Vast X-ray Sky Catalog Reveals Millions of Cosmic Sources

The German eROSITA consortium has released data from its share of the first all-sky survey conducted by the Spectrum-RG (SRG) satellite's soft X-ray telescope. The resulting catalog, eRASS1, contains approximately 900,000 distinct sources, marking the largest X-ray catalog ever published. At the time of release, the catalog included an estimated 710,000 active galactic nuclei, 180,000 X-ray emitting stars within the Milky Way, and 12,000 galaxy clusters.

Coinciding with the data release, nearly 50 new scientific publications were submitted by the consortium, based on the findings. "This catalog of X-ray sources is an important foundation for the development of Artificial Intelligence methods in astrophysics and cosmology," stated Professor Sven Krippendorf of Ludwig-Maximilians-Universität München (LMU).

The eRASS1 observations took place between December 12, 2019, and June 11, 2020. In just six months, eROSITA detected more sources than had been identified in the preceding 60 years of X-ray astronomy. The catalog, along with analysis software, is now available to the global scientific community, promising to advance the understanding of the high-energy universe.

Researchers at LMU are also contributing to the physical interpretation of the eRASS data by comparing it with large-scale cosmological simulations. "It is astonishing to see eRASS data detect for the first time an individual gas filament so far away from a galaxy cluster," noted a research team from LMU.

Future data from eROSITA, which is continuing its sky-scanning mission, will be released to the international scientific community in the coming years.