Discovery of a Relativistic Stripped Envelope Type Ic-BL Supernova at z = 2.83 with JWST

Abstract

We present JWST NIRCam and NIRSpec observations of a Type Ic supernova (SN Ic) and its host galaxy (JADES-GS+53.13533-27.81457) at $z=2.83$. This SN (named SN 2023adta) was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) Program. Follow-up observations with JWST/NIRSpec provided a spectroscopic redshift of $z=2.83$ and the classification as a SN Ic-BL. The light curve of SN 2023adta matches well with other stripped envelope supernovae and we find a high peak luminosity, $M_V=-19.0\pm 0.2$ mag, based on the distribution of best-fit SNe. The broad absorption features in its spectrum are consistent with other SNe Ic-BL 1-3 weeks after peak brightness. We measure a Ca II NIR triplet expansion velocity of $29,000\pm 2,000$ km s${}^{-1}$. The host galaxy of SN 2023adta is irregular, and modeling of its spectral energy distribution (SED) indicates a metallicity of $Z=0.35_{-0.08}^{+0.16}{Z}_{\odot }$. This environment is consistent with the population of low-$z$ SNe Ic-BL which prefer lower metallicities relative to other stripped envelope supernovae, and track long duration ${\hat{I}}^3$-ray burst (LGRB) environments. We do not identify any GRBs that are coincident with SN 2023adta. Given the rarity of SNe Ic-BL in the local universe, the detection of a SN Ic-BL at $z=2.83$ could indicate that their rates are enhanced at high redshift.

16 pages, 7 figures, Published in ApJL