Related papers: Extensive spiral structure and corotation resonanc…
We use high-spatial resolution ($\sim 100 pc$) rotation curves of 83 spiral galaxies to investigate the mass distribution of their innermost kpc. We show that, {\it in this region}, the luminous matter completely accounts for the…
The most important theory of the spiral arms of galaxies is the density wave theory based on the Lin-Shu dispersion relation. However, the density waves move with the group velocity towards the inner Lindblad resonance and tend to…
Azimuthal color (age) gradients across spiral arms are one of the main predictions of density wave theory; gradients are the result of star formation triggering by the spiral waves. In a sample of 13 spiral galaxies of types A and AB, we…
The mechanism causing breaks in the radial surface brightness distribution of spiral galaxies is not yet well known. Despite theoretical efforts, there is not a unique explanation for these features and the observational results are not…
The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…
In this article we introduce a technique for finding resonance radii in a disk galaxy. We use a two-dimensional velocity field in H{\alpha} emission obtained with Fabry-Perot interferometry, derive the classical rotation curve, and subtract…
Density waves in galaxy disks have been proposed over the years, in a variety of specific models, to explain spiral arm structure and its relation to the mass distribution, notably in barred galaxies. An important parameter in dynamical…
We present a new method for estimating the corotation radius in tightly wound spiral galaxies, through analysis of the radial variation of the offset between arms traced by the potential (P-arms) and those traced by dust (D-arms). We have…
We consider seven distant galaxies with clearly evident spiral structure from HST images. Three of these were chosen from Vogt et al. (1996) (VFP) and have measured rotational velocities. Five were chosen from the Medium Deep Survey and are…
We present deep optical imaging of three face-on disk galaxies together with a detailed description of the reduction and calibration methods used, in order to measure the intrinsic shape of their outer stellar edges. Whereas it is now well…
The correlation between the breaks in the metallicity distribution and the corotation radius of spiral galaxies has been already advocated in the past and is predicted by a chemo-dynamical model of our Galaxy that effectively introduces the…
Spiral density waves can arise in galactic disks as linear instabilities of the underlying stellar distribution function. Such an instability grows exponentially in amplitude at some fixed growth rate $\beta$ before saturating nonlinearly.…
We use a homogeneous sample of about 1100 rotation curves (RCs) and relative surface photometry to investigate (out to 2 optical radii and over 6 mag) the main mass structure properties of spirals. We confirm the strong dependence on…
We use an N-body simulation to study the 3-D density distribution of spirals, and the resulting stellar vertical velocities. Relative to the disc's rotation, the phase of the spiral's peak density away from the mid-plane trails that at the…
After a short review of the principal theories of spiral structure in galaxies, I describe two new developments. First, it now seems clear that linear theory cannot yield a full description for the development of spiral patterns because…
We study the dynamics of spiral waves and oscillation modes in relativistic rotating discs around black holes. Generalizing the Newtonian theory, we show that wave absorption can take place at the corotation resonance, where the pattern…
Dark gaps are commonly seen in early-to-intermediate type barred galaxies having inner and outer rings or related features. In this paper, the morphologies of 54 barred and oval ringed galaxies have been examined with the goal of…
This paper continues a series reporting different aspects of the behaviour of disc galaxy simulations that support spiral instabilities. The focus in this paper is to demonstrate how linear spiral instabilities saturate and decay, and how…
The environmental dependencies of the characteristics of spiral galaxy rotation curves are studied in this work. We use our large, homogeneously collected sample of 510 cluster spiral galaxy rotation curves to test the claim that the shape…
This paper concerns the interaction between non-axisymmetric inertial waves and their corotation resonances in a hydrodynamical disk. Inertial waves are of interest because they can localise in resonant cavities circumscribed by Lindblad…