Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=17cm,clip]{1482fig2.eps}\end{figure}$ Figure 2: In contours, we show PdB maps of ¹²CO J=2-1 emission from Frosty Leo (J2000 central coordinates: 9 $^{\rm h}$ 39 $^{\rm m}$ 53. $^{\rm s}$ 99, +11$^$58 $^\prime$ 52 $\hbox{$.\!\!^{\prime\prime}$ }$ 8), for the LSR velocities indicated in the left-upper corner of each box. The contours are superimposed on the optical image of the nebula. We deduce a systemic velocity of $\sim$ -10 km s^-1. For the channels with velocities between -37 and 17 km s^-1, the first contour and the level step, in main-beam temperature units, are 0.54 K (80 mJy/beam). For the rest of channels the first contour is 0.27 K (40 mJy/beam), the second 0.54 K (80 mJy/beam), and from then the level step is 0.54 K. A negative level, equivalent to the first positive one, is shown in dashed contours. The CLEANed beam (at half-power level) is drawn in the right-bottom corner of the last panel.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{1482fig3.eps}\end{figure}$ Figure 3: In contours, we show PdB maps of ¹²CO J=1-0 emission from Frosty Leo, for the LSR velocities indicated in the left-upper corners. These contours are superimposed on the optical image of the nebula. The first level, in main-beam temperature units, is 0.23 K (30 mJy/beam) and the second 0.46 K. Thereafter the level step is 0.46 K (60 mJy/beam). A negative level is shown at -0.23 K with dashed contours. The CLEANed beam (at half-power level) is drawn in the right-bottom corner of the last panel.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{1482fig4.eps}\end{figure}$ Figure 4: In contours, we show OVRO maps of ¹²CO J=1-0 emission from Frosty Leo (same central coordinates as for PdB maps), for the LSR velocities indicated in the left-upper corners. Those contours are superimposed on the optical image of the nebula. The first level and the level step, in main-beam temperature units, are 1.05 K (60 mJy/beam). A negative level is shown at -1.05 K with dashed contours. The CLEANed beam (at half-power level) is drawn in the right-bottom corner of the last panel.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14.7cm,clip]{1482fig6a.eps}\... ...degraphics[angle=-90,width=5.5cm,clip]{1482fig6c.eps}\hspace*{1cm}} \end{figure}$ Figure 6: Upper plots present in contours the average of the intensity detected for CO J=2-1 from Frosty Leo, for the velocity ranges shown in the left-upper corner, over the optical image obtained by the HST. Velocity ranges has been chosen to best identify the ring (central nebular emission) and the jet features (elongated along the symmetry axis) in the complex nebula maps. In the left and right plots, the compact clumps at the extreme of the jets correspond to the ranges of highest expansion velocity. The central plot coincides with that shown in Fig. 2 corresponding to the systemic velocity. Below, for the same transition, the position-velocity diagrams of the emission detected along axes a and b are shown. Contours indicate the same level steps as shown in Fig. 2.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=270,width=8.25cm,clip]{1482fig7.eps}\end{figure}$ Figure 7: Model of the molecular nebula whose emission fits our maps of ¹²CO J=2-1 and J=1-0. The velocity field is presented by arrows. The spatial and density scales are also shown.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{1482fig8.eps}\end{figure}$ Figure 8: Predictions for the ¹²CO J=2-1 emission coming from a spatio-kinematical nebular model, composed of a ring and two jets ejected along the symmetry axis of the ring, which is inclined -40 $^\circ$ with respect to the sky plane, at a PA of 110 $^\circ$ . Note that this symmetry axis does not fit with the symmetry axis of the optical nebula. The same velocity channels and contours as those in Fig. 2 are shown. The brightness temperature obtained by the model has been convolved with the CLEANed beam obtained in the analysis of the data.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{1482fig1.ps}\end{figure}$ Figure 1: Processed image from the original one at 0.6 $\mu$ m observed by the Hubble Space Telescope (with the wide-band F606W/POLQ filter/polariser; see Sahai et al. 2000), which enphasizes the sharp features of Frosty Leo. Several jets (J1, J2, J3, J1', J2') are identified and labeled in the figure. Inset shows expanded view of jets J1 and J3. Northern and eastern directions are shown in right-upper corner. The PA of the (main) symmetry axis of this optical nebula is 150 $^\circ$ .
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=-90,width=5.6cm,clip]{1482fig5a.eps}\h... ...ce*{3mm} \includegraphics[angle=-90,width=5.6cm,clip]{1482fig5c.eps}\end{figure}$ Figure 5: Profiles of the emission coming from Frosty Leo for the rotational ¹²CO transitions ( left) J=2-1, by the PdB interferometer, ( center) J=1-0, by the PdB array, and ( right) 1-0, by the OVRO array. The PdV profiles are presented with a black line, and with a red line those of PdB or OVRO. With a dashed line the PdB J=1-0 profile decreased by 20 $\%$ is shown. In general, the fitting of the PdB and OVRO profiles with the PdV data is very satisfactory. In particular, the global intensity difference found for the transition J=1-0 between the PdB and PdV data is probably caused by an inconsistence in the flux calibration used for both observatories. The shape of the OVRO profile fits less well that of PdV, due to noise limitation.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14.8cm,clip]{1482fig9.eps}\end{figure}$ Figure 9: In contours, the average of the intensity predicted by modeling the CO J=2-1 emission, for the velocity ranges shown in the left-upper corner, over the optical image obtained by the HST. Contour levels, box sizes, velocity ranges and all labels are the same that in Fig. 6 to compare the most remarkable detected nebular components with those modeled.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[angle=270,width=8.25cm,clip]{1482fig7.eps}\end{figure}$	Figure 7: Model of the molecular nebula whose emission fits our maps of ¹²CO J=2-1 and J=1-0. The velocity field is presented by arrows. The spatial and density scales are also shown.
Open with DEXTER

$\begin{figure} \par\includegraphics[angle=-90,width=14.8cm,clip]{1482fig9.eps}\end{figure}$	Figure 9: In contours, the average of the intensity predicted by modeling the CO J=2-1 emission, for the velocity ranges shown in the left-upper corner, over the optical image obtained by the HST. Contour levels, box sizes, velocity ranges and all labels are the same that in Fig. 6 to compare the most remarkable detected nebular components with those modeled.
Open with DEXTER