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

Andrew J Levan^{1

2}, Benjamin P Gompertz^{3

4}, Om Sharan Salafia^{5

6}, Mattia Bulla^{7

8

9}, Eric Burns¹⁰, Kenta Hotokezaka^{11

12}, Luca Izzo^{13

14}, Gavin P Lamb^{15

16}, Daniele B Malesani^{17

18

19}, Samantha R Oates^{3

4}, Maria Edvige Ravasio^{17

5}, Alicia Rouco Escorial²⁰, Benjamin Schneider²¹, Nikhil Sarin^{22

23}, Steve Schulze²³, Nial R Tanvir¹⁶, Kendall Ackley²⁴, Gemma Anderson²⁵, Gabriel B Brammer^{18

19}, Lise Christensen^{18

19}, Vikram S Dhillon^{26

27}, Phil A Evans¹⁶, Michael Fausnaugh^{21

28}, Wen-Fai Fong^{29

30}, Andrew S Fruchter³¹, Chris Fryer^{32

33

34

35}, Johan P U Fynbo^{18

19}, Nicola Gaspari¹⁷, Kasper E Heintz^{18

19}, Jens Hjorth¹³, Jamie A Kennea³⁶, Mark R Kennedy^{37

38}, Tanmoy Laskar^{17

39}, Giorgos Leloudas⁴⁰, Ilya Mandel^{41

42}, Antonio Martin-Carrillo⁴³, Brian D Metzger^{44

45}, Matt Nicholl⁴⁶, Anya Nugent^{29

30}, Jesse T Palmerio⁴⁷, Giovanna Pugliese⁴⁸, Jillian Rastinejad^{29

30}, Lauren Rhodes⁴⁹, Andrea Rossi⁵⁰, Andrea Saccardi⁴⁷, Stephen J Smartt^{46

49}, Heloise F Stevance^{49

51}, Aaron Tohuvavohu⁵², Alexander van der Horst³⁵, Susanna D Vergani⁴⁷, Darach Watson^{18

19}, Thomas Barclay⁵³, Kornpob Bhirombhakdi³¹, Elmé Breedt⁵⁴, Alice A Breeveld⁵⁵, Alexander J Brown²⁶, Sergio Campana⁵, Ashley A Chrimes¹⁷, Paolo D'Avanzo⁵, Valerio D'Elia^{56

57}, Massimiliano De Pasquale⁵⁸, Martin J Dyer²⁶, Duncan K Galloway^{41

42}, James A Garbutt²⁶, Matthew J Green⁵⁹, Dieter H Hartmann⁶⁰, Páll Jakobsson⁶¹, Paul Kerry²⁶, Chryssa Kouveliotou³⁵, Danial Langeroodi¹³, Emeric Le Floc'h⁶², James K Leung^{42

63

64}, Stuart P Littlefair²⁶, James Munday^{24

65}, Paul O'Brien¹⁶, Steven G Parsons²⁶, Ingrid Pelisoli²⁴, David I Sahman²⁶, Ruben Salvaterra⁶⁶, Boris Sbarufatti⁵, Danny Steeghs^{24

42}, Gianpiero Tagliaferri⁵, Christina C Thöne⁶⁷, Antonio de Ugarte Postigo⁶⁸, David Alexander Kann⁶⁹

