Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f01a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f01b.eps} \end{figure}$ Figure 1: NOAA AR 7981 in EIT Fe XV ( $\lambda ~ 28.4 ~$ nm) image ( left) observed at 12:35 UTC and MDI magnetogram ( right) at 12:51 UTC on 2 August 1996. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f02a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f02b.eps} \end{figure}$ Figure 2: NOAA AR 8534 in EIT Fe XII ( $\lambda ~ 19.5 ~$ nm) image ( left) observed at 13:12 UTC and MDI magnetogram ( right) at 14:24 UTC on 13 May 1999. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=12.2cm]{1060f03.eps} \end{figure}$ Figure 3: Sunspot associated with the AR 7981 of 2 August 1996. The SUMER rear-slit camera image in visible light is shown, indicating the large spot and a related group of smaller spots. The time sequence from 11:19 to 14:21 UTC shows the slow evolution of the spot during solar rotation, which is responsible for the displacement of the spot in the FOV.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=3.9cm,clip]{1060f04a.eps}\hspace*{5mm}... ....eps}\hspace*{5mm} \includegraphics[width=3.9cm,clip]{1060f04d.eps} \end{figure}$ Figure 4: Sunspot associated with the AR 7981 of 2 August 1996. Solar ultraviolet images of the sunspot in the intensities of the lines ( from left to right): H I Ly $\beta$ ( $\lambda ~ 102.5 ~$ nm), N V ( $\lambda ~ 123.8 ~$ nm), O VI ( $\lambda ~ 103.1 ~$ nm), and finally Ne VIII ( $\lambda ~ 77 ~$ nm).
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=3.9cm,clip]{1060f05a.eps}\hspace*{4mm}... ...m}\includegraphics[width=8.3cm,clip]{1060f05e.eps}\hspace*{4.4cm}}\end{figure}$ Figure 5: Sunspot associated with the AR 7981 of 2 August 1996. Solar ultraviolet Doppler images of the sunspot in the shifts of the lines ( from left to right): H I Ly $\beta$ ( $\lambda ~ 102.5 ~$ nm), N V ( $\lambda ~ 123.8 ~$ nm), O VI ( $\lambda ~ 103.1 ~$ nm), and finally Ne VIII ( $\lambda ~ 77 ~$ nm). Note the sharp red-blue boundaries indicating a change in topology from open to closed of the magnetic field confining the plasma and guiding its flow. The red "needle'' pointing into the spot indicates plasma downflow, perhaps guided along a magnetic flux tube ending in the spot.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=5.2cm,clip]{1060f06a.eps}\hspace*{6mm}... ....eps}\hspace*{6mm} \includegraphics[width=5.2cm,clip]{1060f06c.eps} \end{figure}$ Figure 6: Solar ultraviolet images of the emerging AR 8534 of 13 May 1999, which is associated with a sunspot. The images were taken in the radiances of the lines ( from left to right) of Si II ( $\lambda ~ 153.3 ~$ nm), C IV ( $\lambda ~ 154.8 ~$ nm), and Ne VIII ( $\lambda ~ 77 ~$ nm). Note the strong structuring of the region indicating a complex field geometry including loops and fans. The Sun was scanned from east to west between 13:01 and 13:55 UT with the nominal step minus solar rotation ( top panels), and then from west to east between 13:55 and 14:49 UT with the nominal step plus solar rotation ( bottom panels). Each scan took 54 min. The offset of the field of view in the top frames is due to solar rotation.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=5.2cm,clip]{1060f07a.eps}\hspace*{6mm}... ...m}\includegraphics[width=8.4cm,clip]{1060f05e.eps}\hspace*{4.3cm}}\end{figure}$ Figure 7: Solar ultraviolet Dopplergrams of the emerging AR 8534 of 13 May 1999 in the line shifts of the lines ( from left to right) of Si II ( $\lambda ~ 153.3 ~$ nm), C IV ( $\lambda ~ 154.8 ~$ nm), and Ne VIII ( $\lambda ~ 77 ~$ nm). Note the varying and sharp red-blue boundaries, indicating changes in field topology on scales much smaller than the whole sunspot area. The Sun was scanned from east to west between 13:01 and 13:55 UT with the nominal step minus solar rotation ( top panels), and then from west to east between 13:55 and 14:49 UT with the nominal step plus solar rotation ( bottom panels). Each scan took 54 min. The offset of the field of view in the top frames is due to solar rotation.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f08a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f08b.eps}\end{figure}$ Figure 8: NOAA AR 7953 in EIT Fe XII ( $\lambda ~ 19.5 ~$ nm) image ( left) observed at 23:37 UTC and NSO/KP magnetogram ( right) between 14:54 and 15:48 UTC on 23 March 1996. