Light Curve and SED Modeling of the Gamma-Ray Binary 1FGL J1018.6–5856: Constraints on the Orbital Geometry and Relativistic Flow
Light Curve and SED Modeling of the Gamma-Ray Binary 1FGL J1018.6–5856: Constraints on the Orbital Geometry and Relativistic Flow
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DOI：
10.3847/1538-4357/aa6623
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发表时间：
2017-03
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影响因子：
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通讯作者：
H. An;R. Romani
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作者：
H. An;R. Romani
我们给出了伽马射线双星1FGL J1018.6−5856在X射线和伽马射线波段的宽带光谱能量分布和光变曲线。我们发现，在低能γ射线波段的轨道调制是类似的，在X射线波段，这表明一个共同的光谱成分。然而，在GeV以上，轨道光变曲线会发生显著变化。我们认为，GeV波段包含显着的通量从脉冲星磁层，而X射线TeV的光变曲线占主导地位的同步辐射和康普顿发射的intrabinary冲击（IBS）。我们发现，一个简单的单区模型是不足以解释IBS的排放，但光束同步加速器自康普顿辐射的冲击脉冲星风中的加速等离子体可以重现复杂的多波段光变曲线，包括可变的X射线尖峰与伽马射线最大值一致。该模型要求倾角为150 °，轨道偏心率为10.35，这与现有光学观测的有限限制是一致的。这张照片激发了人们寻找来自能量充沛的年轻脉冲星的脉动，为风震提供动力。
We present broadband spectral energy distributions and light curves of the gamma-ray binary 1FGL J1018.6−5856 measured in the X-ray and the gamma-ray bands. We find that the orbital modulation in the low-energy gamma-ray band is similar to that in the X-ray band, suggesting a common spectral component. However, above a GeV the orbital light curve changes significantly. We suggest that the GeV band contains significant flux from a pulsar magnetosphere, while the X-ray to TeV light curves are dominated by synchrotron and Compton emission from an intrabinary shock (IBS). We find that a simple one-zone model is inadequate to explain the IBS emission, but that beamed Synchrotron-self Compton radiation from adiabatically accelerated plasma in the shocked pulsar wind can reproduce the complex multiband light curves, including the variable X-ray spike coincident with the gamma-ray maximum. The model requires an inclination of ∼50° and an orbital eccentricity of ∼0.35, consistent with the limited constraints from existing optical observations. This picture motivates searches for pulsations from the energetic young pulsar powering the wind shock.