Related papers: Post-T Tauri stars: a false problem
I briefly review recent observations of regions forming low mass stars. The discussion is cast in the form of seven questions that have been partially answered, or at least illuminated, by new data. These are the following: where do stars…
We review observational evidence and open issues related to the process of magnetospheric accretion in T Tauri stars. Emphasis is put on recent numerical simulations and observational results which suggest that the interaction between the…
We review the history and structure of star formation in the Taurus-Auriga dark clouds. Our discussion includes a summary of the macroscopic cloud properties, the population of single and binary pre-main sequence stars, the properties of…
We review the present knowledge of disk accretion in young low mass stars, and in particular, the mass accretion rate and its evolution with time. The methods used to obtain mass accretion rates from ultraviolet excesses and emission lines…
Stellar population models with abundance distributions determined from the analytic Simple model of chemical evolution fail to match observations of the nuclei of bulge-dominated galaxies in three respects. First, the spectral energy…
We revisit the problem of the formation of dense protostellar cores due to ambipolar diffusion within magnetically supported molecular clouds, and derive an analytical expression for the core formation timescale. The resulting expression is…
In this short communication I compare recent findings suggesting a low binary star fraction for late type stars with knowledge concerning the forms of the stellar initial and present day mass functions for masses down to the hydrogen…
Using studies of nearby star formation with Spitzer, I will argue that star formation is restricted to dense cores within molecular clouds. The nature of these dense cores and their connection to star formation will be discussed. Their…
How do stars manage to form within low-density, HI-dominated gas? Such environments provide a laboratory for studying star formation with physical conditions distinct from starbursts and the metal-rich disks of spiral galaxies where most…
An overview of our current understanding of the formation and evolution of star clusters is given, with main emphasis on high-mass clusters. Clusters form deeply embedded within dense clouds of molecular gas. Left-over gas is cleared within…
We study star formation history and stellar metallicity distribution in galaxies in a Lambda cold dark matter universe using a hydrodynamic cosmological simulation. Our model predicts star formation rate declining in time exponentially from…
We construct a protostellar disk model that takes into account the combined effect of viscous evolution, photoevaporation and the differential radial motion of dust grains and gas. For T Tauri disks, the lifetimes of dust disks that are…
Early-type galaxies are considered to be the end-products of massive galaxy formation. Optical spectroscopic studies reveal that massive early-type galaxies formed the bulk of their stars over short timescales (1<Gyr) and at high redshift…
We report mid--IR observations of two young stars found in the Taurus dark cloud spatially resolving for the first time their 10 $\mu$m emission. The weak-emission T Tauri star DI Tau, tentatively identified by Skrutskie et al. (1990) on…
We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…
Our current knowledge of carbon stars in the Local Group and beyond, is discussed. Although many carbon stars and late M-stars have been identified in external galaxies a coherent understanding in terms of the chemical evolution- and star…
Early-type galaxies are not the simple Population II systems they have long been assumed to be. While upwards of 80% of the stellar mass of early-type galaxies likely formed at high redshift, small frostings of intermediate-age stellar…
Transition disc systems are young stars that appear to be on the verge of dispersing their protoplanetary discs. We explore the nature of these systems by comparing the stellar accretion rates and disc masses of transition discs and normal…
Residual gas in disks around young stars can spin down stars, circularize the orbits of terrestrial planets, and whisk away the dusty debris that is expected to serve as a signpost of terrestrial planet formation. We have carried out a…
An objective prism H alpha survey has shown that there is a population of early type spiral galaxies in nearby clusters with strong central bursts of star formation which could be due to galaxy--galaxy tidal interactions. Such galaxies are…