Context. Starbursts and substantial variations in the star formation histories are a common phenomenon in galaxies. Although predominantly found in interacting galaxies, they also occur in isolated galaxies. Aims. We study the stability properties of isolated star-forming dwarf galaxies with the aim of identifying starburst modes. The impact of the stellar birth function, i.e. a spontaneous and...

Aims. We investigate the nature of the massive star [OMN2000] LS1 and use these results to constrain the history of star formation within the host complex W51. Methods. We utilised a combination of near-IR spectroscopy and non-LTE model atmosphere analysis to derive the physical properties of [OMN2000] LS1, and a combination of theoretical evolutionary calculations and Monte Carlo simulations t...

Nuclear star clusters (NSCs) are the densest stellar systems in Universe and found centres of all types galaxies. They thought to form via mergers such as ancient globular (GCs) that spiral centre a result dynamical friction or through situ formation directly at galaxy centre. There is evidence both paths occur, but relative contribution either channel their correlation with properties not yet ...

Aims. This study of 117 low-redshift Im and Sm galaxies investigates the star formation rates of late-type galaxies, to determine whether they are quasi-continuous or dominated by bursts with quiescent interludes. Methods. We analyse the distribution of star formation timescales (stellar masses/star formation rates) for the entire sample, and of gas depletion timescales for those galaxies with ...

We model gravitational instability in a wide range of isolated disk galaxies, using GADGET, a three-dimensional, smoothed particle hydrodynamics code. The model galaxies include a dark matter halo and a disk of stars and isothermal gas. Absorbing sink particles are used to directly measure the mass of gravitationally collapsing gas. Below the density at which they are inserted, the collapsing g...

It has been argued that the specific star formation rates of star-forming galaxies inferred from observational data decline more rapidly below z = 2 than is predicted by hierarchical galaxy formation models. We present a detailed analysis of this problem by comparing predictions from the GALFORM semi-analytic model with an extensive compilation of data on the average star formation rates of sta...

Recently, there has been great progress toward observationally determining the mean star formation history of the universe. When accurately known, the cosmic star formation rate could provide much information about Galactic evolution, if the Milky Way’s star formation rate is representative of the average cosmic star formation history. A simple hypothesis is that our local star formation rate i...