Spectropolarimetric Observations of the Ca II λ8498 and λ8542 in the Quiet Sun

Pietarila, A.; Socas-Navarro, H.; Bogdan, T.
Bibliographical reference

The Astrophysical Journal, Volume 663, Issue 2, pp. 1386-1405.

Advertised on:
7
2007
Number of authors
3
IAC number of authors
0
Citations
31
Refereed citations
29
Description
The Ca II infrared triplet is one of the few magnetically sensitive chromospheric lines available for ground-based observations. We present spectropolarimetric observations of the 8498 and 8542 Å lines in a quiet Sun region near a decaying active region and compare the results with a simulation of the lines in a high plasma-β regime. Cluster analysis of Stokes V profile pairs shows that the two lines, despite arguably being formed fairly close, often do not have similar shapes. In the network, the local magnetic topology is more important in determining the shapes of the Stokes V profiles than the phase of the wave, contrary to what our simulations show. We also find that Stokes V asymmetries are very common in the network, and the histograms of the observed amplitude and area asymmetries differ significantly from the simulation. Both the network and internetwork show oscillatory behavior in the Ca II lines. It is stronger in the network, where shocking waves, similar to those in the high-β simulation, are seen and large self-reversals in the intensity profiles are common.
Type