Related papers: The spiral structure of galaxies
We review progress in the development of physically realistic three dimensional simulated models of the galaxy.We consider the scales from star forming molecular clouds to the full spiral disc. Models are computed using hydrodynamic (HD) or…
Based on previously published alternative reflections on gravitation, additional conclusions concerning anomalous gravitational effects in the universe are derived. For systems with spherical mass distribution and high central density of…
Theoretical studies on the response of interstellar gas to a gravitational potential disc with a quasi-stationary spiral arm pattern suggest that the gas experiences a sudden compression due to standing shock waves at spiral arms. This…
The motion of a stellar compact object around a supermassive black hole can be approximated by the motion of a spinning test particle. The equations of motion describing such systems are in general non-integrable, and therefore, chaotic…
We derive the geodesic equation of motion in the presence of weak gravitational fields produced by relativistic sources such as cosmic strings, decomposed into scalar, vector and tensor parts. We find that the vector (gravito-magnetic)…
In spite of much work, the overall spiral structure morphology of the Milky Way remains somewhat uncertain. In the last two decades, accurate distance measurements have provided us with an opportunity to solve this issue. Using the precise…
We study equilibrium configurations of infinitely many identical particles on the real line or finitely many particles on the circle, such that the (repelling) force they exert on each other depends only on their distance. The main question…
Gravity directs the paths of light rays and the growth of structure. Moreover, gravity on cosmological scales does not simply point down: it accelerates the universal expansion by pulling outward, either due to a highly negative pressure…
The gravitational field of a particle of small mass $\mu$ moving through curved spacetime, with metric $g_{ab}$, is naturally and easily decomposed into two parts each of which satisfies the perturbed Einstein equations through $O(\mu)$.…
Spiral galaxies have distinct internal structures including a stellar bulge, disk and spiral arms. It is unknown when in cosmic history these structures formed. We analyze observations of BRI 1335-0417, an intensely star-forming galaxy in…
The physical phenomena contributing to the galaxy growth can be tested all the way to z= 1. Galaxy mass, extinction, star formation and gas metal abundance can be measured in a robust way, as well as the distribution of the galaxy…
Results from kinematic observations of the central regions of spiral galaxies are reviewed, with particular emphasis on starburst and AGN hosts. While morphological studies lead to important insight, a more complete understanding of the…
Galactic disks lie at the heart of many of the most pressing astrophysical puzzles. There are sophisticated kinetic theories that describe some aspects of galaxy disk dynamics, but extracting quantitative predictions from those theories has…
Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…
By means of simple dynamical experiments we study the combined effect of gravitational and gas dynamics in the evolution of an initially out-of-equilibrium, uniform and rotating massive over-density thought of as in isolation. The rapid…
A kinematical analysis applied to a sample of galaxy clusters indicates that the differences between the velocity distribution of elliptical and spiral galaxies are associated with the shape of their orbit families. The orbital anisotropies…
The onset of spiral structure in galaxies appears to occur between redshifts 1.4 and 1.8 when disks have developed a cool stellar component, rotation dominates over turbulent motions in the gas, and massive clumps become less frequent.…
The origin and types of spiral arms are reviewed with an emphasis on the connections between these arms and star formation. Flocculent spiral arms are most likely the result of transient instabilities in the gas that promote dense cloud…
We describe a system for the automatic quantification of structure in spiral galaxies. This enables translation of sky survey images into data needed to help address fundamental astrophysical questions such as the origin of spiral…
The force acting on the charged particle moving along an arbitrary trajectory near the straight cosmic string is calculated. This interaction leads to the scattering of particles by the cosmic string. The scattering cross section is…