Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{ne_fig1.ps}\end{figure}$ Figure 1: Coronal electron density as a function of heliocentric distance, obtained with visible light coronagraph data (Koutchmy 1977; Munro & Jackson 1977; Fisher & Guhathakurta 1995; Kohl et al. 1998; Guhathakurta et al. 1999) and with ultraviolet spectroscopic observations (Wilhelm et al. 1998a).
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In the text

$\begin{figure} \par\includegraphics[height=16.8cm,width=13.3cm,clip]{fig2.ps}\end{figure}$ Figure 2: Electron density of the polar coronal hole observed on May 21, 1996, as a function of outflow velocity at different heliocentric distance, derived for radial kinetic temperature $T_{{\rm k,r}}$ equal to: $T_{\rm e}$ (bold solid lines), $T_{\rm p}$ (dotted lines), (4 $\times$ $T_{\rm p}$ ) (dashed lines), (8 $\times$ $T_{\rm p}$ ) (dot-dashed lines), $T_{{\rm l.o.s.}}$ (bold dot-dashed lines).
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In the text

$\begin{figure} \par\includegraphics[height=16.8cm,width=13.4cm,clip]{fig3.ps}\end{figure}$ Figure 3: Electron flux of the polar coronal hole observed on May 21, 1996, as a function of outflow velocity, extrapolated to 1 AU from the ( $n_{\rm e},w$ ) curves of Fig. 2, derived for each heliocentric distance by assuming a radial kinetic temperature $T_{{\rm k,r}}$ equal to: $T_{\rm e}$ (bold solid lines), $T_{\rm p}$ (dotted lines), (4 $\times$ $T_{\rm p}$ ) (dashed lines), (8 $\times$ $T_{\rm p}$ ) (dot-dashed lines), $T_{{\rm l.o.s.}}$ (bold dot-dashed lines). The horizontal line corresponds to an electron flux $(n_{\rm e}\times w)_{{\rm 1~AU}}$ equal to the proton flux, $2\times 10^8$ cm^-2 s^-1, typical of the fast wind.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{fig4.ps}\end{figure}$ Figure 4: Electron density of the polar coronal hole observed on May 21, 1996, as a function of height in the extended corona, derived with the spectroscopic technique based on the OVI line intensities. The present results are compared with density results obtained from white light observations. Full dots correspond to the case of maximum anisotropy of the oxygen ion velocity distribution. Only at 1.9 $R_{\odot }$ the full dot corresponds to $T_{{\rm k,r}} = T_{\rm p}$ . Open dots correspond to isotropic ion velocity distribution out to 1.9 $R_{\odot }$ , and beyond this height to the lowest degree of anisotropy allowed in the analysis, $T_{{\rm k,r}} = 8$ $\times$ $T_{\rm p}$ . Full and open squares, mostly overlapping, indicate the results derived from the second intersection at higher velocity (in Fig. 3), for maximum and minimum anisotropy, respectively.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{fig5.ps}\end{figure}$ Figure 5: Outflow velocity of the polar coronal hole observed on May 21, 1996, as a function of height in the extended corona, derived with the spectroscopic technique based on the OVI line intensities. Full dots correspond to the case of maximum anisotropy of the oxygen ion velocity distribution. Only at 1.9 $R_{\odot }$ the full dot corresponds to $T_{{\rm k,r}} = T_{\rm p}$ . Open dots correspond to isotropic ion velocity distribution out to 1.9 $R_{\odot }$ , and beyond this height to the lowest degree of anisotropy allowed in the analysis, $T_{{\rm k,r}} = 8$ $\times$ $T_{\rm p}$ . Full and open squares, mostly overlapping, indicate the results derived from the second intersection at higher velocity (in Fig. 3), for maximum and minimum anisotropy, respectively.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{ne_fig1.ps}\end{figure}$	Figure 1: Coronal electron density as a function of heliocentric distance, obtained with visible light coronagraph data (Koutchmy 1977; Munro & Jackson 1977; Fisher & Guhathakurta 1995; Kohl et al. 1998; Guhathakurta et al. 1999) and with ultraviolet spectroscopic observations (Wilhelm et al. 1998a).
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