All Figures

$\begin{figure} \par\includegraphics[angle=0,width=8.5cm,clip]{3334f01.eps} \end{figure}$ Figure 1: Slit-jaw images of the scanned area during the July observations. The black rectangle in both images delineates the scanned area. Top: while-light broad-band image. The excellent seeing conditions during this observing run is apparent from the sharpness of the granulation. Bottom: Ca II K image. The absence of brightness at this wavelength in the scanned rectangle suggests that it is representative of the inter-network.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f02.eps} \end{figure}$ Figure 2: Stokes V class profiles $\vec{S}_{\rm class}$ resulting from a PCA classification. Vertical dotted lines indicates the average wavelength of the $\lambda$ 15 648 Å line in the nearly field-free part of the quiet Sun (see Sect. 2). Horizontal dotted lines indicate the continuum or zero level. The two spectral lines were classified simultaneously. The values at the vertical axis are arbitrary. The number of the profiles belonging to each class is given in percent at the top of each panel. The values are given for the July and September data separately and for both datasets together. The variation in the number of profiles is a standard deviation from the mean value (see text for details). The classes are sorted out according to the number of observed profiles assigned to them.
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In the text

$\begin{figure} \par\includegraphics[width=15.6cm,clip]{3334f03.eps} \end{figure}$ Figure 3: Stokes V maps of the inter-network regions. Upper panel: July data; lower panel: September data. The horizontal direction corresponds to the direction of the slit, the vertical to the scan direction. Each pixel is represented by a coloured square with the corresponding Fe I 15 648 Å Stokes V profile drawn inside. The different colours represent the various classes of profiles. The colour coding is the same as in Fig. 2. The two pixel columns with noisy profiles in the July map are due to a bad flatfield correction.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f04.eps} \end{figure}$ Figure 4: Stokes Q and U class profiles $\vec{S}_{\rm class}$ resulting from a PCA classification. All the notations are the same as in Fig. 2.
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In the text

$\begin{figure} \par\includegraphics[width=17.4cm,clip]{3334f05.eps} \end{figure}$ Figure 5: Distribution of various parameters over the inter-network region (July data). Panels (from the left to the right, from the top to the bottom) are intrinsic unsigned magnetic field strength, inclination of the magnetic vector, logarithm of the filling factor, logarithm of magnetic flux, Stokes Vzero-crossing velocity, V amplitude asymmetry. The values of each parameter are indicated by the corresponding colour bars. Pixels coloured black either harbor signal below the threshold or profiles of 3-lobe classes for Stokes V.
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In the text

$\begin{figure} \par\includegraphics[width=17.5cm,clip]{3334f06.eps} \end{figure}$ Figure 6: Histograms of Zeeman splitting. Left panel: Stokes V $\sigma$ -component splitting. Only profiles of the 2-lobe classes 1, 2, 4, 6 from Fig. 2 are used. Dotted line: fit by an exponential function $A\exp(-B/B_0)$ to the right part of the histogram beyond the maximum. The upper horizontal axes indicate the splitting in Å, the lower axes in G (i.e. converted into field strength). Right panel: Stokes Q and U $\sigma$ -component splitting. Only classes 1, 2, 3 from Fig. 4 are used. Dashed line: Histogram of Stokes V splitting for the pixels where a significant signal in Stokes Q and/or U is present.
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In the text

$\begin{figure} \par\includegraphics[width=17.3cm,clip]{3334f07.eps} \end{figure}$ Figure 7: The Stokes V splitting as a function of continuum intensity (left panel) and Stokes V zero crossing velocities (right panel). 7808 profiles from Stokes V classes 1, 2, 4, 6 are used. The values of the splitting are binned into 9 intervals containing an equal number of points. Error bars show the standard deviation within each interval. Zero crossing velocities are measured with respect to the wavelength of the minimum Stokes I.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{3334f08.eps} \end{figure}$ Figure 8: Histograms of Zeeman splitting. Only profiles of the 2-lobe classes 1, 2, 4, 6 from Fig. 2 of the July data are used. The format of the figure is the same as Fig. 5. Solid line - histogram over all the points. Dotted line - only Stokes V from the pixels with $I_{\rm c} < 1$ (intergranular lanes). Dashed line - only Stokes V from the pixels with $I_{\rm c} > 1$ (granules).
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In the text

