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arXiv 1602.03528astro-ph.HEastro-ph.SR
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AXP 4U 0142+61的无特征不变光谱能量分布

The featureless and non-variable optical spectral energy distribution of AXP 4U 0142+61

T. Muñoz-Darias, A. de Ugarte Postigo, J. Casares

摘要:

本文介绍了反常X射线脉冲星4U 0142+61的微弱(r ~26)光学对应物的GTC-10.4m光谱学和多波段测光。5000 - 9000 Angs的光谱-第一次获得的磁星-是没有特征的,允许我们设置一个等效宽度上限EW < 25 Angs,以在Halfa区域存在发射线。在12年多的不同时期获得的g,r,i,z SDSS波段的多波段测光显示,从分钟到年的时间尺度没有显着的变化。光度计首次根据SDSS本身进行了校准,得到了可变性的可靠上限,范围从~0.2 mag(i)(12年)到0.05 mag(z)(1.5年)。由于沿视线的高消光,光学+近红外(文献值)光谱能量分布的形状没有得到很好的约束。用马尔可夫链蒙特卡罗分析,发现它可用幂律描述,谱指数β =-0.7+-0.5,E_(B-V)=1.5+-0.4。我们还讨论了从文献中添加硬X射线通量值的光谱拟合的影响。

英文摘要:

We present GTC-10.4m spectroscopy and multi-band photometry of the faint (r ~26) optical counterpart of the anomalous X-ray pulsar 4U 0142+61. The 5000 - 9000 Angs spectrum -- the first obtained for a magnetar -- is featureless, allowing us to set an equivalent width upper limit EW < 25 Angs to the presence of emission lines in the Halfa region. Multi-band photometry in the g, r, i, z SDSS bands obtained at different epochs over 12 years shows no significant variability from minutes-to-years time scales. The photometry has been calibrated, for the first time, against the SDSS itself, resulting in solid upper limits to variability ranging from ~0.2 mag in i (over 12 years) to 0.05 mag in z (over 1.5 years). The shape of the optical + near-infrared (literature values) spectral energy distribution is not well constrained due to the high extinction along the line of sight. Using a Markov Chain Monte Carlo analysis we find that it can be described by a power-law with a spectral index beta=-0.7+-0.5 and E_(B-V)=1.5+-0.4. We also discuss on the implications of adding hard X-ray flux values from literature to the spectral fitting.

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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