INVERSE COMPTON SCATTERING MODEL FOR X-RAY EMISSION OF THE GAMMA-RAY BINARY LS 5039
INVERSE COMPTON SCATTERING MODEL FOR X-RAY EMISSION OF THE GAMMA-RAY BINARY LS 5039
复制标题
DOI：
10.1088/0004-637x/761/2/146
复制
发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
M. Yamaguchi;F. Takahara
中科院分区：
文献类型：
--
作者：
M. Yamaguchi;F. Takahara
提出了一个γ射线双星LS 5039的模型，其中X射线发射是由于逆康普顿（IC）过程，而不是同步辐射。虽然同步加速器模型在以前的研究中已经讨论过，但它需要一个强磁场，这导致TeV伽马射线通量的严重抑制，与H.E.S.S.意见。本文计算了汤姆逊区低能电子（γe <$103）的IC发射。我们发现，如果注入电子的最小洛伦兹因子γmin在103左右，则低能电子的IC发射可以解释朱雀观测到的X射线通量和谱。此外，我们还证明了，当注入电子在较高能量下的分布函数固定时，如果γmin与费米通量成比例变化，则Suzaku光变曲线可以很好地再现。我们的结论是，从LS 5039的发射是很好地解释了模型与IC发射的电子，其注入特性是依赖于轨道相位。由于X射线通量主要是由冷却电子的总数决定的，这个结论是相当可靠的，尽管在目前的公式中仍然存在模型和GeV波段观测之间的一些不匹配。
We propose a model for the gamma-ray binary LS 5039 in which the X-ray emission is due to the inverse Compton (IC) process instead of the synchrotron radiation. Although the synchrotron model has been discussed in previous studies, it requires a strong magnetic field which leads to a severe suppression of the TeV gamma-ray flux in conflict with H.E.S.S. observations. In this paper, we calculate the IC emission by low energy electrons (γe ≲ 103) in the Thomson regime. We find that IC emission of the low energy electrons can explain the X-ray flux and spectrum observed with Suzaku if the minimum Lorentz factor of injected electrons γmin is around 103. In addition, we show that the Suzaku light curve is well reproduced if γmin varies in proportion to the Fermi flux when the distribution function of injected electrons at higher energies is fixed. We conclude that the emission from LS 5039 is well explained by the model with the IC emission from electrons whose injection properties are dependent on the orbital phase. Since the X-ray flux is primarily determined by the total number of cooling electrons, this conclusion is rather robust, although some mismatches between the model and observations at the GeV band remain in the present formulation.