James Webb Space Telescope Feed Post

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

Paper 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^{+0.16}_{-0.08} 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 \gamma-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.