Heavy-element production in a compact object merger observed by JWST
A. J. Levan, B. P. Gompertz, O. S. Salafia, Mattia Bulla, Eric Burns, Kenta Hotokezaka, L. Izzo, Gavin P. Lamb, D. Malesani, S. R. Oates, M. E. Ravasio, Alicia Rouco Escorial, Benjamin Schneider, Nikhil Sarin, S. Schulze, N. R. Tanvir, K. Ackley, G. E. Anderson, Gabriel Brammer, L. Christensen, V. S. Dhillon, P. A. Evans, Michael Fausnaugh, Wen‐fai Fong, A. S. Fruchter, Chris L. Fryer, J. P. U. Fynbo, Nicola Gaspari, K. E. Heintz, J. Hjorth, J. A. Kennea, Mark Kennedy, T. Laskar, G. Leloudas, Ilya Mandel, A. Martín-Carrillo, Brian D. Metzger, M. Nicholl, Anya E. Nugent, J. T. Palmerio, G. Pugliese, Jillian Rastinejad, L. Rhodes, A. Rossi, Andrea Saccardi, Stephen J. Smartt, Heloise F. Stevance, Aaron Tohuvavohu, Alexander van der Horst, Susanna D. Vergani, Darach Watson, Thomas Barclay, Kornpob Bhirombhakdi, Elmé Breedt, Alice A. Breeveld, Alexander J. Brown, Sergio Campana, Ashley A. Chrimes, Paolo D’Avanzo, Valerio D’Elia, Massimiliano De Pasquale, Martin J. Dyer, Duncan K. Galloway, James A. Garbutt, Matthew J. Green, Dieter H. Hartmann, Páll Jakobsson, Paul Kerry, Chryssa Kouveliotou, Danial Langeroodi, Emeric Le Floc’h, James K. Leung, Stuart P. Littlefair, James Munday, Paul O’Brien, Steven G. Parsons, Ingrid Pelisoli, David I. Sahman, Ruben Salvaterra, Boris Sbarufatti, Danny Steeghs, Gianpiero Tagliaferri, Christina C. Thöne, Antonio de Ugarte Postigo, David Alexander Kann
Abstract
Abstract The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs) 1 , sources of high-frequency gravitational waves (GWs) 2 and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (the r -process) 3 . Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers 4–6 and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. 7–12 ). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic mass A = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r -process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe.