In an earlier paper, we presented the first evidence for a bow-shock nebula surrounding the X-ray binary LMC X-1 on a scale of ~15 pc, which we argued was powered by a jet associated with an accretion disk. We now present the first evidence for an ionization cone extending from an X-ray binary, a phenomenon only seen to date in active galactic nuclei (AGN). The ionization cone, detected in the HeII4686/Hbeta and [OIII]5007/Hbeta line ratio maps, aligns with the direction of the jet inferred from the bow-shock nebula. The cone has an opening angle ~45 deg and radial extent ~3.8 pc. Since the HeII emission cannot be explained by the companion O star, the gas in the ionization cone must be exposed to the `naked' accretion disk, thereby allowing us to place constraints on the unobservable ionizing spectrum. The energetics of the ionization cone give unambiguous evidence for an "ultraviolet - soft X-ray" (XUV) excess in LMC X-1. Any attempt to match the hard X-ray spectrum (>1keV) with a conventional model of the accretion disk fails to account for this XUV component. We propose two likely sources for the observed anisotropy: (1) obscuration by a dusty torus, or (2) a jet-blown hole in a surrounding envelope of circumstellar absorbing material. We discuss the implications of our discovery in the context of the mass-scaling hypothesis for accretion onto black holes and suggest avenues for future research.
Wind ionization structure of the short-period eclipsing LMC Wolf-Rayet binary BAT99-129: preliminary results
BAT 99 -129是一颗罕见的、位于大麦云星云中的短周期食沃尔夫-拉叶双星。我们在这里提出中等分辨率的NTT/EMMI光谱，使我们能够解开的光谱的两个组件，并找到轨道参数的二进制。我们还提出了VLT/FORS 1光谱的二次日食期间，即当伴星通过在前面的沃尔夫-拉叶星。有了这些数据，我们能够提取，第一次在绝对单位的WR+O二进制，线发射区域的大小。
我总结了远紫外光谱探测器（FUSE）对12个早期型恒星在大麦云（LMC），最近的盘星系银河系的OVI吸收观测。在所有12颗恒星中都可以看到LMC O VI，其性质（平均柱密度，运动学）与银河系晕非常相似，尽管LMC中的O/H比低约2.5倍。视线投射到已知的LMC超级气泡显示在OVI柱密度相比，视线朝向静止区域的LMC几乎没有增强。O-VI吸收从与大体积LMC气体相关联的相应低电离吸收位移约-30 km/sec。的LMC O VI最有可能出现在一个垂直延伸的分布，我讨论的背景下，由辐射冷却热气体的晕的测量。在这种情况下，大麦哲伦星系盘一侧的质量流率是1太阳质量/年的量级。
Thermal and Non-thermal X-Rays from the LMC Super Bubble 30 Dor C
本文报道了在大麦云云（LMC）中发现的30 Dor C超级气泡（SB）壳层中的热X射线和非热X射线。X射线形态为半径约40秒差距的近圆形壳，北侧和西侧明亮。壳层的光谱在不同的区域是不同的。南壳层的发射谱线清晰，符合非平衡电离（NEI）中的薄热等离子体（kT = 0.21keV）加幂律分量的模型。这种热等离子体位于H α发射的内部，这是SB壳的外缘。SB的北侧和西侧在H α发射中是暗淡的，但在非热（幂律）X射线中是明亮的，光子指数为2.1-2.9。非热X射线壳层追踪射电壳层的外边界。薄热和非热X射线的这些特征与同步加速器X射线壳原型SN 1006相似，但30 Dor C的非热分量比SN 1006亮约10倍。30 Dor C是河外SB的第一个候选者，其中高能电子在壳层中加速。其年龄比SN 1006的年龄大得多，因此该SB中的粒子加速时间可能比正常壳状SNR中的粒子加速时间长。我们发现了与一些紧密星团有关的点状源。它的X射线光度和光谱与年轻的大质量恒星团一致。在SB中还发现了具有非热光谱的点状源，这些可能是背景物体（AGN）或恒星残骸（中子星或黑洞）。
Probing the wind-wind collision in Gamma Velorum with high-resolution Chandra X-ray spectroscopy: evidence for sudden radiative braking and non-equilibrium ionization
