The Low Frequency Array enables studies of low-frequency carbon radio recombination lines with unprecedented sensitivity, spectral and spatial resolution. In this thesis we benefit from the... Show moreThe Low Frequency Array enables studies of low-frequency carbon radio recombination lines with unprecedented sensitivity, spectral and spatial resolution. In this thesis we benefit from the capabilities of LOFAR to study the cold interstellar medium through carbon radio recombination lines. We find that at low-frequencies these lines trace cold gas, associated with the C+/CI/CO interface of photo-dissociation regions. This opens up the possibility to study these interfaces over large regions of the Milky Way. Show less
Laboratory, observation and modeling work on the dissociation of polycyclic aromatic hydrocarbons in interstellar environments and the formation of new molecular species through the fragmentation... Show moreLaboratory, observation and modeling work on the dissociation of polycyclic aromatic hydrocarbons in interstellar environments and the formation of new molecular species through the fragmentation process. Show less
Schnitzeler, Dominic Hubertus Franciscus Maria 2008
In this thesis I use the novel technique of Rotation Measure synthesis (RMS) to study the Galactic interstellar medium. With RMS we can study Faraday rotation and synchrotron emission along the... Show moreIn this thesis I use the novel technique of Rotation Measure synthesis (RMS) to study the Galactic interstellar medium. With RMS we can study Faraday rotation and synchrotron emission along the line of sight. I apply RMS to 4 data sets that we obtained with the WSRT. With RMS we can separate the signal of a polarized extragalactic source from the signal from our own Milky Way. Depending on the viewing direction in the Milky Way, the rotation measures of extragalactic sources and diffuse emission (dis)agree. We supplement our observations with MHD simulations of the Galactic ISM, to better understand how we can interpret the observed features as structure in the Galactic ISM and the Galactic magnetic field. Finally, we combined our results with literature values on pulsars, extragalactic sources, and the diffuse emission. We found a way to calculate the electron-density weighted line-of-sight magnetic field strength from the RM and DM that we can either measure or model for these sources. With all this information we determined that the large-scale magnetic field in the second Galactic quadrant shows much more structure than what the currently best available model can predict. Show less
