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arXiv · 2609.00477

SPIRITS 19q: Dust Production by a Subsolar-metallicity Carbon-rich Wolf-Rayet Star in NGC 2403

Sam Rose·Ryan M. Lau·Jacob E. Jencson·Mansi M. Kasliwal·Andreas A. C. Sander·Howard E. Bond·Michael F. Corcoran·Izumi Endo·Matthew J. Hankins·Olivia C. Jones·Viraj R. Karambelkar·Astrid Lamberts·Thomas Madura·Anthony F. J. Moffat·Patrick W. Morris·Takashi Onaka·Michael E. Ressler·Noel D. Richardson·Christopher M. P. Russell·Itsuki Sakon·J. Sanchez-Bermudez·Gerd Weigelt·Peredur M. Williams
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Abstract

We present JWST/NIRSpec IFU observations of SPIRITS 19q, the highly dust-producing carbon-rich (WC) binary candidate located in a subsolar-metallicity region of the nearby spiral galaxy NGC 2403. The observations, taken in April of 2024, confirm the association of a dusty outburst observed in 2019 by the Spitzer Space Telescope with an early-type WC star. Using models from the Potsdam Wolf-Rayet (PoWR) LMC model grid we find that the WC star of SPIRITS 19q likely has an especially high mass-loss rate ($\gtrsim$ 10$^{-4}$ $M_{\odot}$ yr$^{-1}$). From the flux peak of the IR transient as measured by Spitzer/IRAC as well as constraints on dust composition and size from the JWST spectrum, we estimate a total dust mass formed in the outburst of 6.6 $\pm$ 0.4 $\times$ 10$^{-6}$ $M_{\odot}$. Assuming a minimum orbital period of 12 years, this corresponds to a period-averaged dust production rate of $\lesssim$ 5.5 $\times$ 10$^{-7}$ $M_{\odot}$ yr$^{-1}$. These observations suggest that even a single WC system can contribute to the dust budget at subsolar metallicities, and that such systems are an important source of carbonaceous dust grains in the early universe.

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Sam Rose, Ryan M. Lau, Jacob E. Jencson, Mansi M. Kasliwal, Andreas A. C. Sander, Howard E. Bond, Michael F. Corcoran, Izumi Endo, Matthew J. Hankins, Olivia C. Jones, Viraj R. Karambelkar, Astrid Lamberts, Thomas Madura, Anthony F. J. Moffat, Patrick W. Morris, Takashi Onaka, Michael E. Ressler, Noel D. Richardson, Christopher M. P. Russell, Itsuki Sakon, J. Sanchez-Bermudez, Gerd Weigelt, Peredur M. Williams. 2026-08-31. SPIRITS 19q: Dust Production by a Subsolar-metallicity Carbon-rich Wolf-Rayet Star in NGC 2403. https://arxiv.org/abs/2609.00477

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