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arXiv 0907.4616astro-ph.HE
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安静但仍然明亮:软gamma-ray中继器SGR 0526-66的XMM-牛顿观测

Quiet but still bright: XMM-Newton observations of the soft gamma-ray repeater SGR 0526-66

A. Tiengo, P. Esposito, S. Mereghetti, G. L. Israel, L. Stella, R. Turolla, S. Zane. N. Rea, D. Götz, M. Feroci

摘要:

SGR 0526-66是第一个在1979年3月探测到巨大耀斑的软伽马射线中继器(SGR),这表明磁星的存在,即中子星由其极强的磁场衰变提供动力。自那时以来,关于该天体的资料很少,主要是因为它自1983年以来一直没有爆发活动,而且由于它距离遥远,而且位于大麦云云中的一个X射线明亮的超新星遗迹中,因此对它的持续X射线发射的研究受到阻碍。在这里,我们报告了对SGR 0526-66的所有可用XMM-牛顿观测的全面分析。特别是,由于在2007年进行了深入的观察,我们测量了它的脉动周期(P = 8.0544 +/- 0.0002秒)6年后,它的最新检测钱德拉。这使我们能够第一次检测到其自旋下降速率的显着降低。通过与2000年和2001年进行的两次较短的XMM-牛顿观测进行比较,我们发现光谱没有显著变化,这可以用吸收幂律模型很好地模拟,nH = 4.6 E +21 cm^-2,光子指数= 3.27。在最近一次观测到爆发活动后的25年左右,SGR 0526-66仍然观测到高光度(约4 E +35 erg/s,在1-10 keV能量带),这使它成为明亮和持久的候选磁星。

英文摘要:

SGR 0526-66 was the first soft gamma-ray repeater (SGR) from which a giant flare was detected in March 1979, suggesting the existence of magnetars, i.e. neutron stars powered by the decay of their extremely strong magnetic field. Since then, very little information has been obtained on this object, mainly because it has been burst-inactive since 1983 and the study of its persistent X-ray emission has been hampered by its large distance and its location in a X-ray bright supernova remnant in the Large Magellanic Cloud. Here we report on a comprehensive analysis of all the available XMM-Newton observations of SGR 0526-66. In particular, thanks to a deep observation taken in 2007, we measured its pulsation period (P = 8.0544 +/- 0.0002 s) 6 years after its latest detection by Chandra. This allowed us to detect for the first time a significant reduction of its spin-down rate. From a comparison with two shorter XMM-Newton observations performed in 2000 and 2001, we found no significant changes in the spectrum, which is well modelled by an absorbed power-law with nH = 4.6E+21 cm^-2 and photon index = 3.27. The high luminosity (about 4E+35 erg/s, in the 1-10 keV energy band) still observed about 25 years after the latest detection of bursting activity places SGR 0526-66 in the group of bright and persistent magnetar candidates.

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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