Narrowband HST WFPC2 images reveal a bow-shock–like halo around the H II region N30B toward the B[e] supergiant Hen S22 located within the larger DEM L106 nebula in the Large Magellanic Cloud. High-dispersion spectra of N30B show a narrow Hα emission component from the ionized gas; the velocity variations indicate a gas flow of -5 to -10 km s-1 in the vicinity of the H II regions, which is resultant from interactions with Hen S22's stellar wind and responsible for the bow-shock morphology. Spectra of N30B's halo show broad Hα profiles extending over more than 1000 km s-1, similar to that of Hen S22, indicating that the halo is a reflection nebula of Hen S22. Broadband morphologies of N30B's halo are also consistent with the reflection nebula interpretation. We use dust-scattering properties and the observed brightnesses of the reflection nebula and Hen S22 to constrain the reflection geometry. The reflected stellar Hα emission and absorption vary across the reflection nebula as a result of viewing S22's anisotropic wind from different angles. This reflection nebula, together with the edge-on orientation of Hen S22's disk, provides an invaluable opportunity to study the disk and polar winds of a B[e] supergiant.
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机译：窄带HST WFPC2图像显示了H II区域N30B周围朝向大麦哲伦星云中较大DEM L106星云中的超大型变种Hen S22的弓形震晕。 N30B的高分散光谱显示出来自离子化气体的Hα发射组分较窄;速度变化表明，在H II区附近的气流为-5至-10 km s-1，这是由于与Hen S22的恒星风相互作用而引起的，并导致了弓形波的形态。 N30B的光晕光谱显示宽Hα分布范围超过1000 km s-1，类似于Hen S22，表明该光晕是Hen S22的反射星云。 N30B光晕的宽带形态也与反射星云解释一致。我们使用尘埃散射特性以及反射星云和Hen S22观测到的亮度来约束反射几何形状。由于从不同角度观察了S22的各向异性风，反射恒星Hα的发射和吸收在整个反射星云中会发生变化。这种反射星云以及Hen S22盘的边缘指向，为研究B [e]超巨星的盘和极风提供了宝贵的机会。
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