FAST长周期脉冲星的计时、偏振与单脉冲特性
Timing, Polarization, and Single-Pulse Properties of Long-Period FAST Pulsars
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中文总结 AI 辅助
该研究对5颗FAST-CRAFTS长周期脉冲星开展计时、偏振与单脉冲分析，明确其发射态类型、明亮脉冲特征及散射时标，揭示慢旋转中子星磁层变异性的多样性。
中文摘要 AI 辅助
我们对两颗FAST-CRAFTS长周期脉冲星——PSR J0000+6252和PSR J2131+3642开展了相位连接的计时与偏振测量，并将单脉冲发射态分析扩展至包含PSR J1903+1407、PSR J1502+4653和PSR J2112+4058的五源样本。FAST L波段计时基线跨度为414至511天；这两颗脉冲星的自转周期为1.11至1.55秒，周期导数为(3.99至4.06)×10^-15 s·s^-1，特征年龄为4.34至6.16百万年，表面磁场强度为(2.15至2.52)×10^12高斯，自转减速光度为(4.21×10^31至1.16×10^32)尔格·秒^-1。它们的旋转测量值分别为70.2±26.7和-44.6±7.6 rad·m^-2，线偏振度为17.6%至27.2%。PSR J2131+3642呈现出一段短的单调偏振角（PA）序列，可进行形式上的旋转矢量模型拟合，但经度覆盖有限导致几何参数约束较差；PSR J0000+6252的偏振角点数过少，无法进行此类拟合。对单脉冲能量分布的高斯混合模型（GMM）分析，在PSR J0000+6252、PSR J1903+1407、PSR J1502+4653和PSR J2112+4058中识别出零、弱和爆发成分，而J2131+3642仅呈现弱和爆发态。我们还识别出明亮单脉冲（峰值强度≥积分平均轮廓的10倍）：J0000+6252中有42个，J1903+1407和J2112+4058中各有4个，J2131+3642和J1502+4653中无此类脉冲。这些明亮脉冲均出现在主发射窗口内，无周期性重现迹象，符合正常射电发射束的 sporadic增强特征。对于PSR J2112+4058，我们在参考频率ν_ref=1.25 GHz处测得散射时标τ_sc=5.84±0.18毫秒。综上，这些结果凸显了慢旋转中子星磁层变异性的多样性。
英文摘要
We present phase-connected timing and polarization measurements for two long-period FAST-CRAFTS pulsars, PSRs J0000+6252 and J2131+3642, and extend single-pulse emission-state analysis to a five-source sample including PSRs J1903+1407, J1502+4653, and J2112+4058. FAST L-band timing baselines span 414 to 511 days; the two pulsars have spin periods of 1.11 to 1.55 s, period derivatives of $(3.99$ to $4.06)\times10^{-15}~{\rm s~s^{-1}}$, characteristic ages of 4.34 to 6.16 Myr, surface magnetic fields of $(2.15$ to $2.52)\times10^{12}$ G, and spin-down luminosities of $(4.21\times10^{31}$ to $1.16\times10^{32})~{\rm erg~s^{-1}}$. Their rotation measures are $70.2\pm26.7$ and $-44.6\pm7.6~{\rm rad~m^{-2}}$, with linear polarization fractions of 17.6\% to 27.2\%. PSR J2131+3642 shows a short monotonic PA segment permitting a formal rotating-vector-model fit, though limited longitude coverage leaves the geometric parameters poorly constrained; PSR J0000+6252 has too few PA points for such a fit. Gaussian mixture modeling (GMM) of single-pulse energy distributions identifies null, weak, and burst components in PSRs J0000+6252, J1903+1407, J1502+4653, and J2112+4058, while J2131+3642 shows only weak and burst states. We also identify bright single pulses (peak intensity $\geq10\times$ the integrated average profile): 42 in J0000+6252, four each in J1903+1407 and J2112+4058, and none in J2131+3642 or J1502+4653. These bright pulses occur within the main emission window with no evidence of periodic recurrence, consistent with sporadic enhancements of the normal radio-emission beam. For J2112+4058, we measure a scattering timescale $τ_{\rm sc}=5.84\pm0.18$ ms at $ν_{\rm ref}=1.25$ GHz. Together, these results highlight the diversity of magnetospheric variability among slowly rotating neutron stars.
