The research in this thesis follows two directions: The first, using high performance computing currently available, we studied atomic and molecular emissions in astrophysical environment. The radiative transfer model was applied to explain the characteristics of the recombination line masers Hnα in the envelope of the star MWC 349A. | MINISTRY OF EDUCATION VIETNAM ACADEMY AND TRAINING OF SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY - TRAN NGOC HUNG ROTATIONAL SPECTRAL LINE FORMATION AND RADIATIVE TRANSFER IN CIRCUMSTELLAR ENVELOPES Specialization Optics Numerical code 944 01 10 SUMMARY OF MATERIALS SCIENCE DOCTORAL THESIS HANOI 2021 The thesis was completed at Department of Physics Graduate University of Science and Technology VAST Center of Engineering Physics Institute of Physics VAST Supervisors Assoc. Prof. Dr. Dinh Van Trung Assoc. Prof. Dr. Pham Hong Minh Reviewer 1 . . Reviewer 2 . . Reviewer 3 . . The thesis will be defended at . . Time . The thesis could be found at National Library of Vietnam Library of Graduate University Science and Technology Library of Institute of Physics PREFACE The atomic and molecular emission in the radio region is the opportunity for us to explore the kinetic and physical properties of astrophysical environments. Strong and directional maser emissions allow high angular resolution up to milliseconds to study astro-objects at unprecedented details. In recent decades advances in computational techniques have greatly assisted the analysis of astronomical data. Numerically modeling can accurately simulate the optical images or radio spectrum to help us understand the processes going on in the universe. Predictions from these numerical models serve as guidance for many studies. The research in this thesis follows two directions The first using high performance computing currently available we studied atomic and molecular emissions in astrophysical environment. The radiative transfer model was applied to explain the characteristics of the recombination line masers Hnα in the envelope of the star MWC 349A. The seconds we modeled a gaseous envelope of a binary system of stars by using numerically hydrodynamic calculation. The hydrodynamic simulation using the open-source PLUTO program models envelopes of asymptotic giant branches AGBs to .
