Selection function for the TGAS and TGAS+RAVE samples from Gaia DR1. Requires numpy, matplotlib and healpy.
The module is called tgas_sf.
To install using pip, type
pip install https://github.com/anguswilliams91/SelectTGAS/archive/master.zip
The selection function is constructed by dividing the sky into equal-area bins using HEALPix, and then evaluating the completeness in a range of J-band magnitude bins relative to the 2MASS point source catalog. There are two resolutions: low (NSIDE=8) and high (NSIDE=32).
The selection function is implemented as a class SelectionFunctionTGAS and the __call__ method
evaluates the selection function at (l,b,J) using nearest-neighbour interpolation. For TGAS+RAVE, the class is called SelectionFunctionTGASRAVE and the __call__ method takes four arguments (l,b,J,J-K), because RAVE did not observe stars with J-K<0.5 at |b|<25 degrees.
Example snippet:
import tgas_sf as sf
#load high-res SF for the sample
selecTGAS = sf.SelectionFunctionTGAS(nside=32)
#plot the completeness at J=8.
selecTGAS.sky_plot(9.)
#Find the completeness at l=40 degrees , b=30 degrees , J=8
selecTGAS(40.,30.,8.)