Microquasars, the local siblings of extragalactic quasars, are binary systems comprising a compact object and a companion star. By accreting matter from their companions, microquasars launch powerful winds and jets, influencing the interstellar environment around them. Steady gamma-ray emission is expected to rise from their central objects, or from interactions between their outflows and the surrounding medium. The latter prediction was recently confirmed with the detection of SS 433 at high (TeV) energies¹. In this report, we analyse more than ten years of gigaelectronvolt gamma-ray data from the Fermi Gamma-ray Space Telescope on this source. Detailed scrutiny of the data reveal emission in the vicinity of SS 433, co-spatial with a gas enhancement, and hints of emission possibly associated with a terminal lobe of one of the jets. Both gamma-ray excesses are relatively far from the central binary, and the former shows evidence of a periodic variation at the precessional period of SS 433, linking it with the microquasar. This result challenges obvious interpretations and is unexpected from previously published theoretical models. It provides us with a chance to unveil the particle transport from SS 433 and to probe the structure of the magnetic field in its vicinity.

微类星体是银河系类星体的本地同胞，是由一个紧凑的物体和一个伴星组成的双星系统。微类星体通过从同伴身上吸收物质，发射出强大的风和喷射流，影响着它们周围的星际环境。预计会从其中心物体或它们的流出物与周围介质之间的相互作用中产生稳定的伽马射线发射。最近通过在高（TeV）能量下检测到SS 433证实了后者的预测¹。在此报告中，我们分析了费米伽马射线太空望远镜在此源上十多年的千兆电子伽马射线数据。对数据的详细检查显示，SS 433附近的发射与气体增强同空间，并且可能与其中一个喷头的末端波瓣相关。两种伽玛射线的超额距离中心双星都相对较远，前者显示出SS 433进动期间周期性变化的证据，并将其与微类星体联系起来。这一结果挑战了显而易见的解释，这是以前发表的理论模型所无法预料的。它为我们提供了揭示SS 433的粒子传输并探究其附近磁场结构的机会。