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The NGC 6334 Star Forming region

Most stars tend to form within embedded clusters containing high-mass stars. Therefore, the embedded clusters (i.e., protoclusters) with masses larger than 100 M are the primary laboratories to constrain the physical process by which high-mass stars form.

To study (high-) mass star formation in cluster environment, we firstly need to characterise the physical properties of the young massive protoclusters such as core mass function and the spatial distribution of the cluster members which can be highly affected by the interaction between the members as well as the mechanical feedback and turbulence.

Furthermore, it is necessary to study how material is transported from the large-scale filament to the protoclusters and their members.  In this science project, we have used ALMA as the largest ground-based facility for observations at mm/submm wavelengths to image the massive protoclustets in NGC 6334 filamentary cloud as well as the gas connects them to the large scale filament. NGC 6334 is a nearby high-mass star forming complex (1.3 kpc) which contains five star-forming regions at various stages of evolution which are named as sources NGC6334-I to V. ALMA observations toward the three massive protoclusters in NGC 6334 (I, I(N) and V) reveals:

(i) more than 100 new compact millimetre sources distributed over an area of 0.3 pc around clusters.

(ii) extended and elongated structures in the morphology of the dense gas tracers with longitudinal velocity gradient likely tracing accretion channels that connect the large-scale cloud to the clusters. 

(iii) Widespread SiO shocked gas emission tracing outflow/jets as well as reminiscent slow shocks

produced during the accretion process.

 

Analysis of the kinematics of the dense gas tracers will lead us to investigate the accretion process. Furthermore, by investigating high-velocity components of SiO molecular emission and its spatial association with mm sources we will be able to characterize jets and bipolar outflows on the one hand, and other shock structures (e.g. accretion/collision) in the other hand.

This work is part of the PhD thesis of Mahya Sadaghiani and Atefeh Aghababaei

 

Outflows in the high-mass star-forming region G327

This research work (master thesis of Niraj Kandpal) involves the study of molecular outflows in the star forming region G327.3-0.6.

 Molecular outflows are an energetic mass-ejection phenomenon associated with very early stage of stellar evolution. Depending on whether flow is moving towards or away from us they can be assigned as blue and red shifted. Molecular outflows can be useful tool for understanding the underlying formation process of stars of all masses, as they provide a record of mass-loss history of the system . 

 Using various astronomical software we try to visualize and identify blue and red shifted outflows. We are also interested in studying and modelling outflow in 3 dimensions . One of the significant aspect of this study is quantifying these outflows for which work on determining the outflow parameters( mass, momentum, energy) is in progress. 

This work is part of the Master Thesis of Niraj Kandpal,