Rotation, spectral variability, magnetic geometry and magnetosphere of the Of?p star CPD -28 2561
| العنوان: | Rotation, spectral variability, magnetic geometry and magnetosphere of the Of?p star CPD -28 2561 |
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| المؤلفون: | Wade, G. A., Barba, R. H., Grunhut, J., Martins, F., Petit, V., Sundqvist, J. O., Townsend, R. H. D., Walborn, N. R., Alecian, E., Alfaro, E. J., Maíz Apellaniz, J, Arias, Julia Ines, Gamen, Roberto Claudio, Morrell, Nidia Irene, Naze, Y., Sota, A, ud-Doula, A., MiMeS Collaboration |
| المساهمون: | Royal Military College of Canada, Universidad de La Serena (USERENA), European Southern Observatory (ESO), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), University of Delaware [Newark], Florida Institute of Technology [Melbourne], Ludwig-Maximilians-Universität München (LMU), University of Wisconsin-Madison, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Facultad de Ciencias Astronómicas y Geofísicas [La Plata] (FCAGLP), Universidad Nacional de la Plata [Argentine] (UNLP), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Pennsylvania State University (Penn State), Penn State System, Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC) |
| المصدر: | Monthly Notices of the Royal Astronomical Society Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2015, 447 (3), pp.2551-2567. ⟨10.1093/mnras/stu2548⟩ SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| سنة النشر: | 2014 |
| مصطلحات موضوعية: | Ciencias Astronómicas, stars: individual: CPD, Rotation, 28° 2561, Ciencias Físicas, Phase (waves), FOS: Physical sciences, Magnetosphere, Geometry, Astrophysics, 7. Clean energy, Spectral line, purl.org/becyt/ford/1 [https], symbols.namesake, stars: rotation, Massive stars, massive [Stars], Astrophysics::Solar and Stellar Astrophysics, CPD -28° 2561 (estrella), individual: CPD [Stars], Solar and Stellar Astrophysics (astro-ph.SR), Physics, Zeeman effect, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Stars: rotation, stars: magnetic field, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Magnetic field, rotation [Stars], stars: massive, Astronomía, magnetic field [Stars], Dipole, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Magnetic fields, symbols, Polar, Equivalent width, CIENCIAS NATURALES Y EXACTAS |
| الوصف: | We report magnetic and spectroscopic observations and modelling of the Of?p star CPD-28° 2561. Using more than 75 new spectra, we have measured the equivalent width variations and examined the dynamic spectra of photospheric and wind-sensitive spectral lines. A period search results in an unambiguous 73.41 d variability period. High-resolution spectropolarimetric data analysed using least-squares deconvolution yield a Zeeman signature detected in the mean Stokes V profile corresponding to phase 0.5 of the spectral ephemeris. Interpreting the 73.41 d period as the stellar rotational period, we have phased the equivalent widths and inferred longitudinal field measurements. The phased magnetic data exhibit a weak sinusoidal variation, with maximum of about 565 G at phase 0.5, and a minimum of about -335 G at phase 0.0, with extrema approximately in phase with the (double-wave) Hα equivalent width variation. Modelling of the Hα equivalent width variation assuming a quasi-3D magnetospheric model produces a unique solution for the ambiguous couplet of inclination and magnetic obliquity angles: (i, β) or (β, i) = (35°, 90°). Adopting either geometry, the longitudinal field variation yields a dipole polar intensity Bd = 2.6 ± 0.9 kG, consistent with that obtained from direct modelling of the Stokes V profiles. We derive a wind magnetic confinement parameter η* ≃ 100, leading to an Alfvén radius RA ≃ 3-5R*, and a Kepler radius RK ≃ 20R*. This supports a physical scenario in which the Hα emission and other line variability have their origin in an oblique, corotating 'dynamical magnetosphere' structure resulting from a magnetically channelled wind. Nevertheless, the details of the formation of spectral lines and their variability within this framework remain generally poorly understood. Este documento tiene una corrección (ver documento relacionado). Instituto de Astrofísica de La Plata |
| وصف الملف: | application/pdf |
| اللغة: | English |
| تدمد: | 0035-8711 1365-2966 |
| DOI: | 10.1093/mnras/stu2548⟩ |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::54a51bc9996aeff6fd4ed003675d9a27 http://arxiv.org/abs/1411.7926 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....54a51bc9996aeff6fd4ed003675d9a27 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00358711 13652966 |
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| DOI: | 10.1093/mnras/stu2548⟩ |