The Old Host-galaxy Environment of SSS17a, the First Electromagnetic Counterpart to a Gravitational-wave Source

Y. -C. Pan, C. D. Kilpatrick, J. D. Simon, E. Xhakaj, K. Boutsia, D. A. Coulter, M. R. Drout, R. J. Foley, D. Kasen, N. Morrell, A. Murguia-Berthier, D. Osip, A. L. Piro, J. X. Prochaska, E. Ramirez-Ruiz, A. Rest, C. Rojas-Bravo, B. J. Shappee, M. R. Siebert