build_patch_map

gaiaunlimited.selectionfunctions.build_patch_map(coord, radius, min_points=20)

Query the Gaia database and create a high-resolution healpix map of the M_10 parameter for a given circular patch of sky. The pixels without a sufficient number of sources will be grouped together.

Parameters:

• coord (astropy.coordinates.SkyCoord) – sky coordinates of the center of the patch, as an astropy SkyCoord object

• radius (float) – the radius of the patch, in degrees

• min_points (int) – minimum number of sources used to compute M_10 in a given pixel. A given region will be subdivided into four higher-order regions if all its subdivisions contain more than min_points points.

Returns:

A numpy array of shape (3,N) where the first column is the order of the maximum resolution reached, the second column is the healpixel number, and the third is the M_10 value in that healpixel.