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来自通常类型Ic超新星2007gr的轻微相对论无线电射流
Z Paragi1, G B Taylor, C Kouveliotou
1Joint Institute for VLBI in Europe (JIVE), Postbus 2, 7990AA Dwingeloo, The Netherlands. zparagi@jive.nl
Nature
|January 30, 2010
概括
无线电观测显示Ic型超新星SN 2007gr的轻微相对论扩张,这表明它是一种低能喷气. 这一发现挑战了以前关于超新星缺乏相对论外流的假设.
科学领域:
- 天文学和天体物理学
- 宇宙爆炸,宇宙爆炸.
- 恒星进化中的恒星演变
背景情况:
- 类型Ic超新星与长时间的马射线爆发 (GRB) 相关,这两种爆发都源于巨大的恒星核心崩.
- 虽然GRB具有相对论喷流,但在Ic型超新星中还没有明确观察到相对论外流.
- 之前对超新星中相对论外流的搜索没有得出结论.
研究的目的:
- 调查IC型超新星中相对论外流的存在.
- 使用无线电观测来描述SN 2007gr的膨胀特性.
- 为了协调SN 2007gr.的光学和无线电观测.
主要方法:
- 利用60天间隔的两个时代对SN 2007gr的无线电干扰度观测.
- 分析了无线电源的膨胀,以确定膨胀速度.
- 将无线电膨胀数据与光学观测和光谱极极度测量进行比较.
主要成果:
- 在SN 2007gr中检测到源扩张,确定了0.6c的表面扩张速度的下限.
- 光学观测显示了典型的Ic型超新星喷射速度 (~6,000公里/秒),远低于GRB相关的超新星.
- 结论是,SN 2007gr从喷射物的一小部分产生了低能量的,轻微相对论的双极无线电射流,而大部分仍然较慢和轻微无球形.
结论:
- SN 2007gr 显示出轻微相对论扩张的证据,表明存在双极无线电喷流.
- 大部分SN 2007gr的喷射物以典型的非相对论速度膨胀.
- 这项研究表明,一些Ic型超新星可以产生相对论的外流,尽管可能是低能量的外流,使无线电和光学观测相协调.
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