斯隆数字巡天（SDSS）发布了第20次数据发布（DR20），包含超过330万条光学光谱，覆盖50万个星系和150万颗恒星的观测数据[1]。这次发布首次纳入来自智利Las Campanas天文台的南半球光学观测[1]。
通过SPIDERS项目，研究人员将SDSS的光学光谱与eROSITA X射线数据结合，为约20万个X射线源提供了光学识别和精确的距离测量[1]。数据分析表明，70%-90%的超大质量黑洞生长发生在尘埃和气体的遮挡下或X射线被抑制的阶段[1]。此外，研究发现早期宇宙中存在比预期更多的快速生长的超大质量黑洞[1]。SDSS黑洞绘图仪（BHM）的多个时间域子程序被用于追踪类星体的长期变化[1]。
The Sloan Digital Sky Survey (SDSS) has released its 20th data release (DR20), delivering over 3.3 million optical spectra from observations of approximately 500,000 galaxies and 1.5 million stars [1]. This milestone release marks the first time the survey has incorporated southern hemisphere optical observations from Las Campanas Observatory in Chile, significantly expanding its celestial coverage [1].
A major component of DR20 involves the SPIDERS project, which combines SDSS optical spectroscopy with X-ray data from eROSITA to provide optical identification and precise distance measurements to roughly 200,000 X-ray sources [1]. The collaborative analysis has yielded significant discoveries about supermassive black hole populations, revealing that rapidly growing supermassive black holes are more common in the early universe than previously expected [1]. Additionally, research indicates that 70 to 90 percent of supermassive black hole growth occurs during phases when these objects are obscured by dust and gas or when their X-ray emission is suppressed [1]. The SDSS Black Hole Mapper (BHM) employs multiple time-domain subprograms to track changes in quasars over time, contributing to a more comprehensive understanding of black hole evolution across cosmic history [1].