Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001a%26a...367.1033s&link_type=abstract
Astronomy and Astrophysics, v.367, p.1033-1048 (2001)
Astronomy and Astrophysics
Astrophysics
17
Polarization, Scattering, Sun: Magnetic Fields, Atomic Processes, Techniques: Polarimetric
Scientific paper
To clarify the physical nature of the enigmatic scattering polarization in the Na i D1 and D2 line cores we have explored their behavior with full Stokes vector polarimetry in regions with varying degree of magnetic activity near the solar limb. These observations represent the first time that ZIMPOL II, the second generation of our CCD based imaging polarimeter systems, has been used for a scientific program. With ZIMPOL II the four Stokes images can be demodulated and recorded with a single CCD sensor such that the resulting images of the fractional polarization Q/I, U/I, and V/I are entirely free from spurious features due to seeing or flat-field effects. The polarization in the cores of the lines, in particular in D2, exhibits dramatic and unexpected spatial variations in both Q/I and U/I, including polarization self-reversals of the D2 Q/I core peak. As the fluctuations in the Q, U, and V parameters appear to be relatively uncorrelated, we have parametrized the profiles and made scatter plots of the extracted parameters. Comparison with synthetic scatter plots based on different theoretical models suggests that the polarization signals in the cores of the D2 and D1 lines have different physical origins: While the D1 core is likely to be governed by ground-state atomic polarization, the D2 core is dominated by the alignment of the excited state and by effects of partial frequency redistribution.
Gandorfer Achim
Keller Christoph U.
Stenflo Jan Olof
Wenzler T.
No associations
LandOfFree
Influence of magnetic fields on the coherence effects in the Na I D1 and D2 lines does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Influence of magnetic fields on the coherence effects in the Na I D1 and D2 lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Influence of magnetic fields on the coherence effects in the Na I D1 and D2 lines will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1002335