DOI: 10.1051/0004-6361:20030595
Imaging spectroscopy of solar pores
J. HirzbergerInstitut für Geophysik, Astrophysik und Meteorologie, Universitätsplatz 5, 8010 Graz, Austria
(Received 11 February 2003 / Accepted 10 April 2003)
Abstract
Time series of two-dimensional spectra and corresponding
broad band images of solar pore regions have been obtained with
the "Göttingen" Fabry-Perot Interferometer at the Vacuum Tower
Telescope in Izaña, Tenerife. Line bisector shifts have been used
for the computation of line-of-sight velocities in the studied regions.
Additionally, a local correlation tracking (LCT) algorithm has been
applied to obtain horizontal flow velocities from the time series of
broad band images. Resulting velocity maps show that within the pore
umbrae the flows are almost completely inhibited by the magnetic
fields. This also holds for umbral dots and light bridges. On the
boundaries of several pore umbrae persistent downflow channels are
visible. The structure and temporal evolution of these phenomena
have been studied. Finally, the formation of a protopore out of
magnetic bright points has been analyzed. The obtained observational
results are in good agreement with numerical models and common
theoretical scenarios explaining the behaviour and formation of
solar pores.
Key words: Sun: photosphere -- Sun: magnetic fields -- Sun: sunspots
© ESO 2003



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