The relationship between galaxies and their supermassive black holes (SMBHs) is an area of active research. One way to investigate this relationship is to compare parsec-scale jets formed by SMBHs to the projected shape of their kiloparsec-scale host galaxies. Here we analyse very-long-baseline interferometry (VLBI) images of active galactic nuclei (AGNs) and optical images of their host galaxies by comparing the inner-jet position angle in VLBI-detected radio sources with the optical shapes of galaxies as measured by several large optical surveys. In total, 6,273 galaxy–AGN pairs were found. We carefully account for the systematics of the cross-matched sources and find that Dark Energy Spectroscopic Instrument Legacy Imaging Surveys (DESI LS) data are significantly less affected by them. Using DESI LS data, with which 5,853 galaxy–AGN pairs were cross-matched, we find a weak but significant alignment signal (with P ≲ 0.01) between the parsec-scale AGN jet and the kiloparsec-scale projected minor axis of the optical host galaxy in sources with measured spectroscopic redshifts. Our results show that the observed source properties are connected over three orders of magnitude in scale. This finding points towards an intimate connection between a SMBH, its host galaxy and its subsequent evolution.

星系与其超大质量黑洞 （SMBH） 之间的关系是一个积极研究的领域。研究这种关系的一种方法是将 SMBH 形成的秒差距喷流与其千秒差距宿主星系的投影形状进行比较。在这里，我们通过将 VLBI 探测到的射电源中的流位置角与几次大型光学巡天测量的星系的光学形状进行比较，分析了活动星系核 （AGN） 的超长基线干涉 （VLBI） 图像及其宿主星系的光学图像。总共发现了 6,273 个星系-AGN 对。我们仔细考虑了交叉匹配源的系统学，发现暗能量光谱仪遗留成像巡天 （DESI LS） 数据受它们的影响要小得多。使用与 5,853 个星系-AGN 对交叉匹配的 DESI LS 数据，我们发现在具有测量光谱红移的源中，秒差距度 AGN 射流和光学宿主星系的千秒差距投影短轴之间有一个微弱但重要的对准信号（P≲ 0.01）。我们的结果表明，观察到的源属性在尺度上连接了三个数量级。这一发现指出了 SMBH、其宿主星系和随后的演化之间的密切联系。