A long-awaited German-Russian telescope to survey the X-ray sky in unprecedented detail was successfully launched from Kazakhstan’s Baikonur Cosmodrome on 13 July. The Spectrum-Roentgen-Gamma (Spektr-RG) mission is designed to detect 100 000 galactic clusters allowing astrophysicists to constrain the properties of dark matter and dark energy, and hence test models of the expansion of the universe.
Its enormous sensitivity will allow us to constrain cosmological parameters
Spektr-RG consists of two instruments, one of which is eROSITA – an X-ray survey telescope designed and built by Germany’s Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, which will operate between 0.2–10 keV. “It will provide a map of the entire sky in the 2–10 keV band for the first time,” says Esra Bulbul from the Harvard-Smithsonian Center for Astrophysics, who will become chair of MPE’s eROSITA cluster and cosmology team in September.
Bulbul says that the mission is about 30 times more sensitive than ROSAT — the previous all-sky survey X-ray telescope — in the soft X-ray band between 0.2–2 keV. “Its enormous sensitivity in that band will allow us to detect galactic clusters and constrain cosmological parameters,” she adds.