Structural-Dynamical Relations of Disk Galaxies Interpreted by Gravitational Flux Distribution Transition Across a Critical Field Te Chun Wang ^{1*}^{1}Li-Chih high school, Kaohsiung, Taiwan* Presenter:Te Chun Wang, email:tctedwang@yahoo.com It has been found that objects in disk galaxies can show Non-Keplerian rotational behaviors below a critical acceleration of the order of ~10
^{-10} m/s^{2}. The MOND(Modified Newtonian Dynamics) theory workers provided pretty good fits for the rotation curves and the Tully-Fisher relation by postulating that the Newton’s force law turns into a acceleration square dependence below the critical acceleration.
In this report, an alternative approach of modifying the Newtonian gravity is proposed with a gravitational field flux picture by the Integral Gauss’s law of gravity. Three disk galaxy related results are shown as follows. Firstly, 1/r field dependence together with a disk thickness dependence and in turn flat rotation curves are shown to be obtained by a Gaussian surface with cylindrical symmetry where most of the gravitational fluxes are distributed eventually along the radial direction of the disk plane. The Gaussian disk thickness as a dynamical variable is discussed with observational evidences. Additionally, the monotonically rising rotation curves of low surface brightness galaxies(LSBGs) are compared with the flat rotation curves of high surface brightness galaxies(HSBGs) by the flux distribution picture. Secondly, a spherical to cylindrical transition of the Gaussian surface symmetry is shown to result in the exact M∝v ^{4} Tully-Fisher relation(TF relation). The possible deviation from the exact TF relation of the LSBGs are explained by their lack of both flat rotation curves and the spherical to cylindrical Gaussian surface symmetry transition.
Thirdly, the structural-dynamical relations revealed from radial acceleration relation of SPARC(Spitzer Photometry and Accurate Rotation Curves ) data of Stacy Mcgaugh's team are compared to the field flux distribution picture. The Newtonian dynamics above the critical field of ~10 ^{-10} N/Kg near the core bulge region of HSBGs can be explained by the spherical distribution of the gravitational flux. The transition from Newtonian to Non-Newtonian behavior across the critical field can be interpreted with the transition from Gaussian sphere to Gaussian disk of the flux distribution while the Non-Newtonian behaviors of the LSBGs and the outskirts of the HSBGs can be attributed to the focused flux distribution below the critical field.
The possible applications of this focused gravitational field flux picture to larger scales and other implications are discussed. Keywords: MOND, gauss's law of gravity, Tully-Fisher relation, low surface brightness galaxy, rotation curve |