UV-NIR obs. compilation of GW170817 counterpart

By assembling all of the available data from 18 different papers and 46 different instruments, we are able to identify and mitigate systematic offsets between individual data sets and to identify clear outlying measurements, with the resulting pruned and adjusted data set offering an opportunity to expand the study of the kilonova.

The unified data set includes 647 individual flux measurements, spanning 0.45-29.4d post-merger, and thus has greater constraining power for physical models than any single data set. We test a number of semi-analytical models and find that the data are well modeled with a three-component kilonova model: a "blue" lanthanide-poor component ({kappa}=0.5cm^2^/g) with M_ej_~0.020M_{sun}_ and v_ej_~0.27c; an intermediate opacity "purple" component ({kappa}=3cm^2^/g) with M_ej_~0.047M_{sun}_ and v_ej_~0.15c; and a "red" lanthanide-rich component ({kappa}=10cm^2^/g) with M_ej_~0.011M_{sun}_ and v_ej_~0.14c.