Affiliations

¹ Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, Nijmegen, The Netherlands. a.levan@astro.ru.nl.
² Department of Physics, University of Warwick, Coventry, UK. a.levan@astro.ru.nl.
³ Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham, UK.
⁴ School of Physics and Astronomy, University of Birmingham, Birmingham, UK.
⁵ INAF - Osservatorio Astronomico di Brera, Merate, Italy.
⁶ INFN - Sezione di Milano Bicocca, Milano, Italy.
⁷ Department of Physics and Earth Science, University of Ferrara, Ferrara, Italy.
⁸ INFN - Sezione di Ferrara, Ferrara, Italy.
⁹ INAF - Osservatorio Astronomico d'Abruzzo, Teramo, Italy.
¹⁰ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, USA.
¹¹ Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, Bunkyo, Japan.
¹² Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba, Japan.
¹³ DARK, Niels Bohr Institute, University of Copenhagen, Copenhagen N, Denmark.
¹⁴ INAF - Osservatorio Astronomico di Capodimonte, Naples, Italy.
¹⁵ Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK.
¹⁶ School of Physics and Astronomy, University of Leicester, Leicester, UK.
¹⁷ Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, Nijmegen, The Netherlands.
¹⁸ Cosmic Dawn Center (DAWN), Copenhagen, Denmark.
¹⁹ Niels Bohr Institute, University of Copenhagen, Copenhagen N, Denmark.
²⁰ European Space Agency (ESA), European Space Astronomy Centre (ESAC), Madrid, Spain.
²¹ Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
²² Nordita, Stockholm University and KTH Royal Institute of Technology, Stockholm, Sweden.
²³ The Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova University Center, Stockholm, Sweden.
²⁴ Department of Physics, University of Warwick, Coventry, UK.
²⁵ International Centre for Radio Astronomy Research, Curtin University, Perth, Western Australia, Australia.
²⁶ Department of Physics and Astronomy, University of Sheffield, Sheffield, UK.
²⁷ Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain.
²⁸ Department of Physics & Astronomy, Texas Tech University, Lubbock, TX, USA.
²⁹ Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, IL, USA.
³⁰ Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA.
³¹ Space Telescope Science Institute, Baltimore, MD, USA.
³² Center for Theoretical Astrophysics, Los Alamos National Laboratory, Los Alamos, NM, USA.
³³ Department of Astronomy, The University of Arizona, Tucson, AZ, USA.
³⁴ Department of Physics and Astronomy, The University of New Mexico, Albuquerque, NM, USA.
³⁵ Department of Physics, The George Washington University, Washington, DC, USA.
³⁶ Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA, USA.
³⁷ School of Physics, University College Cork, Cork, Ireland.
³⁸ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
³⁹ Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, USA.
⁴⁰ DTU Space, National Space Institute, Technical University of Denmark, Lyngby, Denmark.
⁴¹ School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia.
⁴² ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), Monash University, Clayton, Victoria, Australia.
⁴³ School of Physics and Centre for Space Research, University College Dublin, Dublin, Ireland.
⁴⁴ Columbia Astrophysics Laboratory, Department of Physics, Columbia University, New York, NY, USA.
⁴⁵ Center for Computational Astrophysics, Flatiron Institute, New York, NY, USA.
⁴⁶ Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast, UK.
⁴⁷ GEPI, Observatoire de Paris, Université PSL, CNRS, Meudon, France.
⁴⁸ Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, The Netherlands.
⁴⁹ Department of Physics, University of Oxford, Oxford, UK.
⁵⁰ INAF - Osservatorio di Astrofisica e Scienza dello Spazio, Bologna, Italy.
⁵¹ Department of Physics, The University of Auckland, Auckland, New Zealand.
⁵² Department of Astronomy & Astrophysics, University of Toronto, Toronto, Ontario, Canada.
⁵³ NASA Goddard Space Flight Center, Greenbelt, MD, USA.
⁵⁴ Institute of Astronomy, University of Cambridge, Cambridge, UK.
⁵⁵ Mullard Space Science Laboratory, University College London, Holmbury St. Mary, UK.
⁵⁶ Agenzia Spaziale Italiana (ASI) Space Science Data Center (SSDC), Rome, Italy.
⁵⁷ INAF - Osservatorio Astronomico di Roma, Rome, Italy.
⁵⁸ Department of Mathematics, Physics, Informatics and Earth Sciences, University of Messina, Polo Papardo, Messina, Italy.
⁵⁹ School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel.
⁶⁰ Department of Physics and Astronomy, Clemson University, Clemson, SC, USA.
⁶¹ Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Reykjavik, Iceland.
⁶² CEA, IRFU, DAp, AIM, Université Paris-Saclay, Université Paris Cité, Sorbonne Paris Cité, CNRS, Gif-sur-Yvette, France.
⁶³ Sydney Institute for Astronomy, School of Physics, The University of Sydney, Sydney, New South Wales, Australia.
⁶⁴ CSIRO Space and Astronomy, Epping, New South Wales, Australia.
⁶⁵ Isaac Newton Group of Telescopes, Santa Cruz de La Palma, Spain.
⁶⁶ INAF IASF-Milano, Milano, Italy.
⁶⁷ Astronomical Institute of the Czech Academy of Sciences, Ondřejov, Czechia.
⁶⁸ Artemis, Observatoire de la Côte d'Azur, Université Côte d'Azur, Nice, France.
⁶⁹ Hessian Research Cluster ELEMENTS, Giersch Science Center (GSC), Goethe University Frankfurt, Campus Riedberg, Frankfurt am Main, Germany.

