A1 Refereed original research article in a scientific journal
SN 2023tsz: a helium-interaction-driven supernova in a very low-mass galaxy
Authors: Warwick, B.; Lyman, J.; Pursiainen, M.; Coppejans, D. L.; Galbany, L.; Jones, G. T.; Killestein, T. L.; Kumar, A.; Oates, S. R.; Ackley, K.; Anderson, J. P.; Aryan, A.; Breton, R. P.; Chen, T. W.; Clark, P.; Dhillon, V. S.; Dyer, M. J.; Gal-Yam, A.; Galloway, D. K.; Gutierrez, C. P.; Gromadzki, M.; Inserra, C.; Jimenez-Ibarra, F.; Kelsey, L.; Kotak, R.; Kravtsov, T.; Kuncarayakti, H.; Magee, M. R.; Matilainen, K.; Mattila, S.; Mueller-Bravo, T. E.; Nicholl, M.; Noysena, K.; Nuttall, L. K.; O'Brien, P.; O'Neill, D.; Palle, E.; Pessi, T.; Petrushevska, T.; Pignata, G.; Pollacco, D.; Ragosta, F.; Ramsay, G.; Sahu, A.; Sahu, D. K.; Singh, A.; Sollerman, J.; Stanway, E.; Starling, R.; Steeghs, D.; Teja, R. S.; Ulaczyk, K.
Publisher: Oxford University Press (OUP)
Publishing place: OXFORD
Publication year: 2025
Journal: Monthly Notices of the Royal Astronomical Society
Journal name in source: Monthly Notices of the Royal Astronomical Society
Journal acronym: MON NOT R ASTRON SOC
Volume: 536
Issue: 4
First page : 3588
Last page: 3600
Number of pages: 13
ISSN: 0035-8711
eISSN: 1365-2966
DOI: https://doi.org/10.1093/mnras/stae2784
Web address : https://doi.org/10.1093/mnras/stae2784
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/485110017
SN 2023tsz is a Type Ibn supernova (SN Ibn), an uncommon subtype of stripped-envelope core-collapse supernovae (SNe), discovered in an extremely low-mass host. SNe Ibn are characterized by narrow helium emission lines in their spectra and are believed to originate from the collapse of massive Wolf-Rayet (WR) stars, though their progenitor systems still remain poorly understood. In terms of energetics and spectrophotometric evolution, SN 2023tsz is largely a typical example of the class, although line profile asymmetries in the nebular phase are seen, which may indicate the presence of dust formation or unshocked circumstellar material. Intriguingly, SN 2023tsz is located in an extraordinarily low-mass host galaxy that is in the second percentile for stripped-envelope SN host masses and star formation rates (SFRs). The host has a radius of 1.0 kpc, a g-band absolute magnitude of -12.72 +/- 0.05, and an estimated metallicity of log(Z(*)/Z(circle dot)) approximate to -1.6. The SFR and metallicity of the host galaxy raise questions about the progenitor of SN 2023tsz. The low SFR suggests that a star with sufficient mass to evolve into a WR would be uncommon in this galaxy. Further, the very low metallicity is a challenge for single stellar evolution to enable H and He stripping of the progenitor and produce an SN Ibn explosion. The host galaxy of SN 2023tsz adds another piece to the ongoing puzzle of SNe Ibn progenitors, and demonstrates that they can occur in hosts too faint to be observed in contemporary sky surveys at a more typical SN Ibn redshift.
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Funding information in the publication:
https://academic.oup.com/mnras/article/536/4/3588/7929872#499797813
