Thesis

Role of the magnetic field in the formation and evolution of star-forming hub-filament systems

• Call:

  IDPASC Portugal - PHD Programme 2019

• Academic Year:

  2019 / 2020

• Domain:

  Astrophysics

• Supervisor:

  Doris Arzoumanian

• Co-Supervisor:

  Nanda Kumar

• Institution:

  Universidade do Porto

• Host Institution:

  Centro de Astrofisica da Universidade do Porto

• Abstract:

  Understanding how stars form is one of the most important and wide research topics in astrophysics. Low mass stars, like our Sun, may host planets where life could emerge, and the most massive stars govern the physics and chemical enrichment of the interstellar medium of galaxies. Although the evolutionary sequence of solar type stars is relatively well described today, the physics of the early stages of star formation is still largely unknown, especially that of high-mass stars. Recent observations of the interstellar medium (the gas and dust filling the space between stars) have revealed the impressive organization of the matter into complex networks of filaments. The densest filaments are now identified as the main birthplaces of stars and the hubs formed by the intersection of several filaments host embedded clusters of stars from low to high masses. Much progress has been accomplished in recent years on the characterization of the density and velocity structures of filaments and hubs. However, the structure of the magnetic field and its role in their formation and evolution is still unexplored. The goal of the proposed PhD project is to unveil the detailed structure of the magnetic field in star-forming hub-filament complexes. The PhD candidate is expected to analyse observations of thermal dust emission in total and polarized intensity to study the density and magnetic field structures of star-forming hub-filament systems. The data will be obtained with state-of-the-art international telescopes. The candidate will be involved in writing the observational proposals, carrying out the observations, and reducing and analysing the data. The observational results will be compared to theoretical models and numerical simulations to infer the role of the magnetic field in the physics at play in hub-filament systems and its interplay with turbulence and gravity leading to fragmentation and formation of stars. The outcome of the PhD project will provide new insights on the role of the magnetic field in the formation of hub-filament systems and their star-formation activity. These results may also be a founding block to understand the global star formation process in galaxies. The candidate will be based at IA (Porto University) and integrated to the activities of the star-formation group of CAUP. To reach the proposed scientific objectives, the PhD thesis will be co-supervised by an expert in high-mass star-formation studies from the observatory in Bordeaux (France). Several visits to Bordeaux will be planed. Close interactions with theorists in Japan are also foreseen. Thanks to the proposed project, the candidate will gain deep knowledge in the physics of the interstellar medium and star-formation studies, building strong skills in observations and developing a key sense in theoretical interpretation. The expertise acquired during the PhD will provide key opportunities for future research in star-formation studies, especially in polarization astronomy, which will be highly valued in the coming years with the numerous polarization instruments newly installed on telescopes or planned for the near future.