A1 Refereed original research article in a scientific journal

A Late-time Radio Survey of Type Ia-CSM Supernovae with the Very Large Array




AuthorsGriffith, Olivia; Showerman, Grace; Sarbadhicary, Sumit K.; Harris, Chelsea E.; Chomiuk, Laura; Sollerman, Jesper; Lundqvist, Peter; Moldón, Javier; Pérez-Torres, Miguel; Kool, Erik C.; Moriya, Takashi J.

PublisherInstitute of Physics Publishing

Publication year2025

Journal: Astrophysical Journal

Article number54

Volume995

Issue1

ISSN0004-637X

eISSN1538-4357

DOIhttps://doi.org/10.3847/1538-4357/ae17b0

Publication's open availability at the time of reportingOpen Access

Publication channel's open availability Open Access publication channel

Web address https://doi.org/10.3847/1538-4357/ae17b0

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/506338826

Self-archived copy's licenceCC BY

Self-archived copy's versionPublisher`s PDF


Abstract

Type Ia-CSM supernovae (SNe) are a rare and peculiar subclass of thermonuclear SNe characterized by emission lines of hydrogen or helium, indicative of high-density circumstellar medium (CSM). Their implied mass-loss rates of ∼10−4–10−1 M yr−1 (assuming ∼100 km s−1 winds) from optical observations are generally in excess of values observed in realistic SN Ia progenitors. In this paper, we present an independent study of CSM densities around a sample of 29 archival Ia-CSM SNe using radio observations with the Karl G. Jansky Very Large Array at 6 GHz. Motivated by the late (∼2 yr) radio detection of the Ia-CSM SN 2020eyj, we observed old (>1 yr) SNe, when we are more likely to see the emergent synchrotron emission that may have been suppressed earlier by free–free absorption by the CSM. We do not detect radio emission down to 3σ limits of ∼35 μJy in our sample. The only radio-detected candidate in our sample, SN 2022esa, was likely misclassified as a Ia-CSM with early spectra, and appears more consistent with a peculiar Ic based on later epochs. Assuming wind-like CSM with temperatures between 2 × 104 K and 105 K, and a magnetic field-to-shock energy fraction epsilonB = 0.01 − 0.1, the radio upper limits rule out mass-loss rates between ∼10−4 and 10−2 M yr−1 (100 km s−1)−1. This is somewhat in tension with the estimates from optical observations, and may indicate that more complex CSM geometries and/or lower values of epsilonB may be present.


Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.




Funding information in the publication
O.G., G.S., C.E.H., and L.C. are grateful for support from NSF grants AST-2107070 and AST-2205628. J.M. and M.P.T. acknowledge financial support through the Severo Ochoa grant CEX2021-001131-S and the Spanish National grant PID2023-147883NB-C21, funded by MCIU/AEI/10.13039/501100011033, as well as support through ERDF/EU.


Last updated on 14/01/2026 02:12:01 PM