PSR B 0540 -69在其持续状态下具有制动指数测量值：n=2.129 \pm 0.012。最近，据报道，它的自旋下降状态发生了变化：自旋下降速率突然增加了36%。结合持续状态制动指数测量和不同的自旋下降状态，PSR B 0540 -69在约束脉冲星自旋下降模型方面比间歇性脉冲星更强大。脉冲星风模型被用来解释PSR B 0540 -69的变时行为。PSR B 0540 -69的持续状态制动指数是磁偶极子辐射和粒子风的综合效应。粒子密度实时反映了磁层的活动，并可能是导致自旋下降行为变化的原因。对应于PSR B 0540 -69的自旋下降速率增加36%，在真空间隙模型中颗粒密度的相对增加为88%。模型计算出新状态下的制动指数为n=1.79。PSR B 0540 -69在新的自旋下降状态下的未来制动指数观测将非常有力地区分不同的脉冲星自旋下降模型和不同的粒子加速模型。PSR J1846-0258的可变定时行为在脉冲星风模型中也是可以理解的。
英文摘要：
PSR B0540-69 has braking index measurement in its persistent state: n=2.129 \pm 0.012. Recently, it is reported to have spin-down state changes: a suddenly 36 % increase in the spin-down rate. Combining the persistent state braking index measurement and different spin-down states, PSR B0540-69 is more powerful than intermittent pulsars in constraining pulsar spin-down models. The pulsar wind model is applied to explain the variable timing behavior of PSR B0540-69. The persistent state braking index of PSR B0540-69 is the combined effect of magnetic dipole radiation and particle wind. The particle density reflects the magnetospheric activity in real-time and may be responsible for the changing spin-down behavior. Corresponding to the 36 % increase in the spin-down rate of PSR B0540-69, the relative increase in the particle density is 88 % in the vacuum gap model. And the model calculated braking index in the new state is n=1.79. Future braking index observation of PSR B0540-69 in the new spin-down state will be very powerful in distinguishing between different pulsar spin-down models and different particle acceleration models in the wind braking scenario. The variable timing behavior of PSR J1846-0258 is also understandable in the pulsar wind model.
On the braking index of the unusual high-B rotation-powered pulsar PSR J1846-0258
PSR J1846-0258是一个跨越磁星和旋转动力磁星之间边界的天体。虽然多年来一直表现为旋转动力的脉冲星，但在2006年，它表现出明显的类似磁铁的行为-发射几个短的硬X射线爆发，通量增加。在这里，我们报告7年后爆发时序观测PSR J1846-0258使用罗西X射线定时探测器和雨燕X射线望远镜。我们测量的制动指数超过后磁星爆发期间是$n=2.19\pm0.03$。这代表了$Δn=-0.46\pm0.03$的变化，或与爆发前制动指数$n=2.65\pm0.01$相差14.5 $\;σ$，后者本身是在6.5年的跨度内测量的。脉冲星制动指数的变化如此之大且持续时间如此之长，是前所未有的，对脉冲星自旋下降模型构成了重大挑战。
On the new braking index of PSR B0540-69: further support for magnetic field growth of neutron stars following submergence by fallback accretion
新生中子星的磁场可以通过快速的回退吸积被淹没在地壳中，并在生命后期扩散到表面。根据这种野外埋藏的情况，年轻的恒星可能有不断增长的磁场，这一过程的制动指数小于三个;制动指数越大，磁场增长的时间尺度就越长。具有较大反冲速度的初生中子星将吸积较少的物质，导致其场的埋藏较浅，场的增长更快。这种从制动指数推断的场增长时间尺度与空间速度之间的反比关系在过去被认为是对场埋情景的预测。在制动指数为$n\sim 2$和大空速的情况下，PSR~ B 0540--69是所要求关系中的异常值。该物体最近过渡到一个快速的自旋下降状态，伴随着低制动指数。这一新的制动指数意味着场增长的时间尺度要短得多，这与物体的高空间速度是一致的，与所要求的关系更好地吻合。这一观察结果支持了野外埋葬的假设，并意味着磁场的增长并不是以恒定的速度进行的，而是有时会减慢或完全停止。在2011年之前，与高制动指数相关的缓慢自旋下降状态持续了至少约30年，当时就是这样一个缓慢场增长的插曲。
The braking index of PSR B0540-69 and the associated pulsar wind nebula emission after spin-down rate transition
2011年12月，PSR B 0540 -69经历了一次自旋下降速率跃迁（SRT），之后脉冲星的自旋下降功率增加了约36%。在SRT之后大约1000天，发现脉冲星风星云（PWN）的X射线亮度变亮了32+/-8%。SRT后，PSR B 0540 -69的制动指数n从n=2.12变为n=0.03，然后保持该值约5年，然后在接下来的几年中上升至n=0.9。我们发现，大多数现有的模型在解释实测制动指数时存在困难。PSR B 0540 -69的制动指数演化的一个例外模型是增加的偶极磁场。我们认为，磁场的增加可能是由于脉冲星核内的某些不稳定性导致的，这些不稳定性以磁场的环向分量为代价增强了极向分量。偶极磁场的增加将导致PWN的X射线增亮。我们通过两种模型拟合PWN的X射线光变曲线：一种模型假设在增亮期间PWN内存在恒定的磁场，另一种模型假设增强的磁场与PWN的能量密度成比例。看起来这两个模型都很好地拟合了数据，尽管后一个模型似乎更好地拟合了数据。这提供了临界观测证据，证明PWN中的磁场是由终止激波产生的。需要未来的高质量和高节奏的数据来得出可靠的结论。
PSR J0537$-$6910 is the most active glitching pulsar with a glitch rate $\sim0.3$ yr $^{-1}$. We have reanalysed 45 glitches of PSR J0537$-$6910 published in the literature and have done post-glitch timing fits within the vortex creep model. Moment of inertia fractions of the superfluid regions participating in glitches are obtained for each event and the model predictions for the inter-glitch time are confronted with the observed time-scales. Similarities and differences with the glitching behaviours of the well studied Crab and Vela pulsars are highlighted. From superfluid recoupling time-sc…
