Papers › Final Moments II: Observational Properties and Physical Modeling of CSM-Interacting...
Final Moments II: Observational Properties and Physical Modeling of CSM-Interacting Type II Supernovae
W. V. Jacobson-Galán, L. Dessart, K. W. Davis, C. D. Kilpatrick, R. Margutti, R. J. Foley, R. Chornock, G. Terreran, D. Hiramatsu, M. Newsome, E. Padilla Gonzalez, C. Pellegrino, D. A. Howell, A. V. Filippenko, J. P. Anderson, C. R. Angus, K. Auchettl, K. A. Bostroem, T. G. Brink, R. Cartier, D. A. Coulter, T. de Boer, M. R. Drout, N. Earl, K. Ertini, J. R. Farah, D. Farias, C. Gall, H. Gao, M. A. Gerlach, F. Guo, A. Haynie, G. Hosseinzadeh, A. L. Ibik, S. W. Jha, D. O. Jones, D. Langeroodi, N LeBaron, E. A. Magnier, A. L. Piro, S. I. Raimundo, A. Rest, S. Rest, R. Michael Rich, C. Rojas-Bravo, H. Sears, K. Taggart, V. A. Villar, R. J. Wainscoat, X-F. Wang, A. R. Wasserman, S. Yan, Y. Yang, J. Zhang, W. Zheng
The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.
We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early-time (δt < 2 days) spectra show transient, narrow emission lines from shock ionization of confined (r < 10¹⁵ cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) of HI, He I/II, C III/IV, and N III/IV/V from the CSM persist on a characteristic timescale (t_(IIn)) that marks a transition to a lower-density CSM and the emergence of Doppler-broadened features from the fast-moving SN ejecta. Our sample, the largest to date, consists of 39 SNe with early-time IIn-like features in addition to 35 "comparison" SNe with no evidence of early-time IIn-like features, all with ultraviolet observations. The total sample consists of 50 unpublished objects with 474 previously unpublished spectra and 50 multiband light curves, collected primarily through the Young Supernova Experiment and Global Supernova Project collaborations. For all sample objects, we find a significant correlation between peak ultraviolet brightness and both t_(IIn) and the rise time, as well as evidence for enhanced peak luminosities in SNe II with IIn-like features. We quantify mass-loss rates and CSM density for the sample through matching of peak multiband absolute magnitudes, rise times, t_(IIn) and optical SN spectra with a grid of radiation hydrodynamics and non-local thermodynamic equilibrium (nLTE) radiative-transfer simulations. For our grid of models, all with the same underlying explosion, there is a trend between the duration of the electron-scattering broadened line profiles and inferred mass-loss rate: t_(IIn) ≈3.8[Ṁ/(0.01 M_⊙ yr⁻¹)] days.
Code
Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.
Code Syntology ran Syntology
Not run by Syntology. Nothing on this page verifies that the listed code works.
Results from the paper archive 2025-07-28
No leaderboard rows for this paper in the archive.
Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections