The focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed. With arrays of radio telescopes, I observed the environments where the first stages of... Show moreThe focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed. With arrays of radio telescopes, I observed the environments where the first stages of star and planet formation occur. This thesis focuses on characterizing different components of young protostellar systems, most notably their jets and disks. Using interferometric radio observations with ALMA array, I provided information on key chemical tracers of different components of the protostellar systems. By characterizing the radio signal from young stars with ALMA and VLA interferometers, I was able to disentangle an emission from the jet and the disk. This led to an unexpected development: I was able to compare dust masses of young disks with those of older disks for the first time. By comparing this information with masses of the extrasolar planets detected so far I showed that the solid cores of gas giants must form in the first 0.1 Myr of stellar life. That is an important time constrain, that pushes the onset of planet formation earlier and highlights the importance of characterization of the youngest protostars in understanding the origin of Solar System and Earth. Show less
The formation and evolution of galaxies is fundamentally driven by the formation of new stars out of cold gas. Observations of young stars in distant galaxies in the early universe, such as we can... Show moreThe formation and evolution of galaxies is fundamentally driven by the formation of new stars out of cold gas. Observations of young stars in distant galaxies in the early universe, such as we can see in the Hubble Ultra Deep Field, have unveiled how the cosmic star formation rate density evolves. Yet, while the effect of star formation—the young stars—has been mapped in ever-increasing detail, the cause—the cold molecular gas that fuels star formation—has been elusive. This thesis presents an observational study of the cold interstellar medium of distant galaxies in the early universe, using the most sensitive submillimeter telescope to date, the Atacama Large Millimeter Array, together with new integral-field spectrographs, such as the Multi Unit Spectroscopic Explorer on the Very Large Telescope. It unveils the physical properties of star-forming galaxies and their molecular gas reservoirs, and describes the evolution of the cosmic molecular gas density—the fuel for star formation. Show less
Radio observations provide a unique view of black holes in the Universe. This thesis presents low frequency radio images and uses the radio sources in those images to study the evolution of black... Show moreRadio observations provide a unique view of black holes in the Universe. This thesis presents low frequency radio images and uses the radio sources in those images to study the evolution of black holes and galaxies through the age of the Universe. Show less
In this thesis we use the very large telescope interferometer in order to observe dust residing in the nuclei of active galaxies. We compare our observations with the commonly accepted unified... Show moreIn this thesis we use the very large telescope interferometer in order to observe dust residing in the nuclei of active galaxies. We compare our observations with the commonly accepted unified model for active galaxies Show less