The braking index of PSR J1734-3333 and the magnetar population
PSR J1734-3333是一颗射电脉冲星，其自转周期为P=1.17 s，减速周期导数为Pdot=2.28 x 10^{-12}，在自转脉冲星中排名第三。这些性质介于正常旋转动力中子星和磁星之间，这两种中子星的辐射性质明显不同。在这里，我们报告的PSR J1734-3333的旋转的第二周期导数的测量和计算的制动指数n=0.9 +-0.2。这个值远低于3，即恒定磁偶极子电磁制动的预期值，表明该脉冲星可能很快具有磁星的旋转特性。虽然有几种机制可能导致如此低的制动指数，我们讨论了这一观察结果，以及其他一些高Pdot旋转动力的磁星所表现出的特性，并将其解释为磁星通过无线电脉冲星阶段的可能进化路线的证据，支持这两类物体的统一描述。
Braking index of the frequently glitching PSR J0537$-$6910
School of Arts and Sciences, Qingdao Binhai University（青岛滨海学院文理学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Department of Astronomy and Space Sciences, Istanbul University（伊斯坦布尔大学天文学与空间科学系）；Bahçeşehir College（巴切希尔学院）；Faculty of Engineering and Natural Sciences, Sabancı University（萨班哲大学工程与自然科学学院）；Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester（曼彻斯特大学物理与天文学系乔德雷尔银行天体物理学中心）；Departamento de Física, Universidad de Santiago de Chile (USACH)（圣地亚哥智利大学物理系）
We present timing solutions of PSR B0950+08, using 14 years of observations at Nanshan 26-m Radio Telescope of Xinjiang Astronomical Observatory. The braking index of PSR B0950+08 varies from --367 392 to 168 883, which shows an oscillation with large amplitude ($\sim 10^5$) and uncertainty. Considering the variation of braking indices and the most probable kinematic age of PSR B0950+08, a model withe long-term magnetic field decay modulated by short-term oscillations is proposed to explain the timing data. With this magnetic field decay model, we discuss the spin and thermal evolution of PSR …
We performed deep observations to search for radio pulsations in the directions of 375 unassociated Fermi Large Area Telescope (LAT) gamma-ray sources using the Giant Metrewave Radio Telescope (GMRT) at 322 and 607 MHz. In this paper we report the discovery of three millisecond pulsars (MSPs), PSR J0248+4230, PSR J1207$-$5050 and PSR J1536$-$4948. We conducted follow up timing observations for around 5 years with the GMRT and derived phase coherent timing models for these MSPs. PSR J0248$+$4230 and J1207$-$5050 are isolated MSPs having periodicities of 2.60 ms and 4.84 ms. PSR J1536-4948 is a …
The double pulsar (PSR J0737-3039A/B) provides some of the most stringent tests of general relativity (GR) and its alternatives. The success of this system in tests of GR is largely due to the high-precision, long-term timing of its recycled-pulsar member, pulsar A. On the other hand, pulsar B is a young pulsar that exhibits significant short-term and long-term timing variations due to the electromagnetic-wind interaction with its companion and geodetic precession. Improving pulsar B's timing precision is a key step towards improving the precision in a number of GR tests with PSR J0737-3039A/B…
We present radio observation of a millisecond pulsar PSR J0621+1002 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulsar shows periodic pulse intensity modulations for both the first and the third pulse components. The fluctuation spectrum of the first pulse component has one peak of 3.0$\pm$0.1 pulse periods, while that of the third pulse component has two diffused peaks of 3.0$\pm$0.1 and 200$\pm$1 pulse periods. The single pulse timing analysis is carried out for this pulsar and the single pulses can be divided into two classes based on the post-fit timing resi…
