Gravitational wave effects on astrometric observables

Abstract

Observational data from the ESA astrometric mission Gaia determining the positions of celestial objects within an accuracy of few microarcseconds will be soon fully available. Other satellite-based space missions are currently planned to significantly improve such precision in the next years. The data reduction process needs high-precision general relativistic models, allowing one to solve the inverse ray-tracing problem in the gravitational field of the Solar System up to the requested level of accuracy and leading then to the estimate of astrometric parameters. Besides a satisfactory description of the background field due to the planets (which should include their multipolar structure), one should consider also other effects which may induce modifications to the light propagation. For instance, the interaction of the light signal with the superposed gravitational field of a gravitational wave emitted by a distant source would cause a shift in the apparent positions of the stars. We compute here the main astrometric observables needed for data reduction of satellite-based missions in the presence of a passing plane gravitational wave. We also take into account the effect of the mass quadrupole moment of the planets, improving previous results obtained for Gaia.

Spin Dynamics of Moving Bodies in Rotating Black Hole Spacetimes

“…Then introducing a spin four‐vector perpendicular to $$u^{a}$$ (see Equation (2.5) of ref. [98]), it will be parallel transported along the trajectory. The geodesic equations with parallel transported spin vector was investigated in ref.…”

The Science of Fundamental Catalogs

“…Direct astrometric measurements of gravitational waves from a single source are not possible with the current pulsar timing or VLBI technology. However, it was noticed that the stochastic ensemble of these waves produced by various mechanisms can be detected in a roundabout way by studying temporal and angular correlations in the times of arrival (TOA) of radio pulses from the pulsar timing array (PTA) (Hellings and Downs, 1983;Foster and Backer, 1990;van Haasteren et al, 2009;Manchester, 2013;Taylor et al, 2017), or in the redshifts of quasars (Seto and Cooray, 2006), or in the pattern of their proper motions in an astrometric fundamental catalog (Pyne et al, 1996;Gwinn et al, 1997;Kaiser and Jaffe, 1997;Jaffe, 2004;Makarov, 2010;Book and Flanagan, 2011;Bini and Geralico, 2018;Qin et al, 2019).…”

The Science of Fundamental Catalogs

“…Direct astrometric measurements of gravitational waves from a single source are not possible with the current pulsar timing or VLBI technology. However, it was noticed that the stochastic ensemble of these waves produced by various mechanisms can be detected in a roundabout way by studying temporal and angular correlations in the times of arrival (TOA) of radio pulses from the pulsar timing array (PTA) [123][124][125][126][127], or in the redshifts of quasars [128], or in the pattern of their proper motions in an astrometric fundamental catalog [129][130][131][132][133][134][135][136].…”