Rings and spirals in barred galaxies. II. Ring and spiral morphology - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado




Rings and spirals in barred galaxies. II. Ring and spiral morphology - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: In this series of papers, we propose a theory to explain the formation andproperties of rings and spirals in barred galaxies. The building blocks ofthese structures are orbits guided by the manifolds emanating from the unstableLagrangian points located near the ends of the bar. In this paper we focus on acomparison of the morphology of observed and of theoretical spirals and ringsand we also give some predictions for further comparisons. Our theory canaccount for spirals as well as both inner and outer rings. The model outerrings have the observed $R 1$, $R 1-$, $R 2$, $R 2-$ and $R 1R 2$ morphologies,including the dimples near the direction of the bar major axis. We explain whythe vast majority of spirals in barred galaxies are two armed and trailing, anddiscuss what it would take for higher multiplicity arms to form. We show thatthe shapes of observed and theoretical spirals agree and we predict thatstronger non-axisymmetric forcings at and somewhat beyond corotation will drivemore open spirals. We compare the ratio of ring diameters in theory and inobservations and predict that more elliptical rings will correspond to strongerforcings. We find that the model potential may influence strongly the numericalvalues of these ratios.



Autor: E. Athanassoula, M. Romero-Gomez, A. Bosma, J.J. Masdemont

Fuente: https://arxiv.org/







Documentos relacionados