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arXiv 0911.0680astro-ph.HE
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由年轻磁星提供动力的超新星光变曲线

Supernova Light Curves Powered by Young Magnetars

Daniel Kasen, Lars Bildsten

摘要:

我们发现,高磁性(B ~ 5 x 10^14 G)中子星以P ~ 2-20 ms的初始周期旋转,将能量沉积到膨胀的超新星遗迹中,可以大大增亮光变曲线。对于参数在这个范围内的磁星,旋转能量在几天到几周的时间尺度上释放,这与超新星遗迹的有效扩散时间相当。然后,可以辐射后期能量注入,而不会遭受压倒性的绝热膨胀损失。磁星的输入还产生了一个中央气泡,它将喷出物扫入内部致密的壳层,导致观测光谱中光球速度几乎恒定的时间延长。我们推导出的光变曲线上升时间和峰值亮度的函数的B,P和超新星喷出物的属性,允许直接推断有关的明亮的超新星的潜在磁星的解析表达式。我们进行数值辐射流体动力学计算的几个特定的情况下,并比较所得到的光变曲线观察到的事件。磁星活动可能会影响所有核心坍缩超新星的百分之几以上,并可能自然地解释一些有史以来最明亮的事件(例如,SN 2005 ap和SN 2008 es),L > 10^44尔格/秒。

英文摘要:

We show that energy deposited into an expanding supernova remnant by a highly magnetic (B ~ 5 x 10^14 G) neutron star spinning at an initial period of P ~ 2-20 ms can substantially brighten the light curve. For magnetars with parameters in this range, the rotational energy is released on a timescale of days to weeks, which is comparable to the effective diffusion time through the supernova remnant. The late time energy injection can then be radiated without suffering overwhelming adiabatic expansion losses. The magnetar input also produces a central bubble which sweeps ejecta into an internal dense shell, resulting in a prolonged period of nearly constant photospheric velocity in the observed spectra. We derive analytic expressions for the light curve rise time and peak luminosity as a function of B, P and the properties of the supernova ejecta that allow for direct inferences about the underlying magnetar in bright supernovae. We perform numerical radiation hydrodynamical calculations of a few specific instances and compare the resulting light curves to observed events. Magnetar activity is likely to impact more than a few percent of all core collapse supernovae, and may naturally explain some of the brightest events ever seen (e.g., SN 2005ap and SN 2008es) at L > 10^44 ergs/s.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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