Asphericity, Interaction, and Dust in the Type II-P/II-L Supernova 2013ej in Messier 74
| Autor: | Lifan Wang, Melissa L. Graham, Schuyler D. Van Dyk, Maokai Hu, Joel Johansson, Isaac Shivvers, Ori D. Fox, Jon C. Mauerhan, Alexei V. Filippenko |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Photosphere 010308 nuclear & particles physics Infrared Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Light curve 01 natural sciences Galaxy Supernova Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Circumstellar dust Astrophysics::Solar and Stellar Astrophysics Red supergiant Astrophysics - High Energy Astrophysical Phenomena Spectroscopy 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.1611.07930 |
| Popis: | SN 2013ej is a well-studied core-collapse supernova (SN) that stemmed from a directly identified red supergiant (RSG) progenitor in galaxy M74. The source exhibits signs of substantial geometric asphericity, X-rays from persistent interaction with circumstellar material (CSM), thermal emission from warm dust, and a light curve that appears intermediate between supernovae of Types II-P and II-L. The proximity of this source motivates a close inspection of these physical characteristics and their potential interconnection. We present multi-epoch spectropolarimetry of SN 2013ej during the first 107 days, and deep optical spectroscopy and ultraviolet through infrared photometry past ~800 days. SN 2013ej exhibits the strongest and most persistent continuum and line polarization ever observed for a SN of its class during the recombination phase. Modeling indicates that the data are consistent with an oblate ellipsoidal photosphere, viewed nearly edge-on, and probably augmented by optical scattering from circumstellar dust. We suggest that interaction with an equatorial distribution of CSM, perhaps the result of binary evolution, is responsible for generating the photospheric asphericity. Relatedly, our late-time optical imaging and spectroscopy shows that asymmetric CSM interaction is ongoing, and the morphology of broad H-alpha emission from shock-excited ejecta provides additional evidence that the geometry of the interaction region is ellipsoidal. Alternatively, a prolate ellipsoidal geometry from an intrinsically bipolar explosion is also a plausible interpretation of the data, but would probably require a ballistic jet of radioactive material capable of penetrating the hydrogen envelope early in the recombination phase (abridged). Comment: Post-proof edit. Accepted to ApJ on Nov. 23 2016; 21 pages, 16 figures |
| Databáze: | OpenAIRE |
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