FRB 121102：无超新星（supernova）样抛射物或磁陀星（magnetar）驱动，暗示其源于白矮星（white dwarf）双星并合

本文通过对重复快速射电暴 FRB 121102 的频散量（dispersion measure）及相关射电源（radio source）的射电观测（radio observation）分析，对其中心能源（energy source）进行了严格限制。研究结果表明，该源的特征与典型的超新星抛射物（supernova ejecta）不符，并指出白矮星双星并合可能是其前身系统。

arXiv:2608.26567v1 Announce Type: new Abstract: We use measurements of the time-dependent dispersion measure of the repeating FRB 121102, together with earlier radio observations of its associated persistent radio source (PRS), to derive stringent constraints on its underlying ``engine.'' The energy held by the relativistic PRS plasma is $>10^{49.5}$ erg, and its age is $\approx60$ yr, corresponding to an underlying source power exceeding $10^{40}$ erg s$^{-1}$. If the underlying source is a neutron star, this implies a rotational rather than a magnetic energy source, consistent with a $\sim10$ ms, $\sim10^{12.5}$ G neutron star. Alternatively, accretion may also be a viable energy source. The velocity and the kinetic energy of the cold plasma confining the relativistic PRS plasma are inconsistent with it being typical supernova ejecta (unless a significant fraction of the ejecta mass is carried by high-density clumps of $\approx10^{-2.5}$ fractional size)- its expansion speed is limited to a few hundred km/s, which also implies that it was ejected from the source more than $\approx 10^3$ yr preceding the onset of relativistic PRS plasma emission. These constraints may be satisfied by a white dwarf binary merger progenitor system, where a fraction of a solar mass was ejected at a slow speed