LSQ13fn: A type II-Plateau supernova with a possibly low metallicity progenitor that breaks the standardised candle relation
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Fecha
2016-04
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
EDP SCIENCES
Nombre de Curso
Licencia CC
Licencia CC
Resumen
We present optical imaging and spectroscopy of supernova (SN) LSQ13fn, a type II supernova with several hitherto-unseen properties. Although it initially showed strong symmetric spectral emission features attributable to He ii, N iii, and C iii, reminiscent of some interacting SNe, it transitioned into an object that would fall more naturally under a type II-Plateau (IIP) classification. However, its spectral evolution revealed several unusual properties: metal lines appeared later than expected, were weak, and some species were conspicuous by their absence. Furthermore, the line velocities were found to be lower than expected given the plateau brightness, breaking the SN IIP standardised candle method for distance estimates. We found that, in combination with a short phase of early-time ejecta-circumstellar material interaction, metal-poor ejecta, and a large progenitor radius could reasonably account for the observed behaviour. Comparisons with synthetic model spectra of SNe IIP of a given progenitor mass would imply a progenitor star metallicity as low as 0.1 Z⊙. LSQ13fn highlights the diversity of SNe II and the many competing physical effects that come into play towards the final stages of massive star evolution immediately preceding core-collapse.
Notas
Indexación: Web of Science; Scopus.
Palabras clave
Supernovae: general, Supernovae: individual: LSQ13fn
Citación
Astronomy and Astrophysics. Volume 588, 1 April 2016, Article number A1