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Spektr-RG: one third of the sky in X-ray

Spektr-RG Russian orbital observatory (designed by NPO Lavochkin, part of Roscosmos) has reached a major milestone mapping one third of the sky in X-ray. The map built by the Russian ART-XC telescope (16.7% of the whole sky) aboard the spacecraft has registered more than 95,000 X-ray sources. The one and only full X-ray map of the sky built by the German ROSAT spacecraft in 1990 has only one sixth of the sources detected.

The image above shows that the longest exposure and highest density of sources (per square inch) are observed at the poles of the ecliptic, where all the scans of the sky cross. The inset to the left shows a rich A426 galaxy cluster, to the right – a brightest supernova remnant (Cas A), Cassiopeia constellation. The dark strip seen on the X-ray sky image is caused by soft X-rays absorbed by gas and dust in the galactic plane.

Spektr-RG orbital observatory continues scanning the sky by its telescopes. Roscosmos specialists control the spacecraft; deep space communication antennas receive scientific data and send commands to the scientific instruments on a daily basis. Russian scientists of the Space Research Institute conduct online processing of scientific data. The similar map on the opposite side of the sky is built by the German Max Planck Institute for Extraterrestrial Physics.

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Spektr-RG spacecraft was designed by NPO Lavochkin and launched on July 13, 2019. The creation process went in cooperation with Germany as part of Russia’s Federal Space Program on behalf of the Russian Academy of Sciences. The space observatory is equipped with two unique X-ray telescopes: ART-XC (Russia) and eROSITA (Germany), its functioning based on oblique incidence principle.

The main task of the mission is mapping the sky in the soft (0.3-8 keV) and hard (4-20 keV) X-ray ranges with unprecedented sensibility. The observatory is expected to work in space for not less than 6.5 years.