2010/06/30 by Joanna Jałocha, Łukasz Bratek, Marek Kutschera +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Azimuth #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy rotation curve #Hubble sequence #Mass distribution #Rotation (mathematics) #Spiral (railway) #Spiral galaxy #astro-ph.GA
paper · pdf · doi:10.1111/j.1365-2966.2010.17906.x
published as (2011) MNRAS 412: 331-336 · 5 pgs, 9 figs
openalex publication_date 2010/12/14 · arxiv created 2011/04/25 · arxiv updated 2011/04/27 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
We estimate the vertical gradient of rotational velocity for several spiral galaxies in the framework of a global thin-disc model, using the approximation of quasi-circular orbits. We obtain gradients having a broad range of values, in agreement with measurements, for galaxies with both low and high gradients. To model the gradient, it suffices to know the rotation curve only. We illustrate, using the example of galaxy NGC 4302 with particularly high gradients, that mass models of galactic rotation curves that assume a significant spheroidal mass component reduce the predicted gradient value, which may suggest that the mass distribution is dominated by a flattened disc-like component. We conclude that the value and behaviour of the vertical gradient in rotational velocity can be used to study the mass distribution in spiral galaxies.