论文标题
GBNCC调查首次发现350 MHz的快速无线电爆发
First Discovery of a Fast Radio Burst at 350 MHz by the GBNCC Survey
论文作者
论文摘要
我们报告了第一次发现了绿色银行北部天体帽(GBNCC)PULSAR调查的FRB 20200125a的快速无线电爆发(FRB),该爆炸是350 MHz的绿色银行望远镜进行的。在58.43度的银河纬度上检测到FRB 20200125a,分散度度为179 pc cm $^{ - 3} $,而电子密度模型则预测最大银河系的贡献为25 pc cm $^{ - 3} $。此外,在该区域的多波长调查中,没有明显的离子气体的明显银河前景来源可见。这认为来源是外层面的。主机银河系的最大红移为$ z_ {max} = 0.17 $,对应于大约750 mpc的最大comoving距离。 FRB 20200125a的测得的峰值密度为0.37 JY,我们测量的脉冲宽度为3.7 ms,与在较高频率下观察到的FRB宽度的分布一致。基于此检测并假设FRB的欧几里得通量密度分布,我们计算出350 MHz的全套速率,$ 3.4^{+15.4} _ { - 3.3} \ times 10^3 $ frbs sky $^{ - 1} $ day $ day $ day $^{ - 1} $ day $^{ - 1} $超过0.42的脉冲,以下是0.42 Jy的脉冲, MS,与较高频率报道的速率一致。鉴于我们的单脉冲搜索管道的最新改进,我们还重新审视了GBNCC对各种爆发特性的敏感性。最后,我们没有发现在FRB 20200125a中散布星际散射的证据,这增加了越来越多的证据表明,某些FRB具有自由无吸收和散射不重要的环形环境。
We report the first discovery of a fast radio burst (FRB), FRB 20200125A, by the Green Bank Northern Celestial Cap (GBNCC) Pulsar Survey conducted with the Green Bank Telescope at 350 MHz. FRB 20200125A was detected at a Galactic latitude of 58.43 degrees with a dispersion measure of 179 pc cm$^{-3}$, while electron density models predict a maximum Galactic contribution of 25 pc cm$^{-3}$ along this line of sight. Moreover, no apparent Galactic foreground sources of ionized gas that could account for the excess DM are visible in multi-wavelength surveys of this region. This argues that the source is extragalactic. The maximum redshift for the host galaxy is $z_{max}=0.17$, corresponding to a maximum comoving distance of approximately 750 Mpc. The measured peak flux density for FRB 20200125A is 0.37 Jy, and we measure a pulse width of 3.7 ms, consistent with the distribution of FRB widths observed at higher frequencies. Based on this detection and assuming an Euclidean flux density distribution of FRBs, we calculate an all-sky rate at 350 MHz of $3.4^{+15.4}_{-3.3} \times 10^3$ FRBs sky$^{-1}$ day$^{-1}$ above a peak flux density of 0.42 Jy for an unscattered pulse having an intrinsic width of 5 ms, consistent with rates reported at higher frequencies. Given the recent improvements in our single-pulse search pipeline, we also revisit the GBNCC survey sensitivity to various burst properties. Finally, we find no evidence of interstellar scattering in FRB 20200125A, adding to the growing evidence that some FRBs have circumburst environments where free-free absorption and scattering are not significant.