The CoRoT and Kepler space missions have commenced a golden era in the field of asteroseismology. The precise and long-term uninterrupted photometric time series from space, now available for thousands of stars, enable the detection of low-amplitude frequencies, revealing new and surprising pulsational results. From the following overview of the

We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the source made during outburst (with the Rossi X-ray Timing Explorer) reveal tracks in its X-ray color-color and hardness-intensity diagrams that closely resemble those of the neutron-star Z

We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 1 is already significant by z ~ 0.3.

The topic of this thesis is the study of the morphology, kinematics and star formation of nearby galaxies, aiming to clarify a number of long-standing open questions about their formation, evolution and physical properties. First, I have addressed the star formation and its distribution across the Hubble sequence of galaxies. In particular, I have

The heart of this thesis is the study of the multifrequency behaviour of a very special family of active galactic nuclei (AGNs) called blazars. The emission of these sources is generally dominated by non-thermal radiation from a plasma jet, making them the best candidates to investigate the properties of jets in AGNs. We present an analysis of the

The evolution and fate of very massive stars (VMS) is tightly connected to their mass-loss properties. Their initial and final masses differ significantly as a result of mass loss. VMS have strong stellar winds and extremely high ionising fluxes, which are thought to be critical sources of both mechanical and radiative feedback in giant H ii