SN 2023tsz: A helium-interaction driven supernova in a very low-mass galaxy

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., Gutiérrez, C. P., Gromadzki, M., Inserra, C. ORCID: https://orcid.org/0000-0002-3968-4409, Jiménez-Ibarra, F., Kelsey, L., Kotak, R., Kravtsov, T., Kuncarayakti, H., Magee, M. R., Matilainen, K., Mattila, S., Müller-Bravo, T. E., Nicholl, M., Noysena, K., Nuttall, L. K., O’Brien, P., O’Neill, D., Pallé, 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. and Ulaczyk, K. 2024. SN 2023tsz: A helium-interaction driven supernova in a very low-mass galaxy. Monthly Notices of the Royal Astronomical Society 10.1093/mnras/stae2784

PDF - Accepted Post-Print Version Download (4MB)

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.

Item Type:	Article
Date Type:	Published Online
Status:	In Press
Schools:	Physics and Astronomy
Additional Information:	License information from Publisher: LICENSE 1: URL: https://creativecommons.org/licenses/by/4.0/, Start Date: 2024-12-21
Publisher:	Oxford University Press
ISSN:	0035-8711
Date of First Compliant Deposit:	7 January 2025
Last Modified:	07 Jan 2025 15:15
URI:	https://orca.cardiff.ac.uk/id/eprint/175081

Actions (repository staff only)

Edit Item