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宽线活跃星系核的旋转速度快于窄线的活跃星系核
Wolfram Kollatschny1, Matthias Zetzl
1Institut für Astrophysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany. wkollat@astro.physik.uni-goettingen.de
Nature
|February 19, 2011
概括
活跃星系核 (AGN) 中的超大质量黑洞显示出辐射线宽度和形状之间的新关系. 这一发现揭示了占主导地位的凯普勒旋转和流,改进了黑洞质量估计.
科学领域:
- 天体物理学 天体物理学
- 银河系的进化 银河系的进化
- 黑洞物理学 黑洞物理学
背景情况:
- 活跃的银河系核 (AGN) 拥有超大质量黑洞 (10^6到10^9 M).
- 围绕AGN的宽线区域 (BLR) 是至关重要的,但它们的结构和动态仍然不太清楚.
- 之前的研究缺乏对BLRs的主导运动 (入流,出流,旋转,流) 和几何 (盘,球) 的明确洞察力.
研究的目的:
- 研究活跃银河系核中的宽线区域的结构和动态.
- 建立一个基本的关系,规范BLRs观察到的光谱属性.
- 为了完善中央超大质量黑洞的质量测量.
主要方法:
- 对排放线宽的分析,特别是半最大时的全宽度 (FWHM).
- 检查排放线形状,用FWHM/σ (线) 的比率量化.
- 频谱特性与推断的物理条件和宽线区域的几何关系.
主要成果:
- 在AGN频谱中发现了FWHM和FWHM/σ(线) 之间的基本关系.
- 结合流的凯普勒旋转被确定为BLR中占主导地位的运动.
- BLR几何与旋转速度相关:对于快速旋转器来说更平,对于慢速旋转器来说更为球形.
- 观察到一个趋势,即向银河系中心增加几何厚度.
结论:
- 建立的关系为BLR动态和结构提供了新的见解.
- 使用这些发现得出的黑洞质量比以前的估计小2-10倍.
- 这项研究提供了一种更准确的方法来确定AGN中的中央黑洞质量.
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