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The Chandra Ray Tracer (ChaRT) simulates the best available point spread function (PSF) for a point source at any off-axis angle and for any energy or spectrum. Technical details are available from the About ChaRT page.

It is important to read the caveats before running ChaRT and using the resulting PSF simulations in analysis.

There are three steps to using ChaRT:

1. Prepare to run ChaRT: determine the input parameters for the PSF raytrace.

2. Run ChaRT: run the raytrace.

3. Analyse the results: run MARX to make an event file and create an image of the PSF.

If you need to run multiple ray traces, you should consider installing SAOTrace and running the traces locally.

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Citing ChaRT in a Publication

If you are writing a paper and would like to cite ChaRT, we recommend the following paper:

The specific version of CIAO and CALDB (if applicable) used for the analysis should be mentioned as well.