Very deep X-ray observations of the anomalous X-ray pulsar 4U 0142+614
Very deep X-ray observations of the anomalous X-ray pulsar 4U 0142+614
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异常X射线脉冲星4U 0142 614的极深X射线观测
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
L. Angelini
中科院分区：
文献类型：
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作者：
N. Rea;E. Nichelli;G. Israel;R. Perna;T. Oosterbroek;A. Parmar;R. Turolla;S. Campana;L. Stella;S. Zane;L. Angelini
我们报告了 2004 年 3 月和 7 月对异常 X 射线脉冲星 (AXP) 4U 0142+614 进行的两次新的 XMM-Newton 观测，收集了该源最准确的光谱。此外，我们分析了 2002 年 2 月和 2003 年 1 月进行的两次简短的档案观察，以研究该 AXP 的长期行为。 4U 0142+614 在 2002 年至 2004 年之间的变化似乎相对稳定，并且相位平均频谱在四个时期之间没有显示出任何显着的变化。我们得出了迄今为止 4U 0142+614 谱线中存在的线的最深上限作为能量的函数：对于窄线和宽线，1‐3 keV 能量范围内的等效宽度分别 <4 和 <8 eV。检测到脉冲轮廓和脉冲分数中显着的能量依赖性，因此脉冲相位光谱显示光谱可变性作为相位的函数。利用XMM-Newton和INTEGRAL数据，我们成功地用三种模型对4U 0142+614的1-250 keV谱进行了建模，即规范吸收黑体加两个幂律、共振回旋散射模型加一个幂律和两个对数抛物线函数。
We report on two new XMM‐Newton observations of the anomalous X-ray pulsar (AXP) 4U 0142+614 performed in 2004 March and July, collecting the most accurate spectrum for this source. Furthermore, we analyse two short archival observations performed in 2002 February and 2003 January in order to study the long-term behaviour of this AXP. 4U 0142+614 appears to be relatively steady in flux between 2002 and 2004, and the phase-averaged spectrum does not show any significant variability between the four epochs. We derive the deepest upper limits to date on the presence of lines in 4U 0142+614 spectrum as a function of energy: equivalent width in the 1‐3 keV energy range <4 and <8 eV for narrow and broad lines, respectively. A remarkable energy dependence in both the pulse profile and the pulsed fraction is detected, and consequently pulse‐phase spectroscopy shows spectral variability as a function of phase. By making use of XMM‐Newton and INTEGRAL data, we successfully model the 1‐250 keV spectrum of 4U 0142+614 with three models, namely the canonical absorbed blackbody plus two power laws, a resonant cyclotron scattering model plus one power-law and two logparabolic functions.