Heavy-element production in a compact object merger observed by JWST

• Published in: Nature (London) 2024-02, Vol.626 (8000), p.737-741
• Main Authors: Levan, Andrew J., Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-Carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, van der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’Avanzo, Paolo, D’Elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’Brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., de Ugarte Postigo, Antonio, Kann, David Alexander
• Format: Article
• Language: English
• Subjects: 639/33/34/4118; 639/33/34/864; Astrophysics; Atomic properties; Binary stars; Black holes; Emission lines; Gamma ray bursts; Gamma rays; Gravitational waves; Gravity; Humanities and Social Sciences; Infrared imaging; Infrared spectroscopy; Infrared telescopes; James Webb Space Telescope; Lanthanides; multidisciplinary; Neutron stars; Neutrons; Nuclear capture; Nuclear fusion; Progenitors (astrophysics); Science; Science & Technology - Other Topics; Science (multidisciplinary); Space telescopes; Spectroscopy; Spectrum analysis; Tellurium
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-023-06759-1

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. Observations from the JWST of the second brightest GRB ever detected, GRB 230307A, indicate that it belongs to the class of long-duration GRBs resulting from compact object mergers, with the decay of lanthanides powering the longlasting optical and infrared emission.