Dinosaur in a Haystack: X-Ray View of the Entrails of SN 2023ixf and the Radio Afterglow of Its Interaction with the Medium Spawned by the Progenitor Star (Paper I)*
Abstract We present the results from our extensive hard-to-soft X-ray (NuSTAR, Swift-XRT, XMM-Newton, Chandra) and meter-to-millimeter-wave radio (Giant Metrewave Radio Telescope, Very Large Array, NOEMA) monitoring campaign of the very nearby ( d = 6.9 Mpc) Type II supernova (SN) 2023ixf spanning ≈4–165 days post-explosion. This unprecedented data set enables inferences on the explosion’s circumstellar medium (CSM) density and geometry. In particular, we find that the luminous X-ray emission is well modeled by thermal free–free radiation from the forward shock with rapidly decreasing photoelectric absorption with time. The radio spectrum is dominated by synchrotron radiation from the same shock. Similar to the X-rays, the level of free–free absorption affecting the radio spectrum rapidly decreases with time as a consequence of the shock propagation into the dense CSM. While the X-ray and the radio modeling independently support the presence of a dense medium corresponding to an effective mass-loss rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi>M</mml:mi> <mml:mo>̇</mml:mo> </mml:mover> <mml:mo>≈</mml:mo> <mml:mn>1</mml:mn> <mml:msup> <mml:mn>0</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> <mml:mspace width="0.25em"/> <mml:msup> <mml:mi>yr</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> at R = (0.4–14) × 10 15 cm (for v w = 25 km s −1 ), our study points at a complex CSM density structure with asymmetries and clumps. The inferred densities are ≈10–100 times those of typical red supergiants, indicating an extreme mass-loss phase of the progenitor in the ≈200 yr preceding core collapse, which leads to the most X-ray luminous Type II SN and the one with the most delayed emergence of radio emission. These results add to the picture of the complex mass-loss history of massive stars on the verge of collapse and demonstrate the need for panchromatic campaigns to fully map their intricate environments.
Authors
- Ava Polzin (ORCID: https://orcid.org/0000-0002-5283-933X)
- Kohta Murase (ORCID: https://orcid.org/0000-0002-5358-5642)
- B. Marcote (ORCID: https://orcid.org/0000-0001-9814-2354)
- D. Tsuna (ORCID: https://orcid.org/0000-0002-6347-3089)
- David Matthews (ORCID: https://orcid.org/0000-0002-4513-3849)
- Fabio De Colle (ORCID: https://orcid.org/0000-0002-3137-4633)
- Roger A. Chevalier (ORCID: https://orcid.org/0000-0002-9117-7244)
- W. V. Jacobson-Galán (ORCID: https://orcid.org/0000-0003-1103-3409)
- K. D. Alexander (ORCID: https://orcid.org/0000-0002-8297-2473)
- T. Laskar (ORCID: https://orcid.org/0000-0003-1792-2338)
- Giulia Migliori (ORCID: https://orcid.org/0000-0003-0216-8053)
- Rebecca Diesing (ORCID: https://orcid.org/0000-0002-6679-0012)
- P. Chandra (ORCID: https://orcid.org/0000-0002-0844-6563)
- A. Reguitti (ORCID: https://orcid.org/0000-0003-4254-2724)
- E. Berger (ORCID: https://orcid.org/0000-0002-9392-9681)
- Brian W. Grefenstette (ORCID: https://orcid.org/0000-0002-1984-2932)
- Alak Ray (ORCID: https://orcid.org/0000-0003-2404-0018)
- R. Chornock (ORCID: https://orcid.org/0000-0002-7706-5668)
- Keiichi Maeda (ORCID: https://orcid.org/0000-0003-2611-7269)
- Dan Milisavljevic (ORCID: https://orcid.org/0000-0002-0763-3885)
- S. Campana (ORCID: https://orcid.org/0000-0001-6278-1576)
- Luc Dessart (ORCID: https://orcid.org/0000-0003-0599-8407)
- M. F. Bietenholz (ORCID: https://orcid.org/0000-0002-0592-4152)
- R. Margutti (ORCID: https://orcid.org/0000-0003-4768-7586)
- Eli Wiston (ORCID: https://orcid.org/0009-0002-4843-2913)
- Melanie Krips (ORCID: https://orcid.org/0000-0001-6971-4851)
- A. J. Nayana (ORCID: https://orcid.org/0000-0002-8070-5400)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-05-14
- DOI
- https://doi.org/10.3847/1538-4357/adc2fb
- Citations
- 12
- Primary Topic
- Gamma-ray bursts and supernovae
- Type
- article
- Field-Weighted Citation Impact
- 13.86
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Gordon and Betty Moore Foundation
- California Institute of Technology
- Aspen Center for Physics
- University of Leicester
- European Commission
- Tata Institute of Fundamental Research
- Nuclear Safety and Security Commission
- Max-Planck-Gesellschaft
- Centre National de la Recherche Scientifique
- Ministerio de Ciencia e Innovación
- Goddard Space Flight Center
- Japan Society for the Promotion of Science
- Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México
- Agencia Estatal de Investigación
- Astrophysics Science Division