Rotation Curves of Spiral Galaxies: Influence of Magnetic Fields and Energy Flows
نویسندگان
چکیده
Physical mechanisms that can influence rotation curves of spiral galaxies are discussed. For dark matter studies, possible contributions due to magnetic fields and non-Newtonian gravitational accelerations should be carefully acconted for. We point out that magnetic fields are particularly important in outermost parts of the disk. In the framework of general relativity the physical reason of an enhanced gravity in spiral galaxies depends on the assumed metric. The additional gravity is provided for Schwarzschild metric by nonluminous mass, whereas for Vaidya metric [1] by emission of radiative energy. In the latter case the non-Newtonian acceleration displays 1/r behaviour. Also matter flows contribute to non-Newtonian gravity.
منابع مشابه
Galactic Dynamos and Galactic Winds
Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 μG) in the spiral arms where they are mostly turbulent or tangled. Polarized synchrotron emission shows that the resolved regular fields are generally strongest in the interarm regions (up to 15 μG). Faraday rotation measu...
متن کاملEvaluation of New MOND Interpolating Function with Rotation Curves of Galaxies
The rotation curves of a sample of 46 low- and high-surface brightness galaxies are considered in the context of Milgrom's modi_ed dynamics (MOND) to test a new interpolating function proposed by Zhao et al. (2010) [1] and compare with the results of simple interpolating function. The predicted rotation curves are calculated from the total baryonic matter based on the B-band surface photometry,...
متن کاملMeasuring interstellar magnetic fields by radio synchrotron emission
Radio synchrotron emission, its polarization and its Faraday rotation are powerful tools to study the strength and structure of interstellar magnetic fields. The total intensity traces the strength and distribution of total magnetic fields. Total fields in gas-rich spiral arms and bars of nearby galaxies have strengths of 20–30 μGauss, due to the amplification of turbulent fields, and are dynam...
متن کاملMultiscale magnetic fields in spiral galaxies: evolution and reversals
Context. Magnetic fields in nearby, star-forming galaxies reveal large-scale patterns, as predicted by dynamo models, but also a variety of small-scale structures. In particular, a large-scale field reversal may exist in the Milky Way while no such reversals have been observed so far in external galaxies. Aims. The effects of star-forming regions in galaxies need to be included when modelling t...
متن کاملMagnetic fields and rotation of spiral galaxies
We present a simplified model in which we suggest that two important galactic problems -the magnetic field configuration at large scales and the flat rotation curvemay be simultaneously explained. A highly convective disc produces a high turbulent magnetic diffusion in the vertical direction, stablishing a merging of extragalactic and galactic magnetic fields. The outer disc may then adquire a ...
متن کامل