标题： 射电脉冲星PSR B1451-68中的圆偏振：相干模式跃迁和同束干扰 显示英文标题

标题： Circular polarization in radio pulsar PSR B1451-68: coherent mode transitions and intrabeam interference

摘要： 脉冲星B1451-68的射电辐射包含两个强度相似的偏振模式，这两个模式产生两条清晰的正交偏振角轨迹。 当在庞加莱球上观察时，辐射由两个通量斑块组成，这些斑块随脉冲经度的函数而沿经向旋转，并通过斯托克斯V极点，从而导致正交偏振模式（OPMs）之间的转换。 此外，在轮廓窗口内，斑块中的功率比反转一次。 研究表明，经向圆化是由固定四分之一波长相位滞后下的模式比变化产生的相干正交偏振模式转换（COMT）引起的。 COMTs可能在射电脉冲星数据中普遍存在且难以检测，因为它们在偏振分数中不留痕迹，并且由类似于旋转矢量模型的方程描述。 与较低频率处的通量极小值一致的圆化现象表明，轮廓成分是由具有振荡相位的辐射形成的，该相位每成分增加90度。 这些特性可以理解为涉及两对线性正交模式（或两组非正交椭圆波）的干涉图案。 共平面振荡的频率依赖性相干叠加可以产生脉冲轮廓中的极小值，从而造成成分作为独立实体的假象。 经过这种负干涉后留下的正交偏振信号解释了在轮廓成分之间的极小值中通常观察到的偏振度增强现象。 显示英文摘要

摘要： The radio emission of pulsar B1451-68 contains two polarization modes of similar strength, which produce two clear orthogonal polarization angle tracks. When viewed on a Poincare sphere, the emission is composed of two flux patches that rotate meridionally as function of pulse longitude and pass through the Stokes V poles, which results in transitions between orthogonal polarization modes (OPMs). Moreover, the ratio of power in the patches is inversed once within the profile window. It is shown that the meridional circularization is caused by a coherent OPM transition (COMT) produced by a varying mode ratio at a fixed quarter-wave phase lag. The COMTs may be ubiquitous and difficult to detect in radio pulsar data, because they can leave no trace in polarized fractions and they are described by equation similar to the rotating vector model. The circularization, which coincides with flux minima at lower frequency, requires that profile components are formed by radiation with an oscillation phase which increases with longitude in steps of 90 degrees per component. The properties can be understood as an interference pattern involving two pairs of linear orthogonal modes (or two nonorthogonal elliptic waves). The frequency-dependent coherent superposition of coplanar oscillations can produce the minima in the pulse profile, and thereby the illusion of components as separate entities. The orthogonally polarized signal which is left after such negative interference explains the enhancement of polarization degree which is commonly observed in the minima between profile components.