Papers › Type II supernova spectral diversity I: Observations, sample characterization and...
Type II supernova spectral diversity I: Observations, sample characterization and spectral line evolution
Claudia P. Gutiérrez, Joseph P. Anderson, Mario Hamuy, Nidia Morrell, Santiago González-Gaitan, Maximilian D. Stritzinger, Mark M. Phillips, Lluis Galbany, Gastón Folatelli, Luc Dessart, Carlos Contreras, Massimo Della Valle, Wendy L. Freedman, Eric Y. Hsiao, Kevin Krisciunas, Barry F. Madore, José Maza, Nicholas B. Suntzeff, Jose Luis Prieto, Luis González, Enrico Cappellaro, Mauricio Navarrete, Alessandro Pizzella, Maria T. Ruiz, R. Chris Smith, Massimo Turatto
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 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, and ranging between 3 and 363 days post explosion. In this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of SNe~II. A statistical analysis of the spectral matching technique is discussed as an alternative to non-detection constraints for estimating SN explosion epochs. The time evolution of spectral lines is presented and analysed in terms of how this differs for SNe of different photometric, spectral, and environmental properties: velocities, pseudo-equivalent widths, decline rates, magnitudes, time durations, and environment metallicity. Our sample displays a large range in ejecta expansion velocities, from ∼9600 to ∼1500 km s⁻¹ at 50 days post explosion with a median H_α value of 7300 km s⁻¹. This is most likely explained through differing explosion energies. Significant diversity is also observed in the absolute strength of spectral lines, characterised through their pseudo-equivalent widths. This implies significant diversity in both temperature evolution (linked to progenitor radius) and progenitor metallicity between different SNe~II. Around 60\% of our sample show an extra absorption component on the blue side of the H_α P-Cygni profile ("Cachito" feature) between 7 and 120 days since explosion. Studying the nature of Cachito, we conclude that these features at early times (before ∼35 days) are associated with \ion{Si}{2} λ6355, while past the middle of the plateau phase they are related to high velocity (HV) features of hydrogen lines.
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