What does the edge of the universe look like?

 We can only ‘see’ those parts of the universe that are observable with telescopes. These range from those that can capture infrared sources to those that capture optical, X-ray, and Gamma-ray sources.

Today the eRosita consortium, housed at the Max Planck Institute for Extraterrestrial Physics (MPE), released an image from their latest data analysis from their first all-sky survey from the soft X-ray imaging telescope on board the Spectrum-RG (SRG) satellite. Using about 900,000 distinct sources has resulted in the largest X-ray image of the observable universe ever published. It includes about 710,000 supermassive black holes in distant galaxies, 180,000 X-ray-emitting stars in our own Milky Way, and 12,000 clusters of galaxies, plus several other exotic classes of sources such as X-ray-emitting binary stars, supernova remnants, pulsars, and other objects.

The "eRosita" image of the X-ray sky: The Milky Way is on the left in the picture, and the particularly bright point in the middle is the Vela supernova remnant Photo: J. Sanders / eROSITA consortium / MPE.

The eROSITA consortium’s scientific objective is to use the data from the telescope to find the constraints of cosmological models using clusters of galaxies.

Source:

The SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere

The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. Here we present catalogues of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky whose proprietary data rights lie with the German eROSITA Consortium. We describe the observation process, the data analysis pipelines, and the characteristics of the X-ray sources. With nearly 930000 entries detected in the most sensitive 0.2-2.3 keV energy range, the eRASS1 main catalogue presented here increases the number of known X-ray sources in the published literature by more than 60%, and provides a comprehensive inventory of all classes of X-ray celestial objects, covering a wide range of physical processes. A smaller catalogue of 5466 sources detected in the less sensitive but harder 2.3-5 keV band is the result of the first true imaging survey of the entire sky above 2 keV. We show that the number counts of X-ray sources in eRASS1 are consistent with those derived over narrower fields by past X-ray surveys of a similar depth, and we explore the number counts variation as a function of the location in the sky. Adopting a uniform all-sky flux limit (at 50% completeness) of F_{0.5-2 keV} > 5 \times 10^{-14}$ erg\,s$^{-1}$\,cm$^{-2}$, we estimate that the eROSITA all-sky survey resolves into individual sources about 20% of the cosmic X-ray background in the 1-2 keV range. The catalogues presented here form part of the first data release (DR1) of the SRG/eROSITA all-sky survey. Beyond the X-ray catalogues, DR1 contains all detected and calibrated event files, source products (light curves and spectra), and all-sky maps. Illustrative examples of these are provided.

https://arxiv.org/abs/2401.17274

The X-ray sky opens to the world

First eROSITA sky-survey data release makes public the largest ever catalogue of high-energy cosmic sources

https://www.mpg.de/21468451/0126-ext0-the-x-ray-sky-opens-to-the-world-151510-x