PMID: 37879361
PMCID: PMC10881391
DOI: 10.1038/s41586-023-06759-1

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

Andrew J Levan et al. Nature. 2024 Feb.

. 2024 Feb;626(8000):737-741.

doi: 10.1038/s41586-023-06759-1. Epub 2023 Oct 25.

Authors

Affiliations

¹ Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, Nijmegen, The Netherlands. a.levan@astro.ru.nl.
² Department of Physics, University of Warwick, Coventry, UK. a.levan@astro.ru.nl.
³ Institute for Gravitational Wave Astronomy, University of Birmingham, Birmingham, UK.
⁴ School of Physics and Astronomy, University of Birmingham, Birmingham, UK.
⁵ INAF - Osservatorio Astronomico di Brera, Merate, Italy.
⁶ INFN - Sezione di Milano Bicocca, Milano, Italy.
⁷ Department of Physics and Earth Science, University of Ferrara, Ferrara, Italy.
⁸ INFN - Sezione di Ferrara, Ferrara, Italy.
⁹ INAF - Osservatorio Astronomico d'Abruzzo, Teramo, Italy.
¹⁰ Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, USA.
¹¹ Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, Bunkyo, Japan.
¹² Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba, Japan.
¹³ DARK, Niels Bohr Institute, University of Copenhagen, Copenhagen N, Denmark.
¹⁴ INAF - Osservatorio Astronomico di Capodimonte, Naples, Italy.
¹⁵ Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK.
¹⁶ School of Physics and Astronomy, University of Leicester, Leicester, UK.
¹⁷ Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, Nijmegen, The Netherlands.
¹⁸ Cosmic Dawn Center (DAWN), Copenhagen, Denmark.
¹⁹ Niels Bohr Institute, University of Copenhagen, Copenhagen N, Denmark.
²⁰ European Space Agency (ESA), European Space Astronomy Centre (ESAC), Madrid, Spain.
²¹ Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
²² Nordita, Stockholm University and KTH Royal Institute of Technology, Stockholm, Sweden.
²³ The Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova University Center, Stockholm, Sweden.
²⁴ Department of Physics, University of Warwick, Coventry, UK.
²⁵ International Centre for Radio Astronomy Research, Curtin University, Perth, Western Australia, Australia.
²⁶ Department of Physics and Astronomy, University of Sheffield, Sheffield, UK.
²⁷ Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain.
²⁸ Department of Physics & Astronomy, Texas Tech University, Lubbock, TX, USA.
²⁹ Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, IL, USA.
³⁰ Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA.
³¹ Space Telescope Science Institute, Baltimore, MD, USA.
³² Center for Theoretical Astrophysics, Los Alamos National Laboratory, Los Alamos, NM, USA.
³³ Department of Astronomy, The University of Arizona, Tucson, AZ, USA.
³⁴ Department of Physics and Astronomy, The University of New Mexico, Albuquerque, NM, USA.
³⁵ Department of Physics, The George Washington University, Washington, DC, USA.
³⁶ Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA, USA.
³⁷ School of Physics, University College Cork, Cork, Ireland.
³⁸ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
³⁹ Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, USA.
⁴⁰ DTU Space, National Space Institute, Technical University of Denmark, Lyngby, Denmark.
⁴¹ School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia.
⁴² ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), Monash University, Clayton, Victoria, Australia.
⁴³ School of Physics and Centre for Space Research, University College Dublin, Dublin, Ireland.
⁴⁴ Columbia Astrophysics Laboratory, Department of Physics, Columbia University, New York, NY, USA.
