All Figures

$\begin{figure} \par\includegraphics[angle=-90,width=12cm,clip]{1055fig1.ps} \end{figure}$ Figure 1: This plot shows the variation of halo parameters as a function of its axis ratio (see Eq. (7)). Figures 1a and b show the variation in the central density and the core radius, with oblateness (q = minor axis/major axis). Figures 1c and d show the same as a function of prolateness (q = minor axis/major axis). This dependence on axis ratio arises from keeping the mass within a thin spheroidal shell of the halo and the terminal velocity of the halo invariant of q.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{1055fig2.ps} \end{figure}$ Figure 2: The calculated HI scaleheight is shown as a function of the galactocentric radius in the outer region of the Galaxy. The shape of an initially spherical isothermal halo ( $\rho_{\circ} = 0.035~M_{\odot}$ pc^-3; $R_{\rm c} = 5$ kpc) is changed keeping its mass constant. This plot shows the results from our model for different axis ratios. The solid line is due to spherical shape ( q = c/a = 1); the dashed lines are due to oblate halos (c/a = 0.8, 0.6, 0.4) and the dotted lines are due to prolate halos (a/c = 0.8, 0.6, 0.4). The points show the observed values. Note that neither the oblate nor the prolate-shaped halos are clearly favoured by the data.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{1055fig3.ps} \end{figure}$ Figure 3: The best fit (based on the least square value) for the observed HI scaleheight is given by a halo with p = 2 where p is the index in the halo density profile (solid line). For comparison, results for a typical isothermal halo (p = 1) is also shown (dashed line).
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In the text

$\begin{figure} \par\subfigure[]{\includegraphics[angle=-90,width=6.2cm,clip]{105... ...gure[]{\includegraphics[angle=-90,width=6.2cm,clip]{1055fg4c.ps} }\end{figure}$ Figure 4: a) Log-normal plot of the halo mass density (in units of $M_{\odot }$ pc^-3) as a function of the galactocentric radius, for the best-fit halo (p=2) and the isothermal halo (p=1). Although the two begin to differ around the optical edge of the stellar disk itself, the effect on HI scaleheight becomes noticeable only after 20 kpc (see Fig. 3). The corresponding p=1.5 profile (which is equivalent to the NFW density profile at large radii) falls between the two shown profiles but is closer to the p=2 profile. b) The behaviour of M(R) (mass contained within a spheroid of radius R) as a function of R, is shown here for the two kinds of halos. For an isothermal halo, the mass tends to infinity whereas for p=2, it tends converges to a finite value as R increases. The mass tends to infinity for p=1.5 as well, but rather gradually compared to that of p=1. c) Rotation curves for the cases p=1and p=2. For p=1, the rotation curve becomes flat at large radii whereas for p=2, the curve begings to fall beyond a radius of $\sim$ 12 kpc.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{1055fig3.ps} \end{figure}$	Figure 3: The best fit (based on the least square value) for the observed HI scaleheight is given by a halo with p = 2 where p is the index in the halo density profile (solid line). For comparison, results for a typical isothermal halo (p = 1) is also shown (dashed line).
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