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{1060f09a.eps}\vspace*{1.8cm} \par\includegraphics[width=6.7cm,clip]{1060f09b.eps}\end{figure}$ Figure 9: Top: EIT picture of the active region AR 7953 and the 2-D projection of some reconstructed magnetic field lines, with the force-free parameter times the scale length obeying: $\alpha ~ L=-2.0, \; (\alpha=-1.1 \times 10^{-8}~{\rm{m}}^{-1})$ . Bottom: the same picture, but also showing additional contours of the source magnetic field strength (in Gauss) on the photospheric boundary layer.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{1060f10a.eps}\vspace*{2mm} \includegraphics[width=7.5cm,clip]{1060f10b.eps}\end{figure}$ Figure 10: The magnetic field topology in three dimensions. Magnetic field lines with |B_z| > 50 G on the photosphere are plotted. Here the colour coding, respectively, represents the magnetic field strength in the top panel and the intensity of the EUV emission in the EIT image projected onto the bottom of the coronal box in the bottom panel.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{1060f11a.eps}\vspace*{1.8cm} \par\includegraphics[width=6.7cm,clip]{1060f11b.eps}\end{figure}$ Figure 11: SUMER Dopplergram in Ne VIII ( $\lambda ~ 77 ~$ nm) and a 2-D-projection of some reconstructed magnetic field lines with $\alpha \cdot L=-2.0$ , $(\alpha=-1.1 \times 10^{-8} ~\rm{m}^{-1})$ . The bottom picture shows additional contours of the magnetic field strength on the photosphere. For the white stripes in the left and lower part of the picture SUMER data are not available.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=5.2cm,clip]{1060f12a.eps}\vspace*{5mm} \includegraphics[width=5.2cm,clip]{1060f12b.eps}\end{figure}$ Figure 12: Illustration of the topology of magnetic field lines in the AR. Top: magnetic fields with magnitude larger than 200 G; Bottom: magnetic fields with magnitude smaller than 200 G. The background images show the intensity map of the Ne VIII line, with its Dopplershift contours overlaid. Note the correlation between the Dopplershift pattern and the field being either closed or open.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=90,width=12.1cm,clip]{1060f13a.eps}\pa... ...ace*{1mm} \includegraphics[angle=90,width=12.1cm,clip]{1060f13d.eps}\end{figure}$ Figure 13: Comparisons of magnetic field strength maps, angle maps and Dopplermaps of the active region at four different heights in the atmosphere. Heights from the top to the bottom: 0, 3, 5, 10 Mm. The coloured contours correspond to shifts of $\pm$ 10 km s^-1 (dotted lines) and $\pm$ 5 km s^-1 (continuous lines). Left: magnetograms with Dopplershift contours of the C IV (only upper frame) and Ne VIII (all other frames) lines overlaid. Right: field angle maps with the same contours overlaid.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.2cm,clip]{1060f14a.eps}\vspace*{9mm}... ...\vspace*{1.8cm} \par\includegraphics[width=7.2cm,clip]{1060f14d.eps}\end{figure}$ Figure 14: Illustration of a magnetic flux tube associated with the exemplary active region AR 7953 shown previously. Top: individual perpendicular cuts through the tube, indicating the increasing size of the area with height in the atmosphere. Second row: loop area in arbitrary units (unit area at the right footpoint). Third row: linear loop diameter in arbitrary units (unity at the right footpoint): Bottom: visualization of the entire longitudinal extent of the flux tube, showing its expansion in diameter with height and constriction at the foot points.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{1060f15.eps} \end{figure}$ Figure 15: Dopplergram of the C IV line overlaid by Dopplershift contours of the Ne VIII line, illustrating the difference in plasma velocities as seen, respectively, in the lower and upper transition region. The colour bar gives the coding for the carbon shift. The neon contours correspond to shifts of $\pm 10$ km s^-1 (dotted lines) and $\pm$ 5 km s^-1 (continuous lines). Note the close correlation between the carbon-shift background colour pattern and the neon-shift coloured contours.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{1060f16.eps}\end{figure}$ Figure 16: Scatter plots of the mass flux density derived from the Ne VIII line shift used as a marker of plasma flow, plotted as a function of magnetic flux density derived from the data obtained by NSO/KP. Note that the unit of the mass flux is set at arbitrary values, with negative values indicating upflows and positive downflows.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{1060f17.eps}\end{figure}$ Figure 17: Mass flux densities in arbitrary units as inferred in a coronal loop as a function of normalized coordinate along the loop. For the loop geometry see the previous figures. The averaged data almost form a straight line.