Christoph Keller
NSO/T Scientific Staff, Associate Astronomer
Areas of Interest
Solar Magnetic Fields, Asteroseismology, High-precision Imaging Polarimetry,
Image Reconstruction Techniques, Telescope and Instrument Design
Recent Research Results
Speckle polarimetry with the Dunn Solar Telescope has provided images of 79
individual
magnetic elements close to disk center in the quiet network at a spatial
resolution approaching
0.2. The average filling factor of 0.73 indicates that many of the elements
are almost spatially
resolved. A statistical analysis of these elements shows that almost all of
them are brighter in
white light than the average solar photosphere, in contrast to magnetic
elements in plages.
Typical diameters range from 200 to 400 km; magnetic fluxes range from 2e17
to 3e18 Mx.
Future Research Plans
Apart from working on SOLIS, which will use the major fraction of Keller's
time during the next
two years, he will use the McMath-Pierce facility to investigate scattering
polarization in the
photosphere and the chromosphere, which gives new insight into atoms and
molecules and
their radiation in the solar atmosphere and properties of weak, turbulent
magnetic fields.
Observations with the Dunn Solar Telescope using adaptive optics in
combination with phase-diverse speckle imaging will be used to study the dynamics of magnetic elements
.
Service
Keller is the telescope scientist for the McMath-Pierce telescope. He
provides observing support
at the McMath-Pierce and sometimes at the Sacramento Peak facilities. He is
the lead scientist
for the real-time software and hardware efforts for SOLIS and co-leads the
Vector-Spectromagnetograph effort. Keller is a member of the local and NSO-wide
Project Review
Committees and the NOAO Exploration of Technology group.
For further information go to
Christoph Keller's Home Page.
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Updated: 28Jun1999