Quantitative Spectroscopy of Early-Type Stars

The chemical and structural evolution of galaxies is dominated by the evolution of massive early-type stars because these objects are the progenitors of core-collapse supernova explosions, which shape their ambient interstellar medium by injecting large amounts of energy and processed matter to it. Understanding those stars is thus a necessary prerequisite for understanding our universe. Determining atmospheric parameters and chemical elemental surface abundances, i.e., carrying out a quantitative spectroscopic analysis, with very high precision is the first and probably most crucial step in this search for insight.

Comparison of observed (black line) and best-fitting synthetic (red line) spectrum for a B-type star (Courtesy of A. Irrgang).

Our working group performs cutting-edge research on spectral diagnostics of early-type stars. For instance, we make use of state-of-the-art radiative transfer codes which are continuously developed further by us. Moreover,  we are steadily trying to improve our analysis strategy. For example, two new features have been recently added to our analysis procedure, namely the possibility to analyze spectra of pulsating stars as well as of double-lined spectroscopic binary systems.

Research fields in our working group cover a variety of different topics related to the quantitative spectroscopy of early-type stars, such as the present-day chemical composition in the solar neighborhood as anchor point for Galactic chemical evolution models, chemically peculiar stars, the nature and origin of runaway and hypervelocity stars, stellar pulsations, and the evolution of stars in binary systems.