Touchard-Paxton, C-G and Frohmaier, C and Pursiainen, M and Sullivan, M and Polin, A and Dimitriadis, G and Galbany, L and Killestein, T L and Kumar, A and Lyman, J (2025) SN 2023xwi : Forbidden line emission in the peak spectrum of a Ca-strong transient. Monthly Notices of the Royal Astronomical Society, 537 (2). pp. 1015-1027. ISSN 0035-8711
Full text not available from this repository.Abstract
We present an extensive optical photometric and spectroscopic investigation into the calcium-rich supernova (SN) – SN2023xwi. Observations from a variety of ground-based telescopes follow the SN from 8 days pre-peak brightness to 87 days post-peak, covering both early-time (photospheric) and late-time (nebular) phases of the supernova. Objects of this class are characterised by nebular spectra that are dominated by [Ca II] λλ 7291, 7324 emission. SN 2023xwi displays a unique peculiarity in that its forbidden [Ca II] feature is visible in its peak photospheric spectrum – far earlier than expected in current models. This is one of the strongest and earliest detections of this feature in Ca-rich SNe in photospheric-phase spectra. We investigate the velocity evolution of this spectral feature and show that it cannot be easily explained by conventional progenitor systems. From our observations, we propose a SN progenitor embedded in an environment polluted by a recurrent He-nova AM CVn system.