We have monitored the spectral variations of the carbon rich AGB star R Scl in the 2−45 μm range using the ISO-SWS instrument. We have also computed hydrostatic and hydrodynamic model atmospheres and corresponding synthetic spectra representative for two phases of R Scl. There is good qualitative agreement between observations and models in the near IR. This demonstrates the theoretical progres...

Various models for electromagnetic emissions correlated with the gravitational wave signals expected to be detectable by the current and planned gravitational wave detectors are studied. The position error on the location of a gravitational wave source is estimated, and is used to show that it could be possible to observe the electromagnetic counterparts to neutron star-neutron star or neutron ...

Star cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent starbursts. These newly-formed clusters are built from recycled gas, pre-enriched to various levels within the interacting galaxies. Hence, star clusters of different ages represent a fossil record of the chemical enrichment history of their host galaxy, as well as of the host ...

The amount, timing and ultimate location of mass transfer and induced star formation in galaxy collisions are sensitive functions of orbital and galaxy structural parameters. I discuss the role of detailed case studies and describe the results for two systems, Arp 284 and NGC 2207/IC 2163, that have been studied with both multiwaveband observations, and detailed dynamical models. The models yie...

We include feedback in global hydrodynamic simulations in order to study the star formation properties, and gas structure and dynamics, in models of galactic disks. In previous work we studied the growth of clouds and spiral substructure due to gravitational instability.We extend thesemodels by implementing feedback in gravitationally bound clouds; momentum (due to massive stars) is injected at...

We independently redetermine the reddening and age of the globular cluster 037-B327 in M31 by comparing independently obtained multicolour photometry with theoretical stellar population synthesis models. 037-B327 has long been known to have a very large reddening value, which we confirm to be E(B − V) = 1.360 ± 0.013, in good agreement with the previous results. We redetermine its most likely a...

Relativistic spectral lines from the accretion disc of a neutron star low-mass X-ray binary can be modelled to infer the disc inner edge radius. A small value of this radius tentatively implies that the disc terminates either at the neutron star hard surface, or at the innermost stable circular orbit (ISCO). Therefore an inferred disc inner edge radius either provides the stellar radius, or can...

We present evolutionary synthesis models of starbursts on top of old stellar populations to investigate in detailed time evolution the relation between Hα luminosity and star formation rate (SFR). The models show that several effects have an impact on the ratio between L(Hα) and SFR. Metallicity different from solar abundance, a time delay between star formation and maximum Hα-luminosity, and a...

We show that the mass fraction of giant molecular cloud (GMC) gas (n 100 cm−3) in dense (n 104 cm−3) star-forming clumps, observable in dense molecular tracers (LHCN/LCO(1–0)), is a sensitive probe of the strength and mechanism(s) of stellar feedback, as well as the star formation efficiencies in the most dense gas. Using high-resolution galaxy-scale simulations with pc-scale resolution and exp...

Understanding the formation of stars in galaxies is central to much of modern astrophysics. However, a quantitative prediction of the star formation rate and the initial distribution of stellar masses remains elusive. For several decades it has been thought that the star formation process is primarily controlled by the interplay between gravity and magnetostatic support, modulated by neutral-io...