⁴⁵ Center for Computational Astrophysics, Flatiron Institute, New York, NY, USA.
⁴⁶ Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast, UK.
⁴⁷ GEPI, Observatoire de Paris, Université PSL, CNRS, Meudon, France.
⁴⁸ Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, The Netherlands.
⁴⁹ Department of Physics, University of Oxford, Oxford, UK.
⁵⁰ INAF - Osservatorio di Astrofisica e Scienza dello Spazio, Bologna, Italy.
⁵¹ Department of Physics, The University of Auckland, Auckland, New Zealand.
⁵² Department of Astronomy & Astrophysics, University of Toronto, Toronto, Ontario, Canada.
⁵³ NASA Goddard Space Flight Center, Greenbelt, MD, USA.
⁵⁴ Institute of Astronomy, University of Cambridge, Cambridge, UK.
⁵⁵ Mullard Space Science Laboratory, University College London, Holmbury St. Mary, UK.
⁵⁶ Agenzia Spaziale Italiana (ASI) Space Science Data Center (SSDC), Rome, Italy.
⁵⁷ INAF - Osservatorio Astronomico di Roma, Rome, Italy.
⁵⁸ Department of Mathematics, Physics, Informatics and Earth Sciences, University of Messina, Polo Papardo, Messina, Italy.
⁵⁹ School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel.
⁶⁰ Department of Physics and Astronomy, Clemson University, Clemson, SC, USA.
⁶¹ Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Reykjavik, Iceland.
⁶² CEA, IRFU, DAp, AIM, Université Paris-Saclay, Université Paris Cité, Sorbonne Paris Cité, CNRS, Gif-sur-Yvette, France.
⁶³ Sydney Institute for Astronomy, School of Physics, The University of Sydney, Sydney, New South Wales, Australia.
⁶⁴ CSIRO Space and Astronomy, Epping, New South Wales, Australia.
⁶⁵ Isaac Newton Group of Telescopes, Santa Cruz de La Palma, Spain.
⁶⁶ INAF IASF-Milano, Milano, Italy.
⁶⁷ Astronomical Institute of the Czech Academy of Sciences, Ondřejov, Czechia.
⁶⁸ Artemis, Observatoire de la Côte d'Azur, Université Côte d'Azur, Nice, France.
⁶⁹ Hessian Research Cluster ELEMENTS, Giersch Science Center (GSC), Goethe University Frankfurt, Campus Riedberg, Frankfurt am Main, Germany.

PMID: 37879361
PMCID: PMC10881391
DOI: 10.1038/s41586-023-06759-1

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.

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Conflict of interest statement

The authors declare no competing interests.

Figures

**Fig. 1. The high-energy properties of GRB 230307A.**
a, The light curve of the GRB at 64-ms time resolution with the Fermi/GBM. The shaded region indicates the region in which saturation may be an issue. The burst begins very hard, with the count rate dominated by photons in the hardest (100–900-keV) band, but rapidly softens, with the count rate in the hard band being progressively overtaken by softer bands (such as 8–25 keV and 25–100 keV) beyond about 20 s. This strong hard-to-soft evolution is reminiscent of GRB 211211A (ref. ) and is caused by the motion of two spectral breaks through the gamma-ray regime (see Methods). b, The X-ray light curves of GRBs from the Swift X-ray telescope. These have been divided by the prompt fluence of the burst, which broadly scales with the X-ray light curve luminosity, resulting in a modest spread of afterglows. The greyscale background represents the ensemble of long GRBs. GRB 230307A is an extreme outlier of the >1,000 Swift GRBs, with an extremely faint afterglow for the brightness of its prompt emission. Other merger GRBs from long bursts, and those suggested to be short with extended emission (EE), occupy a similar region of the parameter space. This suggests that the prompt to afterglow fluence could be a valuable tool in distinguishing long GRBs from mergers and those from supernovae.

