[DISK]

[Disk model]

       The disk can either be <simple>, <isothermal>, or
       <reprocessing>. For all models, the height of the 
       disk at radius r is computed as a + b * r^c.

       For a simple disk, c = 1, a is set equal to half 
       of the <thickness> parameter, and b is set equal 
       to the <H/R> parameter. Setting H/R to zero results 
       in a flat disk. The <temperature> is constant and 
       equal to the respective input parameter.

       For the isothermal disk, the exponent c is set to 
       c = 1.5, which is the correct value for an isothermal 
       disk. Furthermore, the H/R parameter is ignored, 
       the constant a is set to a = 0.0, and the factor
       b is chosen such that at the inner disk radius, the 
       disk thickness equals the thickness input parameter.

       The reprocessing disk is the model for a disk that 
       is reprocessing (absobing/re-radiating) the radiation 
       from the central star.  The exponent c is set to 
       c = 9/8, which is the correct value for a reprocessing 
       disk. Furthermore, the H/R parameter is ignored, the 
       constant a is set to a = 0.0, and the factor b is 
       chosen such that at the inner disk radius, the disk 
       thickness equals the thickness input parameter. Lastly, 
       the temperature falls off with radius r^(-3/4).

[Disk parameters]

       The <inner radius> (in units of the maximum radius) 
       is the location of the inner edge of the disk.

       The <outer radius> (in units of the maximum radius) 
       is the location of the inner edge of the disk.

       The <thickness> of the disk is given at the inner edge.

       The <H/R> (height/radius) is only relevant for the
       simple disk model (see above).

       The <temperature> is constant for the simple and
       isothermal disk models. In the reprocessing disk
       model, this is the temperature at the inner edge.

[Hot spot parameters]

       The <temperature> is constant for the hot spot.

       The <longitude> is the location of the centre of
       the hot spot along the outer edge of the disk.

       The <extent> is the angular size of the hot spot
       along the outer edge.

       The <depth> measures how far the hot spot penetrates
       into the disk (in units of the maximum radius).