AI 中文总结
本研究以 NGC 4438 为对象，通过多波段分析明确 AGN 驱动气泡的能量分配随尺度的变化，发现小尺度核区气泡与大尺度外流的喷流功率关联存在差异，揭示了 AGN 反馈的尺度依赖性。
AI 中文摘要
由吸积超大质量黑洞产生的喷流是活动星系核（AGN）反馈的主要模式，但其能量在整体动能、热气体、磁场、宇宙射线（CR）和辐射之间的分配方式，以及这种分配如何随空间尺度变化，目前仍知之甚少。NGC 4438 为研究这种演化提供了独特的实验室，它拥有两个 200 秒差距（pc）尺度的核区气泡，以及一个可能与同一 AGN 相关的、不对称的约 10 千秒差距（kpc）星系尺度外流。我们开展多波段分析，以研究这些结构的形态、辐射机制和能量学。射电-X 射线联合建模显示，核区气泡中的非热辐射可能需要两类不同的宇宙射线电子，这表明除了气泡边缘的激波加速外，最高能粒子可能与更靠近未分辨中心引擎的加速过程相关。空间分辨的能量清单显示，整体动能主导核区气泡当前的能量预算，而约一半的注入能量已转化为热能、宇宙射线能、磁能以及辐射损失。在所有气泡尺度上，热压力和磁压力在不确定度范围内一致，意味着磁场在所有研究的空间尺度上仍具有动力学重要性。此外，千秒差距尺度喷流气泡的射电光度与喷流功率之间的经验关联（Merloni-Heinz 2007），与星系尺度外流的能量学匹配，但会显著高估 200 pc 尺度核区气泡的功率，凸显了喷流能量耗散的尺度依赖性。
英文摘要
Jets launched by accreting supermassive black holes represent a major mode of active galactic nucleus (AGN) feedback. However, how their energy is divided among bulk kinetic motion, thermal gas, magnetic fields, cosmic rays (CRs), and radiation - and how this distribution changes with spatial scale - remains poorly constrained. NGC 4438 provides a unique laboratory for probing this evolution, hosting two 200-pc-scale nuclear bubbles and a lopsided ~10 kpc galaxy-scale outflow plausibly associated with the same AGN. We present a multi-wavelength analysis to investigate the morphology, radiation mechanisms, and energetics of these structures. Joint radio-X-ray modeling shows that the non-thermal emission in the nuclear bubbles may require two distinct populations of cosmic-ray electrons, suggesting that in addition to shock acceleration at the bubble rim, the highest-energy particles may be linked to acceleration processes closer to the unresolved central engine. A spatially resolved energy inventory reveals that bulk kinetic energy dominates the current energy budget of the nuclear bubbles, while roughly half of the injected energy has already been transformed into thermal, CR, and magnetic energy, as well as radiative losses. Across all bubble sizes, the thermal and magnetic pressures are consistent within the uncertainties, implying that magnetic fields remain dynamically significant on all examined spatial scales. Furthermore, the empirical correlation between radio luminosity and jet power, established for kiloparsec-scale jet bubbles (MerloniHeinz2007), matches the energetics of the galaxy-scale outflow but substantially overestimates the power of the 200-pc-scale nuclear bubbles, underscoring the scale dependence of jet energy dissipation.
Comments20 pages, 7 figures, Accepted by ApJ, comments welcome
