Testing for Intrinsic Type Ia Supernova Luminosity Evolution at z>2 with JWST
Abstract
The James Webb Space Telescope (JWST) is opening new frontiers of transient discovery and follow-up at high-redshift. Here we present the discovery of a spectroscopically confirmed Type Ia supernova (SN Ia; SN 2023aeax) at z=2.15 with JWST, including a NIRCam multi-band light curve. SN 2023aeax lands at the edge of traditional low-z cosmology cuts because of its blue color (peak rest-frame B-V-0.3) but with a normal decline rate ( m15(B)1.25), and applying a fiducial standardization with the BayeSN model we find the SN 2023aeax luminosity distance is in 0.1σ agreement with . SN 2023aeax is only the second spectroscopically confirmed SN Ia in the dark matter-dominated Universe at z>2 (the other is SN 2023adsy), giving it rare leverage to constrain any potential evolution in SN Ia standardized luminosities. Similar to SN 2023adsy (B-V0.8), SN 2023aeax has a fairly extreme (but opposite) color, which may be due to the small sample size or a secondary factor, such as host galaxy properties. Nevertheless, the SN 2023aeax spectrum is well-represented by normal low-z SN Ia spectra and we find no definitive evolution in SN Ia standardization with redshift. Still, the first two spectroscopically confirmed z>2 SNe Ia have peculiar colors and combine for a 1σ distance slope relative to , though in agreement with recent SN Ia cosmological measurements.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.