| Autor: |
Michael A. Tucker, Jason Hinkle, Charlotte R. Angus, Katie Auchettl, Willem B. Hoogendam, Benjamin Shappee, Christopher S. Kochanek, Chris Ashall, Thomas de Boer, Kenneth C. Chambers, Dhvanil D. Desai, Aaron Do, Michael D. Fulton, Hua Gao, Joanna Herman, Mark Huber, Chris Lidman, Chien-Cheng Lin, Thomas B. Lowe, Eugene A. Magnier, Bailey Martin, Paloma Mínguez, Matt Nicholl, Miika Pursiainen, S. J. Smartt, Ken W. Smith, Shubham Srivastav, Brad E. Tucker, Richard J. Wainscoat |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
The Astrophysical Journal, Vol 976, Iss 2, p 178 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/ad8448 |
| Popis: |
We present extensive observations of the Type II supernova (SN II) SN 2023ufx, which is likely the most metal-poor SN II observed to date. It exploded in the outskirts of a low-metallicity ( Z _host ∼ 0.1 Z _⊙ ) dwarf ( M _g = −13.39 ± 0.16 mag, r _proj ∼ 1 kpc) galaxy. The explosion is luminous, peaking at M _g ≈ −18.5 mag, and shows rapid evolution. The r -band (pseudobolometric) light curve has a shock-cooling phase lasting 20 (17) days followed by a 19 (23) day plateau. The entire optically thick phase lasts only ≈55 days following explosion, indicating that the red supergiant progenitor had a thinned H envelope prior to explosion. The early spectra obtained during the shock-cooling phase show no evidence for narrow emission features and limit the preexplosion mass-loss rate to $\dot{M}\lesssim {10}^{-3}$ M _⊙ yr ^−1 . The photospheric-phase spectra are devoid of prominent metal absorption features, indicating a progenitor metallicity of ≲0.1 Z _⊙ . The seminebular (∼60–130 days) spectra reveal weak Fe ii , but other metal species typically observed at these phases (Ti ii , Sc ii , and Ba ii ) are conspicuously absent. The late-phase optical and near-infrared spectra also reveal broad (≈10 ^4 km s ^−1 ) double-peaked H α , P β , and P γ emission profiles suggestive of a fast outflow launched during the explosion. Outflows are typically attributed to rapidly rotating progenitors, which also prefer metal-poor environments. This is only the second SN II with ≲0.1 Z _⊙ and both exhibit peculiar evolution, suggesting a sizable fraction of metal-poor SNe II have distinct properties compared to nearby metal-enriched SNe II. These observations lay the groundwork for modeling the metal-poor SNe II expected in the early Universe. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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