The population of radio-quiet and thermally emitting isolated neutron stars. A comprehensive picture of neutron star evolution in the Galaxy

观测到的中子星以射电脉冲星为主。然而，近年来发现了孤立中子星的不同观测表现，包括磁星、x射线暗孤立中子星和旋转射电瞬变体。特别地，xdin由7个相邻的冷却ins组成一个同质组，显示出独特的属性。虽然目前探测到的源数量较少，但特殊的INS亚群可能代表了银河系中相当大的一部分中子星，并且由于许多原因非常重要。首先，对单个来源的研究可以极大地影响我们对重力和磁场极端条件下物质物理学的理解。其次，各子群之间的关系有助于我们理解决定中子星现象学的主要性质。最后，随着新天体的发现，银河系中子星诞生和演化的全面图景可以成为目标。我们建议研究银河系中子星群，特别是关注XDINS，以表征中子星的特性和演化状态，以及了解特殊亚群如何相互关联以及与大部分“正常”射电脉冲星群的关系。这些目标将通过进一步研究现有的特殊INS样本，通过在更远的距离上识别新的INS候选者，以及通过利用当前和未来的x射线设备对银河系中热发射INS的产生、演化和可探测性进行建模来实现。

The observed population of neutron stars is dominated by radio pulsars. In recent years, however, different observational manifestations of isolated neutron stars (INSs) have been discovered, which include magnetars, X-ray dim isolated neutron stars (XDINS) and rotating radio transients (RRATs). In particular, XDINS constitute a homogeneous group of seven nearby, cooling INSs displaying unique properties. While currently fewer in number of detected sources, the peculiar INS subgroups might represent a considerable fraction of the neutron stars in the Galaxy and are very important for a number of reasons. First, the investigation of individual sources can greatly impact our understanding of the physics of matter at extreme conditions of gravity and magnetic field. Second, the relations between the various subgroups help us to understand the main properties determining the neutron star phenomenology. Finally, as new objects are discovered, a comprehensive picture of neutron star birth and evolution in the Milky Way can be aimed for. We propose to investigate the Galactic population of neutron stars, especially focusing on XDINS, in order to characterise neutron star properties and evolutionary state, as well as to understand how the peculiar subgroups relate to each other and to the bulk of the “normal” radio pulsar population. These goals will be pursued by studying further the existing sample of peculiar INSs, by identifying new INS candidates at greater distances and by modeling the creation, evolution and detectability of thermally emitting INSs in the Milky Way with current and future X-ray facilities.