Single Pulse Dispersion Measure of the Crab Pulsar
Single Pulse Dispersion Measure of the Crab Pulsar
复制标题
DOI：
10.3847/1538-4357/ac8055
复制
发表时间：
2022-07
期刊：
影响因子：
--
通讯作者：
N. Lewandowska;P. Demorest;M. Mclaughlin;P. Kilian;T. Hankins
中科院分区：
文献类型：
--
作者：
N. Lewandowska;P. Demorest;M. Mclaughlin;P. Kilian;T. Hankins
本文研究了利用蟹状星云脉冲星的亮单脉冲分别确定主脉冲和脉冲间分量的色散测度。我们开发了两种方法，使用互相关函数（CCF）。第一种方法计算64个频率通道中的每一个与参考通道的总强度的CCF，并将最大相关的时滞转换为DM。第二种方法分别计算每个单独的亮脉冲的每对通道之间的CCF，并从所有通道对DM的分布中提取平均DM。这两种方法都允许以优于10−5的相对不确定度确定DM，并为最佳拟合值的不确定度提供稳健的估计。我们发现DM之间的差异，主脉冲，低频间脉冲，和高频间脉冲使用这两种方法在4至6 GHz的频率范围内。Hankins等人（2016年）对高频间脉冲进行的早期观测导致DMHFIP-DMMP为0.010 ± 0.016 pc cm−3。我们的结果表明，DMHFIP-DMMP为0.0127 ± 0.0011 pc cm−3（DMcomp是相应发射分量的DM值），证实了早期使用独立方法的结果。在我们的研究过程中，我们还发现高频间脉冲中单个脉冲的亮度与其DM之间存在关系。我们还讨论了快速射电爆发的情况下的子结构的识别方法的应用。
We investigate the use of bright single pulses from the Crab pulsar to determine separately the dispersion measure (DM) for the Main Pulse and Interpulse components. We develop two approaches using cross-correlation functions (CCFs). The first method computes the CCF of the total intensity of each of the 64 frequency channels with a reference channel and converts the time lag of maximum correlation into a DM. The second method separately computes the CCF between every pair of channels for each individual bright pulse and extracts an average DM from the distribution of all channel-pair DMs. Both methods allow the determination of the DM with a relative uncertainty of better than 10−5 and provide robust estimates for the uncertainty of the best-fit value. We find differences in DM between the Main Pulse, the Low Frequency Interpulse, and the High Frequency Interpulse using both methods in a frequency range from 4 to 6 GHz. Earlier observations of the High Frequency Interpulse carried out by Hankins et al. (2016) resulted in DMHFIP–DMMP of 0.010 ± 0.016 pc cm−3. Our results indicate a DMHFIP–DMMP of 0.0127 ± 0.0011 pc cm−3 (with DMcomp being the DM value of the respective emission component), confirming earlier results with an independent method. During our studies we also find a relation between the brightness of single pulses in the High Frequency Interpulse and their DM. We also discuss the application of the developed methods on the identification of substructures in the case of Fast Radio Bursts.