标题： X射线和光学观测的毫秒脉冲星双星PSRJ1431-4715 显示英文标题

标题： X-ray and optical observations of the millisecond pulsar binary PSRJ1431-4715

摘要： 我们报告了对能量毫秒脉冲星双星PSR J1431-4715的首次X射线观测，该观测使用了XMM-Newton，并辅以通过ESO-NTT的ULTRACAM仪器获得的快速光学多波段测光数据。 它被发现是一个微弱的X射线源，没有显著的轨道调制。 这与大多数显示显著X射线轨道变化的系统形成对比。 X射线谱主要由非热辐射主导，由于缺乏轨道调制，不支持起源于脉冲星和伴星风之间的双星内激波。 尽管在软X射线中不能排除中子星极帽的热辐射，但同步加速器辐射的优势表明其起源于脉冲星磁层，我们在X射线和伽马射线能量下用同步加速器弯曲模型描述了这一现象。 光学多色光变曲线在10.8小时轨道周期上折叠后呈双峰状，主要受椭圆效应支配，但也受到辐射影响。 ULTRACAM光变曲线通过几个模型拟合，包括直接加热和冷斑点，或通过对流或对流加扩散后的辐射再分布。 尽管无法限制最佳的辐射模型，但拟合提供了一致的系统参数，给出了轨道倾角59$\pm$6度和距离3.1$\pm$0.3千秒差距。 伴星被发现是一颗F型恒星，填充其洛希瓣不足（f_RL = 73$\pm$4%），质量为0.20$\pm$0.04太阳质量，确认了红背状态，尽管比大多数红背更热。 日面和夜面温度分别为7500K和7400K，表明伴星受到较弱的辐射影响，可能是由于其高固有亮度。 虽然脉冲星的质量不能精确得出，但一个重（1.8-2.2太阳质量）的中子星更受欢迎。 显示英文摘要

摘要： We present the first X-ray observation of the energetic millisecond pulsar binary PSR J1431-4715, performed with XMM-Newton and complemented with fast optical multi-band photometry acquired with the ULTRACAM instrument at ESO-NTT. It is found as a faint X-ray source without a significant orbital modulation. This contrasts with the majority of systems that instead display substantial X- ray orbital variability. The X-ray spectrum is dominated by non-thermal emission and, due to the lack of orbital modulation, does not favour an origin in an intrabinary shock between the pulsar and companion star wind. While thermal emission from the neutron star polar cap cannot be excluded in the soft X-rays, the dominance of synchrotron emission favours an origin in the pulsar magnetosphere that we describe at both X-ray and gamma-ray energies with a synchro-curvature model. The optical multi-colour light curve folded at the 10.8h orbital period is double-humped, dominated by ellipsoidal effects, but also affected by irradiation. The ULTRACAM light curves are fit with several models encompassing direct heating and a cold spot, or heat redistribution after irradiation either through convection or convection plus diffusion. Despite the inability to constrain the best irradiation models, the fits provide consistent system parameters, giving an orbital inclination of 59$\pm$6deg and a distance of 3.1$\pm$0.3 kpc. The companion is found to be an F-type star, underfilling its Roche lobe ( f_RL = 73$\pm$4%), with a mass of 0.20$\pm$0.04 M_sun, confirming the redback status, although hotter than the majority of redbacks. The stellar dayside and nightside temperatures of 7500K and 7400K, respectively, indicate a weak irradiation effect on the companion, likely due to its high intrinsic luminosity. Although the pulsar mass cannot be precisely derived, a heavy (1.8-2.2 M_sun) neutron star is favoured