Numerical study of interacting galaxy systems with low-mass companions.

详细信息   

• 作者：Li ; Pak Shing.
• 学历：Doctor
• 年：1999
• 毕业院校：University of Wyoming
• 专业：Physics, Astronomy and Astrophysics.;Computer Science.
• ISBN：0599412577
• CBH：9939266
• Country：USA
• 语种：English
• FileSize：9146086
• Pages：233

文摘

More and more observational evidence shows that galaxies are interacting with each other, probably starting from the earliest stage of galaxy formation. We will expect galaxies to have tremendous changes in structures when equally massive galaxies collide with each other. However, observations indicate that galaxy with low-mass companions also show unnatural distorted structures. As with most of the other branches in astronomy, studies on dynamic interaction among galaxies are restricted by both spatial and temporal limitation. With-the advance of sophisticated numerical algorithms and high speed computing platforms, numerical simulation becomes the most important tool in studying the dynamical interaction of galaxies.;Most of the galaxies are believed to have low-mass satellite galaxies, including our Milky Way galaxy. By using numerical simulation techniques, we can study the interactions in galaxy systems basically with a massive central galaxy and more than one companion. I have developed a TreeSPH code in different versions, which can be used on different computing platforms, including vectorized and massively paralleled processors. Physical models for the interstellar medium, star formation, and material and energy return in the stellar evolution process are incorporated into the modified TreeSPH. Realistic 4-component (halo, stellar disk, gaseous disk, and bulge) disk galaxy models are generated for simulations.;In this research, the Milky Way-LMC-SMC and M81-M82-NCG3077 systems are studied in detail. Simulations have been performed for these two systems to understand the interaction history of the systems. Simulation results are compared with the previous simulations by other groups and the latest observations. Orbital parameters are found to be crucial to the survival of the satellite galaxies and the degree of perturbation to the central galaxy. By incorporating hydrodynamic calculations into the code, computational results can be compared to the latest VLA images of the gas content in the systems to provide better constraint to the orbital parameters. Special algorithms are also developed for data analysis and for visualization of the simulation results.