A1 Refereed original research article in a scientific journal
GRB 241105A: a test case for GRB classification and rapid r-process nucleosynthesis channels
Authors: Dimple; Gompertz, B. P.; Levan, A. J.; Malesani, D. B.; Laskar, T.; Bala, S.; Chrimes, A. A.; Heintz, K.; Izzo, L.; Lamb, G. P.; O'neill, D.; Palmerio, J. T.; Saccardi, A.; Anderson, G. E.; De barra, C.; Huang, Y.; Kumar, A.; Li, H.; McBreen, S.; Mukherjee, O.; Oates, S. R.; Pathak, U.; Qiu, Y.; Roberts, O. J.; Sonawane, R.; Veres, P.; Ackley, K.; Han, X.; Julakanti, Y.; Wang, J.; D'avanzo, P.; Martin-Carrillo, A.; Ravasio, M. E.; Rossi, A.; Tanvir, N. R.; Anderson, J. P.; Arabsalmani, M.; Belkin, S.; Breton, R. P.; Brivio, R.; Burns, E.; Casares, J.; Campana, S.; Chastain, S., I; D'Elia, V; Dhillon, V. S.; Dyer, M. J.; Fynbo, J. P. U.; Galloway, D. K.; Gulati, A.; Godson, B.; Goodwin, A. J.; Gromadzki, M.; Hartmann, D. H.; Jakobsson, P.; Killestein, T. L.; Kotak, R.; Leung, J. K.; Lyman, J. D.; Melandri, A.; Mattila, S.; McGee, S.; Morley, C.; Mukherjee, T.; Müller-Bravo, T. E.; Noysena, K.; Nuttall, L. K.; O'brien, P.; De pasquale, M.; Pignata, G.; Pollacco, D.; Pugliese, G.; Ramsay, G.; Sahu, A.; Salvaterra, R.; Schady, P.; Schneider, B.; Steeghs, D.; Starling, R. L. C.; Tsalapatas, K.; Ulaczyk, K.; van der Horst, A. J.; Wang, C.; Wiersema, K.; Worssam, I; Wortley, M. E.; Xiong, S.; Zafar, T.
Publisher: Oxford University Press
Publication year: 2025
Journal: Monthly Notices of the Royal Astronomical Society
Volume: 544
Issue: 1
First page : 548
Last page: 571
ISSN: 0035-8711
eISSN: 1365-2966
DOI: https://doi.org/10.1093/mnras/staf1574
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : Open Access publication channel
Web address : https://doi.org/10.1093/mnras/staf1574
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/505497676
Gamma-ray bursts (GRBs) offer a powerful window to probe the progenitor systems responsible for the formation of heavy elements through the rapid neutron capture (r-) process, thanks to their exceptional luminosity, which allows them to be observed across vast cosmic distances. GRB 241105A, observed at a redshift of z = 2.681, features a short initial spike (∼1.5 s) and a prolonged weak emission lasting about 64 s, positioning it as a candidate for a compact binary merger and potentially marking it as the most distant merger-driven GRB observed to date. However, the emerging ambiguity in GRB classification necessitates further investigation into the burst's true nature. Prompt emission analyses, such as hardness ratio, spectral lag, and minimum variability time-scales, yield mixed classifications, while machine-learning-based clustering places GRB 241105A near both long-duration mergers and collapsar GRBs. We conducted observations using the James Webb Space Telescope (JWST) to search for a potential supernova counterpart. Although no conclusive evidence was found for a supernova, the host galaxy's properties derived from the JWST observations suggest active star formation with low metallicity, and a sub-kpc offset of the afterglow from the host, which appears broadly consistent with a collapsar origin. Nevertheless, a compact binary merger origin cannot be ruled out, as the burst may plausibly arise from a fast progenitor channel. This would have important implications for heavy element enrichment in the early Universe.
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Funding information in the publication:
Dimple and BPG acknowledge support from STFC grant no. ST/Y002253/1. BPG and DO acknowledge support from the Leverhulme Trust grant no. RPG-2024-117. Dimple acknowledges Inter University Centre for Astronomy and Astrophysics (IUCAA), India, for their warm hospitality during her stay on the campus. The Gravitational-wave Optical Transient Observer (GOTO) project acknowledges support from the Science and Technology Facilities Council (STFC, grant nos ST/T007184/1, ST/T003103/1, ST/T000406/1, ST/X001121/1, and ST/Z000165/1) and the GOTO consortium institutions; University of Warwick; Monash University; University of Sheffield; University of Leicester; Armagh Observatory & Planetarium; the National Astronomical Research Institute of Thailand (NARIT);University of Manchester; Instituto de Astrofísica de Canarias (IAC); University of Portsmouth; University of Turku. AAC acknowledges support through the European Space Agency (ESA) research fellowship programme. AS acknowledges support by a postdoctoral fellowship from the CNES. AK is supported by the UK Science and Technology Facilities Council (STFC) Consolidated grant ST/V000853/1. TEMB is funded by Horizon Europe ERC grant no. 101125877. KT acknowledges support from the Dynamical Universe, funded by the KAW foundation. SM acknowledges financial support from the Research Council of Finland project 350458. AS acknowledges the Warwick Astrophysics PhD prize scholarship, made possible thanks to a generous philanthropic donation. JDL acknowledges support from a UK Research and Innovation Future Leaders Fellowship (MR/T020784/1). RB acknowledges funding from the Italian Space Agency, contract ASI/INAF n.I/004/11/6. SB, OM, and OR gratefully acknowledge NASA funding from cooperative agreement 80NSSC24M0035. CdB and SMB acknowledge support from funded by Taighde Eireann – Research Ireland under grant nos 21/FFP-A/9043. PV gratefully acknowledges NASA funding from cooperative agreement 80MSFC22M0004. RLCS acknowledges support from The Leverhulme Trust grant no. RPG-2023-240. AR acknowledges support from INAF minigrant 1.05.24.07.04. RB, SC, PDA, AM, and RS acknowledge funding from the Italian Space Agency, contract ASI/INAF n. I/004/11/6. MER is supported by the European Union (ERC, Starstruck, 101095973, PI:Jonker). TLK acknowledges a Warwick Astrophysics prize postdoctoral fellowship made possible thanks to a generous philanthropic donation. IW and MEW are supported by the UKRI Science and Technology Facilities Council (STFC). This work is based [in part] on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy,Inc., under NASA contract NAS 5–03127 for JWST. These observations are associated with program 9228.
