Related papers: On the Timescale for Star Formation in Galaxies
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…
I review observational studies of the large-scale star formation process in nearby galaxies. A wealth of new multi-wavelength data provide an unprecedented view on the interplay of the interstellar medium and (young) stellar populations on…
The physics of star formation and the deposition of mass, momentum, and energy into the interstellar medium by massive stars (`feedback') are the main uncertainties in modern cosmological simulations of galaxy formation and evolution. These…
We offer a simple parameterization of the rate of star formation in galaxies. In this new approach, we make explicit and decouple the timescales associated (a) with disruptive effects the star formation event itself, from (b) the timescales…
The concept that stars form in the modern era began some 60 years ago with the key observation of expanding OB associations. Now we see that these associations are an intermediate scale in a cascade of hierarchical structures that begins on…
Star formation depends on the available gaseous "fuel" as well as galactic environment, with higher specific star formation rates where gas is predominantly molecular and where stellar (and dark matter) densities are higher. The partition…
Young galaxies are clumpy, gas-rich, and highly turbulent. Star formation appears to occur by gravitational instabilities in galactic disks. The high dispersion makes the clumps massive and the disks thick. The star formation rate should be…
Observations of the interstellar medium are key to deciphering the physical processes regulating star formation in galaxies. However, observational uncertainties and detection limits can bias the interpretation unless carefully modeled.…
The inner few hundred parsecs of the Milky Way harbours gas densities, pressures, velocity dispersions, an interstellar radiation field and a cosmic ray ionisation rate orders of magnitude higher than the disc; akin to the environment found…
It has been known for more than 30 years that star formation in giant molecular clouds (GMCs) is slow, in the sense that only ~1% of the gas forms stars every free-fall time. This result is entirely independent of any particular model of…
We use the first systematic data sets of CO molecular line emission in z~1-3 normal star forming galaxies for a comparison of the dependence of galaxy-averaged star formation rates on molecular gas masses at low and high redshifts, and in…
We estimate a characteristic timescale for star formation in the spiral arms of disk galaxies, going from atomic hydrogen (HI) to dust-enshrouded massive stars. Drawing on high-resolution HI data from The HI Nearby Galaxy Survey and…
We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time,…
Observations suggest that star formation occurs in only one or two crossing times for a range of scales spanning a factor of 1000. These observations include (1) measurements of embedded cluster ages in comparison with the cloud core…
We argue for implementing star formation on a viscous timescale in hydrodynamical simulations of disk galaxy formation and evolution. Modelling two-dimensional isolated disk galaxies with the Bhatnagar-Gross-Krook (BGK) hydrocode, we verify…
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…
Over the past decade increasingly robust estimates of the dense molecular gas content in galaxy populations between redshift 0 and the peak of cosmic galaxy/star formation from redshift 1-3 have become available. This rapid progress has…
From the time the first stars formed over 13 billion years ago to the present, star formation has had an unexpectedly dynamic history. At first, the star formation rate density increased dramatically, reaching a peak 10 billion years ago…
The formation and evolution of galactic disks are complex phenomena, where gas and star dynamics are coupled through star formation and the related feedback. The physical processes are so numerous and intricate that numerical models focus,…
Observations show that star formation in galaxies is closely correlated with the abundance of molecular hydrogen. Modeling this empirical relation from first principles proves challenging, however, and many questions regarding its…