Approximately 8% of the $\sim$2800 known pulsars exhibit "nulling," a temporary broadband cessation of normal pulsar emission. Nulling behaviour can be coarsely quantified by the nulling fraction, which describes the percentage of time a given pulsar will be found in a null state. In this paper, we perform the most thorough statistical analysis thus far of the properties of 141 known nulling pulsars. We find weak, non-linear correlations between nulling fraction and pulse width, as well as nulling fraction and spin period which could be attributed to selection effects. We also further investigate a recently-hypothesized gap at 40% nulling fraction. While a local minimum does exist in the distribution, we cannot confirm a consistent and unique break in the distribution when we investigate with univariate and multivariate clustering methods, nor can we prove the existence of two statistically distinct populations about this minimum. Using the same methods, we find that nulling pulsars are a statistically different population from normal, radio, non-nulling pulsars, which has never been quantitatively verified. In addition, we summarize the findings of the prior nulling pulsar statistics literature, which are notoriously contradictory. This study, in context, furthers the idea that nulling fraction alone does not contain enough information to describe the behaviour of a nulling pulsar and that other parameters such as null lengths and null randomness, in addition to a better understanding of selection effects, are required to fully understand this phenomenon.
FAST Pulsar Database III. Snapshots of nulling, mode-changing and subpulse modulation of 374 pulsars
National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);School of Astronomy and Space Science, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院);State Key Laboratory of Radio Astronomy and Technology(射电天文学与技术国家重点实验室)
Institute of Optoelectronic Technology, Lishui University(丽水大学光电技术研究所);School of Computer Science and Engineering, Sichuan University of Science and Engineering(四川理工学院计算机科学与工程学院);Xinjiang Astronomical Observatory, Chinese Academy of Sciences(中国科学院新疆天文台);University of Chinese Academy of Sciences(中国科学院大学)
A new model for nulling and moding in radio pulsars
射电望远镜的单脉冲行为通常用射电波束的ExB漂移来解释。结果表明,射电亮区的反对称排列可以产生几种观测到的单脉冲现象:子脉冲调制相位的半周跳变、左-右-中间子脉冲序列以及核心主导和锥主导脉动模式之间的切换。几何体也可以产生零化,包括零星的和多模态的。该模型意味着,无线电安静间隔,分离主脉冲和脉冲间PSR B 0826 -34对应于无线电波束的方位角休息,而不是余纬度休息。
脉冲星零化是脉冲发射突然停止若干周期的现象。零化分数常被用来表征这种现象。提出了一种分析脉冲星零陷现象的新方法,该方法引入了两个关键参数:零陷度$χ$和零陷尺度$ N $,零陷度定义为零陷周期和爆发周期在直角坐标系中的夹角,零陷尺度定义为连续零陷周期和爆发周期的有效长度.调零程度$χ$可以通过$\tan χ= N_{\rm nulling} / N_{\rm bursting} $计算,并且平均值与调零分数相关,而调零尺度$ N $也是新定义的基本参数,其指示调零发生的频率。本文利用文献资料测定了10个标本的$χ$和$ N $的分布。我们发现零化度$χ$表示零化与爆发的相对长度,零化尺度$ N $与旋转频率的导数有关,从而与恒星旋转能量的损失率有关。它们的偏差反映了调零过程的随机性。
Institute for Gravitational Wave Astronomy and School of Physics and Astronomy, University of Birmingham(伯明翰大学引力波天文研究所与物理天文学学院);Quantum Formatics(量子计算公司);Department of Physics and Astronomy, West Virginia University(西弗吉尼亚大学物理与天文学系);Center for Gravitational Waves and Cosmology, West Virginia University(西弗吉尼亚大学引力波与宇宙学中心);Department of Physics, Indian Institute of Science Education and Research Bhopal(印度科学教育研究学院博帕尔分校物理系)
The Thousand-Pulsar-Array programme on MeerKAT XIX: Single-pulse data analysis, nulling and pulse energy distributions
University of Manchester(曼彻斯特大学);University of Southampton(南安普顿大学);University of Cambridge(剑桥大学);University of Oxford(牛津大学);ASTRON, the Netherlands Institute for Radio Astronomy(荷兰射电天文研究所);CSIRO(澳大利亚联邦科学与工业研究组织)
Single-Pulse Study of the Pseudo-nulling Pulsar PSR J1820-0509 Based on FAST Observations
Guizhou Normal University(贵州师范大学);Huazhong University of Science and Technology(华中科技大学);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);Tsinghua University(清华大学);Beijing Normal University(北京师范大学);Qilu Normal University(齐鲁工业大学)
