This paper describes the database of optical spectra of BL Lacertae (BLL) objects (Z BLL objects) available at https://web.oapd.inaf.it/zbllac/. At present, it contains calibrated spectra for 295 BLL. For about 35% of them, we report a firm measure of redshift z, while for 35 sources we set a lower limit on z based on the detection of intervening absorption systems, mainly ascribed to Mg ii (λ2800 Å). We report here on the architecture of the database and on its website front-end that permits us to filter, query, and interactively explore the data. We discuss some properties of the objects in the present data set by giving the distribution of the redshifts and reporting on the detected emission lines, which turn out to be mainly forbidden and ascribed to [O ii] (λ3737 Å) and [O iii] (λ5007 Å). Finally, we discuss on intervening absorption systems detected in 35 BLLs that allow us to set lower limits to their distance.

本文描述了可在 https://web.oapd.inaf.it/zbllac/ 获得的 BL Lacertae (BLL) 天体（Z BLL 天体）的光谱数据库。目前，它包含 295 BLL 的校准光谱。对于其中大约 35%，我们报告了对红移z 的可靠测量，而对于 35 个源，我们根据对介入吸收系统的检测设置了z的下限，主要归因于 Mg ii ( λ2800 埃）。我们在此报告数据库的架构及其网站前端，允许我们过滤、查询和交互式探索数据。我们通过给出红移的分布并报告检测到的发射线来讨论当前数据集中物体的一些特性，结果证明这些发射线主要被禁止并归因于 [O ii ] ( λ 3737 Å) 和 [O iii ] ( λ 5007 Å)。最后，我们讨论了在 35 个 BLL 中检测到的介入吸收系统，这些系统使我们能够为它们的距离设置下限。