$\begin{figure} \par\includegraphics[width=8.6cm,clip]{3334f09.eps} \end{figure}$ Figure 9: Error of the derived inclination $\gamma$ . Filled circles indicate values of $\delta \gamma =\gamma -\gamma _0$ , averaged over the input values $\gamma _0$ ranging from 10 $^\circ$ to 80 $^\circ$ . Values of the inclination $\gamma$ are inferred from the synthesized profiles using the relation (5) involving the amplitudes of the fitted Gaussians. Error bars show the standard deviation of $\delta \gamma$ .
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{3334f10.eps} \end{figure}$ Figure 10: Histogram of the ratio of Stokes Q and U amplitudes to Stokes V amplitude. The values of the amplitudes of the Stokes parameters were taken from the Gaussian fit to the profiles. The horizontal upper axis denotes the amplitude ratio, and the lower axis the values of the inclination angle derived from this ratio. Solid line: histogram over all points where signal in at least one of the Stokes Q, U or V profiles is above the noise level. Dashed line: histogram over points where signal in Stokes V exists. Dotted line: histogram over points where signal in Stokes Q and/or Stokes U exists.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{3334f11.eps}\end{figure}$ Figure 11: Histogram of magnetic flux per pixel. Upper horizontal axis indicates values of the spatially averaged magnetic field strength per pixel. Lower horizontal axis indicates flux.
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In the text

$\begin{figure} \par\includegraphics[width=17.1cm,clip]{3334f12.eps} \end{figure}$ Figure 12: Left panel: scatter plot of the splitting vs. magnetic flux. Right panel: the same, but for binned values.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f13.eps} \end{figure}$ Figure 13: Histograms of the line-of-sight velocities in the magnetized and in the (nearly) field-free atmospheres. Top panel: Stokes V zero-crossing velocity. Solid line: all V profiles. Dashed line: zero-crossing velocities at the pixels where signal in Stokes V is accompanied by a signal in Stokes Q and/or U. Middle panel: histogram of the Stokes Q and U $\pi$ -component velocities. Bottom panel: LOS velocities from Stokes I. Solid line: only pixels with the magnetic signal below the threshold were used. Dotted line: only pixels with the splitting in Stokes V larger than 500 G were used.
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In the text

$\begin{figure} \par\includegraphics[width=17.8cm,clip]{3334f14.eps} \end{figure}$ Figure 14: Velocity correlations. Top left: $v_{\rm zc}$ vs. v_I. Solid points are binned values. Error bars indicate standard deviation. Top right: $v_{\rm zc}$ vs. v_qu. Bottom left: v_Ivelocities vs. continuum intensity at the non-magnetic pixels. Bottom right: $v_{\rm zc}$ vs. continuum intensity $I_{\rm c}$ . Only the July dataset was used for this plot due to the better seeing conditions.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f15.eps} \end{figure}$ Figure 15: Histograms of the amplitude and area asymmetries of the $\sigma$ -components of Stokes V (two upper panels) and amplitude asymmetry of the $\sigma$ -components of the Stokes Q and Uprofiles (lower panel). The asymmetries are given in percent.
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In the text

$\begin{figure} \par\includegraphics[width=17.5cm,clip]{3334f16.eps} \end{figure}$ Figure 16: Stokes V amplitude and area asymmetries for different classes. The three top panels are for classes 2, 3 and 5 from Fig. 2. Solid line: class 2, dotted line: class 3, dashed line: class 5. Top left: amplitude asymmetry vs. $v_{\rm zc}$ , Top middle: area asymmetry vs. $v_{\rm zc}$ , Top right: area asymmetry vs. amplitude asymmetry. Error bars indicate standard deviation of the data points. The three bottom panels are for classes 1, 4 and 6 from Fig. 2. Thick solid line: class 1, dotted line: class 4, dashed line: class 6.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f04.eps} \end{figure}$	Figure 4: Stokes Q and U class profiles $\vec{S}_{\rm class}$ resulting from a PCA classification. All the notations are the same as in Fig. 2.
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{3334f08.eps} \end{figure}$	Figure 8: Histograms of Zeeman splitting. Only profiles of the 2-lobe classes 1, 2, 4, 6 from Fig. 2 of the July data are used. The format of the figure is the same as Fig. 5. Solid line - histogram over all the points. Dotted line - only Stokes V from the pixels with $I_{\rm c} < 1$ (intergranular lanes). Dashed line - only Stokes V from the pixels with $I_{\rm c} > 1$ (granules).
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{3334f11.eps}\end{figure}$	Figure 11: Histogram of magnetic flux per pixel. Upper horizontal axis indicates values of the spatially averaged magnetic field strength per pixel. Lower horizontal axis indicates flux.
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$\begin{figure} \par\includegraphics[width=17.1cm,clip]{3334f12.eps} \end{figure}$	Figure 12: Left panel: scatter plot of the splitting vs. magnetic flux. Right panel: the same, but for binned values.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{3334f15.eps} \end{figure}$	Figure 15: Histograms of the amplitude and area asymmetries of the $\sigma$ -components of Stokes V (two upper panels) and amplitude asymmetry of the $\sigma$ -components of the Stokes Q and Uprofiles (lower panel). The asymmetries are given in percent.
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