Outflows are crucially important for the gas budget and evolution of luminous star-forming galaxies and AGNs, with observed mass outflow rates of the same order as the star formation rate. Greater... Show moreOutflows are crucially important for the gas budget and evolution of luminous star-forming galaxies and AGNs, with observed mass outflow rates of the same order as the star formation rate. Greater star formation and black hole growth lead to more intense feedback and outflows, resulting in self-regulated galaxy growth. Multi-phase observations show that the cool molecular and atomic gas dominate the mass and momentum budget of massive galaxy outflows which additionally remove the direct fuel for star formation. In this thesis we target the molecular and atomic outflows at cosmic noon and dawn where the most extreme star formation and black hole activity is found but where current observations are severely lacking. Techniques commonly used to detect outflows in the nearby universe with emission lines are, however, challenging or impossible with current technology at the high-redshifts of this thesis. Molecular absorption lines provide a powerful and reliable alternative which is demonstrated with the OH+ and OH molecules in this thesis. With observations from the Atacama Large Millimeter/submillimeter Array (ALMA), this thesis provides cutting-edge comparisons of molecular/neutral outflows at cosmic dawn/noon between star-forming galaxies and dusty quasar hosts. Show less
Butler, K.M.; Werf, P.P. van der; Topkaras, T.; Rybak, M.; Venemans, B.P.; Walter, F.; Decarli, R. 2023
The origin and evolution of galaxies are closely tied to the cyclic feedback processes between stars and the interstellar medium (ISM). The aim of this thesis is to explore characteristics of the... Show moreThe origin and evolution of galaxies are closely tied to the cyclic feedback processes between stars and the interstellar medium (ISM). The aim of this thesis is to explore characteristics of the ISM, on global (galactic) scales down to sub-cloud (pc) scales. We explore new methods to investigate the ISM in external galaxies, through radio recombination line observations, and develop the tools and strategies needed to process new low-frequency observations with the Low Frequency Array. We also infer the presence of massive stars and characterize their properties and influence on the ISM. This thesis addresses the questions:- How does low-density ionized gas affect the evolution of the massive, galactic star-forming region, Cygnus X? Are the same fingerprints present in surveys of low-density ionized gas in our Galaxy?- What are the properties of star formation (star clusters) in the central starburst of the galaxy NGC 4945?- Can the ISM be explored outside of the local universe through radio recombination line observations? What are the ISM properties of a dwarf-like galaxy at z=1.1?- What techniques are best suited to detect faint radio recombination lines (at a previously unknown redshift) in extragalactic sources? Show less
Levy, R.C.; Bolatto, A.D.; Leroy, A.K.; Emig, K.L.; Gorski, M.; Krieger, N.; ... ; Zwaan, M.A. 2021
The space between stars is filled with a dilute mixture of atoms, molecules, and dust grains, which we call the interstellar medium (ISM). The physics of the ISM is a crucial part in many areas of... Show moreThe space between stars is filled with a dilute mixture of atoms, molecules, and dust grains, which we call the interstellar medium (ISM). The physics of the ISM is a crucial part in many areas of astronomy, such as the formation and evolution of stars and entire galaxies. It regulates molecule- and dust grain synthesis, which together constitute the very building blocks of planetesimals required to form planetary systems and, ultimately, life itself. Recent observations have revealed that a significant fraction of the ISM is dynamic and filamentary, likely caused by radiation, winds, and supernova explosions from massive stars that constantly stir the material that resides in the ISM. However, the exact mechanisms and contributions of these interactions remain poorly understood. To advance our knowledge of the ISM of galaxies, in first principle, we need to acquire a deep understanding of the interplay between stars and their surroundings. In this thesis, I investigate the interactions between gas, dust, and stars in the ISM, by using the Orion region as a benchmark model. Show less
