Related papers: The relation between dynamics and star formation i…
We have performed deep imaging of a diverse sample of 26 low surface brightness galaxies (LSBGs) in the optical and the near-infrared. Using stellar population synthesis models, we find that it is possible to place constraints on the ratio…
Using deep, narrowband imaging of the nearby spiral galaxy M101, we present stellar age information across the full extent of the disk of M101. Our narrowband filters measure age-sensitive absorption features such as the Balmer lines and…
Barred structures are widespread in a considerable fraction of galactic discs, spanning diverse environments and galaxy luminosities. The environment likely exerts a significant influence on bar formation. It is plausible that the…
More than 10% of the barred galaxies with a direct measurement of the bar pattern speed host an ultrafast bar. These bars extend beyond the corotation radius and challenge our understanding of the orbital structure of barred galaxies. Most…
The nebular properties (electronic density, extinction, age, O/H abundances) of HII regions found along the bars of the sample of barred spiral galaxies studied by Martin & Friedli (1997) are examined. From line ratio diagnostic diagrams,…
Over the last decade it has become clear that there is a decoupling between the old stellar disk and young stellar disk in spiral galaxies. This has led to a scheme for classifying galaxies on the basis of their near-infrared morphology.…
High resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred disks present spiral arms nearly…
Context. Bars are elongated structures developed by a large fraction of disk galaxies in their central few kiloparsecs. However, the bar formation process is still not fully understood, particularly the role played by the galaxy environment…
We continue the exploration of the BaLROG (Bars in Low Redshift Optical Galaxies) sample: 16 large mosaics of barred galaxies observed with the integral field unit SAURON. We quantify the influence of bars on the composition of the stellar…
The density-wave theory of galactic spiral-arm structure makes a striking prediction that the pitch angle of spiral arms should vary with the wavelength of the galaxy's image. The reason is that stars are born in the density wave but move…
In this paper we present building blocks which can explain the formation and properties both of spirals and of inner and outer rings in barred galaxies. We first briefly summarise the main results of the full theoretical description we have…
Scaling relations between galactic parameters represent key pieces of evidence for investigating the processes of galaxy formation and evolution. In most studies, these relations have been obtained for large portions of the galaxies (i.e.,…
Stars in disks of spiral galaxies are usually assumed to remain roughly at their birth radii. This assumption is built into decades of modelling of the evolution of stellar populations in our own Galaxy and in external systems. We present…
Based on the colour measurements from a multi-band, multi-component 2D decomposition's of S0 and spiral galaxies using SDSS images, we found that bars are bluer in S0 galaxies compared to the spiral galaxies. Most of the S0s in our sample…
This study numerically investigates the dynamics of barred spiral galaxies using 3D Ferrers bar response models. A total of 708 models were analyzed, incorporating variations in the axisymmetric potential (nucleus, bulge, disk, halo), bar…
We present a study of the broadband UBV color profiles for 257 Sbc barred and non-barred galaxies. In our sample, the color gradients are negative (reddish inward) in approximately 59% of the objects, are almost null in 27%, and are…
Large-scale galactic shocks, predicted by density wave theory, trigger star formation (SF-arms) downstream from the potential of the oldest stars (P-arms), resulting in a color jump from red to blue across spiral arms in the direction of…
We have done a robust statistical analysis of UBV color profiles of 257 Sbc barred and unbarred galaxies. We found that there is an excess of barred galaxies among the objects with null or positive (bluish inward) color gradients, which…
We have analyzed the redshift-dependent fraction of galactic bars over 0.2<z<0.84 in 2,157 luminous face-on spiral galaxies from the COSMOS 2-square degree field. Our sample is an order of magnitude larger than that used in any previous…
An overwhelming majority of galactic spiral arms trail with respect to the rotation of the galaxy, though a small sample of leading spiral arms has been observed. The formation of these leading spirals is not well understood. Here we show,…