  Considering increasing requirements to the coordinates measurement precision
by the end of XX century International Astronomical Union commenced
implementation of the new astrometric system ICRF (International Celestial
Reference Frame). This quasi-inertial reference frame system centered in the
barycenter of the Solar System and has axes defined by the positions of distant
extragalactic sources - frames. Unlike equatorial system ICRF has no
shortcomings of the coordinates identification due to the Earth axis
precession, stellar proper motions and other factors. Extragalactic frames of
the ICRF system are mostly quasars, radio galaxies, blazars and Seyfert
galaxies i.e. different types of the active galaxy nuclei (AGN). Active galaxy
nuclei are characterized by processes with significant. Such processes quite
often are followed by X-ray emission generation. The purpose of this work is to
consider X-ray emission of ICRF sources and features of their possible proper
motions. Among 295 selected reference frames of the system we identified 54
X-ray sources which were observed by space observatory XMM Newton and noticed
rapid variability of the blazars 2E 2673 (W Com) and 2E 1802 which enables to
conclude that they have some very active processes in the sources centers. With
regards to the future more detailed analysis we beleive that evidences of the
objects proper motion could be found in their spectra. Based on the constructed
luminosity and spectral graphs we could conclude that apart from above
mentioned AGNs rest 52 objects do not show veriability and special attention
should be paid to blazars within ICRF system development and use. Major part of
the X-ray sources between the reference frames are stable.
