论文标题
将突破性聆听附近的星星调查扩展到现场的其他恒星对象
Extending the Breakthrough Listen nearby star survey to other stellar objects in the field
论文作者
论文摘要
我们扩展了通过包括其他恒星（由Gaia测得的视差）以及GBT和Parkes射程望远镜目标场内的其他恒星（由Gaia测得的视差），扩展了最近观察到的源样本。这些恒星估计距离Gaia DR2目录的扩展中列出的距离。将样品从1327扩大到288315恒星对象使我们能够获得比以前的任何分析更好地取得更好的连续波形发射器发射器速率（CWTFM），并且使我们能够对附近的高衰老周期外发射器的普遍性置于最紧密的限制。结果表明$ \ lyssim 0.0660^{+0.0004} _ { - 0.0003} $％的恒星系统在50个PC主机内（假设EIRP $ \ gtrsim 10^{13} $ W）和$ \ $ \ $ \ lyssim 0.039^{+0.004}^{+0.004}^{+0.004} _} $ \ gtrsim 2.5 \ times 10^{14} $ w）。我们进一步将分析扩展到更大的距离，尽管我们警告说，检测到几百个PC以外的窄带信号可能会受到星际闪烁的影响。扩展的样本还允许我们对恒星类型和光谱类别的外星发射器的流行构成新的约束。我们的结果表明，对SETI无线电数据的有针对性分析可以从考虑到野外中心的目标之外的事实中受益，许多其他宇宙对象还位于抛物线射电望远镜的主要光束响应中。这些包括前景和背景银河星，但还包括乳清外系统。通过Gaia测得的距离，这些其他来源可用于对外星发射器的流行率提高限制，并将分析扩展到广泛的宇宙对象。
We extend the source sample recently observed by the Breakthrough Listen Initiative by including additional stars (with parallaxes measured by Gaia) that also reside within the FWHM of the GBT and Parkes radio telescope target fields. These stars have estimated distances as listed in the extensions of the Gaia DR2 catalogue. Enlarging the sample from 1327 to 288315 stellar objects permits us to achieve substantially better Continuous Waveform Transmitter Rate Figures of Merit (CWTFM) than any previous analysis, and allows us to place the tightest limits yet on the prevalence of nearby high-duty-cycle extraterrestrial transmitters. The results suggest $\lesssim 0.0660^{+0.0004}_{-0.0003}$% of stellar systems within 50 pc host such transmitters (assuming an EIRP $ \gtrsim 10^{13}$ W) and $\lesssim 0.039^{+0.004}_{-0.008}$% within 200 pc (assuming an EIRP $\gtrsim 2.5 \times 10^{14}$ W). We further extend our analysis to much greater distances, though we caution that the detection of narrow-band signals beyond a few hundred pc may be affected by interstellar scintillation. The extended sample also permits us to place new constraints on the prevalence of extraterrestrial transmitters by stellar type and spectral class. Our results suggest targeted analyses of SETI radio data can benefit from taking into account the fact that in addition to the target at the field centre, many other cosmic objects reside within the primary beam response of a parabolic radio telescope. These include foreground and background galactic stars, but also extragalactic systems. With distances measured by Gaia, these additional sources can be used to place improved limits on the prevalence of extraterrestrial transmitters, and extend the analysis to a wide range of cosmic objects.
