Dynamics of the Transversal Magnetic Fields in Photospheric Quiet Regions

Abstract

Investigation of the properties of photospheric magnetic fields could shed light on the generation mechanism of small-scale magnetic fields in quiet regions. In this work, we studied the transversal magnetic fields by analyzing the linear polarization (LP) features with Sunrise IMaX data. We calculated the area coverage of LP features, and found that they are 16.1%, 8.6%, and 3% for signals above 3, 3.5, and 4.5 times of noise level, respectively. Those LP features extracted above 4.5 times of noise level are further analyzed. A proper value of 1.5 × 1015 Mx for the net magnetic flux contained in LP features is selected to divide the LP features into two types (I and II). Among all detected snapshot LP features, 86% of them are in type I and the rest are in type II. The length scales of LP features in these two types follow Gauss and power-law distributions, separately. For the topology of magnetic fields in type I, the magnetic flux patches might be footpoints of flux loops that root inside transversal magnetic fields with one unipolar thick leg or one thick leg together with one thin leg in opposite polarity. For those in type II, about 50% of them contain bipolar magnetic flux patches, but the rest appear without magnetic flux patches.

Quantifying Poynting Flux in the Quiet Sun Photosphere

“…As can be seen in Figure 1, the polarimetric signal, particularly in Q and U (panels (b) and (c)), is quite weak in our data (<200 G in most of the FOV). This is of course to be expected in the QS regime, where magnetic fields are only strong enough to produce distinct linear polarization features in 3%-16% of pixels in the FOV of SUNRISE/IMaX (Kianfar et al 2018;Liu et al 2022). In parts of the analysis that follows, we only consider regions of the FOV with signal strengths above a certain threshold.…”