We consider electromagnetic fields having an angular momentum density in a locally nonrotating reference frame in Schwarzschild, Kerr, and Kerr-Newman spacetimes. The nature of such fields is assessed with two families of observers, the locally nonrotating ones and those of vanishing Poynting flux. The velocity fields of the vanishing-Poynting observers in the locally nonrotating reference frames are determined using the decomposition formalism. From a methodological point of view and considering a classification of the electromagnetic field based on its invariants, it is convenient to separate the consideration of the vanishing-Poynting observers into two cases corresponding to the pure and nonpure fields; additionally, if there are regions where the field rotates with the speed of light (light surfaces), it becomes necessary to split these observers into two subfamilies. We present several examples of relevance in astrophysics and general relativity, such as pure rotating dipolar-like magnetic fields and the electromagnetic field of the Kerr-Newman solution. For the latter example, we see that vanishing-Poynting observers also measure a vanishing super-Poynting vector, confirming recent results in the literature. Finally, for all nonnull electromagnetic fields, we present the 4-velocity fields of vanishing Poynting observers in an arbitrary spacetime.

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Kerr 和 Kerr-Newman 时空中消失的坡印亭观测者和电磁场分类

我们考虑在 Schwarzschild、Kerr 和 Kerr-Newman 时空中的局部非旋转参考系中具有角动量密度的电磁场。这种场的性质是用两个观察者家族来评估的，局部非旋转的和消失的坡印廷通量的。在局部非旋转参考系中消失-坡印亭观察者的速度场由分解形式主义。从方法论的观点和考虑基于其不变量的电磁场分类，将消失-坡印亭观测者的考虑分为对应于纯场和非纯场的两种情况是方便的；此外，如果存在场以光速旋转的区域（光表面），则有必要将这些观察者分成两个亚族。我们提出了几个与天体物理学和广义相对论相关的例子，例如纯旋转类偶极磁场和 Kerr-Newman 解的电磁场。对于后一个例子，我们看到消失的坡印亭观察者还测量了消失的超级坡印廷向量，证实了文献中的最新结果。最后，对于所有非零电磁场，