Related papers: Galaxy formation and chemical evolution
The disks of Active Galactic Nuclei (AGNs) are expected to be populated by numerous stars, either formed in the outer regions of the disk via gravitational instability, or captured from the nearby nuclear star cluster. Regardless of their…
So how did the Galactic disk form and can the sequence of events ever be unravelled from the vast stellar inventory? This will require that some of the residual inhomogeneities from prehistory escaped the dissipative process at an early…
Using modern published data on velocities and spectroscopic definitions of chemical elements in stellar objects of the Galaxy, we investigated the relationship of chemical composition with the kinematics of different populations. The paper…
We develop a model for the outer gravitationally unstable regions of accretion disks around massive black holes, for primeval or solar abundances. First we study star formation and evolution in a purely gaseous marginally unstable disk, and…
Initial conditions are set by Big bang nucleosynthesis from which we know that 90 per cent of baryons are dark and have essentially unknown chemical composition. In our own Galaxy, there are many clues from individual stars in different…
Dramatic recent progress in understanding galactic chemical evolution (GCE) has been driven partly by direct observations of the distant past with HST and JWST of stellar abundances from giant high-resolution spectroscopic surveys (APOGEE,…
Elements heavier than hydrogen and helium, collectively termed metals, were created inside stars and dispersed through space at the final stages of stellar evolution. The relative amounts of different isotopes (variants of the same element…
Here we explore the evolution of galaxy ensembles at early times by writing the in situ stellar mass growth of galaxies purely as a stationary stochastic (e.g., quasi-steady state) process. By combining the mathematics of such processes…
The determination of chemical abundances in star-forming galaxies and the study of their evolution on cosmological timescales are powerful tools for understanding galaxy formation and evolution. This contribution presents the latest results…
Galaxy interactions expel a significant amount of stars and gas into the surrounding environment. I review the formation and evolution of the tidal debris spawned during these collisions, and describe how this evolution depends on the large…
The {\it best} chemical evolution models for the galactic disk computed by different groups with different assumptions are compared with each other and with the observational constraints. Differences and similarities between the models are…
The Milky Way is surrounded by large amounts of gaseous matter that are slowly being accreted over cosmic timescales to support star formation in the disk. The corresponding gas-accretion rate represents a key parameter for the past,…
We analyze the evolution of oxygen abundance radial gradients resulting from our chemical evolution models calculated with different prescriptions for the star formation rate (SFR) and for the gas infall rate, in order to assess their…
We reexamine the systematic properties of local galaxy populations, using published surveys of star formation, structure, and gas content. After recalibrating star formation measures, we are able to reliably measure specific star formation…
The cosmic star formation rate density first increases with time towards a pronounced peak 10 Gyrs ago (or z=1-2) and then slows down, dropping by more than a factor 10 since z=1. The processes at the origin of the star formation quenching…
We use a semi-analytic model for disk galaxies to explore the origin of the time evolution and small scatter of the galaxy SFR sequence -- the tight correlation between star-formation rate (SFR) and stellar mass (M_star). The steep decline…
Ongoing accretion of low-metallicity gas onto the disk is a natural prediction of semi-analytical Galactic chemical evolution models. This star formation fuel ameliorates the overproduction of metal-poor G- and K-dwarfs in the solar…
Dynamical evolution of spiral galaxies is strongly dependent on non-axisymmetric patterns that develop from gravitational instabilities, either spontaneously or externally triggered. Some evolutionary sequences are described through which a…
In this review we re-evaluate our observational and theoretical understanding of the chemical evolution of protoplanetary disks. We discuss how improved observational capabilities have enabled the detection of numerous molecules exposing an…
Long-term evolution of a stellar orbit captured by a massive galactic center via successive interactions with an accretion disc has been examined. An analytical solution describing evolution of the stellar orbital parameters during the…