This collection contains both the Planet Nine reference population
as well as results from a ZTF search for Planet Nine. It includes
the following files:

-reference_population.csv
 a list of 100000 sythetic Planets Nine draw from the samples of Brown & Baygin (2021a).
 The first three line, appended with "#", are comments. The file can be read using,
 for example, pandas in python, with the command 
    p9=pandas.read_csv('reference_population.csv',comment='#')

-mag_limit.fits
 the 95% completeness limit from the ZTF survey, in the form of a ring-ordered HEALPix map

-draw_mag_limits.pro
 An example program, in IDL, to plot the magnitude limits in a Mollweide projection

-overview_map.pro
 An example program, in IDL, to plot probability density functions of space location, 
 magnitude, and heliocentric distance for both the full reference population and for 
 the population remaining after the ZTF survey

-overview_map.png, _with_ZTF.png
  The output from overview_map.pro for the full population and for the population
  remaining after the ZTF survey.