eROSITA is an X-ray instrument built by the Max Planck Institute for Extraterrestrial Physics (MPE) in

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. It is part of the Russian–German

Spektr-RG Spektr-RG ( Russian: Спектр-РГ, ''Spectrum'' + '' Röntgen'' + ''Gamma''; also called Spectrum-X-Gamma, SRG, SXG) is a Russian–German high-energy astrophysics space observatory which was launched on 13 July 2019. It follows on from t ...

space observatory, which also carries the Russian telescope ART-XC. It was launched by

Roscosmos The State Corporation for Space Activities "Roscosmos", commonly known simply as Roscosmos (), is a State corporation (Russia), state corporation of the Russian Federation responsible for space science, space flights, List of space agencies, c ...

on 13 July 2019 from

Baikonur Baikonur ( ; ) is a city in Kazakhstan on the northern bank of the Syr Darya river. It is currently leased and administered by the Russian Federation as an enclave until 2050. It was constructed to serve the Baikonur Cosmodrome with adminis ...

, and deployed in a 6-month halo orbit around the second

Lagrange point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies. Mathematically, this involves t ...

(L2). It began collecting data in October 2019. Due to the breakdown of institutional cooperation between Germany and Russia after the invasion of Ukraine, the instrument stopped collecting data on February 26, 2022.

Overview

eROSITA was originally designed by the ESA for the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

, and it was concluded in 2005 that its accommodation on a dedicated free flyer would provide significantly improved scientific output. The eROSITA telescopes are based on the design of the ABRIXAS observatory launched in April 1999, whose battery was accidentally overcharged and destroyed three days after the mission started. The plan was eROSITA imaging the entire sky in the X-ray band for seven years. The eROSITA all-sky survey (eRASS) was the first image of the entire sky in the 2-10 keV band. In the 0.3-2 keV band, it is expected to be 25 times more sensitive than the pioneering ROSAT mission of the 1990s, and will effectively supersede it. eROSITA is expected to detect 100,000

galaxy clusters A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. Clusters consist of galax ...

, 3 million

active galactic nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...

and 700,000 stars in the Milky Way. The primary science goal is to measure

dark energy In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. It also slows the rate of structure format ...

through the structure and history of the Universe traced by galaxy clusters. eROSITA was launched on 13 July 2019 by

from

. It achieved first light on 17 October 2019 and completed its first all-sky survey on 11 June 2020. In the summer of 2021 the first eROSITA X-ray data release to the public was announced. The operations of eROSITA were suspended on 26 February 2022 after the Russian attack into Ukraine. The science operations of the instrument were paused, but the analysis of the data already received in Germany continued. At the time, eROSITA had completed four of its planned eight full-sky surveys. In June 2022, Roscosmos announced its intent to restore the operation of eROSITA unilaterally, which was criticized by experts for its potential to damage the telescope.

Construction

The telescope consists of seven identical Wolter-type mirror modules with 54 nested

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

-coated mirrors. The mirrors are arranged to collect the high-energy X-ray photons and guide them to the eROSITA X-ray sensitive cameras. The cameras were also custom-built at MPE, with X-ray CCDs manufactured from high-purity silicon. For optimum performance, the cameras are cooled to . File:EROSITA mirror modules.jpg, The seven mirror modules from the front File:EROSITA X-ray detectors.jpg, X-ray detectors behind each mirror

Instruments

Collaboration

eROSITA was developed at the Max Planck Institute for Extraterrestrial Physics in collaboration with institutes in Bamberg, Hamburg, Potsdam und Tübingen. The instrument principal investigator is Peter Predehl. The project scientist is Andrea Merloni. The German eROSITA consortium has members from institutes all across Germany, but also from international institutes, and has established collaborations with ground-based telescopes for follow-up observations of the millions of sources that will be detected by eROSITA. EROSITA consortium meeting 2019

Science results

First science verification results were released on October 22, 2019, including high-resolution spectra of Supernova 1987a, images of the

Large Magellanic Cloud The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around , the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal Galaxy, Sagittarius Dwarf ...

and

galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. Clusters consist of galax ...

s, as well as light curves of a highly variable

Active Galactic Nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...

. The first all-sky survey was completed on June 11, 2020, cataloging 1.1 million sources, including mostly Active Galactic Nuclei (77%), stars with strong, magnetically active hot coronae (20%) and clusters of galaxies (2%), but also bright X-ray binaries,

supernova remnants A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...

, extended star-forming regions as well as transients such as

Gamma-Ray Burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic events occurring in distant Galaxy, galaxies which represent the brightest and most powerful class of explosion in the universe. These extreme Electromagnetic radiation, ele ...

s. The map includes extended features of the Milky Way, including mushroom-like bubbles and absorbing galactic gas in the disk (blue). SRG-eROSITA all-sky image

Overview

Construction

Instruments

Collaboration

Science results

See also

References

External links