Unveiling a multiscale view of massive star and cluster formation
Licentiate thesis, 2022
This licentiate thesis first presents a study of a massive protostar (G28.2-0.05) that appears to be forming in relative isolation. Observational data, especially from the Atacama Large Millimeter/Submillimeter Array (ALMA), are used to investigate the nature of the system, including its dense and ionized gas structures, small-scale kinematics and dynamics and large-scale outflows. Mid to Far Infrared observations and archival data are used to measure the spectral energy distribution (SED) to further constrain protostellar properties. We conclude the system is a massive (∼ 24 M ) protostar that has an accretion powered wide angle bipolar molecular outflow and is also in the first stages of producing significant ionizing feedback. An examination of the mm dust continuum emission in the surroundings finds a near complete dearth of other sources, which is evidence for the system’s isolation and a strong constraint on competitive accretion models. Overall, core accretion models appear to give a good description of the protostar.
We also present first results of an observational program that attempts to use molecular gas kinematics and dust polarized continuum emission to measure properties of turbulence and magnetic fields across a range of scales from GMCs to IRDCs to individual massive protostars. We discuss the methods to be used and present the first data collected for the project. The overall work of this thesis leads in a direction of characterization of both large-scale molecular cloud environments and individual massive protostars forming within them to reveal a holistic, multi-scale view of the birth of massive stars and clusters
Star Formation
Author
Chi Yan Law
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
The links between magnetic fields and filamentary clouds - III. Field-regulated mass cumulative functions
Monthly Notices of the Royal Astronomical Society,;Vol. 498(2020)p. 850-858
Journal article
Filament Rotation in the California L1482 Cloud
Astrophysical Journal,;Vol. 908(2021)
Journal article
ALMA-IRDC: dense gas mass distribution from cloud to core scales
Monthly Notices of the Royal Astronomical Society,;Vol. 503(2021)p. 4601-4626
Journal article
ALMA-IRDC - II. First high-angular resolution measurements of the N-14/N-15 ratio in a large sample of infrared-dark cloud cores
Monthly Notices of the Royal Astronomical Society,;Vol. 503(2021)p. 4320-4335
Journal article
Subject Categories
Astronomy, Astrophysics and Cosmology
Infrastructure
C3SE (Chalmers Centre for Computational Science and Engineering)
Onsala Space Observatory
Publisher
Chalmers
EA Lecture Hall, Hörsalsvägen 11
Opponent: Prof. James M. Jackson, Green Bank Observatory, US