[Last Change: 15 Feb 2012 (rev 6)]

How to Raytrace a Single Point Source

SAOTrace provides a short cut for raytracing a single point source. All that you need set are the following Lua variables:
name units description
theta arcminutes The off-axis angle in Mirror Spherical Coordinates
phi degrees The azimuthal angle in Mirror Spherical Coordinates
spectrum spectrum specification a spectrum specification

Note: You cannot mix this short cut with other methods for specifying source parameters. If you do so a source created with these short cuts will be ignored.


  • A point source with a position of θ=5' and φ=22 and a mono-energetic spectrum at 1.49 keV with a flux of 1 photon/s/cm2 for one kilosecond:
    trace-nest \
        tag=point \
        srcpars='theta = 10; phi = 22; spectrum=1.49;' \
        limit_type=ksec \

  • A point source with a position of θ=10" and φ=33 and spectrum read from two files, one scaled by 0.5 for one kilosecond. This is a bit much for the command line, so this example puts the source parameters in a file, point.lua
    theta = {10, "arcseconds"}
    phi = 22
    spectrum={ { file = "power-law.rdb", units = "ergs/s/cm2/kev", scale = 0.5, format = "rdb" },
               { file = "thermal.rdb", units = "ergs/s/cm2/kev", format = "rdb" }
    and trace-nest is run as:
    trace-nest \
        tag=point \
        srcpars=point.lua \
        limit_type=ksec \
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