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dc.contributor.authorWu, Ya-Lin*
dc.contributor.authorSmith, Nathan*
dc.contributor.authorClose, Laird M.*
dc.contributor.authorMales, Jared R.*
dc.contributor.authorMorzinski, Katie M.*
dc.date.accessioned2017-06-28T20:45:03Z
dc.date.available2017-06-28T20:45:03Z
dc.date.issued2017-05-17
dc.identifier.citationResolving the H alpha-emitting Region in the Wind of eta Carinae 2017, 841 (1):L7 The Astrophysical Journalen
dc.identifier.issn2041-8213
dc.identifier.doi10.3847/2041-8213/aa70ed
dc.identifier.urihttp://hdl.handle.net/10150/624482
dc.description.abstractThe massive evolved star. Carinae is the most luminous star in the Milky Way and has the highest steady wind mass-loss rate of any known star. Radiative transfer models of the spectrum by Hillier et al. predict that Ha is mostly emitted in regions of the wind at radii of 6-60 au from the star (2.5-25 mas at 2.35 kpc). We present diffraction-limited images (FWHM similar to 25 mas) with Magellan adaptive optics in two epochs, showing that. Carinae consistently appears similar to 2.5-3 mas wider in Ha emission compared to the adjacent 643 nm continuum. This implies that the H alpha line-forming region may have a characteristic emitting radius of 12 mas or similar to 30 au, in very good agreement with the Hillier stellar-wind model. This provides direct confirmation that the physical wind parameters of that model are roughly correct, including the mass-loss rate of M= 10(-3)M(circle dot) yr(-1), plus the clumping factor, and the terminal velocity. Comparison of the Ha images (ellipticity and PA) to the continuum images reveals no significant asymmetries at H alpha. Hence, any asymmetry induced by a companion or by the primary's rotation do not strongly influence the global H alpha emission in the outer wind.
dc.description.sponsorshipNational Science Foundation [1506818]; NSF AAG [1615408]; NASA Origins of Solar Systems award; TRIF fellowship; NSF [AST-1312221]; NASA Exoplanets Research Program (XRP) [NNX16AD44G]en
dc.language.isoenen
dc.publisherIOP PUBLISHING LTDen
dc.relation.urlhttp://stacks.iop.org/2041-8205/841/i=1/a=L7?key=crossref.8a499dbd94720eff65567616026442c8en
dc.rights© 2017. The American Astronomical Society. All rights reserved.en
dc.subjectcircumstellar matteren
dc.subjectstars: individual (Eta Carinae)en
dc.subjectstars: winds, outflowsen
dc.titleResolving the H alpha-emitting Region in the Wind of eta Carinaeen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Steward Observen
dc.identifier.journalThe Astrophysical Journal Lettersen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-09-11T20:36:25Z
html.description.abstractThe massive evolved star. Carinae is the most luminous star in the Milky Way and has the highest steady wind mass-loss rate of any known star. Radiative transfer models of the spectrum by Hillier et al. predict that Ha is mostly emitted in regions of the wind at radii of 6-60 au from the star (2.5-25 mas at 2.35 kpc). We present diffraction-limited images (FWHM similar to 25 mas) with Magellan adaptive optics in two epochs, showing that. Carinae consistently appears similar to 2.5-3 mas wider in Ha emission compared to the adjacent 643 nm continuum. This implies that the H alpha line-forming region may have a characteristic emitting radius of 12 mas or similar to 30 au, in very good agreement with the Hillier stellar-wind model. This provides direct confirmation that the physical wind parameters of that model are roughly correct, including the mass-loss rate of M= 10(-3)M(circle dot) yr(-1), plus the clumping factor, and the terminal velocity. Comparison of the Ha images (ellipticity and PA) to the continuum images reveals no significant asymmetries at H alpha. Hence, any asymmetry induced by a companion or by the primary's rotation do not strongly influence the global H alpha emission in the outer wind.


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