A unique filament is identified in the {\it Herschel} maps of the Orion A giant molecular cloud. The filament, which, we name the Stick, is ruler-straight and at an early evolutionary stage. Transverse position-velocity diagrams show two velocity components closing in on the Stick. The filament shows consecutive rings/forks in C$^{18}$O(1-0) channel maps, which is reminiscent of structures generated by magnetic reconnection. We propose that the Stick formed via collision-induced magnetic reconnection (CMR). We use the magnetohydrodynamics (MHD) code Athena++ to simulate the collision between two diffuse molecular clumps, each carrying an anti-parallel magnetic field. The clump collision produces a narrow, straight, dense filament with a factor of $>$200 increase in density. The production of the dense gas is seven times faster than free-fall collapse. The dense filament shows ring/fork-like structures in radiative transfer maps. Cores in the filament are confined by surface magnetic pressure. CMR can be an important dense-gas-producing mechanism in the Galaxy and beyond.

中文翻译：

---

CARMA-NRO 猎户座调查：通过碰撞诱导的磁重联形成细丝——猎户座 A 中的棒

在猎户座 A 巨型分子云的 {\it Herschel} 图中确定了一种独特的细丝。细丝，我们称之为棒，是直尺直的，处于早期进化阶段。横向位置-速度图显示两个速度分量接近棒。细丝在 C$^{18}$O(1-0) 通道图中显示出连续的环/叉，这让人想起磁重联产生的结构。我们建议通过碰撞诱导磁重联（CMR）形成棒。我们使用磁流体动力学 (MHD) 代码 Athena++ 来模拟两个扩散分子团块之间的碰撞，每个分子团块都带有一个反平行磁场。团块碰撞产生窄、直、致密的细丝，密度增加 200 美元以上。密集气体的产生比自由落体坍塌快七倍。密集的细丝在辐射传输图中显示出环状/叉状结构。灯丝中的芯受到表面磁压的限制。CMR 可能是银河系及其他地区的一种重要的致密气体产生机制。