LONG-TERM X-RAY CHANGES IN THE EMISSION FROM THE ANOMALOUS X-RAY PULSAR 4U 0142+61
LONG-TERM X-RAY CHANGES IN THE EMISSION FROM THE ANOMALOUS X-RAY PULSAR 4U 0142+61
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DOI：
10.1088/0004-637x/716/2/1345
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发表时间：
2007-08
期刊：
影响因子：
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通讯作者：
M. Gonzalez;R. Dib;V. Kaspi;P. Woods;C. Tam;F. P. G. M. University;Dynetics;Inc. Nsstc;Nasa Gsfc
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文献类型：
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作者：
M. Gonzalez;R. Dib;V. Kaspi;P. Woods;C. Tam;F. P. G. M. University;Dynetics;Inc. Nsstc;Nasa Gsfc
我们给出了利用XMM-牛顿、钱德拉和斯威夫特在2000-2008年间对反常X射线脉冲星(AXP)4U 0142+61进行X射线观测所获得的结果。这些观测结果与之前使用Rossi X射线计时探测器(RXTE)报告的长期变化和爆发时期不谋而合。在2006年前的观测中，我们发现随着时间的推移，脉冲轮廓变得更加正弦，脉冲分数增加。这些结果证实了用RXTE得到的结果，并将观测到的演化扩展到2keV以下的能量。在2006年前的观测中，用XMM-牛顿方法测得的0.5keV-10keV区的总通量基本保持不变，而在此之后观测到的∼增加了10%，这与2006年-2007年从源探测到的爆发活动相吻合。在这些爆发之后，当通量和脉冲分数恢复到爆发前的水平时，向更正弦的脉冲轮廓的演化停止。没有证据表明爆发导致排放发生了大规模、长期的变化。我们还报告了双子座望远镜在两次爆发后所进行的观测，这些观测显示了与之前测量结果一致的震源震级。我们的结果展示了在AXPS中看到的广泛的X射线变异性特征，并根据这些源的当前发射模型对其进行了讨论。
We present results obtained from X-ray observations of the anomalous X-ray pulsar (AXP) 4U 0142+61 taken between 2000 and 2008 using XMM-Newton, Chandra, and Swift. These observations coincide with periods of long-term changes and burst epochs previously reported using the Rossi X-ray Timing Explorer (RXTE). In observations taken before 2006, we find that the pulse profile became more sinusoidal and the pulsed fraction increased with time. These results confirm those derived using RXTE and expand the observed evolution to energies below 2 keV. The total flux in the 0.5–10 keV band determined with XMM-Newton is observed to be nearly constant in observations taken before 2006, while an increase of ∼10% is seen afterwards and coincides with the burst activity detected from the source in 2006–2007. After these bursts, the evolution toward more sinusoidal pulse profiles ceased while the flux and pulsed fraction returned to pre-bursts levels. No evidence for large-scale, long-term changes in the emission as a result of the bursts is seen. We also report on observations taken with the Gemini telescope after two bursts which show source magnitudes consistent with previous measurements. Our results demonstrate the wide range of X-ray variability characteristics seen in AXPs and we discuss them in light of current emission models for these sources.