Institute for Geophysics, Astrophysics, and Meteorology 2D spectropolarimetric analysis of a small active region in the solar photosphere Stefan Stangl Institute for Geophysics, Astrophysics, and Meteorology

Observations date: 11.05.2002 device: VTT Tenerife and ‘‘Göttingen“ Fabry-Perot Interferometer wavelength: 2 Fe I lines 6301.5 Å, 6302.5 Å + telluric O2 data: 40 scans with 150 images at 30 wavelength positions (5 images/position), exposure time 30 ms, total time per scan 51 s (-> time series of 34 minutes), one wavelength step is 31.74 m Å region: small pore position: x = -152.3‘‘, y = -86.4‘‘ seeing: good (9.9 < r0 < 11.8), from scan 24 moderate (r0 < 9.8), with r0 as Fried parameter (cm)

Lineprofiles Fe I 6302.5 Å O2 6302.76 Å 1/2 (I+V) 1/2 (I-V) Original line profiles, broadband -> speckle reconstructed, narrowband -> similar reconstruction 1/2 (I+V) 1/2 (I-V)

Bright points in speckle image Field strength Velocity Linecore Speckle image The aim of my work is to reveal details of small bright points in the broadband speckle image and to infer some physical properties like LOS velocity and magnetic field strength (, and evolution, life times). This region was selected due to the bright point in the middle of the snapshots and it is 25% brighter than the mean continuum intensity. We see that this points is not at all bright in the linecore image and has only moderate field strength. In the velocity maps there is no suspicous signal associated with this point. However, in the last image this point has merged with the adjacent granule and now it is bright in the linecore image, separated in the velocity image and also in the magnetic map. Subfield 4 x 4 arcsec2, FOV 11.7 x 16.5 arcsec2, contours: ILC + 1.33 sLC

Bright points in linecore image Field strength Velocity Linecore Speckle image Contrary to the previous slide this area was selected due to an increased number of bright points in the linecore images. Subfield 4 x 4 arcsec2, FOV 11.7 x 16.5 arcsec2, contours: ILC + 1.33 sLC

two selected subfields Histograms whole FOV Histograms of the two shown regions which exhibit the detailed distribution of the small FOV whereas the histograms on the right side smear out all of the fine details (whole FOV) and give therefore no useful information of the interested areas. two selected subfields

3D scatter plots These 3D scatter plots were computed by considering all pixels in the total field of view and the whole time series of 32 images. Linecore intensity – normalised to the broadband continuum intesity as reference – is shown as a function of the LOS velocity and additionally color coded with the LOS magnetic field strength. The adjacent colorbars show the values of the field strength for each pixel. Similar but not the same Left 6301.5, right 6302.5 Dark blue: pore and pore like structures, bulk in the middle: granulation, LC bright points above granulation: have nearly same velocity distribution as pore, but weaker field strength, and smaller in spatial directions.

Relation of 6301.5 to 6302.5 v(6303)/v(6302) = 1.105 Do we measure different physical quantities (LOS velocity, LOS field strength) with two different spectral lines in the same way? If the relation of the results from the line 6301.5 and 6302.5 is 4/3 (ratio of the effective Lande factors of the two lines) or nearly 4/3 the measurements provide information from the nearly same layer in the solar photosphere. And we are relatively far away from these values, i.e. the gained results (maps of velocity and field strength) are not exactly compareable. v(6303)/v(6302) = 1.105 B(6303)/B(6302) = 1.097

Movie of 6302 magnitudes