We present analysis of the timing noise in PSR J1733-3716, which combines data from Parkes 64-m radio telescope and nearly 15 years of timing data obtained from the Nanshan 25-m radio telescope. The variations in the spin frequency and frequency derivative are determined. The fluctuation in the spin frequency is obvious with an amplitude of 1.94(7)*10 -9 Hz. Variations of the integrated profile at 1369 MHz are detected with the changes occur in the relative peak intensity from the right profile component. From analysis of the single pulse data at 1382 MHz, we detect weak emission states that a…
The 559 Hz black-widow pulsar PSR J1555-2908, originally discovered in radio, is also a bright gamma-ray pulsar. Timing its pulsations using 12 yr of Fermi-LAT gamma-ray data reveals long-term variations in its spin frequency that are much larger than is observed from other millisecond pulsars. While this variability in the pulsar rotation rate could be intrinsic "timing noise", here we consider an alternative explanation: the variations arise from the presence of a very-low-mass third object in a wide multi-year orbit around the neutron star and its low-mass companion. With current data, this…
Generalized Non-linear Bayesian Pulsar Timing with Enterprise
West Virginia University（西弗吉尼亚大学）；Oregon State University（俄勒冈州立大学）；Cornell University（康奈尔大学）；University of Colorado, Boulder（科罗拉多大学博尔德分校）；Vanderbilt University（范德堡大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）
Improving timing sensitivity in the microhertz frequency regime: limits from PSR J1713$+$0747 on gravitational waves produced by super-massive black-hole binaries
We report the discovery of PSR J1555-2908, a 1.79 ms radio and gamma-ray pulsar in a 5.6 hr binary system with a minimum companion mass of 0.052 $M_\odot$. This fast and energetic ($\dot E = 3 \times 10^{35}$ erg/s) millisecond pulsar was first detected as a gamma-ray point source in Fermi LAT sky survey observations. Guided by a steep spectrum radio point source in the Fermi error region, we performed a search at 820 MHz with the Green Bank Telescope that first discovered the pulsations. The initial radio pulse timing observations provided enough information to seed a search for gamma-ray pul…
New and updated timing models for seven young energetic X-ray pulsars, including the Big Glitcher PSR J0537-6910
Haverford College（哈弗福德学院）；Space Research Organisation Netherlands（荷兰空间研究组织）；Universidad de Santiago de Chile (USACH)（智利圣地亚哥大学）；Center for Interdisciplinary Research in Astrophysics and Space Sciences (CIRAS), Universidad de Santiago de Chile（智利圣地亚哥大学天体物理与空间科学跨学科研究中心）；IRAP, CNRS（法国国家科学研究中心天体物理学研究所）；Université de Toulouse, CNES, UPS-OMP（图卢兹大学、法国国家空间研究中心、 ups-omp）；X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center（NASA戈达德太空飞行中心X射线天体物理实验室）；Theoretical Division, Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室理论部）；Columbia Astrophysics Laboratory, Columbia University（哥伦比亚大学天体物理实验室）
We report on radio timing observations of the black widow binary pulsar J0610$-$2100 and optical observations of its binary companion. The radio timing observations extend the timing baseline to 16yr and reveal a marginal detection of the orbital period derivative, but they show no significant evidence of orbital variations such as those seen in other black widow pulsars. Furthermore, no eclipses are seen in the observations at observing frequencies ranging from 310 to 2700MHz. The optical VRI light curves were modulated with the orbital period, reaching maximum brightness of $V=26.8$, $R=25.4…
