发表机构
INAF-Osservatorio Astrofisico di Catania; California Institute of Technology; Jet Propulsion Laboratory（意大利国家天体物理研究所卡塔尼亚天文台; 加州理工学院; 喷气推进实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究超冷矮星和褐矮星磁层中等离子体的来源，通过间接方法估算磁层等离子体质量流并应用于LSR J1835+3259，发现电离层流出和火山卫星都是可行来源，且火山卫星情况与相关发现同步。
AI 中文摘要
超冷矮星和褐矮星在~GHz频率的射电辐射表明存在类似木星的辐射带。我们研究了主星推断的磁层等离子体是由活跃行星或通过模拟为弱电离层流出的离子逃逸产生的可能性。考虑从极光射电辐射估计磁层等离子体质量流的间接方法并应用于超冷矮星LSR J1835+3259。发现如果电离层有效佩德森电导率低于~0.02姆欧，电离层流出是10^5 kg s^-1量级的可行来源。另一方面，一颗与木卫一质量和半径相同、半长轴低于约10个恒星半径、偏心率（e~10^-3）由系统中其他行星的扰动维持的潮汐加热火山卫星，被发现是磁层等离子体的可行来源，对电离层电导率没有严格限制。火山卫星的情况也与最近的发现自然同步，即有遥远次恒星或恒星伴星的超冷矮星作为射电发射体被探测到的可能性显著更高。
英文摘要
Radio emissions at $\sim$ GHz frequencies of ultra-cool dwarf and brown dwarf stars suggest the presence of radiation belts not unlike Jupiter's. We investigate the possibility the inferred magnetospheric plasma at the primary star is sourced by an active planet or via ion escape modeled as a weak ionospheric outflow. We consider indirect methods to estimate the magnetospheric plasma mass flow from auroral radio emission and apply them to the ultra-cool dwarf LSR J1835+3259. We find that an ionospheric outflow is a viable source of the order of $10^{5}$ kg s$^{-1}$, if the ionospheric effective Pedersen conductance is lower than $\sim 0.02$ mho. On the other hand, a tidally-heated volcanic satellite with the same mass and radius as Io and an orbit with a semimajor axis lower than about $10$ stellar radii, whose eccentricity ($e \sim 10^{-3}$) is maintained by perturbations by other planets in the system, is found to be a viable source of magnetospheric plasma without strong limitations on the ionospheric conductance. The volcanic satellite scenario is also naturally in sync with the recent finding that ultra-cool dwarfs with distant substellar or stellar companions are remarkably more likely to be detected as radio emitters.
Comments12 pages, 4 pages of Appendixes, 4 figures, 3 tables; accepted by A&A - changes from previous version: final corrections and additions to mirror the version accepted by the Journal
