The Emergence of a Lanthanide-rich Kilonova Following the Merger of Two Neutron Stars

DOI: 
10.3847/2041-8213/aa90b6
Publication date: 
01/10/2017
Main author: 
Tanvir, N. R.
IAA authors: 
Cano, Z.;de Ugarte Postigo, A.;Hodosan, G.;Kann, D. A.;Thöne, C. C.
Authors: 
Tanvir, N. R.;Levan, A. J.;González-Fernández, C.;Korobkin, O.;Mandel, I.;Rosswog, S.;Hjorth, J.;D'Avanzo, P.;Fruchter, A. S.;Fryer, C. L.;Kangas, T.;Milvang-Jensen, B.;Rosetti, S.;Steeghs, D.;Wollaeger, R. T.;Cano, Z.;Copperwheat, C. M.;Covino, S.;D'Elia, V.;de Ugarte Postigo, A.;Evans, P. A.;Even, W. P.;Fairhurst, S.;Figuera Jaimes, R.;Fontes, C. J.;Fujii, Y. I.;Fynbo, J. P. U.;Gompertz, B. P.;Greiner, J.;Hodosan, G.;Irwin, M. J.;Jakobsson, P.;Jørgensen, U. G.;Kann, D. A.;Lyman, J. D.;Malesani, D.;McMahon, R. G.;Melandri, A.;O'Brien, P. T.;Osborne, J. P.;Palazzi, E.;Perley, D. A.;Pian, E.;Piranomonte, S.;Rabus, M.;Rol, E.;Rowlinson, A.;Schulze, S.;Sutton, P.;Thöne, C. C.;Ulaczyk, K.;Watson, D.;Wiersema, K.;Wijers, R. A. M. J.
Journal: 
The Astrophysical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
848
Pages: 
L27
Abstract: 

We report the discovery and monitoring of the near-infrared counterpart (AT2017gfo) of a binary neutron-star merger event detected as a gravitational wave source by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo (GW170817) and as a short gamma-ray burst by Fermi Gamma-ray Burst Monitor (GBM) and Integral SPI-ACS (GRB 170817A). The evolution of the transient light is consistent with predictions for the behavior of a “kilonova/macronova” powered by the radioactive decay of massive neutron-rich nuclides created via r-process nucleosynthesis in the neutron-star ejecta. In particular, evidence for this scenario is found from broad features seen in Hubble Space Telescope infrared spectroscopy, similar to those predicted for lanthanide-dominated ejecta, and the much slower evolution in the near-infrared {K}<SUB>{{s</SUB>}}-band compared to the optical. This indicates that the late-time light is dominated by high-opacity lanthanide-rich ejecta, suggesting nucleosynthesis to the third r-process peak (atomic masses A≈ 195). This discovery confirms that neutron-star mergers produce kilo-/macronovae and that they are at least a major—if not the dominant—site of rapid neutron capture nucleosynthesis in the universe.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032015176&doi=10.3847%2f2041-8213%2faa90b6&partnerID=40&md5=f601eee7ce4be5e69fd60c663f60ac75
ADS Bibcode: 
2017ApJ...848L..27T
Keywords: 
gravitational waves;nuclear reactions;nucleosynthesis;abundances;stars: neutron