@article{9dfe933107ee4d8da49e955659c543ad,
title = "Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event",
abstract = "The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted to power a distinctive thermal glow (a {\^a} € kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements. Here we report models that predict the electromagnetic emission of kilonovae in detail and enable the mass, velocity and composition of ejecta to be derived from observations. We compare the models to the optical and infrared radiation associated with the GW170817 event to argue that the observed source is a kilonova. We infer the presence of two distinct components of ejecta, one composed primarily of light (atomic mass number less than 140) and one of heavy (atomic mass number greater than 140) r-process elements. The ejected mass and a merger rate inferred from GW170817 imply that such mergers are a dominant mode of r-process production in the Universe.",
author = "Daniel Kasen and Brian Metzger and Jennifer Barnes and Eliot Quataert and Enrico Ramirez-Ruiz",
note = "Funding Information: Acknowledgements D.K. is supported in part by a Department of Energy (DOE) Office early career award DE-SC0008067, a DOE Office of Nuclear Physics award DE-SC0017616, and by the Director, Office of Energy Research, Office of High Energy and Nuclear Physics, Divisions of Nuclear Physics, of the US DOE under contract number DE-AC02-05CH11231. This work was supported in part by the DOE SciDAC award DE-SC0018297. E.R.-R. acknowledges support from a Niels Bohr Professorship funded by DNRF, and support from UCMEXUS, the David and Lucile Packard Foundation. This research is funded in part by the Gordon and Betty Moore Foundation through grant GBMF5076. E.Q. was funded in part by the Simons Foundation through a Simons Investigator Award. J.B. is supported by the National Aeronautics and Space Administration (NASA) through the Einstein Fellowship Program, grant number PF7-180162, issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the US DOE under contract number DE AC02-05CH11231. J.B. is an Einstein Fellow. Publisher Copyright: {\textcopyright} 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.",
year = "2017",
month = nov,
day = "2",
doi = "10.1038/nature24453",
language = "English (US)",
volume = "551",
pages = "80--84",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "7678",
}