Related papers: Star Formation during Galaxy Formation
Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…
Empirical star formation laws from the last 20 years are reviewed with a comparison to simulations. The current form in main galaxy disks has a linear relationship between the star formation rate per unit area and the molecular cloud mass…
Young stars form on a wide range of scales, producing aggregates and clusters with various degrees of gravitational self-binding. The loose aggregates have a hierarchical structure in both space and time that resembles interstellar…
Properties of normal galactic star formation, including the density dependence, threshold density, turbulent scaling relations, and clustering properties, are applied to the formation of galactic bulges. One important difference is that the…
Galaxies above redshift 1 can be very clumpy, with irregular morphologies dominated by star complexes as large as 2 kpc and as massive as a few 10^8 or 10^9 Mo. Their co-moving densities and rapid evolution suggest that most present-day…
The empirical laws of star formation suggest that galactic-scale gravity is involved, but they do not identify the actual triggering mechanisms for clusters in the final stages. Many other triggering processes satisfy the empirical laws…
Processes that promote the formation of dense cold clouds in the interstellar media of galaxies are reviewed. Those that involve background stellar mass include two-fluid instabilities, spiral density wave shocking, and bar accretion. Young…
Galaxy disk formation must incorporate the multiphase nature of the interstellar medium. The resulting two-phase structure is generated and maintained by gravitational instability and supernova energy input, which yield a source of…
Star formation occurs in hierarchical patterns in both space and time. Galaxies form large regions on the scale of the interstellar Jeans length and these large regions apparently fragment into giant molecular clouds and cloud cores in a…
Recent studies of galaxies ~2-3 Gyr after the Big Bang have revealed large, turbulent rotating systems. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation may suggest that gas accretion…
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…
Recent observations have revealed massive galactic molecular outflows that may have physical conditions (high gas densities) required to form stars. Indeed, several recent models predict that such massive galactic outflows may ignite star…
Star formation in strongly self-gravitating cloud cores should be similar at all redshifts, forming single or multiple stars with a range of masses determined by local magneto-hydrodynamics and gravity. The formation processes for these…
Stars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of…
The rate of star formation varies between galaxy types and evolves with redshift. Most stars in the universe have formed in episodes of an exceptionally high star-forming activity, commonly called a starburst. We here summarize basic…
In the present-day universe, it appears that most, and perhaps all, massive stars are born in star clusters. It also appears that all star clusters contain stars drawn from an approximately universal initial mass function, so that almost…
Observations of high redshift galaxies have revealed a multitude of large clumpy rapidly star-forming galaxies. Their formation scenario and their link to present day spirals is still unknown. In this Letter we perform adaptive mesh…
Although the basic physics of star formation is classical, numerical simulations have yielded essential insights into how stars form. They show that star formation is a highly nonuniform runaway process characterized by the emergence of…
How stars are born from clouds of gas is a rich physics problem whose solution will inform our understanding of not just stars but also planets, galaxies, and the universe itself. Star formation is stupendously inefficient. Take the Milky…
The conversion of gas into stars is a fundamental process in astrophysics and cosmology. Stars are known to form from the gravitational collapse of dense clumps in interstellar molecular clouds, and it has been proposed that the resulting…