Magnetars and neutron stars emission - model development in the IXPE/eXTP era

中子星（NSs）是大质量恒星的终点，是宇宙中最具磁性的物体。该项目将研究两种独特的NSs - XDINS和磁星。它们的超强磁场（高达1E14-1E15 G）使它们成为独特的实验室，可以在地球上无法复制的条件下测试基础物理。有几个问题仍然没有解决：当中子星被活跃的磁层包围时，没有专门的模型大气代码来模拟中子星表面的发射，并且电流向后轰炸表面。此外，考虑到代码的各向异性电导率的真实热图建模问题是开放的。从表面产生的发射预计是高度极化的，并且随着光在磁层中的传播，预计将通过散射获得进一步的极化。学生需要解决这些问题的一部分，重新调整和扩展专用代码来模拟预期的光谱、光曲线和偏振度，并与现有的观测结果进行比较。结果预计将有助于下一代x射线偏振空间任务的科学工作组，如IXPE （NASA）和eXTP （CAS）。

Neutron stars (NSs), the end points of massive stars, are the most magnetic objects in the Universe. The project will study two unique type of NSs - XDINS and magnetars. Their ultra-strong magnetic field (up to 1E14-1E15 G) makes them unique laboratories to test fundamental physics under conditions not reproducible on Earth. Several issues are still unresolved: dedicated model atmosphere codes do not exist to simulate the emission from the star surface when the neutron star is surrounded by an active magnetosphere and current back bombard the surface. Also, the issue of modeling a realistic thermal map taking into account for the very anisotropic conductivity of the code is open. The emission generate from the surface is expected to be highly polarized, and further polarization is expected to be acquired through scattering as the light travel across the magnetosphere. The student is expected to tackle part of these points, readapting and extending dedicated codes to simulate the expected spectrum, lightcurve and polarization degrees, to be compared with existing observations. Results are expected to contribute to the scientific working groups of next generation X-ray polarimetric space missions, as IXPE (NASA) and eXTP (CAS).