Detection of Metal Enrichment by SN 2011jm in NGC 4809

Abstract

Cosmic metals are believed to originate from stellar and supernovae (SNe) nucleosynthesis, dispersed into the interstellar medium (ISM) through stellar winds and supernova explosions. In this paper, we present the clear evidence of metal enrichment by a Type Ic SN 2011jm in the galaxy NGC 4809, utilizing high spatial resolution integral field unit observations obtained from the Very Large Telescope/Multi Unit Spectroscopic Explorer. Despite SN 2011jm being surrounded by metal-deficient ISM (∼0.25 Z _⊙ ) at a scale about 100 pc, we clearly detect enriched oxygen abundance (∼0.35 Z _⊙ ) and a noteworthy nitrogen-to-oxygen ratio at the SN site. Remarkably, the metal pollution is confined to a smaller scale (≲13 pc). We posit that the enhanced ionized metal stems from stellar winds emitted by massive stars or previous SN explosions. This observation may represent the first direct detection of chemical pollution by stellar feedback in star-forming galaxies beyond the Local Volume.

Keywords

• Metallicity
• Interstellar medium
• Type Ic supernovae
• Dwarf irregular galaxies