发表机构
Department of Physics and Astronomy, University of Oregon（俄勒冈大学物理与天文系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用MeerKAT阵列首次直接探测到系外行星$\beta$ Pictoris b的极光射电辐射，识别为电子回旋脉泽辐射，测得磁场强度$\gtrsim 1.25$ kG。
AI 中文摘要
行星磁场塑造大气逃逸，调节与恒星风的相互作用，并编码行星内部的信息，然而对于太阳系以外的行星，它们尚未被直接测量。一个直接的观测特征是电子回旋脉泽不稳定性产生的极光射电辐射，其最高发射频率由源处的磁场强度决定。尽管在太阳系行星和一些超冷矮星中观测到极光射电暴，但此前没有任何射电探测被明确地定位于系外行星而非其宿主恒星。在此，我们报告首次直接探测到来自系外行星——巨行星$\beta$ Pictoris b——的极光射电辐射，使用MeerKAT阵列。我们探测到快速、重复且高度圆偏振的爆发，以及持续辐射，频率为0.85至3.5 GHz。我们将该辐射识别为电子回旋脉泽辐射，这意味着该行星上的磁场强度$\gtrsim 1.25$ kG，这是对系外行星磁场强度的首次直接测量。
英文摘要
Planetary magnetic fields shape atmospheric escape, mediate interactions with stellar winds, and encode information about planetary interiors, yet they have not been directly measured for planets beyond the Solar System. A direct observable signature is auroral radio emission produced by the electron cyclotron maser instability, whose highest emitted frequency is set by the magnetic field strength at its source. Although auroral radio bursts are observed in Solar System planets and in some ultracool dwarfs, no radio detection has previously been unambiguously localized to an extrasolar planet rather than its host star. Here, we report the first direct detection of auroral radio emission from an exoplanet, the giant planet $β$ Pictoris b, with the MeerKAT array. We detect rapid, recurring, and highly circularly polarized bursts, as well as persistent emission, at frequencies of 0.85 to 3.5 GHz. We identify the emission as electron cyclotron maser radiation, which implies a magnetic field of $\gtrsim 1.25$ kG at the planet, the first such direct field strength measurement for an exoplanet.
Comments32 pages, 9 figures, 3 tables. Submitted
