|
|
Slupkové galaxie a modifikovaná Newtonova dynamika
Bílek, Michal ; Jungwiert, Bruno (advisor) ; Růžička, Adam (referee)
Our work has two recherchive parts. The first is devoted to the shell galaxies and we describe the observational facts here, different models of origin and the possibility of determining the gravitational potential with the use of shells. The second part is on the modified Newtonian dynamics (MOND). We explain what it consists in, its implications and its experimental tests. The third part is devoted to our numerical simulations of a shell system evolution both in the classical and modified dynamics. Our mission is to explain the differences in the two simulation theoretically and to verify, whether the result of the modified simulation oppose the observed shells around the galaxy NGC 3923. The conclusion is it doesn't, but our test is not very strong.
|
|
|
Stellar mass-loss in the dynamics of galaxies
Křížek, Miroslav
Title: Stellar mass-loss in galactic dynamics Author: Miroslav Křížek Department: Astronomical Institute of the Charles University Supervisor: RNDr. Bruno Jungwiert, Ph.D., Astronomical Institute - Academy of Sciences of the Czech Republic, v.v.i. and University of California - Riverside Supervisor's e-mail address: bruno@ig.cas.cz Abstract: We present an implementation of the statistical approach to the stars-gas mass exchange cycle into the N-body code. First, we summarize available data on stellar mass-loss and derive the time-dependency of the mass-loss rate of a single stellar population. Since the adopted probabilistic scheme that served as a basis for our implementation was limited to the linear star formation law while observations seem to suggest a non-linearity, we derive the non-linear star formation scheme. Both sides of the mass exchange cycle are then implemented into the code with stellar and gaseous particles and compared with an analytic recipe to test their reliability. In the next step, the comparison of such an extended statistical approach with deterministic scheme is performed for a fully dynamical model. The aim of such comparison is to explore divergence between both models of different natures. As illustration of the code application and sensitivity of the resulting galaxy disk...
|
|
|
Stellar mass-loss in the dynamics of galaxies
Křížek, Miroslav
Title: Stellar mass-loss in galactic dynamics Author: Miroslav Křížek Department: Astronomical Institute of the Charles University Supervisor: RNDr. Bruno Jungwiert, Ph.D., Astronomical Institute - Academy of Sciences of the Czech Republic, v.v.i. and University of California - Riverside Supervisor's e-mail address: bruno@ig.cas.cz Abstract: We present an implementation of the statistical approach to the stars-gas mass exchange cycle into the N-body code. First, we summarize available data on stellar mass-loss and derive the time-dependency of the mass-loss rate of a single stellar population. Since the adopted probabilistic scheme that served as a basis for our implementation was limited to the linear star formation law while observations seem to suggest a non-linearity, we derive the non-linear star formation scheme. Both sides of the mass exchange cycle are then implemented into the code with stellar and gaseous particles and compared with an analytic recipe to test their reliability. In the next step, the comparison of such an extended statistical approach with deterministic scheme is performed for a fully dynamical model. The aim of such comparison is to explore divergence between both models of different natures. As illustration of the code application and sensitivity of the resulting galaxy disk...
|
|
|
Slupkové galaxie a modifikovaná Newtonova dynamika
Bílek, Michal ; Jungwiert, Bruno (advisor) ; Růžička, Adam (referee)
Our work has two recherchive parts. The first is devoted to the shell galaxies and we describe the observational facts here, different models of origin and the possibility of determining the gravitational potential with the use of shells. The second part is on the modified Newtonian dynamics (MOND). We explain what it consists in, its implications and its experimental tests. The third part is devoted to our numerical simulations of a shell system evolution both in the classical and modified dynamics. Our mission is to explain the differences in the two simulation theoretically and to verify, whether the result of the modified simulation oppose the observed shells around the galaxy NGC 3923. The conclusion is it doesn't, but our test is not very strong.
|
guest ::
