Research Project GAČR 209/12/P740

High Frequency Quasi-periodic Oscillations and Compact Object Properties: Theory vs. Observation

Recent developments of the X-ray space observatories bring precise data from strong gravity fields in the vicinity of black holes and neutron or strange stars (compact objects). Among the important related phenomena are the high-frequency quasi-periodic oscillations (QPOs) that most likely originate in accretion discs surrounding these objects. Understanding the origin and other properties of QPOs represents a promising way to explore strong gravity as well as the elementary particle physics which determines the internal structure of neutron stars. Variety of QPO models has been proposed, but there is yet no consensus on their relevance. Within the project we would like to contribute to this important open problem in the areas of both, comparison of observational data with theoretical models, and development of the individual QPO models. We will especially focus on estimating the compact object parameters and developing those models that deal with accretion disc oscillations. In relation to these goals we will investigate the impact of different equations of state on the astronomical phenomena in the vicinity of  neutron stars and study resonant and other behaviour of diverse accretion disc oscillation modes.

The research team consists of researchers dedicated to different aspects of the research field associated with observational data analysis (G. Török), modeling of rotating compact stars (M. Urbanec), and the theory of accretion disc oscillations (E. Šrámková). The project research work will in part follow the research conducted within the projects MSM 4781305903 (Relativistic and particle physics and its astrophysical applications) and LC06014 (Centre for theoretical astrophysics) that both ended in December 2011. Its time frame will be the oncoming three-year period 2012-2014.

Detailed Description:

1 Motivation
2 Compact Object Parameters and QPO Models
3 Research Directions and Goals
4 Institutional and Technological Background