重力弧断层扫描中的红移1的块状和异构星系光环
Sebastian Lopez1, Nicolas Tejos2, Cédric Ledoux3
1Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile.
Nature
|February 8, 2018
概括
绘制遥远星系周围的环银河系介质是一个挑战. 这项研究使用了引力弧来绘制丰富的气体,揭示了块状的异构分布,并表明了回收材料而不是外流.
科学领域:
- 天文学与天体物理学
- 宇宙气体动力学
- 银河系的演变
背景情况:
- 形成恒星的星系拥有超过100千帕塞克的金属丰富气体.
- 以前使用类星体吸收线的研究提供了这个环银河系媒介 (CGM) 的有限,单维视图.
- 了解CGM结构对于解读星系进化中的 baryons循环至关重要.
研究的目的:
- 开发和应用一种用于绘制银河系光环中丰富气体的空间和运动分布的新技术.
- 在红移0.98时研究环银河系介质的结构和特性.
主要方法:
- 使用一个巨大的引力弧背景源的整体场 (断层) 光谱.
- 在中间的星系系统中绘制了II (Mg II) 吸收的分布.
- 分析了环银河系气体的空间范围,凝聚度和运动性质.
主要成果:
- 揭示了一个团状的环银河系介质, 吸收强度随着距离银河系的距离而下降.
- 证明丰富气体没有同位素分布.
- 在一个大预测区域 (大约) 中观察到最小的动力变化. 速度仅限于一个狭窄的范围.
结论:
- 观察到的气体分布和动力学表明银河系光环中存在被回收的物质.
- 这些发现挑战了仅仅依赖银河系外流的气体分布模型.
- 引力弧断层扫描为研究环银河系介质提供了一种强大的新方法.
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