PROPERTIES OF G354.61+0.47 BASED ON ITS CHEMICAL COMPOSITION

• Main Author: Rahmi Izzati, Fathia
• Format: Theses
• Language: Indonesia
• Subjects: Astronomi
• Online Access: https://digilib.itb.ac.id/gdl/view/84496
• Institution: Institut Teknologi Bandung

Massive stars (greater than 8 M ) play a pivotal role in shaping the dynamics of the interstellar medium (ISM). Their short lifetimes make them efficient contributors of material, facilitating the production and dispersal of heavy elements throughout their environments. Complex Organic Molecules (COM) within the ISM is predomi nantly associated with hot cores located in massive star-forming region (SFR). How ever, studying these COMs is challenging due to the rarity of massive SFRs and their high extinction rates. Advancements in radio observation technologies, such as Ata cama Large Millimeter/submillimeter Array (ALMA), have overcome these challenges by enabling the high-angular-resolution detection of molecular tracers. In this study, ALMAdatawereutilized to conduct an in-depth analysis of the structure and chemistry of G354.61+0.47, based on the molecular species identified within the object. Radia tive transfer modeling has been implemented to generate synthetic spectra of species (H13CO+, HCN, CO, CH3OH, etc) and extract the physical features to infer the ex citation conditions of the surroundings. The input data was previously processed us ing the Common Astronomy Software Applications (CASA). The Local Thermodynam ical Equilibrium (LTE) calculation with CASSIS is considered for the modeling. The best-fitted line parameters such as excitation temperature (Tex) and column density (N) are derived, which represent the prevailing physical condition of the two cores. The results revealed 18 different species, including CH3OH (methanol) and CH3OCHO (methyl formate). Our findings suggest that the molecular composition of the gas in G354.61+0.47 is similar to other high-mass star-forming regions with radiatively heated hot cores.