Test and application of gravitational theories in astronomical systems

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6284245

Zhou, Ziye

Constraints are made on a variety of Newtonian perturbations that could conspire to imitate the timing effects of the relativistic two-body model. This will provide an assessment on the quality of the evidence that the decay of the pulsar's orbital period is caused by the energy loss of the binary pulsar system in the form of gravitational radiation. A timing model for the binary pulsar system PSR 1913+16 which includes both relativistic timing effects and the effects of conceivable rotational and tidal distortions of the pulsar's companion star was developed. The deformation of the companion star would modify its Newtonian gravitational field which affects the orbit of the pulsar. The periodic perturbations that occur at harmonics of the pulsar's orbital period were calculated. These characteristic periodic effects can generally indicate distinctively the presence of rotational and tidal distortions of the pulsar's companion star. The analysis shows that the timing effect of the gravitational red shift and second order Doppler shift and the effect of the Shapiro propagation delay of the pulse can be isolated from all these effects. They can be used to obtain a reliable estimate of the masses of the pulsar and its companion star whatever the nature of the companion. This new constraint can rule out any possibility that the pulsar's companion is a helium star and it sharply constrains the rotational distortion of a conceivable white dwarf companion. The deflection of star light by the gravitational field of the sun is also examined. The gravitational field generated by currents of matter within a body influences the deflection of light by the body. In metric theories of gravity the Einstein equivalence principle is shown to imply a deeper connection than had been realized between this deflection and the Lense-Thirring dragging of inertial frames.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 6284245
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
657003 -- Theoretical & Mathematical Physics-- Relativity & Gravitation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
COSMIC RADIO SOURCES
COSMOLOGICAL MODELS
DATA
DOPPLER EFFECT
FIELD THEORIES
GENERAL RELATIVITY THEORY
GRAVITATIONAL FIELDS
INFORMATION
MATHEMATICAL MODELS
NUMERICAL DATA
ORBITS
PULSARS
RED SHIFT
RELATIVITY THEORY
STAR MODELS
STARS
THEORETICAL DATA