The ONs and OFFs of Pulsar Radio Emission: Characterizing the Nulling Phenomenon
International Centre for Radio Astronomy Research, Curtin University(国际射电天文研究中心,科廷大学);Australian SKA Regional Centre (AusSRC), Curtin University(澳大利亚SKA区域中心(AusSRC),科廷大学)
A study of periodic nulling in PSR B0751+32 with FAST
State Key Laboratory of Radio Astronomy and Technology, Xinjiang Astronomical Observatory, CAS(中国科学院新疆天文台);Xinjiang Key Laboratory of Radio Astrophysics(新疆射电天体物理重点实验室)
我们调查的无线电发射行为的PSR B 0823 +26,脉冲星,这是已知的经历脉冲零化,使用153-d的密集序列的观测。脉冲星被发现表现出短期(~min)和异常长期(~小时或更长时间)的零,这不仅表明该源具有零时标的分布,但它也可能提供了一个传统的零脉冲星和长期间歇脉冲星之间的联系。尽管在脉冲星射电辐射中看到了周期性的证据,但由于观测采样对周期性分析的影响,我们不确定它们是否是源所固有的。值得注意的是,我们发现的证据表明,脉冲星可能会经历预点火期间的“发射闪烁”,即无线电(活跃)和无线电(空)发射状态之间的快速变化,然后过渡到一个稳定的无线电发射阶段。我们没有发现直接的证据表明,该对象表现出任何变化的自旋下降率之间的无线电发射模式和关闭。然而,我们确实将模拟中的这种变化的上限设定为<= 6%。这表明,停止发射的恒星并不一定会导致大的变化,自旋下降率。此外,我们表明,这种变化的自旋下降率将不会在大多数对象表现出短期(<= 1天)的发射停止是可辨别的。据此,我们预测许多类星体可能具有与PSR B 0823 +26类似的磁层和发射特性,但尚未被观测到。
The Three Discrete Nulling Timescales of PSR J1717-4054
PSR J1717-4054是在中间(~小时)时间尺度上无效的小类雷达之一。这类双极星代表了经典零化星和间歇性双极星之间的重要联系,前者的发射在几个旋转周期内消失,后者则会持续数月甚至数年。利用Parkes射电望远镜和澳大利亚望远镜紧凑阵,我们研究了PSR J1717-4054在单脉冲到数年的时间间隔内的发射。我们已经确定和特点零在三个离散的时间尺度:脉冲星发射在“活动状态”期间由零持续数千次旋转,而活动状态本身被中断的零与双峰分布的持续时间;一到两个旋转,或数十次旋转。我们没有检测到子脉冲结构或通量密度变化在活跃状态,我们把严格的限制(<0.1%的平均活跃通量密度)的脉冲发射在非活跃状态。最后,我们的高质量数据还使我们能够首次测量PSR J1717-4054的许多重要特性,包括它的位置,自旋下降率,光谱,偏振特性和脉冲展宽在星际介质中。
Mining the time axis with TRON - III. Discovery of a nulling pulsar towards the SMC with MeerKAT
Centre for Radio Astronomy Techniques and Technologies (RATT), Department of Physics and Electronics, Rhodes University(罗德岛大学物理与电子学院射电天文技术与理论中心);South African Radio Astronomy Observatory(南非射电天文观测台);High Energy Physics, Cosmology & Astrophysics Theory (HEPCAT) Group, Department of Mathematics and Applied Mathematics, University of Cape Town(开普敦大学数学与应用数学系高能物理、宇宙学与天体物理学理论组);Department of Astronomy, University of Cape Town(开普敦大学天文学系);Institute for Radioastronomy, National Institute of Astrophysics (INAF IRA)(国家天体物理研究所射电天文研究所);Astrophysics, Department of Physics, University of Oxford(牛津大学物理系天体物理学);Breakthrough Listen, Astrophysics, Department of Physics, University of Oxford(突破聆听计划牛津大学物理系天体物理学)
Pulsar B1237+25 at 111~MHz: average profile, mode switching, nullings, microstructure
Astrospace Center, Lebedev Physical Institute, Astro Space Center, Russian Academy of Science, Moscow,117997 Russia;Lebedev Physical Institute, Astro Space Center, Pushchino Radio Astronomy Observatory, 142290, Moscow region, Pushchino, Russia
RRAT J1541+4703: A Rotating Radio Transient Exhibiting Normal Pulsar States
Guizhou Normal University(贵州师范大学);Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing, Guizhou Normal University(贵州师范大学贵州省射电天文与数据处理重点实验室);Guizhou University(贵州大学);School of Physics and Electronic Science, Guizhou Normal University(贵州师范大学物理与电子科学学院);Guizhou Radio Astronomical Observatory(贵州射电天文观测台);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台)
Discovery of Hidden Extragalactic Pulsars in the Parkes Archival Data
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)(马克斯·普朗克引力物理研究所(爱因斯坦研究所));Leibniz Universität Hannover(汉诺威莱布尼茨大学);Center for Gravitation, Cosmology, and Astrophysics, Department of Physics and Astronomy, University of Wisconsin-Milwaukee(威斯康星大学密尔沃基分校物理与天文学系引力、宇宙学和天体物理学中心);Centre for Astrophysics and Supercomputing, Swinburne University of Technology(斯威本科技大学天体物理学与超级计算中心);Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav)(澳大利亚研究理事会引力波发现卓越中心(OzGrav));Department of Physics and Astronomy, Franklin and Marshall College(富兰克林和马歇尔学院物理与天文学系);Department of Physics and Astronomy, West Virginia University(西弗吉尼亚大学物理与天文学系);Center for Gravitational Waves and Cosmology, West Virginia University(西弗吉尼亚大学引力波与宇宙学中心);School of Engineering, Murray State University(默里州立大学工程学院)