SN 2023xwi: forbidden line emission in the peak spectrum of a Ca-strong transient

We present an extensive optical photometric and spectroscopic investigation into the calcium-rich supernova (SN) - SN 2023xwi. Observations from a variety of ground-based telescopes follow the SN from 8 d pre-peak brightness to 87 d post-peak, covering both early-time (photospheric) and late-time (n...

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Detalhes bibliográficos
Autores: Touchard-Paxton, Charlotte-Grace, Frohmaier, C., Pursiainen, Miika, Sullivan, Mark, Polin, Abigail, Dimitriadis, Georgios, Galbany, Lluís, Killestein, Thomas L., Kumar, A., Lyman, Joe
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2025
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/393061
Acesso em linha:http://hdl.handle.net/10261/393061
https://api.elsevier.com/content/abstract/scopus_id/85216588626
Access Level:Acceso aberto
Palavra-chave:Novae, cataclysmic variables
Supernovae: general
Supernovae: individual: SN 2023xwi
White dwarfs
Descrição
Resumo:We present an extensive optical photometric and spectroscopic investigation into the calcium-rich supernova (SN) - SN 2023xwi. Observations from a variety of ground-based telescopes follow the SN from 8 d pre-peak brightness to 87 d post-peak, covering both early-time (photospheric) and late-time (nebular) phases of the SN. Objects of this class are characterized by nebular spectra that are dominated by [Ca ii] 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 an SN progenitor embedded in an environment polluted by a recurrent He-nova AM CVn system.