Starship Asterisk*

HEAPOW: One Sky (2022 Mar 14)

The beautiful image above shows the first all-sky map of the hot and energetic Universe by the eROSITA telescope aboard the SRG spacecraft, from its parking orbit 1 million miles from earth at the earth-Sun L2 point. This is the deepest map ever obtained of the entire sky in X-rays, revealing about 1,000,000 X-ray sources in the Milky Way (which stretches across the middle of the image from left to right) out to cosmological distances in deep space. The number of sources detected by eROSITA is about double the number of X-ray sources identified over the 50-year history of X-ray astronomy, an impressive feat that took eROSITA only six months to accomplish. Most of the sources detected are actively accreting supermassive black holes at the centers of distant galaxies, detailing the growth of supermassive black holes through cosmic time. The eROSITA map also provides details of the X-ray emitting gas held bound by the enormous gravitational pull of galaxy clusters, crucial probes to understand the mysterious nature of the "Dark Matter" binding the Universe together and the "Dark Energy" driving the Universe apart. Closer to home, the eROSITA map provides a census of all the normal matter within the Milky Way, along with flaring stars, black hole and neutron stars in binary systems eating their companions, winds from massive stars driving powerful shocks in interstellar space, and supernova remnants (including evidence of a nearby stellar explosion which may have helped form our solar system). But eROSITA is not done, by a long shot: over the next 3.5 years, eROSITA will scan the entire sky 7 more times, providing an ever-clearer map of the hot, high-energy, ever-changing X-ray Universe.