Related papers: Counter-Rotation in Disk Galaxies
Kinematical decoupling between two components of a galaxy suggests the occurrence of a second event. In disk galaxies it is usually observed as a counterrotation of the stellar disk with respect to the gaseous component and/or with respect…
Understanding galaxy evolution is key to explaining the structures we observe in the present-day Universe. Counterrotating stellar disks (CRDs), i.e. co-spatial stellar disks rotating with opposite angular momentum, have been proposed as…
In this contribution, we investigate the scenario of major mergers between galaxies of comparable mass to the formation of massive counter-rotating disks. Such a scenario can be ruled out in general because they produce rather ellipticals.…
Can the present dynamics of spiral galaxies tell us something about the merging history, the formation and evolution of disks? Galaxy interactions thicken or destroy disks; the simultaneous presence of thick and thin disks is a tracer of…
Recent observations have revealed the structural properties of the dark and luminous mass distribution in spirals. These results led to the vision of a new and amazing scenario. The investigation of single and coadded objects has shown that…
We present an alternate origin scenario to explain the observed phenomena of (1) counter-rotation between different galaxy components and (2) the formation of ring galaxies. We suggest that these are direct consequences of the galaxy being…
With the help of high-resolution long-slit and integral-field spectroscopy observations, the number of confirmed cases of galaxies with counterrotation is increasing rapidly. The evolution of such counterrotating galaxies remains far from…
Asymmetries in the distribution of light and neutral hydrogen are often observed in spiral galaxies. Here, attention is drawn to the presence of large-scale asymmetries in their kinematics. Two examples of kinematically lopsided galaxies…
In order to try and understand its origins, we present high-quality long-slit spectral observations of the counter-rotating stellar discs in the strange S0 galaxy NGC 4550. We kinematically decompose the spectra into two counter-rotating…
Counter-rotating components in galaxies are one of the most direct forms of evidence for past gas accretion or merging. We discovered ten edge-on disk gaseous counter-rotators in a sample of 523 edge-on galaxies identified in the final…
Stellar counterrotating (CR) galaxies are systems hosting two large-scale stellar components rotating in opposite directions -- a main, preexisting galaxy body with an older stellar population and a younger CR stellar disk likely formed…
We have identified two new galaxies with gas counter-rotation (NGC1596 and NGC3203) and have confirmed similar behaviour in another one (NGC128), this using results from separate studies of the ionized-gas and stellar kinematics of a…
Context. Many disk galaxies host two extended stellar components that rotate in opposite directions. The analysis of the stellar populations of the counter-rotating components provides constraints on the environmental and internal processes…
Stars in galaxies form from the cold rotationally supported gaseous disks that settle at the center of dark matter halos. In the simplest models, such angular momentum is acquired early on at the time of collapse of the halo and preserved…
(Reduced)Using the NewHorizon simulation, we have studied ten gas-versus-star counter-rotating galaxies in field environments with a stellar mass of M*~[1-5]x10^10 Msun. For all of them, the retrograde accretion of gas either from gas…
Disks of bodies orbiting a much more massive central object are extremely common in astrophysics. When the orbits comprising such disks are eccentric, we show they are susceptible to a new dynamical instability. Gravitational forces between…
Galaxies are observed to obey a strict set of dynamical scaling relations. We review these relations for rotationally supported disk galaxies spanning many decades in mass, surface brightness, and gas content. The behavior of these widely…
We review the topic of rotation curves of spiral galaxies emphasizing the standard interpretation as evidence for the existence of dark matter halos. Galaxies other than spirals and late-type dwarfs may also possess great amounts of dark…
Ionized gas and stellar kinematics have been measured along the major axes of seventeen nearby spiral galaxies of intermediate to late morphological type. We discuss the properties of each sample galaxy distinguishing between those…
The ability of digital sky surveys to collect and store very large amounts of data provides completely new ways to study the local universe. Perhaps one of the most provocative observations reported with such tools is the asymmetry between…