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Quasar Microlensing

This program accompanies the paper Understanding micro-image configurations in quasar microlensing.


You should see a button to the left saying Show MicroLens window.   (If not, see here.)   To download, see below.

In the applet window, the left panel shows contours of the arrival-time surface, and micro images according to brightness (red for micro minima, cyan for micro saddles). Stars are not shown, but correspond to maxima of the surface.

The right panel shows the cumulative magnifications of all the micro images. There are really two cumulative plots here: the negative side is for saddle points, while the positive side is for minima and maxima, if any.

Using the text fields, you can specify the scalar magnification (negative for macro saddles), the average density, the number of stars, and the number of contours to show. The contours are equally spaced, unless you ask for zero contours, in which case all contours passing through saddle points are shown.

Pressing return in any of the text fields generates a new configuration. The exception is in the contours field, if you change the number: in that case new contours are shown for the old configuration.

Pressing the run button will make the program loop over random configurations. When and if you then press pause the right hand figure will be replaced by a magnification distribution colour-coded by the number of micro minima.

The MicroLens program is written in literate Java and is free software. For source and Java byte code, download the MicroLens.jar file.