First Results from the eROSITA All-Sky Survey: An Open Window to Precision Cosmology

Clusters of galaxies trace the highest peaks in the cosmic density field and offer an independent and powerful probe of the growth of structure and cosmology. Locating clusters through well-planned multi-wavelength surveys is crucial for testing gravitational theory and cosmology. Successfully launched in July 2019, eROSITA, the German-built telescope array operating between 0.2-8 keV on board the Russian-German Spectrum-RG (SRG) mission, delivers the largest catalogs of clusters of galaxies from its All-Sky Surveys. The first eROSITA all-sky survey, yielding more than 10,000 confirmed clusters of galaxies, constrains the cosmological parameters from cluster mass function and cluster-clustering when combined with the overlapping DES, HSC, and KIDS weak lensing surveys. I will summarise the first cluster science, large scale structure, and cosmology results from eROSITA’s first All-Sky Survey and provide an outlook for future deeper surveys.