Feng, J.Q. Rotating Disk Galaxies without Dark Matter Based on Scientific Reasoning. Galaxies 2020, 8, 9. https://doi.org/10.3390/galaxies8010009
Feng, J.Q. Rotating Disk Galaxies without Dark Matter Based on Scientific Reasoning. Galaxies 2020, 8, 9. https://doi.org/10.3390/galaxies8010009
Feng, J.Q. Rotating Disk Galaxies without Dark Matter Based on Scientific Reasoning. Galaxies 2020, 8, 9. https://doi.org/10.3390/galaxies8010009
Feng, J.Q. Rotating Disk Galaxies without Dark Matter Based on Scientific Reasoning. Galaxies 2020, 8, 9. https://doi.org/10.3390/galaxies8010009
Abstract
The most cited evidence for (nonbaryonic) dark matter has been an apparent lack of visible mass to gravitationally support the observed orbital velocity of matters in rotating disk galaxies. Yet measurement of the mass of celestial objects cannot be straightforward, requiring theories derived from the known physical laws along with some empirically established semi-quantitative relationship. The most reliable means for determining the mass distribution in rotating disk galaxies is to solve a force balance equation according to Newton’s laws from measured rotation curves, similar to calculating the Sun’s mass from the Earth’s orbital velocity. Another common method to estimate galactic mass distribution is to convert measured brightness from surface photometry based on empirically established mass-to-light ratio. For convenience, most astronomers commonly assumed a constant mass-to-light ratio for estimation of the so-called “luminous” or “visible” mass, which should not be expected accurate. The mass determined from rotation curve typically exhibit an exponential-like decline with galactrocentric distance, qualitatively consistent with observed surface brightness. This fact scientifically suggests variable mass-to-light ratio of baryonic matter in galaxies without the need for dark matter.
Keywords
disk galaxies; galactic rotation; Newtonian dynamics; rotation curve; dark matter; mass-to-light ratio
Subject
Physical Sciences, Astronomy and Astrophysics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
