LS 5039 is so far the best studied $γ$-ray binary system at multi-wavelength energies. A time resolved study of its spectral energy distribution (SED) shows that above 1 keV its power output is changing along its binary orbit as well as being a function of energy. To disentangle the energy dependence of the power output as a function of orbital phase, we investigated in detail the orbital light curves as derived with different telescopes at different energy bands. We analysed the data from all existing \textit{INTEGRAL}/IBIS/ISGRI observations of the source and generated the most up-to-date orbital light curves at hard X-ray energies. In the $γ$-ray band, we carried out orbital phase-resolved analysis of \textit{Fermi}-LAT data between 30 MeV and 10 GeV in 5 different energy bands. We found that, at $\lesssim$100 MeV and $\gtrsim$1 TeV the peak of the $γ$-ray emission is near orbital phase 0.7, while between $\sim$100 MeV and $\sim$1 GeV it moves close to orbital phase 1.0 in an orbital anti-clockwise manner. This result suggests that the transition region in the SED at soft $γ$-rays (below a hundred MeV) is related to the orbital phase interval of 0.5--1.0 but not to the one of 0.0--0.5, when the compact object is "behind" its companion. Another interesting result is that between 3 and 20 GeV no orbital modulation is found, although \textit{Fermi}-LAT significantly ($\sim$18$σ$) detects LS 5039. This is consistent with the fact that at these energies, the contributions to the overall emission from the inferior conjunction phase region (INFC, orbital phase 0.45 to 0.9) and from the superior conjunction phase region (SUPC, orbital phase 0.9 to 0.45) are equal in strength. At TeV energies the power output is again dominant in the INFC region and the flux peak occurs at phase $\sim$0.7.
I-band photometry of the quiescent black hole X-ray nova GROJ0422+32=V518 Per: modelling of the orbital light curve and estimation of the black hole mass
Unveiling the super-orbital modulation of LSI +61 303 in X-rays
我们从RXTE最长的监测日期中发现了LS I +61 303 X射线发射的超轨道调制的证据。轨道光变曲线中的调制分数的时间演化可以很好地拟合具有1667天的超轨道周期的正弦函数。然而，我们发现在射频和我们的X射线数据中发现的超轨道变化之间有281.8+/-44.6天的偏移。我们还发现了超轨道调制的最大计数率的轨道光变曲线，与以前的结果，包括移动兼容。
