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Master Colloquium |
Survi Kumari
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MPIfR/AIfA
Massive stars (≥8M⊙) are essential for the evolution of galaxies as
they influence the surrounding medium and the subsequent star formation
activity. They are much rarer than their lower-mass counterparts and are
known to be formed in dense molecular clumps. Moreover, high-mass star
forming clumps
evolve on shorter timescales, within dynamic and complex environments
and are still deeply embedded in their parent molecular cloud during the
earliest phases, making it difficult to study the initial conditions
involved. This makes the study of high-mass star forming regions
extremely important and challenging. In these early stages, the gas
temperature is low, allowing the environments to be probed by molecules
whose rotational lines lie in the sub-millimeter wavelength range.
Ammonia is a key tracer of dense gas and in dense, pre-stellar cores,
reactions with deuterated ions (such as H2D+) convert it into its
deuterated isotopologues NH2D, NHD2, and ND3. The abundance of deuterium
bound in molecules (with respect to its parent species) is orders of
magnitude higher in cold molecular clouds than the primordial [D]/[H]
ratio (∼ 10e−5, Oliveira et al. 2003). The variation in deuterium
fractionation has been used as a tracer of the evolutionary phases in
low-mass star formation, therefore in my master’s thesis I investigate
if the same can be done for the high-mass regime.