Abstract:
The Enhanced X-ray Timing and Polarimetry (eXTP) mission is a space mission
to be launched in the late 2020s that is currently in development led by
China in international collaboration with European partners. Here we
provide a progress report on the Czech contribution to the eXTP science. We
report on our simulation results performed in Opava (Institute of Physics of
the Silesian University in Opava) and Prague (Astronomical Institute of the
Czech Academy of Sciences), where the advanced timing capabilities of the
satellite have been assessed for bright X-ray binaries that contain an
accreting neutron star (NS) and exhibit the quasi-periodic oscillations.
Both stellar-mass, supermassive, and tentative intermediate-mass black holes
can be included in the program portfolio.
Measurements of X-ray variability
originating in oscillations of fluid in the innermost parts of the accretion
region determined by general relativity, such as the radial or
Lense-Thirring precession, can serve for sensitive tests enabling us to
distinguish between the signatures of different viable dense matter
equations of state. We have developed formulae describing non-geodesic
oscillations of accreted fluid and their simplified practical forms that
allow for an expeditious application of the universal relations determining
the NS properties. These relations, along with our software tools for
studying the propagation of light in strong gravity and neutron star models,
can be used for precise modeling of the X-ray variability while focusing on
properties of the intended Large Area Detector (LAD).
We update the status
of our program and set up an electronic repository that will provide
simulation results and gradual updates as the mission specifications
progress toward their final formulation.
Full text version of this article in
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; Klimovičová, K.
