The major scientific goals of the SRG mission all-sky survey are:
The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. To fulfill of these goals, SRG will survey the sky in an energy band up to 11 keV with unprecedented sensitivity and angular resolution. In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas.
The limiting survey sensitivity achieved after 4 years of observations for objects with low surface brightness, ~4x10-14šergšs-1šcm-2, will permit the discovery of all massive galaxy clusters in the observed Universe with masses M ~3.5x1014šh-1šMsun (or Tš~š4.5 keV). Moreover one will be able to discover all galaxy clusters with Mš~š2.3x1014šh-1šMsun (or T ~š3.5škeV), situated at redshifts zš~š1, and all galaxy clusters and galaxy groups with Mš~š1014šh-1šMsun (or Tš~š2škeV), at redshifts zš~š0.4.
These capabilities will allow one to:
These will permit the measurement of the Dark Energy equation of state in the Universe - the most significant element of modern cosmology which defines the dynamics of Universe expansion. Also in the course of the SRG survey, the most complete census of Seyfert galaxies, radio galaxies, quasars and blazars in the giant volume of the Universe will be performed.
Fig.2. Number of clusters of galaxies per 20,000 deg2, depending on Cosmology model, based on a subset of the ~2,000 most rich clusters of the 50,000 clusters which will be detected by SRG. Solid line ? standard model with ΩM = 0.3, ΩΛ = 0.7, h = 0.73.
These census data will allow one to:
The observatory, in survey mode, will perform the most complete X-ray luminosity function study for Galactic X-ray sources. In the course of the survey, SRG will monitor X-ray source variability on both short and long temporal scales.
The Observatory would perform:
Fig.3 A comparison of the planned eROSITA/SRG survey with existing surveysPointing Mode
In pointing mode, a key task of the SRG mission will be to perform some extra observations as:
Last updated: December 17 2015
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