Models for the gravitational field of Mars moon Phobos were developed using the latest shape model and assuming homogeneous density distribution.Three methods were applied in our study.Comparisons were made between th...Models for the gravitational field of Mars moon Phobos were developed using the latest shape model and assuming homogeneous density distribution.Three methods were applied in our study.Comparisons were made between these methods and all were shown to yield consistent results.Notably,the most accurate shape model of Phobos to date,complete up to degree and order 17 was used for the first time in our analysis.A set of spherical harmonic coefficients up to degree and order 17 were derived for the gravitational field of Phobos.Also considered was the gravitational field on the surface of Phobos.Typical characteristics as well as some pronounced surface features of this irregular-shaped small body could be conveniently identified.The results are readily applicable for such purposes as spacecraft orbit analysis and assessing the dynamical environment of Phobos.展开更多
The surface density Σ-map and the convergence κ-map of Bullet Cluster 1E0657-558 show that the center of baryonic matters separates from the center of gravitational force,and the distribution of gravitational force ...The surface density Σ-map and the convergence κ-map of Bullet Cluster 1E0657-558 show that the center of baryonic matters separates from the center of gravitational force,and the distribution of gravitational force do not possess spherical symmetry.This hints that a modified gravity with difference to Newtonian inverse-square law at large scale,and less symmetry is worth investigating.In this paper,we study the dynamics in Randers-Finsler spacetime.The Newtonian limit and gravitational deflection of light in a Rindler-type potential is focused in particular.It is shown that the convergence in Finsler spacetime could account for the observations of Bullet Cluster.展开更多
基金supported by the CAS-DAAD joint scholarship,the National Natural Science Foundation of China (Grant No.10973031)the National High Technology Research and Development Program of China (Grant No.2010AA122206)the Ministry of Education and Science of the Russian Federation (Grant NO.11.G34.31.0021)
文摘Models for the gravitational field of Mars moon Phobos were developed using the latest shape model and assuming homogeneous density distribution.Three methods were applied in our study.Comparisons were made between these methods and all were shown to yield consistent results.Notably,the most accurate shape model of Phobos to date,complete up to degree and order 17 was used for the first time in our analysis.A set of spherical harmonic coefficients up to degree and order 17 were derived for the gravitational field of Phobos.Also considered was the gravitational field on the surface of Phobos.Typical characteristics as well as some pronounced surface features of this irregular-shaped small body could be conveniently identified.The results are readily applicable for such purposes as spacecraft orbit analysis and assessing the dynamical environment of Phobos.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10875129 and 11075166
文摘The surface density Σ-map and the convergence κ-map of Bullet Cluster 1E0657-558 show that the center of baryonic matters separates from the center of gravitational force,and the distribution of gravitational force do not possess spherical symmetry.This hints that a modified gravity with difference to Newtonian inverse-square law at large scale,and less symmetry is worth investigating.In this paper,we study the dynamics in Randers-Finsler spacetime.The Newtonian limit and gravitational deflection of light in a Rindler-type potential is focused in particular.It is shown that the convergence in Finsler spacetime could account for the observations of Bullet Cluster.
