Surface Brightness Profile of a Spherical Nebula with given Radial
Dependence of Density
..... needs to be written up properly .......
How to use the applet:
- Density allows the user to enter the radial dependence
of the density by entering this curve graphically:
click on the plot to create a new datum, or grab an existing point
to move it to a new position. One can zoom in an area by
clicking drag & zoom and then dragging the mouse over
diagonally over the desired rectangle. unZoom brings back
the full view.
Sorry for the funny representation of some numbers, if you are
using Netscape. It's a bug in that browser ...
- Mass Column Density shows the variation of
that quantity across the nebula's face. The units are
normalized. Click on any point of the plot will display the
x and y values just above the plot. Zooming into any small
area is done as described above, clicking again
Mass Column Density will update the profile in more
- Surface Brightness shows the variation of
that quantity from an emission line, produced by recombination
or collisional excitation, across the nebula's face. The units are
normalized. We assume that the emissivity depends only on the
square of the local density, thus we neglect any influence from a
radial variation of the electron temperature...
This is the surface brightness profile from a nebula with a large
central hole (screenshot from an older version...):
If the surface brightness is constant up to the outer rim, one
needs this kind of radial desnity profile:
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