Related papers: The Long-term Evolution of the Galactic Disk Trace…
We present our recent results on the properties of the outskirts of disk galaxies. In particular, we focus on spiral galaxies with stellar disk truncations in their radial surface brightness profiles. Using SDSS, UDF and GOODS data we show…
The problem of dynamical heating of galactic discs by spiral density waves is discussed using the shearing sheet model. The secular evolution of the disc is described quantitatively by a diffusion equation for the distribution function of…
Dynamical evolution plays a key role in shaping the current properties of star clusters and star cluster systems. A detailed understanding of the effects of evolutionary processes is essential to be able to disentangle the properties which…
Open and globular star clusters have served as benchmarks for the study of stellar evolution due to their supposed nature as simple stellar populations of the same age and metallicity. After a brief review of some of the pioneering work…
The dark matter distribution of the Milky Way remains among the major unsolved problems about our home galaxy. The masses of other spiral galaxies can be determined from their rotation curves through long-slit spectroscopy. But for the…
Stellar migration, whether due to trapping by transient spirals (churning), or to scattering by non-axisymmetric perturbations, has been proposed to explain the presence of stars in outer disks. After a review of the basic theory, we…
Since stellar populations enhance particular element abundances according to the yields and lifetimes of the stellar progenitors, the chemical evolution of galaxies serves as one of the key tools that allows the tracing of galaxy evolution.…
We show that spiral waves in galaxy discs churn the stars and gas in a manner that largely preserves the overall angular momentum distribution and leads to little increase in random motion. Changes in the angular momenta of individual stars…
Evolution of galaxies is one of the most actual topics in astrophysics. Among the most important factors determining the evolution are two galactic components which are difficult or even impossible to detect optically: the gaseous disks and…
The Milky Way is a spiral galaxy comprising three main components: the Bulge, the Disk, and the Halo. Of particular interest is the Galactic disk, which holds a significant portion of the baryonic matter angular momentum and harbors at…
The stellar populations of the stellar halo and of the thick disk of the Milky Way reveal much about the merging history that our Galaxy, a typical large disk galaxy, has experienced. Our current understanding, described here, implies a…
Observations of circumstellar disks around stars as a function of stellar properties such as mass, metallicity, multiplicity, and age, provide constraints on theories concerning the formation and evolution of planetary systems. Utilizing…
Deep photometric surveys of the Milky Way have revealed diffuse structures encircling our Galaxy far beyond the "classical" limits of the stellar disk. This paper reviews results from our own and other observational programs, which together…
The star formation rate history of the Milky Way is derived using the chromospheric age distribution for 552 stars in the solar neighborhood. The stars sample birthsites distributed over a very large range of distances because of orbital…
Here we discuss impacts of distance determinations on the Galactic disk traced by relatively young objects. The Galactic disk, about 40 kpc in diameter, is a cross-road of studies on the methods of measuring distances, interstellar…
Dust constitutes only about one percent of the mass of circumstellar disks, yet it is of crucial importance for the modeling of planet formation, disk chemistry, radiative transfer and observations. The initial growth of dust from…
We study the effect of stellar evolution on the dispersal of protoplanatary disks by performing one-dimensional simulations of long-term disk evolution. Our simulations include viscous disk accretion, magnetohydrodynamic winds, and…
We use recent observations of high-redshift galaxies to study the evolution of galactic disks over the redshift range 0<z<1. The data are inconsistent with models in which disks were already assembled at z=1 and have evolved only in…
Frankel et al (2020) reported that the rate of diffusion in angular momentum by stars in the disk of the Milky Way was about ten times faster than the rate of heating, which places a stringent requirement on the nature of disk star…
This contribution presents an overview of the evolution of Li abundances in stars of the Galactic thin and thick discs, from the observational point of view. The focus is on Li abundances obtained by recent projects and surveys. To separate…