Physics And Chemistry Of Star Forming Region And Protoplanetary Disk

TL;DR

This thesis explores the physical and chemical conditions in various star-forming regions and protoplanetary disks, focusing on chemical complexity, molecule formation, and implications for star and planet formation.

Contribution

It provides a comprehensive analysis of chemical processes across different astrophysical environments, emphasizing the role of dust and molecule binding energies in star and planet formation.

Findings

Chemical complexity varies across environments from hot to cold regions.

Molecules formed in cold phases return to gas phase during warm-up stages.

Binding energies influence snow-line formation and disk structure.

Abstract

My thesis work aims to study the inter-relation between various physical and chemical conditions in a wide range of astrophysical environments. Our studied regions range from the super-hot regions (i.e., nebular, photon-dominated, or photodissociation regions, diffuse area, through which the lights of the background stars can reach us) to the super-cold regions (i.e., dense molecular clouds, proto-planetary disks, etc. where interstellar dust particles absorb all background visible and ultra-violet lights). The chemical complexity of the interstellar cloud gradually evolves due to the evolution in physical conditions. The dense molecular clouds are the birth sites of star-formation, where a wide variety of complex organic molecules are observed. Dust particles play an essential role in the formation of these complex organic molecules. During the warm-up stage of a star-forming region, the molecules formed during the cold phase start to return to the gas phase by various thermal and non-thermal evaporation processes. These complex molecules again freeze out to the outer part of the proto-planetary disk during the further evolved stage according to their condensation temperature and form the so-called snow-lines. The binding energies of these molecules with the prevailing dust particles play a crucial role in determining the structural information of this disk. Thus the binding energy of the molecules is vital to understand several critical aspects of the star and planet formation processes. In this thesis, I will discuss the chemical complexity obtained in a wide range of the star-forming region and whether this chemical complexity lead to biomolecules in space.