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Echo Particle Image Velocimetry
Published on: December 27, 2012
光回声揭示了卡里纳在19世纪大爆发期间意外冷却的η卡里纳
A Rest1, J L Prieto, N R Walborn
1Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218, USA. arest@stsci.edu
Nature
|February 17, 2012
概括
卡里纳19世纪的大爆发喷射了超过10个太阳质量. 光回声显示了蓝移吸收线,表明有效温度低于标准模型预测的,可能是由于冲击波.
科学领域:
- 天文学和天体物理学
- 恒星进化 恒星进化
- 巨大的二进制恒星.
背景情况:
- 卡里纳 (Carinae) 是一个巨大的双星系统,因其19世纪的"大爆发"而闻名.
- 这次火山爆发超过了埃丁顿发光限度十年,喷射出超过十个太阳质量.
- 这一事件释放出相当大的能量,相当于超新星,但没有摧毁恒星.
研究的目的:
- 分析来自卡里奈大火山爆发的光回声.
- 为了确定喷射物质的光谱特征和物理条件.
- 为了将喷发的特性与理论模型和银河系外类似物进行比较.
主要方法:
- 观测1838-1858年卡里纳大爆发的光回声.
- 对光回声进行光谱分析,以识别吸收线并测量它们的移位.
- 观测到的光谱与恒星超巨星光谱 (G2-G5) 的比较.
主要成果:
- 光回声的光谱仅表现出在-210公里/秒的蓝移吸收线.
- 频谱特征与G2至G5超巨星一致,表明有效温度约为5000凯尔文.
- 观察到的有效温度低于标准不透明风模型对类似爆发的预测.
结论:
- 大卡里纳火山爆发的有效温度低于以前的假设.
- 标准的不透明风模型可能无法完全解释喷发的物理.
- 一个充满活力的冲击波是触发和影响喷发的潜在机制.
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