A Deep Exposure in High Resolution X-Rays Reveals the Hottest Plasma in the ζ Puppis Wind
A Deep Exposure in High Resolution X-Rays Reveals the Hottest Plasma in the ζ Puppis Wind
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高分辨率 X 射线的深度曝光揭示了 z Puppis 风中最热的等离子体
DOI：
10.3847/1538-4357/ab8005
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
W. Waldron
中科院分区：
文献类型：
--
作者：
D. Huenemoerder;R. Ignace;N. Miller;K. Gayley;W. Hamann;J. Lauer;A. Moffat;Y. Nazé;J. Nichols;L. Oskinova;N. Richardson;W. Waldron
我们使用钱德拉 HETG 光谱仪获得了 z Puppis（O4 超巨星）的深度曝光（813 ks）。在这里，我们报告了 1-9 Å 区域的分析，特别适合钱德拉 (Chandra)，它对高电离物质的分离良好的发射线之间的连续发射有重大贡献。这些数据使我们能够通过连续介质形状和发射线强度来研究最热的等离子体。假设具有高温截止的幂律发射测量分布，我们发现发射与根据相应光谱截止确定的最高温度为 12 MK 的热谱一致。这意味着有效风冲击速度为 900 km s−1，远低于风速 2250 km s−1。对于靠近恒星形成的 X 射线发射，速度和 X 射线通量大于严格自激线遮蔽不稳定性模型可以轻松协调的速度和 X 射线通量，这表明需要一小部分风从底部极快地加速。这与其说是动态不稳定性，不如说是对边界条件变化的非线性响应。
We have obtained a very deep exposure (813 ks) of ζ Puppis (O4 supergiant) with the Chandra HETG Spectrometer. Here we report on analysis of the 1–9 Å region, especially well suited for Chandra, which has a significant contribution from continuum emission between well separated emission lines from high-ionization species. These data allow us to study the hottest plasma present through the continuum shape and emission line strengths. Assuming a power-law emission measure distribution that has a high-temperature cutoff, we find that the emission is consistent with a thermal spectrum having a maximum temperature of 12 MK as determined from the corresponding spectral cutoff. This implies an effective wind shock velocity of 900 km s−1, well below the wind terminal speed of 2250 km s−1. For X-ray emission that forms close to the star, the speed and X-ray flux are larger than can be easily reconciled with strictly self-excited line-deshadowing-instability models, suggesting a need for a fraction of the wind to be accelerated extremely rapidly right from the base. This is not so much a dynamical instability as a nonlinear response to changing boundary conditions.
使用钱德拉档案中 O 星的 X 射线线轮廓测量质量损失率并约束冲击物理
影响因子：
4.8
作者：
Cohen D.H;Wollman;Leutenegger;Sundqvist J.O;Fullerton A.W;Zsargo;Owocki
通讯作者：
Owocki
流体动力学与共动框架辐射传输的耦合 - I OB 和 WR 星的统一方法
影响因子：
6.5
作者：
Sander;A. A. C;Hamann;Hainich;Shenar
通讯作者：
Shenar