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{1060f18a.eps}\vspace*{1.7cm} \hspace*{2mm}\includegraphics[width=6.5cm,clip]{1060f18b.eps}\end{figure}$ Figure 18: Top: illustration of the magnetic field strength in dependence on the normalized coordinate along a single magnetic flux tube associated with the model magnetic field of the exemplary active region AR 7953 shown previously. Bottom: inferred current density distribution in the flux tube, showing a spatial asymmetry and the current concentration at one foot point.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f01a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f01b.eps} \end{figure}$	Figure 1: NOAA AR 7981 in EIT Fe XV ( $\lambda ~ 28.4 ~$ nm) image ( left) observed at 12:35 UTC and MDI magnetogram ( right) at 12:51 UTC on 2 August 1996. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f02a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f02b.eps} \end{figure}$	Figure 2: NOAA AR 8534 in EIT Fe XII ( $\lambda ~ 19.5 ~$ nm) image ( left) observed at 13:12 UTC and MDI magnetogram ( right) at 14:24 UTC on 13 May 1999. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=12.2cm]{1060f03.eps} \end{figure}$	Figure 3: Sunspot associated with the AR 7981 of 2 August 1996. The SUMER rear-slit camera image in visible light is shown, indicating the large spot and a related group of smaller spots. The time sequence from 11:19 to 14:21 UTC shows the slow evolution of the spot during solar rotation, which is responsible for the displacement of the spot in the FOV.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=3.9cm,clip]{1060f04a.eps}\hspace{5mm}... ....eps}\hspace{5mm} \includegraphics[width=3.9cm,clip]{1060f04d.eps} \end{figure}$	Figure 4: Sunspot associated with the AR 7981 of 2 August 1996. Solar ultraviolet images of the sunspot in the intensities of the lines ( from left to right): H I Ly $\beta$ ( $\lambda ~ 102.5 ~$ nm), N V ( $\lambda ~ 123.8 ~$ nm), O VI ( $\lambda ~ 103.1 ~$ nm), and finally Ne VIII ( $\lambda ~ 77 ~$ nm).
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8cm,clip]{1060f08a.eps}\hspace*{6mm} \includegraphics[width=8cm,clip]{1060f08b.eps}\end{figure}$	Figure 8: NOAA AR 7953 in EIT Fe XII ( $\lambda ~ 19.5 ~$ nm) image ( left) observed at 23:37 UTC and NSO/KP magnetogram ( right) between 14:54 and 15:48 UTC on 23 March 1996. The small white frames overlaid represent the FOV of SUMER.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{1060f10a.eps}\vspace*{2mm} \includegraphics[width=7.5cm,clip]{1060f10b.eps}\end{figure}$	Figure 10: The magnetic field topology in three dimensions. Magnetic field lines with \|B_z\| > 50 G on the photosphere are plotted. Here the colour coding, respectively, represents the magnetic field strength in the top panel and the intensity of the EUV emission in the EIT image projected onto the bottom of the coronal box in the bottom panel.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{1060f11a.eps}\vspace*{1.8cm} \par\includegraphics[width=6.7cm,clip]{1060f11b.eps}\end{figure}$	Figure 11: SUMER Dopplergram in Ne VIII ( $\lambda ~ 77 ~$ nm) and a 2-D-projection of some reconstructed magnetic field lines with $\alpha \cdot L=-2.0$ , $(\alpha=-1.1 \times 10^{-8} ~\rm{m}^{-1})$ . The bottom picture shows additional contours of the magnetic field strength on the photosphere. For the white stripes in the left and lower part of the picture SUMER data are not available.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{1060f16.eps}\end{figure}$	Figure 16: Scatter plots of the mass flux density derived from the Ne VIII line shift used as a marker of plasma flow, plotted as a function of magnetic flux density derived from the data obtained by NSO/KP. Note that the unit of the mass flux is set at arbitrary values, with negative values indicating upflows and positive downflows.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{1060f17.eps}\end{figure}$	Figure 17: Mass flux densities in arbitrary units as inferred in a coronal loop as a function of normalized coordinate along the loop. For the loop geometry see the previous figures. The averaged data almost form a straight line.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{1060f18a.eps}\vspace{1.7cm} \hspace{2mm}\includegraphics[width=6.5cm,clip]{1060f18b.eps}\end{figure}$	Figure 18: Top: illustration of the magnetic field strength in dependence on the normalized coordinate along a single magnetic flux tube associated with the model magnetic field of the exemplary active region AR 7953 shown previously. Bottom: inferred current density distribution in the flux tube, showing a spatial asymmetry and the current concentration at one foot point.
Open with DEXTER