All Figures

$\begin{figure} \par\includegraphics[width=9cm,clip]{0030scmd.eps} \end{figure}$ Figure 1: Schematic drawing of the heliospheric interface, which is the boundary region between the solar wind and the Local Interstellar Cloud (LIC).
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0040orbn.eps}\end{figure}$ Figure 2: Ecliptic plane projections of the orbits of Nozomi (solid line) and Earth (dashed line). The numbers at the lines represent the months during the year 2000. The cross marks the position of the spacecraft and the diamond that of the Earth on April 5, 2000, corresponding to Figs. 5, 6. The line of sight of the Lyman $\alpha$ observations discussed in the text are always almost perpendicular to the line connecting the Nozomi spacecraft and Earth. Note that the orbit of Nozomi is inclined at a small angle to the ecliptic plane and the lines of sight discussed in the paper are selected to pass within 5 $^\circ$ of the ecliptic.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{0050scmo.eps} \end{figure}$ Figure 3: Schematic representation of the geometry of Nozomi observations. The spacecraft spin axis, which coincides with the high gain antenna direction, is maintained oriented towards the Earth. The field of view of the UVS instrument is perpendicular to the spin axis of the spacecraft. Thus during each spin of the spacecraft the line of sight intersects twice the ecliptic plane, which happens at points A and B. Since the orbit of Nozomi is inclined at a small angle to the ecliptic plane, the angular separation between A and B s usually a little less than 180 $^\circ$ . The location of the scanned strip of the sky changes in time because of the repositioning of the Nozomi rotation axis, maintained aligned at Earth, which results in changing of the longitude of points A and B. The meshed surface represents a typical distribution of the calculated volume emission rate (source function) of neutral interplanetary hydrogen, which is proportional to the local density divided by the square of solar distance.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{0060losn.eps} \end{figure}$ Figure 4: Circular tracks of the lines of sight of Nozomi UVS (solid) and XUV (broken) instruments on April 5, 2000, projected on a sky map. The line of sight of XUV is inclined by 19 $^\circ$ anti-earthward with respect to the spin plane. The directions of the spin axis and earth are shown by the cross and the diamond, respectively, and are practically identical. The canonical upwind and downwind directions are shown by the double circles. The circles A and B show the intersections of the line of sight of UVS (solid line) with the ecliptic plane. The numbers at the line of sight contour of UVS correspond to the spin angle on the horizontal axis in Fig. 5 and the numbers at the XUV contour to sector numbers on the horizontal axis in Fig. 6.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0070iuvs.eps}\end{figure}$ Figure 5: The Lyman $\alpha$ glow intensity observed by the UVS instrument on April 5, 2000. The units of the intensity are Rayleighs. The solid line shows the original data, and the broken line the data corrected by low- and medium-pass filtering, which reduce noise and the star contamination seen, e.g., at 301 $^\circ$ .
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0080ixuv.eps} \end{figure}$ Figure 6: The He I glow intensity observed by XUV on April 5, 2000. The units of the intensity are Rayleighs. The data around the sector number 32 are excluded from this analysis because of background due to solar stray light.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{0090fxuv.eps}\end{figure}$ Figure 7: Full sky intensity map of the interplanetary He 58.4 nm emission. The maximum is located at day of year (DOY) 90 and in sector 6, which is the gravitational helium focusing cone. The gray pixels show the data excluded from the analysis because of contamination by stray light and energetic particles.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{0100fuvs.eps} \end{figure}$ Figure 8: Full sky intensity map of interplanetary hydrogen Lyman $\alpha$ emission, derived from UVS measurements performed during one year, from 17 March 2000 to 13 March 2001.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm]{0110radp.eps}\end{figure}$ Figure 9: Time variations of the ratio of solar radiation pressure to solar gravity, used in the three-dimensional fully time-dependent hydrogen model. Monthly averages are computed for each moment of the Nozomi observations from a time series of the solar Lyman $\alpha$ flux returned by the SOLAR2000 model.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm]{0120lymp.eps} \end{figure}$ Figure 10: The solar Lyman $\alpha$ line profile for a date corresponding to the Nozomi observation, taken from Lemaire et al. (2002).