**Fig. 2. JWST images of GRB 230307A at 28.5 days post burst.**
a, The wide-field image combining the F115W, F150W and F444W images. The putative host is the bright face-on spiral galaxy, whereas the afterglow appears at a 30-arcsec offset, within the white box. The scale bar at the lower left represents 10″. b–g, Cut-outs of the NIRCam data around the GRB afterglow location. The source is faint and barely detected in the bluer bands but very bright and well detected in the red bands. In the red bands, a faint galaxy is present northeast of the transient position. This galaxy has a redshift of z = 3.87 but we consider it to be a background object unrelated to the GRB (see Supplementary Information).

**Fig. 3. JWST/NIRSpec spectroscopy of the counterpart of GRB 230307A.**
The top portion shows the 2D spectrum rectified to a common wavelength scale. The transient is well detected beyond 2 microns but not shortward, indicative of an extremely red source. Emission lines from the nearby galaxy at z = 3.87 can also be seen offset from the afterglow trace. The lower panel shows the 1D extraction of the spectrum in comparison with the latest (10-day) AT2017gfo epoch and a kilonova model. A clear emission feature can be seen at about 2.15 microns at both 29 and 61 days. This feature is consistent with the expected location of [Te III], whereas redder features are compatible with lines from [Se III] and [W III]. This line is also clearly visible in the scaled late-time spectrum of AT2017gfo (refs. ^,), whereas the red colours are also comparable with those of AT2017gfo as measured with Spitzer (ref. ; shown scaled to the 29-day NIRSpec spectrum). Error bars on photometry refer to the 1σ error bar on the y axis and the filter width on the x axis.

**Fig. 4. A comparison of the counterpart of GRB 230307A with AT2017gfo associated with GW170817.**
AT2017gfo has been scaled to the same distance as GRB 230307A. Beyond about 2 days, the kilonova dominates the counterpart. The decay rates in both the optical and infrared are very similar to those in AT2017gfo. These are too rapid for any plausible afterglow model. There is also good agreement in the late-time slope between the measurements made at 4.4 microns with the JWST and at 4.5 microns for AT2017gfo with Spitzer. Error bars refer to the 1σ uncertainty.

See this image and copyright information in PMC

References

1. Tanvir NR, et al. A ‘kilonova’ associated with the short-duration γ-ray burst GRB 130603B. Nature. 2013;500:547–549. doi: 10.1038/nature12505. - DOI - PubMed
1. Abbott BP, Abbott R, Abbott TD, et al. GW170817: observation of gravitational waves from a binary neutron star inspiral. Phys. Rev. Lett. 2017;119:161101. doi: 10.1103/PhysRevLett.119.161101. - DOI - PubMed
1. Metzger BD. Kilonovae. Living Rev. Relativ. 2020;23:1. doi: 10.1007/s41114-019-0024-0. - DOI - PMC - PubMed
1. Rastinejad JC, et al. A kilonova following a long-duration gamma-ray burst at 350 Mpc. Nature. 2022;612:223–227. doi: 10.1038/s41586-022-05390-w. - DOI - PubMed
1. Troja E, et al. A nearby long gamma-ray burst from a merger of compact objects. Nature. 2022;612:228–231. doi: 10.1038/s41586-022-05327-3. - DOI - PMC - PubMed

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

Affiliations

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

Authors

Affiliations

Abstract

Conflict of interest statement

Figures

References

LinkOut - more resources

Full Text Sources