Solar Magnetograms at 12 μm Using the Celeste Spectrograph
Abstract
We present the first solar vector magnetogram constructed from measurements of infra-red Mg I 12.32-μm line spectra. Observations were made at the McMath-Pierce Telescope using the Celeste spectrometer/polarimeter. Zeeman-split Stokes line spectra were fitted with Seares profiles to obtain the magnetic field parameters. Maps of absolute field strength, line-of-sight angle, and azimuth are presented. Analysis shows that the variation in field strength within a spatial resolution element, 2 arcseconds, is greatest in the sunspot penumbra and that this is most likely caused by vertical field strength gradients, rather than horizontal image smearing. Widths of the Zeeman-split σ components, assuming a formation layer thickness of 200 km, indicate that vertical field strength gradients can be as large as 6.5 G/km in a penumbra.
- Publication:
-
Solar Physics
- Pub Date:
- April 2007
- DOI:
- 10.1007/s11207-007-0271-1
- Bibcode:
- 2007SoPh..241..213M
- Keywords:
-
- Solar Phys;
- Strength Gradient;
- NOAA Region;
- Bipolar Region;
- Component Width