A Central Engine for Cosmic Gamma-Ray Burst Sources
A Central Engine for Cosmic Gamma-Ray Burst Sources
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DOI：
10.1086/309537
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发表时间：
2000-03
期刊：
影响因子：
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通讯作者：
M. Ruderman;L. Tao;W. Kluźniak
中科院分区：
文献类型：
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作者：
M. Ruderman;L. Tao;W. Kluźniak
一个家庭以前提出的“中央引擎”的宇宙伽玛射线暴源被认为是在一些细节。一个稳定吸积的106 G磁白色矮星最终应该崩溃到一个强烈的差异旋转，毫秒旋转周期的中子星星的稳定吸积率和初始质量的范围很广，如果吸积的白色矮星有一个演变的O-Ne-Mg组成。一个类似的中子星星也可能来自最初的碳氧白色矮星，但只有在更严格的吸积速率下。因为坍缩的白色矮星开始时是一个γ =多面体，最后的中子星星的自旋速率随着圆柱半径的增加而强烈增加。中子星星的极向磁场稳定的卷起，然后产生有浮力的磁环，磁环生长、挣脱、上升，并部分穿透中子星星表面，形成一颗瞬变的B 1017 G毫秒自旋周期脉冲星，并产生强大的脉冲星风。这种脉冲星风辐射随后被强烈的恒星差异自转引起的表面剪切运动迅速抑制。这种缠绕和瞬态脉冲星的形成可以发生在不同的圆柱体上的其他时间和/或在同一个圆柱体上重复，（再）缠绕和表面穿透的时间尺度远远长于中子星星的毫秒旋转周期。这样，差速旋转就打开和关闭了一扇大门，使中子星星的自旋能量在脉冲星风的强大爆发中释放出来。该模型的预测相比有利的伽马射线暴源（总能量，出生率，持续时间，亚暴波动和时间尺度，突发事件之间的变异性，重子加载）所需的中央引擎属性。
One of a family previously proposed "central engines" for cosmic gamma-ray burst sources is considered in some detail. A steadily accreting 106 G magnetic white dwarf should ultimately collapse to a strongly differentially rotating, millisecond-rotation-period neutron star for a wide range of steady accretion rates and initial masses if the accreting white dwarf has an evolved O-Ne-Mg composition. A similar neutron star could also result from an initial C-O white dwarf but only for more constrained accretion rates. Because the collapsing white dwarf begins as a γ = polytrope, the final neutron star's spin rate increases strongly with cylindrical radius. A stable windup of the neutron star's poloidal magnetic field then produces buoyant magnetic toroids which grow, break loose, rise, and partly penetrate the neutron star surface to form a transient, B ≈ 1017 G millisecond-spin-period pulsar with a powerful pulsar wind. This pulsar wind emission is then rapidly suppressed by the surface shear motion from the strong stellar differential rotation. This windup and transient pulsar formation can occur at other times on different cylinders and/or repeat on the same one, with (re-)windup and surface penetration timescales hugely longer than the neutron star's millisecond spin period. In this way, differential rotation both opens and closes the doors which allow neutron star spin energy to be emitted in powerful bursts of pulsar wind. Predictions of this model compare favorably to needed central engine properties of gamma-ray burst sources (total energy, birth rate, duration, subburst fluctuations and timescales, variability among burst events, and baryon loading).