High-resolution X-ray spectra of π Aqr, a γ Cas-type star, obtained with the Chandra/HETG spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe; a strong, hard continuum; and a lack of He-like ions, indicating the presence of very hot thermal plasma. The X-ray light curve showed significant fluctuations, with coherent variability at a period of about 3400 s in one observation. The hardness ratio was relatively constant except for one observation in which the spectrum was much harder and more absorbed. We interpret the X-ray emission as arising from accretion onto the secondary, which is likely a magnetic white dwarf, an intermediate polar system.

中文翻译：

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Chandra HETG X 射线光谱和 π Aqr（γ Cas 型 Be 星）的变异性

高分辨率 X 射线光谱π阿奎尔，一个γ使用 Chandra/HETG 光谱仪获得的 Cas 型星揭示了 Mg、Si、S 和 Fe 类 H 离子的发射线；坚固、坚硬的连续体；并且缺乏类氦离子，表明存在非常热的热等离子体。 X射线光曲线显示出显着的波动，在一次观察中在大约3400秒的周期内具有相干变化。硬度比相对恒定，除了一个观察结果，其中光谱更硬且更容易吸收。我们将 X 射线发射解释为副星吸积所产生的，副星很可能是一颗磁性白矮星，一种中间极性系统。