eROSITA DR2 catalog lists nearly 2 million X-ray sources

The German eROSITA Consortium released its second data release this past summer, a catalog combining three full-sky scans from the Spektr-RG observatory launched in 2019. DR2 lists more than 1.9 million point-like sources and about 64,000 extended sources, almost double the original release, drawing on the mission's first 556 days of stacked observations. The team concluded about 88% of identified sources are extragalactic, mostly actively accreting supermassive black holes. The release coincides with SDSS DR20, whose optical spectroscopy supports joint black-hole studies.