Improved Constraints on H $_0$ from a Combined Analysis of Gravitational-wave and Electromagnetic Emission from GW170817

C. Guidorzi, R. Margutti, D. Brout, D. Scolnic, W. Fong, K.~D. Alexander, P.~S. Cowperthwaite, J. Annis, E. Berger, P.~K. Blanchard, R. Chornock, D.~L. Coppejans, T. Eftekhari, J.~A. Frieman, D. Huterer, M. Nicholl, M. Soares-Santos, G. Terreran, V.~A. Villar, P.~K.~G. Williams