[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.

Examples

• 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 \
      limit=1
  

• 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 \
      limit=1