_version_ 1866914303366397952
author Tinyanont, Samaporn
Wangnok, Kittipong
Andrews, Jennifer E.
Foley, Ryan J.
Kaewmookda, Methawee
Jencson, Jacob E.
Rest, Armin
Auchettl, Katie
Bostroem, K. A.
Coulter, David A.
Chainakun, Poemwai
Chornock, Ryan
Davis, Kyle W.
Fox, Ori D.
Galbany, Lluís
Geballe, Thomas R.
Hsu, Brian
Jacobson-Galán, Wynn
Jha, Saurabh W.
Kaur, Ravjit
Kasliwal, Mansi M.
Lau, Ryan M.
LeBaron, Natalie
Margutti, Raffaella
Park, Seong Hyun
Pearson, Jeniveve
Piro, Anthony L.
Ransome, Conor L.
Ravi, Aravind P.
Rho, Jeonghee
Rojas-Bravo, César
Rose, Sam
Sand, David J.
Smith, Nathan
Shrestha, Manisha
Subrayan, Bhagya M.
Valenti, Stefano
author_facet Tinyanont, Samaporn
Wangnok, Kittipong
Andrews, Jennifer E.
Foley, Ryan J.
Kaewmookda, Methawee
Jencson, Jacob E.
Rest, Armin
Auchettl, Katie
Bostroem, K. A.
Coulter, David A.
Chainakun, Poemwai
Chornock, Ryan
Davis, Kyle W.
Fox, Ori D.
Galbany, Lluís
Geballe, Thomas R.
Hsu, Brian
Jacobson-Galán, Wynn
Jha, Saurabh W.
Kaur, Ravjit
Kasliwal, Mansi M.
Lau, Ryan M.
LeBaron, Natalie
Margutti, Raffaella
Park, Seong Hyun
Pearson, Jeniveve
Piro, Anthony L.
Ransome, Conor L.
Ravi, Aravind P.
Rho, Jeonghee
Rojas-Bravo, César
Rose, Sam
Sand, David J.
Smith, Nathan
Shrestha, Manisha
Subrayan, Bhagya M.
Valenti, Stefano
contents We present near-infrared (NIR) spectroscopy of the hydrogen- and helium-poor (Type Ic) supernova (SN) 2024aecx that displays a strong NIR excess emerging 32 days post peak. SN 2024aecx is a peculiar SN Ic that exhibited luminous shock-cooling emission at early times, suggestive of close-in circumstellar medium (CSM), unexpected for this class of SNe. Its early NIR spectra are typical for a SN Ic but with strong CI absorption features. By ~32 days post peak, the spectra show a strong NIR excess, while maintaining normal optical colors, unprecedented for SNe Ic. We find that the NIR excess is well fit with a single-temperature, optically thin dust model with declining temperature, increasing mass, and roughly constant luminosity over time. The NIR excess appears too promptly for dust to have formed in the SN ejecta, indicating an IR echo from pre-existing dust in the CSM. The IR echo is likely powered by the relatively slowly evolving SN peak light, and not the brief shock cooling emission, as the latter requires unrealistically high CSM densities to explain the observed dust mass. We consider different potential CSM geometries and find that a thick face-on disk with an inner edge around $5\times 10^{16}$ cm can best explain the dust mass and temperature evolution. In this scenario, the SN shock should start interacting with this CSM $440\pm200$ days post explosion. CSM around SN Ic is rare, and follow-up observations of SN 2024aecx will probe the mass-loss process responsible for removing hydrogen and helium from their progenitor star.
format Preprint
id arxiv_https___arxiv_org_abs_2602_02691
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle An infrared echo from a circumstellar disk in the hydrogen- and helium-poor SN 2024aecx
Tinyanont, Samaporn
Wangnok, Kittipong
Andrews, Jennifer E.
Foley, Ryan J.
Kaewmookda, Methawee
Jencson, Jacob E.
Rest, Armin
Auchettl, Katie
Bostroem, K. A.
Coulter, David A.
Chainakun, Poemwai
Chornock, Ryan
Davis, Kyle W.
Fox, Ori D.
Galbany, Lluís
Geballe, Thomas R.
Hsu, Brian
Jacobson-Galán, Wynn
Jha, Saurabh W.
Kaur, Ravjit
Kasliwal, Mansi M.
Lau, Ryan M.
LeBaron, Natalie
Margutti, Raffaella
Park, Seong Hyun
Pearson, Jeniveve
Piro, Anthony L.
Ransome, Conor L.
Ravi, Aravind P.
Rho, Jeonghee
Rojas-Bravo, César
Rose, Sam
Sand, David J.
Smith, Nathan
Shrestha, Manisha
Subrayan, Bhagya M.
Valenti, Stefano
High Energy Astrophysical Phenomena
We present near-infrared (NIR) spectroscopy of the hydrogen- and helium-poor (Type Ic) supernova (SN) 2024aecx that displays a strong NIR excess emerging 32 days post peak. SN 2024aecx is a peculiar SN Ic that exhibited luminous shock-cooling emission at early times, suggestive of close-in circumstellar medium (CSM), unexpected for this class of SNe. Its early NIR spectra are typical for a SN Ic but with strong CI absorption features. By ~32 days post peak, the spectra show a strong NIR excess, while maintaining normal optical colors, unprecedented for SNe Ic. We find that the NIR excess is well fit with a single-temperature, optically thin dust model with declining temperature, increasing mass, and roughly constant luminosity over time. The NIR excess appears too promptly for dust to have formed in the SN ejecta, indicating an IR echo from pre-existing dust in the CSM. The IR echo is likely powered by the relatively slowly evolving SN peak light, and not the brief shock cooling emission, as the latter requires unrealistically high CSM densities to explain the observed dust mass. We consider different potential CSM geometries and find that a thick face-on disk with an inner edge around $5\times 10^{16}$ cm can best explain the dust mass and temperature evolution. In this scenario, the SN shock should start interacting with this CSM $440\pm200$ days post explosion. CSM around SN Ic is rare, and follow-up observations of SN 2024aecx will probe the mass-loss process responsible for removing hydrogen and helium from their progenitor star.
title An infrared echo from a circumstellar disk in the hydrogen- and helium-poor SN 2024aecx
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2602.02691