2024/06/07 by J. D. R. Pierel, Justin Pierel, Pierel, J. D. R. +76 · 1 voice · 1 citation
Physics and Astronomy · Earth and Planetary Sciences · #Gamma-ray bursts and supernovae #Geophysics and Gravity Measurements #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.2406.05089
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS+53.13485-27.82088 with a host spectroscopic redshift of 2.903±0.007. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (E(B-V)∼0.9) despite a host galaxy with low-extinction and has a high Ca II velocity (19,000±2,000km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-z Ca-rich population. Although such an object is too red for any low-z cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (\lesssim1σ) with ΛCDM. Therefore unlike low-z Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-z truly diverge from their low-z counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.