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0130iecp.eps}\end{figure}$ Figure 11: Intensity of the Lyman $\alpha$ backscatter emission observed by UVS on scans A and B, normalized to their respective mean values and shown as a function of the ecliptic longitude. The scanning in the longitude was performed by repositioning the spin axis of the spacecraft towards earth; thus each point on a scan line was observed on a different date and from a different location in the heliosphere. The canonical upwind and downwind directions are shown by the vertical bars.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0140cecp.eps} \end{figure}$ Figure 12: Simulated intensities of the Lyman $\alpha$ backscatter emission, calculated for the Nozomi in-ecliptic observations with the use of the one-population hot model (pink lines), normalized to the respective mean values, compared with the observations (black lines) shown in Fig. 11. The horizontal axis is the day number from January 1, 1996. The upwind direction in the calculations was set to the canonical direction (254 $^\circ$ ). The solid lines correspond to scan A, and the dotted lines to scan B. The broken lines represent the 27 day running averages of these observations. The vertical bars show the days when the lines of sight are supposed to pass through the longitude of the canonical upwind and downwind directions.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0150shhm.eps} \end{figure}$ Figure 13: Variations of simulated intensity of the heliospheric Lyman $\alpha$ emission for scans A and B, calculated with the use of the one-population hot model for three different upwind directions of interstellar gas: canonical $254\hbox {$^\circ $ }(orange)$ , $274\hbox {$^\circ $ }(blue)$ , and $234\hbox {$^\circ $ }(green)$ . The black lines are the smoothed observations curves, identical to the black broken lines in Fig. 12. The vertical bars mark the upwind and downwind directions.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0160secc.eps} \end{figure}$ Figure 14: The ratio of the glow intensity from the secondary component to the net intensity along the two sets of Nozomi lines of sight (A and B) in the ecliptic plane. The vertical bars mark the upwind and downwind positions.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0170otot.eps} \end{figure}$ Figure 15: Comparison between the Lyman $\alpha$ intensity observed by UVS and calculated in the simulations. The black lines show the variation of the Lyman $\alpha$ intensity observed by UVS at scans A (solid) and B (dotted) in the ecliptic plane ( $\pm 5\hbox {$^\circ $ }$ ). The green lines show the calculated intensity derived from the two-component model. Each result is plotted as an intensity normalized to its mean value over the time span. The vertical bars mark then upwind and downwind positions.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0180c2md.eps}\end{figure}$ Figure 16: Comparison between Lyman $\alpha$ intensity observed Nozomi/UVS and calculated using the two-component models. The black lines show the variation of the Lyman $\alpha$ intensity observed by UVS on two lines of sight, A (solid) and B (dotted), located within $\pm 5\hbox {$^\circ $ }$ from the ecliptic plane. The green, orange, and blue lines show the calculated intensity for which the upwind longitudes of the secondary component of heliospheric hydrogen are given as $234.68\hbox {$^\circ $ }$ , $254.68\hbox {$^\circ $ }$ , and $274.68\hbox {$^\circ $ }$ . The latitude is unchanged. The vertical bars mark the upwind and downwind positions.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0190down.eps}\end{figure}$ Figure 17: Expanded views of the area in the downwind direction for scans A and B. The format is the same as in Fig. 16.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0200rmsd.eps}\end{figure}$ Figure 18: Diagnostics by residual $\chi ^{2}$ for the scans A and B in the downwind direction, seen in Fig. 17.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{0210clat.eps}\end{figure}$ Figure 19: Comparison between the observations and calculations performed with the use of the two-component model. The upwind directions for the secondary component were set to $1.1\hbox {$^\circ $ }$ , $5.6\hbox {$^\circ $ }$ , $8.5\hbox {$^\circ $ }$ , $11.7\hbox {$^\circ $ }$ , and $14.9\hbox {$^\circ $ }$ in the ecliptic latitude and $254.68\hbox {$^\circ $ }$ in the ecliptic longitude. The red and purple lines show the UVS data, while the yellow, green, and blue lines show the results performed for $1.1\hbox {$^\circ $ }$ , $8.5\hbox {$^\circ $ }$ , $14.9\hbox {$^\circ $ }$ , respectively. The vertical bars mark the canonical upwind and downwind positions.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{0030scmd.eps} \end{figure}$	Figure 1: Schematic drawing of the heliospheric interface, which is the boundary region between the solar wind and the Local Interstellar Cloud (LIC).
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0070iuvs.eps}\end{figure}$	Figure 5: The Lyman $\alpha$ glow intensity observed by the UVS instrument on April 5, 2000. The units of the intensity are Rayleighs. The solid line shows the original data, and the broken line the data corrected by low- and medium-pass filtering, which reduce noise and the star contamination seen, e.g., at 301 $^\circ$ .
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0080ixuv.eps} \end{figure}$	Figure 6: The He I glow intensity observed by XUV on April 5, 2000. The units of the intensity are Rayleighs. The data around the sector number 32 are excluded from this analysis because of background due to solar stray light.
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$\begin{figure} \par\includegraphics[width=9cm,clip]{0090fxuv.eps}\end{figure}$	Figure 7: Full sky intensity map of the interplanetary He 58.4 nm emission. The maximum is located at day of year (DOY) 90 and in sector 6, which is the gravitational helium focusing cone. The gray pixels show the data excluded from the analysis because of contamination by stray light and energetic particles.
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$\begin{figure} \par\includegraphics[width=9cm,clip]{0100fuvs.eps} \end{figure}$	Figure 8: Full sky intensity map of interplanetary hydrogen Lyman $\alpha$ emission, derived from UVS measurements performed during one year, from 17 March 2000 to 13 March 2001.
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$\begin{figure} \par\includegraphics[width=8.5cm]{0110radp.eps}\end{figure}$	Figure 9: Time variations of the ratio of solar radiation pressure to solar gravity, used in the three-dimensional fully time-dependent hydrogen model. Monthly averages are computed for each moment of the Nozomi observations from a time series of the solar Lyman $\alpha$ flux returned by the SOLAR2000 model.
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$\begin{figure} \par\includegraphics[width=8.5cm]{0120lymp.eps} \end{figure}$	Figure 10: The solar Lyman $\alpha$ line profile for a date corresponding to the Nozomi observation, taken from Lemaire et al. (2002).
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0160secc.eps} \end{figure}$	Figure 14: The ratio of the glow intensity from the secondary component to the net intensity along the two sets of Nozomi lines of sight (A and B) in the ecliptic plane. The vertical bars mark the upwind and downwind positions.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0190down.eps}\end{figure}$	Figure 17: Expanded views of the area in the downwind direction for scans A and B. The format is the same as in Fig. 16.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0200rmsd.eps}\end{figure}$	Figure 18: Diagnostics by residual $\chi ^{2}$ for the scans A and B in the downwind direction, seen in Fig. 17.
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