We present the first observations of in situ electron acceleration at corotating interaction region (CIR) shocks near 1 au, utilizing measurements from Wind and Magnetospheric Multiscale (MMS) mission in the interplanetary medium. As the forward (reverse) shock of the 2018 January CIR (the 2020 February CIR) moves from Wind at [206, 92, −7]R _E ([257, 25, 3]R _E ) to MMS1 at [24, 2, 7]R _E ([25, 3, 0.5]R _E ), the shock’s thickness becomes 8 (3) times thinner, but the convective electric field E _drift gets weaker (stronger) along the shock; both the upstream and shocked suprathermal electrons exhibit a flatter flux energy spectrum, while the electron shock acceleration becomes less (more) significant. For the shocked suprathermal electrons with significant flux enhancement, the flux ratio across the shock appears to peak in the direction perpendicular to the magnetic field. Therefore, the CIR shock acceleration of solar wind suprathermal electrons at 1 au exhibits an efficiency increasing with the E _drift strength. These results also suggest that such acceleration through the interplanetary medium can contribute to the formation of solar wind suprathermal electrons.

中文翻译：

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1 au 下共旋转相互作用区域激波的电子加速演化

我们利用行星际介质中风和磁层多尺度 (MMS) 任务的测量结果，首次观测到 1 天文单位附近的同转相互作用区 (CIR) 激波处的原位电子加速。随着 2018 年 1 月 CIR（2020 年 2 月 CIR）的正向（反向）冲击从 Wind 移动到 [206, 92, -7]右 _乙 （[257,25,3]右 _乙 ) 至 [24, 2, 7] 处的 MMS1右 _乙 ([25, 3, 0.5]右 _乙 ），激波的厚度变薄了 8 (3) 倍，但对流电场 乙 _漂移沿激波变弱（变强）；上游和冲击的超热电子都表现出更平坦的通量能谱，而电子冲击加速度变得不那么（更）显着。对于具有显着通量增强的激波超热电子，激波上的通量比似乎在垂直于磁场的方向上达到峰值。因此，太阳风超热电子在 1 au 下的 CIR 激波加速表现出效率随着 乙 _漂移强度。这些结果还表明，这种通过行星际介质的加速可能有助于太阳风超热电子的形成。