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arXiv 0910.2701astro-ph.HEastro-ph.GA
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与高能射电脉冲星J1747-2958有关的脉冲星风星云G359 .23-0.82“老鼠”的自行

A Proper Motion for the Pulsar Wind Nebula G359.23-0.82, "the Mouse," Associated with the Energetic Radio Pulsar J1747-2958

C. A. Hales, B. M. Gaensler, S. Chatterjee, E. van der Swaluw, F. Camilo

摘要:

“老鼠”(PWN G359.23-0.82)是一个壮观的弓形激波脉冲星风星云,由射电脉冲星J1747-2958提供动力。脉冲星和它的星云被认为具有很高的空间速度,但它们的自行还没有被直接测量过。在这里,我们提出了8.5 GHz的干涉观测的鼠标星云的超大阵列,跨越12年的时间基线。我们测得PWN G359.23-0.82(因此也间接测得PSR J1747-2958)向东的自行为12.9+/-1.8 mas/yr,假设距离为5 kpc,对应的横向空间速度为306+/-43 km/s。考虑到弓形激波顶点处的压力平衡,我们计算出系统穿越的星际介质的原位氢数密度约为1.0(-0.2)(+0.4)cm^(-3)。考虑到PSR J1747-2958的潜在出生地,计算得出PSR J1747-2958的年龄下限为163(-20)(+28)kyr。与脉冲星的自旋下降年龄25千年的巨大差异可能是由表面偶极子磁场增长的时间尺度上~15千年,这表明PSR J 1747 -2958可能的未来演变为不同类别的中子星。我们还认为,相邻的超新星遗迹G359.1-0.5与老鼠系统没有物理联系,而是沿着视线的一个不相关的物体。

英文摘要:

The "Mouse" (PWN G359.23-0.82) is a spectacular bow shock pulsar wind nebula, powered by the radio pulsar J1747-2958. The pulsar and its nebula are presumed to have a high space velocity, but their proper motions have not been directly measured. Here we present 8.5 GHz interferometric observations of the Mouse nebula with the Very Large Array, spanning a time baseline of 12 yr. We measure eastward proper motion for PWN G359.23-0.82 (and hence indirectly for PSR J1747-2958) of 12.9+/-1.8 mas/yr, which at an assumed distance of 5 kpc corresponds to a transverse space velocity of 306+/-43 km/s. Considering pressure balance at the apex of the bow shock, we calculate an in situ hydrogen number density of approximately 1.0(-0.2)(+0.4) cm^(-3) for the interstellar medium through which the system is traveling. A lower age limit for PSR J1747-2958 of 163(-20)(+28) kyr is calculated by considering its potential birth site. The large discrepancy with the pulsar's spin-down age of 25 kyr is possibly explained by surface dipole magnetic field growth on a timescale ~15 kyr, suggesting possible future evolution of PSR J1747-2958 to a different class of neutron star. We also argue that the adjacent supernova remnant G359.1-0.5 is not physically associated with the Mouse system but is rather an unrelated object along the line of sight.

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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