Detection of a centrifugal magnetosphere in one of the most massive stars in the ρ Oph star-forming cloud

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Detection of a centrifugal magnetosphere in one of the most massive stars in the ρ Oph star-forming cloud. / Hubrig, S.; Schöller, M.; Järvinen, S. P.; Küker, M.; Kholtygin, A. F.; Steinbrunner, P.

в: Astronomische Nachrichten, Том 339, № 1, 01.01.2018, стр. 72-77.

Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование

Author

Hubrig, S. ; Schöller, M. ; Järvinen, S. P. ; Küker, M. ; Kholtygin, A. F. ; Steinbrunner, P. / Detection of a centrifugal magnetosphere in one of the most massive stars in the ρ Oph star-forming cloud. в: Astronomische Nachrichten. 2018 ; Том 339, № 1. стр. 72-77.

BibTeX

@article{c1f9440b0358450d921d91330f5fdfd5,

title = "Detection of a centrifugal magnetosphere in one of the most massive stars in the ρ Oph star-forming cloud",

abstract = "Recent XMM-Newton observations of the B2 type star ρ Oph A indicated a periodicity of 1.205 day, which was ascribed to rotational modulation. Since variability of X-ray emission in massive stars is frequently the signature of a magnetic field, we investigated whether the presence of a magnetic field can indeed be invoked to explain the observed X-ray peculiarity. Two FORS 2 spectropolarimetric observations in different rotation phases revealed the presence of a negative (⟨Bz⟩all = − 419 ± 101 G) and positive (⟨Bz⟩all = 538 ± 69 G) longitudinal magnetic field, respectively. We estimate a lower limit for the dipole strength as Bd = 1.9 ± 0.2 kG. Our calculations of the Kepler and Alfv{\'e}n radii imply the presence of a centrifugally supported, magnetically confined plasma around ρ Oph A. The study of the spectral variability indicates a behavior similar to that observed in typical magnetic early-type Bp stars.",

keywords = "stars: early-type, stars: formation, stars: individual: ρ Oph A, stars: magnetic field, stars: variables: general, stars: X-rays, DYNAMICAL SIMULATIONS, MAGNETIC-FIELDS, OPHIUCHI, MODEL, O-STARS, stars: individual: Oph A, VARIABILITY, X-RAY-EMISSION, ROAP STARS, FORS-1, DRIVEN STELLAR WINDS",

author = "S. Hubrig and M. Sch{\"o}ller and J{\"a}rvinen, {S. P.} and M. K{\"u}ker and Kholtygin, {A. F.} and P. Steinbrunner",

year = "2018",

month = jan,

day = "1",

doi = "10.1002/asna.201713457",

language = "English",

volume = "339",

pages = "72--77",

journal = "Astronomische Nachrichten",

issn = "0004-6337",

publisher = "Wiley-Blackwell",

number = "1",

}

RIS

TY - JOUR

T1 - Detection of a centrifugal magnetosphere in one of the most massive stars in the ρ Oph star-forming cloud

AU - Hubrig, S.

AU - Schöller, M.

AU - Järvinen, S. P.

AU - Küker, M.

AU - Kholtygin, A. F.

AU - Steinbrunner, P.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Recent XMM-Newton observations of the B2 type star ρ Oph A indicated a periodicity of 1.205 day, which was ascribed to rotational modulation. Since variability of X-ray emission in massive stars is frequently the signature of a magnetic field, we investigated whether the presence of a magnetic field can indeed be invoked to explain the observed X-ray peculiarity. Two FORS 2 spectropolarimetric observations in different rotation phases revealed the presence of a negative (⟨Bz⟩all = − 419 ± 101 G) and positive (⟨Bz⟩all = 538 ± 69 G) longitudinal magnetic field, respectively. We estimate a lower limit for the dipole strength as Bd = 1.9 ± 0.2 kG. Our calculations of the Kepler and Alfvén radii imply the presence of a centrifugally supported, magnetically confined plasma around ρ Oph A. The study of the spectral variability indicates a behavior similar to that observed in typical magnetic early-type Bp stars.

AB - Recent XMM-Newton observations of the B2 type star ρ Oph A indicated a periodicity of 1.205 day, which was ascribed to rotational modulation. Since variability of X-ray emission in massive stars is frequently the signature of a magnetic field, we investigated whether the presence of a magnetic field can indeed be invoked to explain the observed X-ray peculiarity. Two FORS 2 spectropolarimetric observations in different rotation phases revealed the presence of a negative (⟨Bz⟩all = − 419 ± 101 G) and positive (⟨Bz⟩all = 538 ± 69 G) longitudinal magnetic field, respectively. We estimate a lower limit for the dipole strength as Bd = 1.9 ± 0.2 kG. Our calculations of the Kepler and Alfvén radii imply the presence of a centrifugally supported, magnetically confined plasma around ρ Oph A. The study of the spectral variability indicates a behavior similar to that observed in typical magnetic early-type Bp stars.

KW - stars: early-type

KW - stars: formation

KW - stars: individual: ρ Oph A

KW - stars: magnetic field

KW - stars: variables: general

KW - stars: X-rays

KW - DYNAMICAL SIMULATIONS

KW - MAGNETIC-FIELDS

KW - OPHIUCHI

KW - MODEL

KW - O-STARS

KW - stars: individual: Oph A

KW - VARIABILITY

KW - X-RAY-EMISSION

KW - ROAP STARS

KW - FORS-1

KW - DRIVEN STELLAR WINDS

UR - http://www.scopus.com/inward/record.url?scp=85041674584&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/detection-centrifugal-magnetosphere-one-most-massive-stars-%CF%81-oph-starforming-cloud

U2 - 10.1002/asna.201713457

DO - 10.1002/asna.201713457

M3 - Article

AN - SCOPUS:85041674584

VL - 339

SP - 72

EP - 77

JO - Astronomische Nachrichten

JF - Astronomische Nachrichten

SN - 0004-6337

IS - 1

ER -

ID: 27739311