Bibcode
Koutchmy, S.; Molowny-Horas, R.; Baudin, F.
Bibliographical reference
Astronomy and Astrophysics, v.326, p.842-850
Advertised on:
10
1997
Journal
Citations
15
Refereed citations
13
Description
The properties of the photosphere in magnetic and non magnetic regions,
at two levels in the solar atmosphere, have been studied, using two
virtually simultaneous time sequences of 109 mn duration of CCD images
taken at the Vacuum Tower Telescope of the Sacramento Peak Observatory.
The selected wavelengths correspond to the true continuum and to the
wing of the MgIb_1_ line, where brightenings are taken as proxies of
magnetic elements. Averaged intensities, intensity fluctuations and
horizontal motions in different regions and levels of the photosphere
have been compared. We obtained various results concerning: the
intensities inside and outside an active region showing different
behaviours; the granulation keeping a kind of remnant structure at the
continuum level; the mapping of proper motions of the granules imaged in
the continuum outlining clearly the super-granular cells in the deepest
layers of the photosphere; the ``freezing'' influence of the magnetic
field on these motions in active regions; and the temporal variation of
the correlation between images at the two heights indicating that
intensity variations at the higher level precede those of the lower one.
These results are briefly discussed and compared with previous ones and
with published model calculations.