标题： 无奇点时空中的赤道辐射极化图像 显示英文标题

标题： Polarized image of equatorial emission in horizonless spacetimes: naked singularities

摘要： 我们研究弱裸和强裸Janis-Newman-Winicour奇点周围的吸积盘的线性偏振。 我们考虑一个薄磁化流体环在赤道平面上轨道运行并发射同步辐射的解析玩具模型。 计算并比较了可观测的偏振图像与物理参数与射电源M87相容的Schwarzschild黑洞。 对于小倾角，弱裸奇点的直接图像非常类似于Schwarzschild黑洞。 如果考虑更大的倾角或更高阶的图像，偏振特性中的偏差会增加，因为对于间接图像，偏振强度相比黑洞增加了几个数量级。 强裸奇点在直接图像中就产生了显著的观测特征。 它们创建了一个流体环的第二图像，具有更大的偏振强度和偏振方向的特征扭转。 由于这种额外的结构，它们可以在偏振实验中被区分。 显示英文摘要

摘要： We study the linear polarization from the accretion disk around weakly and strongly naked Janis-Newman-Winicour singularities. We consider an analytical toy model of thin magnetized fluid ring orbiting in the equatorial plane and emitting synchrotron radiation. The observable polarized images are calculated and compared to the Schwarzschild black hole for physical parameters compatible with the radio source M87. For small inclination angles the direct images of the weakly naked singularities closely mimic the Schwarzschild black hole. The deviation in the polarization properties increases if we consider larger inclination angles or higher order images as for indirect images the polarization intensity grows several times in magnitude compared to black holes. Strongly naked singularities produce significant observational signatures already in the direct images. They create a second image of the fluid ring with times larger polarization intensity and characteristic twist of the polarization direction. Due to this additional structure they can be distinguished in polarimetric experiments.