We present results on the stellar density radial profile of the outer regions of NGC 6779 , a Milky Way globular cluster recently proposed as a candidate member of the Gaia Sausage structure , a merger remnant of a massive dwarf galaxy with the Milky Way .
Taking advantage of the Pan-STARRS PS1 public astrometric and photometric catalogue , we built the radial profile for the outermost cluster regions using horizontal branch and main sequence stars , separately , in order to probe for different profile trends because of difference stellar masses .
Owing to its relatively close location to the Galactic plane , we have carefully treated the chosen colour-magnitude regions properly correcting them by the amount of interstellar extinction measured along the line-of-side of each star , as well as cleaned them from the variable field star contamination observed across the cluster field .
In the region spanning from the tidal to the Jacobi radii the resulting radial profiles show a diffuse extended halo , with an average power law slope of -1 .
While analysing the relationships between the Galactocentric distance , the half-mass density , the half-light radius , the slope of the radial profile of the outermost regions , the internal dynamical evolutionary stage , among others , we found that NGC 6779 shows structural properties similar to those of the remaining Gaia Sausage candidate globular clusters , namely , they are massive clusters ( > 10 ^ { 5 } M _ { \odot } ) in a moderately early dynamical evolutionary stage , with observed extra-tidal structures .