_version_ 1866910250168221696
author Aparicio, Valeria
Jones, David O.
Hoogendam, Willem B.
Moriya, Takashi J.
Coulter, David A.
Pierel, Justin D. R.
Siebert, Matthew
Wang, Bingjie
Akins, Hollis B.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Fox, Ori D.
Haghjoo, Aryana
Hirschmann, Michaela
Ilbert, Olivier
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
McCracken, Henry Joy
Mobasher, Bahram
Rest, Armin
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
author_facet Aparicio, Valeria
Jones, David O.
Hoogendam, Willem B.
Moriya, Takashi J.
Coulter, David A.
Pierel, Justin D. R.
Siebert, Matthew
Wang, Bingjie
Akins, Hollis B.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Fox, Ori D.
Haghjoo, Aryana
Hirschmann, Michaela
Ilbert, Olivier
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
McCracken, Henry Joy
Mobasher, Bahram
Rest, Armin
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
contents The launch of the James Webb Space Telescope (JWST) has enabled the discovery of a small but increasing sample of high-redshift core-collapse supernovae (CC SNe), which provide new tests of massive star evolution in the early Universe. In this study, we report the discovery of SN 2023aeaf in COSMOS-Web survey observations, which at $z = 3.195$ has one of the highest SN spectroscopic redshifts to date. Using two epochs of JWST photometry separated by $\sim$1 month in the rest frame, we photometrically classify SN 2023aeaf by comparing the JWST photometry to spectrophotometric CC SN and Type Ia (SN Ia) models and UV observations of SNe from the Swift telescope, finding that SN 2023aeaf is highly likely to be a Type II SN. A spectrum of the SN$+$host galaxy was also obtained $\sim$30 rest-frame days after discovery but shows no clearly identifiable SN features, with H$α$ emission from the host potentially masking emission from the SN. Although the limited photometric coverage prevents strong constraints on the explosion properties, we find that the data are most consistent with a $\sim$12$M_\odot$ progenitor with $\sim$0.5$M_{\odot}$ of circumstellar material. We next use the host-galaxy spectrum and photometry to model the host spectral energy distribution (SED) using the Prospector Bayesian inference framework. We find that the host is a star-forming galaxy with a sSFR of $ \log_{10}(\rm sSFR/yr^{-1})= -10.17^{+0.13}_{-0.10}$, a stellar mass of $\log(M_\star/M_\odot) = 9.04^{+0.03}_{-0.04}$, and a gas-phase metallicity of $12 +{\rm log_{10}}({\rm O/H}) = 7.82\pm0.02$. SN 2023aeaf joins a growing sample of early Universe CC SNe with high luminosities, dense CSM, and low-metallicity environments.
format Preprint
id arxiv_https___arxiv_org_abs_2605_24088
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Discovery and Analysis of a Type II Supernova Candidate at z = 3.19 from JWST's COSMOS-Web Survey
Aparicio, Valeria
Jones, David O.
Hoogendam, Willem B.
Moriya, Takashi J.
Coulter, David A.
Pierel, Justin D. R.
Siebert, Matthew
Wang, Bingjie
Akins, Hollis B.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Fox, Ori D.
Haghjoo, Aryana
Hirschmann, Michaela
Ilbert, Olivier
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
McCracken, Henry Joy
Mobasher, Bahram
Rest, Armin
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
High Energy Astrophysical Phenomena
Astrophysics of Galaxies
The launch of the James Webb Space Telescope (JWST) has enabled the discovery of a small but increasing sample of high-redshift core-collapse supernovae (CC SNe), which provide new tests of massive star evolution in the early Universe. In this study, we report the discovery of SN 2023aeaf in COSMOS-Web survey observations, which at $z = 3.195$ has one of the highest SN spectroscopic redshifts to date. Using two epochs of JWST photometry separated by $\sim$1 month in the rest frame, we photometrically classify SN 2023aeaf by comparing the JWST photometry to spectrophotometric CC SN and Type Ia (SN Ia) models and UV observations of SNe from the Swift telescope, finding that SN 2023aeaf is highly likely to be a Type II SN. A spectrum of the SN$+$host galaxy was also obtained $\sim$30 rest-frame days after discovery but shows no clearly identifiable SN features, with H$α$ emission from the host potentially masking emission from the SN. Although the limited photometric coverage prevents strong constraints on the explosion properties, we find that the data are most consistent with a $\sim$12$M_\odot$ progenitor with $\sim$0.5$M_{\odot}$ of circumstellar material. We next use the host-galaxy spectrum and photometry to model the host spectral energy distribution (SED) using the Prospector Bayesian inference framework. We find that the host is a star-forming galaxy with a sSFR of $ \log_{10}(\rm sSFR/yr^{-1})= -10.17^{+0.13}_{-0.10}$, a stellar mass of $\log(M_\star/M_\odot) = 9.04^{+0.03}_{-0.04}$, and a gas-phase metallicity of $12 +{\rm log_{10}}({\rm O/H}) = 7.82\pm0.02$. SN 2023aeaf joins a growing sample of early Universe CC SNe with high luminosities, dense CSM, and low-metallicity environments.
title Discovery and Analysis of a Type II Supernova Candidate at z = 3.19 from JWST's COSMOS-Web Survey
topic High Energy Astrophysical Phenomena
Astrophysics of Galaxies
url https://arxiv.org/abs/2605.24088