The fossil wind structures of Eta Carinae: changes across on 5.54-year cycle
| Autor: | D. John Hillier, Gerd Weigelt, Kenji Hamaguchi, Thomas I. Madura, Noel D. Richardson, M. Teodoro, Theodore R. Gull, Nicola Clementel, Augusto Damineli, Keith Feggans, Michael F. Corcoran, Jose H. Groh, Anthony F. J. Moffat, Don J. Lindler |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Physics
010308 nuclear & particles physics ESTRELAS VARIÁVEIS Far ultraviolet Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astronomy Binary number Astronomy and Astrophysics Photoionization Astrophysics Radiation 01 natural sciences Orbit Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science Primary (astronomy) Ionization 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Supergiant 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Eta Carinae, the closest, active, massive binary containing a highly unstable LBV, exhibits expanding, compressed wind shells, seen in emission, that are spatially and spectrally resolved by \hst/\stis. Starting in June 2009, these structures were mapped across its 5.54-year, highly elliptical, binary orbit to follow temporal changes in the light of [Fe~III] 4659\AA\ and [Fe~II] 4815\AA. The emissions trace portions of fossil wind-shells, that were formed by wind-wind interactions across each cycle. Over the high-ionization state, dense arcs, photo-ionized by far ultraviolet radiation from the hot secondary, are seen in [Fe~III]. Other arcs, ionized by mid-ultraviolet radiation from the primary star, are seen in [Fe II]. The [Fe III] structures tend to be interior to [Fe II] structures that trace extensive, less disturbed primary wind. During the brief periastron passage when the secondary plunges deep into the primary's extremely dense wind, on the far side of primary star, high-ionization [Fe III] structures fade and reappear in [Fe II]. Multiple fossil wind-structures were traced across the 5.7-year monitoring interval. The strong similarity of the expanding [Fe II] shells suggests that the wind and photo-ionization properties of the massive binary have not changed substantially from one orbit to the next over the past several orbital cycles. These observations trace structures that can be used to test three-dimensional hydrodynamical and radiative-transfer models of massive, interacting winds. They also provide a baseline for following future changes in Eta Carinae, especially of its winds and photoionization properties. Comment: 28 pages accepted MNRAS July 22 2016 |
| Databáze: | OpenAIRE |
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