Accurate Intensity Velocity Phase Difference in the Potassium Resonance Line Obtained with VAMOS
Abstract
We present new results about the phase difference between the intensity and velocity fluctuations of the solar photosphere obtained with the Velocity And Magnetic Observations of the Sun (VAMOS) instrument, which uses the magneto-optical filter (MOF) technique. Before this observing run, we applied the calibration method described in Magrì, Oliviero, and Severino (Solar Phys.232, 159, 2005) to reduce the instrumental cross-talk which was present in previous VAMOS data. The quality of this calibration, which can be easily applied to any MOF-based instrument, has been confirmed by comparing with the MOF transmission-profile measurements obtained with a diode laser system. Finally, we discuss the new VAMOS phase-difference value in relation to data obtained by other authors in the same potassium spectral line and in other lines that can be used to study nonadiabatic effects of solar global oscillations.
- Publication:
-
Solar Physics
- Pub Date:
- January 2008
- DOI:
- 10.1007/s11207-007-9035-1
- Bibcode:
- 2008SoPh..247...15M
- Keywords:
-
- Solar photosphere;
- Solar oscillations;
- Magneto-optical filter