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arXiv astro-ph/9702016astro-ph
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PSR B1951 +32的RXTE观察

RXTE Observation of PSR B1951+32

Hsiang-Kuang Chang, Cheng Ho

摘要:

本文报道了1996年3月24日利用主成分分析仪对PSR B1951+32进行19 k秒RXTE观测的结果。我们应用同期的无线电星历和各种统计检验来寻找脉动的证据。这些分析产生了有趣的但不确定的证据的脉动的存在的时间序列:脉动的存在的置信水平是94.5%,在2.0-4.8 keV带和97.6%,在4.8-6.3 keV带的基础上的H-测试。在不检测到脉动的前提下,我们推导出脉冲通量的2-sigma估计上限为2.0-4.8 keV波段的$3.3\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$、4.8-8.5 keV波段的$2.7\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$和8.5-13.0 keV波段的$2.0\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$。这些上限与OSSE上限所建议的高能伽马射线发射的光谱翻转趋势一致。这样的翻转强烈地表明外磁层是脉冲伽马射线的发射场。另一方面,这些X射线脉动的RXTE上限与ROSAT在0.1-2.4 keV波段观察到的点源的幂律谱的外推不一致,假设脉冲分数恒定:ROSAT探测到的脉冲软X射线发射必须遵循比整个点源软得多的谱。

英文摘要:

We report results of RXTE observations of PSR B1951+32 using the PCA instrument for 19k seconds during 1996 March 24th. We applied the contemporaneous radio ephemeris and various statistical tests to search for evidence of pulsation. These analyses yield intriguing yet inconclusive evidence for the presence of the pulsation in the time series: confidence level for the presence of pulsation is 94.5% in the 2.0-4.8 keV band and 97.6% in the 4.8-6.3 keV band based on the H-test. Under the premise of non-detection of pulsation, we derive estimated 2-sigma upper limits for the pulsed flux to be $3.3\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$ in the 2.0-4.8 keV band, $2.7\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$ in the 4.8-8.5 keV band, and $2.0\times 10^{-6} cm^{-2} s^{-1} keV^{-1}$ in the 8.5-13.0 keV band. These upper limits are consistent with the trend of spectral turn-over from high-energy gamma-ray emission as suggested by the OSSE upper limit. Such turn-over strongly suggests the outer magnetosphere as the emission site for pulsed gamma-rays. These RXTE upper limits for X-ray pulsation are, on the other hand, not consistent with the extrapolation of reported power-law spectra from the point source observed by ROSAT in the 0.1-2.4 keV band, assuming a constant pulse fraction: The pulsed soft X-ray emission detected by ROSAT must follow a much softer spectrum than that of the overall point source.

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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