Bibcode
Font, J.; Beckman, J. E.; James, Phil A.; Patsis, Panos A.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 482, Issue 4, p.5362-5378
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2
2019
Citations
18
Refereed citations
18
Description
A method, which we have developed for determining corotation radii, has
allowed us to map in detail the radial resonant structures of barred
spiral galaxies. Here, we have combined this information with new
determinations of the bar strength and the pitch angle of the innermost
segment of the spiral arms to find relationships between these
parameters of relevance to the dynamical evolution of the galaxies. We
show how (1) the bar mass fraction, (2) the scaled bar angular momentum,
(3) the pitch angle, and (4) the shear parameter vary along the Hubble
sequence, and we also plot along the Hubble sequence (5) the scaled bar
length, (6) the ratio of bar corotation radius to bar length, (7) the
scaled bar pattern speed, and (8) the bar strength. It is of interest to
note that the parameters (2), (5), (6), (7), and (8) all show breaks in
their behaviour at type Scd. We find that bars with high shear have only
small pitch angles, while bars with large pitch angles must have low
shear; we also find a generally inverse trend of the pitch angle with
bar strength. An inference that at first seems counter-intuitive is that
the most massive bars rotate most slowly but have the largest angular
momenta. Among a further set of detailed results, we pick out here the
2:1 ratio between the number of spiral arms and the number of
corotations outside the bar. These results give a guideline to theories
of disc-bar evolution.
Related projects
Kinematic, Structural and Composition Studies of the Interstellar and Intergalactic Media
The basic objective of the broject is to investigate the evolution of galaxies by deepening our understanding of the interaction between the insterstellar medium and the stars.The main technique which we use is the two-dimensional kinematic study of whole galaxies observed using our instrument:GHaFaS, a Fabry-Perot interferometer on the William
Prof.
John E. Beckman