论文标题

化学奇特之星V352PEG的磁场

The magnetic field of the chemically peculiar star V352Peg

论文作者

Fréour, L., Neiner, C., Landstreet, J. D., Folsom, C. P., Wade, G. A.

论文摘要

我们提供了热星V352PEG的光谱分析。 We have acquired 18 spectropolarimetric observations of the star with ESPaDOnS at the CFHT between 2018 and 2019 and completed our dataset with one archival ESPaDOnS measurement obtained in 2011. Our analysis of the spectra shows that the star is on the main sequence and chemically peculiar, i.e. it is a Bp star, with overabundances of iron peak elements (Ti, Cr and Fe) and underabundance of He and O.通过每个光谱的最小二乘反向卷积,我们提取了数千个光谱线的平均zeeman签名和平均线曲线,并在V352PEG中检测到磁场。通过对Stokes I和V轮廓进行建模并使用斜旋转器模型,我们确定了V352PEG的几何配置。我们还进行了Zeeman-Doppler Imaging(ZDI),以更详细地表征V352PEG及其表面化学分布的磁场。我们发现一个主要是偶极的磁场,主要是多型螺栓,并且在很大程度上是非轴对称的,其偶极场强度为$ \ sim $ 9 kg,而磁轴几乎垂直于旋转轴。 Stokes I轮廓的强大变化也表明在恒星表面存在化学斑点。

We present a spectropolarimetric analysis of the hot star V352Peg. We have acquired 18 spectropolarimetric observations of the star with ESPaDOnS at the CFHT between 2018 and 2019 and completed our dataset with one archival ESPaDOnS measurement obtained in 2011. Our analysis of the spectra shows that the star is on the main sequence and chemically peculiar, i.e. it is a Bp star, with overabundances of iron peak elements (Ti, Cr and Fe) and underabundance of He and O. Through a Least-Square Deconvolution of each spectrum, we extracted the mean Zeeman signature and mean line profile of thousands of spectral lines and detected a magnetic field in V352Peg. By modelling the Stokes I and V profiles and using the Oblique Rotator Model, we determined the geometrical configuration of V352Peg. We also performed Zeeman-Doppler Imaging (ZDI) to provide a more detailed characterization of the magnetic field of V352Peg and its surface chemical distributions. We find a magnetic field that is mainly dipolar, dominantly poloidal, and largely non-axisymmetric with a dipole field strength of $\sim$9 kG and a magnetic axis almost perpendicular to the rotation axis. The strong variability of Stokes I profiles also suggests the presence of chemical spots at the stellar surface.

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