![\begin{figure}
\par\includegraphics[width=7.6cm,clip]{parab.eps}
\end{figure}](/articles/aa/full/2004/04/aa0015/img13.gif) |
Figure 1:
The light echo paraboloid (Eq. (3)) shown in the xz plane
for ct = 1 and ct = 2. The axes are in units of ct. The dot marks the
source position at
x = 0, z = 0. The observer is at
 . |
| Open with DEXTER | |
In the text
![\begin{figure}
\par\mbox{\includegraphics[width=5.5cm]{sheet50.eps} \includegrap...
....5cm]{sheet400.eps} \includegraphics[width=5.5cm]{sheet500.eps} }
\end{figure}](/articles/aa/full/2004/04/aa0015/img42.gif) |
Figure 2:
The evolution of the echo structure produced by four dust slabs
perpendicular to the line of sight at the z positions of
-0.10, 0.00, 0.30, and 1.00 pc. The source (not shown in the
figure but lying in the centre of each image) has experienced a
50 days long flash of constant luminosity. All the slabs have the same
thickness of 0.02 pc and the same value (constant within the
slabs) of the scattering coefficient
 .
The object is
assumed to be observed from a distance of 5 kpc. The images are
ordered from upper-left to lower-right and correspond to the time
epochs of 50, 150, 250, 300, 400, and 500 days after the beginning
of the source flash. The axes of the images are in arcsec.
The grey scale is logarithmic and is normalized to the
brightest region in the figure.
The brightest centre of the first image and the faintest
outer ring in the last images span  4 orders of magnitude in
the surface brightness. |
| Open with DEXTER | |
In the text
![\begin{figure}
\par\mbox{\includegraphics[width=5.5cm]{spher50.eps} \includegrap...
...5cm]{spher600.eps} \includegraphics[width=5.5cm]{spher750.eps} }
\end{figure}](/articles/aa/full/2004/04/aa0015/img53.gif) |
Figure 3:
The same as Fig. 2 but for three spherical shell of
dust centred on the source. The shells have the same thickness
of 0.02 pc and radii of 0.10, 0.30, and 1.00 pc. The images shows
the echo as observed 50, 150, 250, 400, 600, and
750 days after the beginning of the source flash.
The brightest and the faintest regions in the figure span
2.5 orders of magnitude in the surface brightness. |
| Open with DEXTER | |
In the text
![\begin{figure}
\par\mbox{\includegraphics[width=4.9cm,clip]{d_str_a.eps}\hspace*...
...}\hspace*{5mm}
\includegraphics[width=4.9cm,clip]{d_str_c.eps} }
\end{figure}](/articles/aa/full/2004/04/aa0015/img118.gif) |
Figure 4:
Structure of the dust distribution illuminated by the lihgt echo
of V838 Mon. In all the images the
ordinate is the z axis. The abscissa, x', is inclined to the x
(east-west) axis at an angle,  ,
(clockwise in respect to the x axis)
given in the bottom-left corner of each image. Only the points having the
position angle within
are shown in each image. Open and full
symbols correspond to upper and lower (in the z coordinate) boundaries of
the dusty regions, respectively. Thin curves show the echo paraboloids
(with t0 = 34 days) on Apr. 30 and Dec. 17.
The position of the central star is shown by an asterisk. |
| Open with DEXTER | |
In the text
![\begin{figure}
\par\mbox{ \includegraphics[width=6.1cm,clip]{hole_a.eps}\hspace*...
...s}\hspace*{3mm}
\includegraphics[width=6.1cm,clip]{hole_d.eps} }
\end{figure}](/articles/aa/full/2004/04/aa0015/img125.gif) |
Figure 5:
Structure of the dust-free region near
V838 Mon. The axes and the definition of
the azimuthal angle, ,
given in the bottom-left corner of each part,
are the same as in Fig. 4. Full symbols show
the positions of the inner edge of dust (within
).
Comet-like tails emerging radially from the symbols
indicate directions in which dust extends.
Thin curves show the echo paraboloids corresponding to t0 = 70 days
on May 20 (inner) and Dec. 17 (outer). |
| Open with DEXTER | |
In the text