Intrinsic instrumental polarization and high-precision pulsar timing
Intrinsic instrumental polarization and high-precision pulsar timing
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DOI：
10.1093/mnras/stv1722
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
G. Foster;A. Karastergiou;Remi Paulin;T. Carozzi;S. Johnston;W. Straten
中科院分区：
文献类型：
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作者：
G. Foster;A. Karastergiou;Remi Paulin;T. Carozzi;S. Johnston;W. Straten
在脉冲星定时实验中，射电望远镜被用于精确测量射电脉冲的到达时间（ToA），这些实验主要针对毫秒脉冲星（MSPs），因为它们具有很高的旋转稳定性。这使得对msp的详细研究成为可能，并为探测引力波的实验奠定了基础。除了固有的和传播的影响，比如脉冲-脉冲抖动和星际介质中的色散变化，定时精度在一定程度上受到以下因素的限制：望远镜正交极化受体的偏振纯度、脉冲星轮廓的信噪比和系统的偏振保真度。通过模拟，我们展示了恢复真实偏振的基本限制如何降低ToA测量的精度。任何真实的系统都会对观测到的每个源做出不同的反应，这取决于独特的脉冲星偏振剖面。利用已知msp的概况，我们量化了观察系统规格的极限，从而产生令人满意的ToA测量，并且我们设置了一个实际的设计极限，超过该极限，系统的改进将导致收益递减。我们的目标是证明下一代射电望远镜前端偏振特性的限制，从而导致平方公里阵列。
Radio telescopes are used to accurately measure the time of arrival (ToA) of radio pulses in pulsar timing experiments that target mostly millisecond pulsars (MSPs) due to their high rotational stability. This allows for detailed study of MSPs and forms the basis of experiments to detect gravitational waves. Apart from intrinsic and propagation effects, such as pulse-topulse jitter and dispersion variations in the interstellar medium, timing precision is limited in part by the following: polarization purity of the telescope's orthogonally polarized receptors, the signal-to-noise ratio of the pulsar profile, and the polarization fidelity of the system. Using simulations, we present how fundamental limitations in recovering the true polarization reduce the precision of ToA measurements. Any real system will respond differently to each source observed depending on the unique pulsar polarization profile. Using the profiles of known MSPs, we quantify the limits of observing system specifications that yield satisfactory ToA measurements, and we place a practical design limit beyond which improvement of the system results in diminishing returns. Our aim is to justify limits for the front-end polarization characteristics of next-generation radio telescopes, leading to the Square Kilometre Array.