The star-formation rate and turbulent dissipation in galactic models

Star Formation and Galactic Evolution

Fragmentation and Star Formation in Turbulent Cores

We examine the conditions under which binary and multiple stars may form out of turbulent molecular cloud cores using high resolution 3-D, adaptive mesh refinement (AMR) hydrodynamics (Truelove et al., 1997, 1998; Klein, 1999). We argue that previous conclusions on the conditions for cloud fragmentation have limited applicability, since they did not allow for the nonlinear density and velocity ...

Star Formation from Turbulent Fragmentation

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material. Efficiency, spatial distribution and timescale of star formation in turbulent clouds are estimated by comparing numerical models of self-gravitating...

Density Structure of the Interstellar Medium and the Star Formation Rate in Galactic Disks

The probability distribution functions (PDF) of density of the interstellar medium (ISM) in galactic disks and global star formation rate are discussed. Three-dimensional hydrodynamic simulations show that the PDFs in globally stable, inhomogeneous ISM in galactic disks are well fitted by a single lognormal function over a wide density range. The dispersion of the log-normal PDF (LN-PDF) is lar...

Star Formation Histories of the Galactic Satellites

Late accretion models for formation of the Galactic halo require that many Galactic satellite galaxies have been cannibalised into the halo field. Comparison of the metallicity and age distribution function of stars in the surviving satellites with the apparently exclusively old stars in the field halo can constrain the importance of any such process. We have developed a new objective technique...