Warwick, B and Lyman, J and Pursiainen, M and Coppejans, D L and Galbany, L and Jones, G T and Killestein, T L and Kumar, A and Oates, S R and Ackley, K and Anderson, J P and Aryan, A and Breton, R P and Chen, T W and Clark, P and Dhillon, V S and Dyer, M J and Gal-Yam, A and Galloway, D K and Gutiérrez, C P and Gromadzki, M and Inserra, C and Jiménez-Ibarra, F and Kelsey, L and Kotak, R and Kravtsov, T and Kuncarayakti, H and Magee, M R and Matilainen, K and Mattila, S and Müller-Bravo, T E and Nicholl, M and Noysena, K and Nuttall, L K and O’Brien, P and O’Neill, D and Pallé, E and Pessi, T and Petrushevska, T and Pignata, G and Pollacco, D and Ragosta, F and Ramsay, G and Sahu, A and Sahu, D K and Singh, A and Sollerman, J and Stanway, E and Starling, R and Steeghs, D and Teja, R S and Ulaczyk, K (2025) SN 2023tsz : A helium-interaction driven supernova in a very low-mass galaxy. Monthly Notices of the Royal Astronomical Society, 536 (4). pp. 3588-3600. ISSN 0035-8711
Full text not available from this repository.Abstract
SN 2023tsz is a Type Ibn supernova (SNe Ibn), an uncommon subtype of stripped-envelope core-collapse SNe, discovered in an extremely low-mass host. SNe Ibn are characterised 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 2nd percentile for stripped envelope SN host masses and star formation rates (SFR). 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⊙) ≈−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 a 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.