Object generator: Stars

  • Input Population:
    • Field of view: the size (in arcsec) of the field of view.
    • Objects: the number of objects in the field of view.
    • Brightest mag: the magnitude of the brightest object
    • Faintest mag: the magnitude of the faintest object
  • Distribution of magnitude: the distribution of the object magnitude can be defined as a power law function or a function defined by the user (uploading a txt file).
    • Power law Index: the slope index -α of the power law function expressed as N(x) = x-α that describes the magnitude distribution.
    • User defined Law: a text file containing the values of the magnitude distribution function: the file columns contain the magnitude and the value of the magnitude distribution (number of objects for a given magnitude).
      NOTE: the faintest and brightest magnitude must be encompassed in the minimum and maximum value defined in the user magnitude distribution.
      Here an example of magnitude distribution file GalMagDistrib.txt: 
      
 # GalMagDistrib.txt
 # put comment character #, at the beginning of each comment line
 # Magnitude  Nr of Objects 
 #            
 #
 15.625 6.53
 15.875 4.35
  ... ...
 26.125 290603.29
 26.375 313097.56
  • Spatial distribution in the FoV: Spatial distribution of the simulated objects in the field of view.
    The available options are:
    • Linear gradient: the gradient values along the x-axes (Gx) and y-axes (Gy) are requested.
    • Radial gradient: the required parameters are the radial gradient (Gr), the radius (R) and the center of the distribution (x-y coordinates in arcsec)
    • User defined Law: Spatial object distribution profile defined though a text file with the value of the distribution as function of the x/y-coordinates SpatialDistrib.txt: 
       # SpatialDistrib.txt
 # put comment character #, at the beginning 
 # of each comment line
 # X   Y    
 # 
 0.0009 1 
 0.0025 9.99E-1            
  ... ... 
 469.98 4.07E-7 
 516.28 3.09E-8 
 567.13 0
The CREATE button produces the output table with the sky distribution of the selected objects.
Figure 1: Example of Star Generator output for a list of 1500 stars distributed according to a radial distribution profile; the ''on sky'' spatial distribution is shown in the right panel and the list file can be downloaded here. This file can be used as ''user list'' in the On sky Object Distribution option of the Object Generator tool.