Ground-based and JWST Observations of SN 2022pul. II. Evidence from Nebular Spectroscopy for a Violent Merger in a Peculiar Type Ia Supernova

Copyright and License

© 2024. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Acknowledgement

This work is based on observations made with the NASA/ESA/CSA JWST as part of program #02072. We thank Shelly Meyett for her consistently excellent work scheduling the JWST observations, Sarah Kendrew for assistance with the MIRI observations, and Glenn Wahlgren for help with the NIRSpec observations. We also thank the anonymous referee whose suggestions significantly improved the paper. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under National Aeronautics and Space Administration (NASA) contract NAS 5-03127 for JWST. The specific observations analyzed can be accessed via doi: 10.17909/9293-cs53. Support for this program at Rutgers University was provided by NASA through grant JWST-GO-02072.001.

The SALT observations of SN 2022pul were obtained with Rutgers University program 2022-1-MLT-004 (PI: S. W. Jha). We are grateful to SALT astronomer Rosalind Skelton for taking these data. This work makes use of data from the Las Cumbres Observatory global network of telescopes. The LCO group is supported by NSF grants AST-1911151 and AST-1911225. This work also makes use of data gathered with the 6.5 m Magellan telescopes at Las Campanas Observatory, Chile.

M.R.S. is supported by an STScI Postdoctoral Fellowship. G.D. acknowledges H2020 European Research Council grant #758638. L.A.K. acknowledges support by NASA FINESST fellowship 80NSSC22K1599. C.L. is supported by an NSF Graduate Research Fellowship under grant #DGE-2233066. The UCSC team is supported in part by NASA grant NNG-17PX03C, National Science Foundation (NSF) grant AST-1815935, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation, and a fellowship from the David and Lucile Packard Foundation to R.J.F. The work of A.V.F.'s supernova group at UC Berkeley is generously supported by the Christopher R. Redlich Fund, Gary and Cynthia Bengier, Clark and Sharon Winslow, Alan Eustace and Kathy Kwan, William Draper, Timothy and Melissa Draper, Briggs and Kathleen Wood, and Sanford Robertson (W.Z. is a Bengier-Winslow-Eustace Specialist in Astronomy, T.G.B. is a Draper-Wood-Robertson Specialist in Astronomy, Y.Y. was a Bengier-Winslow-Robertson Fellow in Astronomy), and many other donors.

S.B. acknowledges support from the Alexander von Humboldt Foundation and from the "Programme National de Physique Stellaire" (PNPS) of CNRS/INSU cofunded by CEA and CNES. D.J.H. receives support through NASA astrophysical theory grant 80NSSC20K0524. J.V. and T.S. are supported by the NKFIH-OTKA grants K-142534 and FK-134432 of the Hungarian National Research, Development and Innovation (NRDI) Office, respectively. B.B. and T.S. are supported by the ÚNKP-22-4 and ÚNKP-22-5 New National Excellence Programs of the Ministry for Culture and Innovation from the source of the NRDI Fund, Hungary. T.S. is also supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. The research of J.C.W. and J.V. is supported by NSF grant AST-1813825.

A.F. acknowledges support by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC Advanced Grant KILONOVA #885281). M.D., K.M., and J.H.T. acknowledge support from EU H2020 ERC grant #758638. The research by Y.D. and S.V. is supported by NSF grant AST-2008108. The time-domain research by D.J.S. and the University of Arizona team is supported by NSF grants AST-1821987, 1813466, 1908972, and 2108032, and by the Heising-Simons Foundation under grant #2020–1864. K.M. acknowledges support from the Japan Society for the Promotion of Science (JSPS) KAKENHI grant JP20H00174, and the JSPS Open Partnership Bilateral Joint Research Project (JPJSBP120209937). L.G. acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (MCIN), the Agencia Estatal de Investigación (AEI) 10.13039/501100011033, and the European Social Fund (ESF) "Investing in your future" under the 2019 Ramón y Cajal program RYC2019-027683-I and the PID2020-115253GA-I00 HOSTFLOWS project, from Centro Superior de Investigaciones Científicas (CSIC) under the PIE project 20215AT016, and the program Unidad de Excelencia María de Maeztu CEX2020-001058-M.

J.P.H. acknowledges support from the George A. and Margaret M. Downsbrough bequest. The Aarhus supernova group is funded by a project 2 grant (10.46540/2032-00022B) from the Independent Research Fund Denmark (IRFD), and by a grant from Aarhus University Research Fond (AUFF-E-2023-9-28). This publication was made possible through the support of an LSSTC Catalyst Fellowship to K.A.B., funded through grant 62192 from the John Templeton Foundation to the LSST Corporation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of LSSTC or the John Templeton Foundation.

Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. A major upgrade of the Kast spectrograph on the Shane 3 m telescope at Lick Observatory, led by Brad Holden, was made possible through generous gifts from the Heising-Simons Foundation, William and Marina Kast, and the University of California Observatories. Research at Lick Observatory is partially supported by a generous gift from Google. We thank the Subaru staff for the data taken by the Subaru Telescope (S23A-023).

Facilities

AAVSO - American Association of Variable Star Observers International Database, ATT (WiFeS) - , ASAS-SN - , ATLAS - , GTC (OSIRIS) - , JWST (NIRSpec/MIRI) - , Keck:I (LRIS) - , Keck:II (NIRES) - , Keck:II (DEIMOS) - , LCO/GSP - , Magellan:Baade (IMACS) - , MMT (Binospec) - , SALT (RSS) - , Shane (Kast) - , SOAR (Goodman) - , Subaru (FOCAS) - , UH:2.2m (SNIFS) - , and PO:1.2m (ZTF) -

Software References

Astropy (Astropy Collaboration et al. 2013, 2018, 2022), Matplotlib (Hunter 2007), NumPy (Oliphant 2006), PyRAF (Science Software Branch at STScI 2012), PySALT (Crawford et al. 2010), dust extinction (Gordon et al. 2022), jdaviz (JDADF Developers et al. 2022), jwst (Bushouse et al. 2022), UltraNest (Buchner 2021; Buchner et al. 2022), YSE-PZ (Coulter et al. 2022, 2023), and CMFGEN (Hillier & Dessart 2012)