Illuminating gravitational waves: A concordant picture of photons from a neutron star merger
Fox, O. D.; Cenko, S. B.; Sollerman, J.; Bloom, J. S.; Frail, D. A.; Helou, G.; Harrison, F.; Hallinan, G.; Goobar, A.; Ip, W. -H.; Nugent, P.; Itoh, R.; Yan, L.; Horesh, A.; Xu, Y.; Kaplan, D. L.; Bally, J.; Kasliwal, M. M.; Perley, D. A.; Corsi, A.; Blagorodnova, N.; Cook, D. O.; Fremling, C.; Evans, P. A.; Kuin, N. P. M.; Mazzali, P. A.; Adams, S. M.; Jencson, J. E.; Ofek, E. O.; Sadler, E. M.; Hotokezaka, K.; Lau, R. M.; Anupama, G. C.; Mooley, K.; Rosswog, S.; Brady, P. R.; Ghosh, S.; Nissanke, S.; Schmidt, P.; Williamson, A. R.; Kupfer, T.; Bellm, E.; Kim, H.; De, K.; Bhattacharya, D.; Steele, I.; Kasen, D.; Ngeow, C. -C.; Yatsu, Y.; Murphy, T.; Zhao, W.; Dobie, D.; Zhang, C.; Cobb, B. E.; Frohmaier, C.; Quimby, R. M.; Allison, J. R.; Bannister, K. W.; Piran, T.; Emery, S. W. K.; Nakar, E.; Singer, L. P.; Van Sistine, A.; Gottlieb, O.; Feindt, U.; Yu, P. -C.; Balasubramanian, A.; Barnes, J.; Barway, S.; Bhalerao, V.; Cannella, C.; Chatterjee, D.; Copperwheat, C.; Hinderer, T.; Ho, A. Y. Q.; Lynch, C.; Madsen, K.; Miller, A. A.; Nichols, D.; Qi, H.; Rusu, F.
United States, Israel, Sweden, United Kingdom, Taiwan, Australia, India, South Africa, Netherlands, Japan, Chile, Germany
Abstract
Merging neutron stars offer an excellent laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of an electromagnetic counterpart (EM170817) with gravitational waves (GW170817) detected from merging neutron stars. By synthesizing a panchromatic data set, we demonstrate that merging neutron stars are a long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma rays seen in EM170817 are dissimilar to classical short gamma-ray bursts with ultrarelativistic jets. Instead, we suggest that breakout of a wide-angle, mildly relativistic cocoon engulfing the jet explains the low-luminosity gamma rays, the high-luminosity ultraviolet-optical-infrared, and the delayed radio and x-ray emission. We posit that all neutron star mergers may lead to a wide-angle cocoon breakout, sometimes accompanied by a successful jet and sometimes by a choked jet.