JWST Nebular Spectroscopy of SN 2023qov: Circumstellar Dust Emission in a Normal Type Ia Supernova
Abstract
Abstract We present panchromatic observations of the Type Ia supernova (SN Ia) 2023qov, ranging from ∼2 weeks before to ∼1 yr after maximum light. JWST near- and mid-infrared spectra at +276 and +363 days show ∼400 K dust emission that cools by ∼75 K between epochs, the first unambiguous spectroscopic detection of dust emission in a normal SN Ia. We find that the emission is well described by models of carbonaceous dust placed within ∼1 lt-yr of the SN, with a dust mass of ∼10 −4 M ⊙ . We do not see evidence of active dust creation, suggesting an infrared light echo by preexisting circumstellar dust as the likely source of the emission. The JWST nebular line profiles suggest asymmetric, stratified ejecta, similar to other normal SNe Ia, though a slight double-horn structure in the argon lines indicates a toroidal enhancement. SN 2023qov exhibits a slightly red, fast-declining early light curve (Δ m 15 ( B ) = 1.47 ± 0.05 mag), from which we determine a 56 Ni mass of M 56 = 0.21 ± 0.04 M ⊙ , and a distance of d = 36.0 ± 1.8 Mpc to the SN and its host, NGC 7029. The presence of circumstellar dust around a normal SN Ia has implications both for the progenitor system, suggesting a less than pristine environment, and for cosmology, as a possible source of reddening and extinction that can affect distance inferences.
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Authors: Colin W. Macrie, Conor Larison, Huei Sears, Lindsey A. Kwok, Saurabh W. Jha, Mi Dai, J. Johansson, Stéphane Blondin, Moira Andrews, Katie Auchettl, Carles Badenes, Barnabás Barna, K. Azalee Bostroem, Thomas G. Brink, Kyle W. Davis, Joseph R. Farah, A. V. Filippenko, Ori D. Fox, Or Graur, Saarah Hall, D. Andrew Howell, G. Hosseinzadeh, Anders Jerkstrand, Réka Könyves-Tóth, Christopher E. Lidman, Keiichi Maeda, K. Maguire, Bailey Martin, Adam A. Miller, Megan Newsome, Estefania Padilla Gonzalez, Abigail Polin, A. Rest, Zoe Rosenberg, David J. Sand, Michaela Schwab, Matthew R. Siebert, Mridweeka Singh, Tamás Szalai, Tea Temim, J. Terwel, Brad E. Tucker, József Vinkó, Xiaofeng Wang, Xiaofeng Wang, WeiKang Zheng
Institutions: Hainan Tropical Ocean University, University of Pittsburgh, Northwestern University, Chinese Academy of Sciences, Johns Hopkins University, The University of Melbourne, Kyoto University, University of Virginia, Australian National University, University of Szeged, University of Arizona, The University of Texas at Austin, Tsinghua University, Rutgers, The State University of New Jersey, Purdue University West Lafayette, Princeton University, Aix-Marseille Université, University of Portsmouth, Stockholm University, Rochester Institute of Technology, Eötvös Loránd University, Trinity College Dublin, European Southern Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences, Space Telescope Science Institute, Indian Institute of Astrophysics, European Southern Observatory, Chinese Academy of Science South America Center for Astronomy, Las Cumbres Observatory Global Telescope Network, Central Park West Health Center, Central Park Conservancy