论文标题
部分可观测时空混沌系统的无模型预测
A comprehensive observational study of the FRB 121102 persistent radio source
论文作者
论文摘要
FRB 121102是与持续无线电源（QRS121102）在空间上关联的第一个快速无线电爆发源，其性质仍然未知。我们提出了QRS121102及其宿主星系的详细观察性研究。我们通过测量QRS121102的物理大小来测量其磁通密度的变异性与KU波段（12至18 GHz）和K频段（18至26 GHz）中的VLA的变化。任何此类变异性都可能是由于银河折射闪烁引起的，并且在宿主 - 果胶红移处的源半径<10^17 cm。我们发现无线电的可变性低于如此小的来源的闪烁理论预测，这为QRS121102非AGN模型的可能性打开了。此外，我们使用来自凯克天文台的中分辨率光谱频谱从Hα射出线的宽度中大致估算了与QRS121102相关的任何潜在超质量黑洞（SMBH）的质量。线宽度的速度分散<30 km/s，表明SMBH质量<10^{4〜5} m_sun。如果QRS121102是AGN，我们发现SMBH质量对于观察到的无线电发光度太低，而X射线发光度限制为X射线光度限制。最后，在与伴随系统的潮汐相互作用期间，一些载有SMBH的矮星系可能是大规模星系的堆芯。我们在与低分辨率Keck Spectra或Panstarrs目录中的QRS121102主机相同的红移中没有发现附近的星系。总之，我们没有发现支持以下假设：与FRB 121102相关的持续无线电源是AGN的假设。相反，我们认为推断的尺寸和平坦的无线电频谱有利于一种解释。我们敦促继续对QRS121102进行宽带无线电监控，以搜索长期演变，并且对潜在类似物的详细评估可能会提供对该类别对象本质的更深入的洞察力。
FRB 121102 is the first fast radio burst source to be spatially associated with a persistent radio source (QRS121102), the nature of which remains unknown. We present a detailed observational study of QRS121102 and its host galaxy. We constrain the physical size of QRS121102 by measuring its flux-density variability with the VLA in the Ku-band (12 to 18 GHz) and the K-band (18 to 26 GHz). Any such variability would likely be due to Galactic refractive scintillation and would require the source radius to be <10^17 cm at the host-galaxy redshift. We found the radio variability to be lower than the scintillation theory predictions for such a small source, leaving open the possibility for non-AGN models for QRS121102. In addition, we roughly estimated the mass of any potential supermassive black hole (SMBH) associated with QRS121102 from the width of the Hαemission line using a medium-resolution optical spectrum from the Keck Observatory. The line width gives a velocity dispersion of <30 km/s, indicating a SMBH mass of <10^{4~5} M_sun. We find the SMBH mass too low for the observed radio luminosity, and X-ray luminosity constraints, if QRS121102 were an AGN. Finally, some dwarf galaxies that host SMBH may be the stripped cores of massive galaxies during the tidal interactions with companion systems. We find no nearby galaxy at the same redshift as the QRS121102 host from low-resolution Keck spectra, or from the PanSTARRS catalog. In conclusion, we find no evidence supporting the hypothesis that the persistent radio source associated with FRB 121102 is an AGN. We instead argue that the inferred size, and the flat radio spectrum, favors a plerion interpretation. We urge continued broadband radio monitoring of QRS121102 to search for long-term evolution, and the detailed evaluation of potential analogs that may provide greater insight into the nature of this class of object.
