Journal Article

Electromagnetic evidence that SSS17a is the result of a binary neutron star merger

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

2017

Overview

Eleven hours after the detection of gravitational wave source GW170817 by the Laser Interferometer Gravitational-Wave Observatory and Virgo Interferometers, an associated optical transient, SSS17a, was identified in the galaxy NGC 4993. Although the gravitational wave data indicate that GW170817 is consistent with the merger of two compact objects, the electromagnetic observations provide independent constraints on the nature of that system. We synthesize the optical to near-infrared photometry and spectroscopy of SSS17a collected by the One-Meter Two-Hemisphere collaboration, finding that SSS17a is unlike other known transients. The source is best described by theoretical models of a kilonova consisting of radioactive elements produced by rapid neutron capture (the r-process). We conclude that SSS17a was the result of a binary neutron star merger, reinforcing the gravitational wave result.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Binary stars / Celestial bodies / Collaboration / Electromagnetic radiation / Galaxies / Gravitational waves / Gravity / Heavy elements / Hemispheres / I.R. radiation / Infrared photometry / Infrared spectroscopy / Interferometers / Near infrared radiation / Neutron stars / Neutrons / Nuclear capture / Nuclear reactions / Photometry / Photons / Radioisotopes / Spectroscopy / Spectrum analysis / Star mergers / Telescopes