|
|
Galaxy Generator for Games
Březina, Karel ; Kobrtek, Jozef (referee) ; Starka, Tomáš (advisor)
This thesis is focused on design and implementation of procedural generator of galaxy for games or simulations. Second goal is implementation of demonstration application which is showing possible usage of generator. Generator is able to create galaxy by predefined types or by user created map.
|
|
|
Galaxies and their presentation within lessons at primary school
PRUNNEROVÁ, Hana
My bachelor theses deals with the galaxy topics (including Milky Way) and with their presentations during elementary school lessons. The first part of my theses is devoted to Milky way (how this name was founded, how it is created and structured, it ´s devoted to its history and investigation, to local galaxy groups) and to extragalactical objects (the history of investigation, the Hubble classification of galaxies, the rotation of galaxies and the formation of spiral shoulders, their crashes and the canibalism of galaxies, distances of galaxies, the Hubble constant). The following part involves how to present galaxies as a part of the Framework Education Programme (FEP) and the School Education Programme (SEP) and the textbook analysis. The final part deals with the analysis of the questionnaire among teachers and teachers to be if and how it is possible to implement this topic into elementary school lessons (Milky Way included), how much interest pupils have in this topic and their knowledge.
|
|
|
Galaxy interactions: dark matter vs. Modified Newtonian dynamics (MOND)
Bílek, Michal ; Jungwiert, Bruno (advisor) ; Kroupa, Pavel (referee) ; Stuchlík, Zdeněk (referee)
MOND is an observational rule for predicting the acceleration of stars and galaxies from the distribution of the visible matter. It possibly stems from a new law of physics. I list the theoretical aspects of MOND, its achievements and problems. MOND has been tested mainly in disc galaxies so far. Its tests in elliptical galaxies are rare because the MOND effects are small for them in the parts observable by the conventional methods. In the thesis, I explain the methods and ideas I developed for testing MOND in the ellipticals using stellar shells. Moreover, the shells enable us to test MOND for stars in radial orbits for the first time. The shells are results of galactic interactions. I discuss the shell formation mechanisms and summarize the findings from shell observations and simulations.
|
|
|
Shell galaxies - "sticky particles" hydrodynamical simulations
Zimandl, Martin ; Jungwiert, Bruno (advisor) ; Šolc, Martin (referee)
Shell galaxies are usually ellipticals with concentric faint arc-like stellar structures with sharp outer edges. They originate from galactic collisions (so called mergers). According to observations, some galaxies has also gaseous structures, that can be associated with stellar shells. We carry out a few numerical simulations, in which we recreate gaseous shells throug radial collisions of small and large elliptical galaxies. Then we analyze the differences between stellar and gaseous shells. Our simulations are based on earlier models, which describes gas by using so called "sticky-particles" hydrodynamics. This approach was so far quite succesful in resolving origin of gaseous shells. Our conclusion is, that gas in preset galaxies is not sufficient to make any difference. Higher quantities on the other hand has significant effect. Powered by TCPDF (www.tcpdf.org)
|
|
|
The influence of the stellar mass-loss on the dynamics of star clusters
Dinnbier, František ; Jungwiert, Bruno (advisor) ; Šubr, Ladislav (referee)
This work aims at studying the influence of the stellar mass-loss, resulting from the stellar evolution, on the dynamics of massive star clusters. The emphasis has been put on the mass-loss by low-mass and intermediate-mass stars (m < 8 Mo) that form, at the end of their life, a planetary nebula. The expansion speed of gas released by these stars is lower than the escape speed from sufficiently massive star clusters, and the gas can be retained by the cluster. For modelling of the gas hydrodynamics, a simple sticky-particles method was used. To carry out simulations in which gaseous and stellar particles mutually interact through their gravity, substantial modifications had to be realized in the N-body codes Nbody6 and Hermit. For the sake of comparing the influence of stellar mass-loss and relaxation processes, which are happening in the simplified model, two types of simulations were performed: one with the formation of gaseous particles and the other consisting of purely stellar component. The simulations in which the gas component was present showed out a significantly different evolution in the central part of the cluster than those in which the presence of gas was not considered.
|
|
|
Distance to nearby galaxies
Šándorová, Ivana ; Zasche, Petr (advisor) ; Wolf, Marek (referee)
Title: Distance to nearby galaxies Author: Ivana Šándorová Institute: Astronomical Institute of the Charles University Supervisor: doc. RNDr. Petr Zasche, Ph.D., Astronomical Institute of the Charles University Abstract: The present work is focused on the study of the variable stars, particularly the lumi- nosity of cepheids in The Large Magellanic Cloud. The data were obtained from photometric observations of starfield (image centre coordinates: RA: 5◦13 36 , DE: −69h 22m 42s) using the 1,54 m Danish telescope at the observatory La Silla in Chile. The aim of this work was to find the distance of Large Magellanic Cloud, which was determined by the "period - lu- minosity relation" method for cepheids. We studied 13 cepheids, which were compared with one non-variable star. We computed the average value of distance modulus as (18,42 ± 0,40) mag. The distance modulus from the latest publication (Pietrzi'nski, G. and others, 2019) is (18,477 ± 0,004 (statistic) ± 0,026 (systematic)) mag. SIPS (Scientific Image Processing System) is software for measuring and processing of images of star field and was used in this work for processing of photometric images of star field. Own program was used for creating and editing the light curves. Keywords: galaxy, variable stars, cepheids, distance modulus 1
|
|
|
Distance to the Magellanic clouds
Kulich, Matúš ; Zasche, Petr (advisor) ; Korčáková, Daniela (referee)
Twelve eclipsing binary systems from the region of the Large Magellanic Cloud have been studied in this thesis in order to calculate the distance. The photometric data come from the OGLE survey carried out at the Las Campanas Observatory in Chile and the spectroscopic data come from other papers where they had already been partially ana- lyzed for other purposes. From these data, the light curves and the radial velocity curves of these systems have been constructed and analyzed using the PHOEBE soft- ware, in which the physical parameters and the absolute magnitudes of their individual components have been determined by the method of synthetic curves. By comparing them to the observed apparent magnitudes in I-band deduced from the light curves and taking into account the bolometric corrections and the V-I indices, the distance modu- lus of the Large Magellanic Cloud could be determined to be 18.59 ± 0.4 mag, which fairly corresponds to the quite familiar results determined by using this and other meth- ods in various research papers. However, in order to determine the distance modulus more accurately, it would be necessary to use accurate, much more complex models of stellar atmospheres and not simply rely on the general relations of the main-se- quence stellar parameters, which exhibit quite a large variance.
|
|
|
Galaxy Generator for Games
Březina, Karel ; Kobrtek, Jozef (referee) ; Starka, Tomáš (advisor)
This thesis is focused on design and implementation of procedural generator of galaxy for games or simulations. Second goal is implementation of demonstration application which is showing possible usage of generator. Generator is able to create galaxy by predefined types or by user created map.
|
|
|
Galaxy interactions: dark matter vs. Modified Newtonian dynamics (MOND)
Bílek, Michal ; Jungwiert, Bruno (advisor) ; Kroupa, Pavel (referee) ; Stuchlík, Zdeněk (referee)
MOND is an observational rule for predicting the acceleration of stars and galaxies from the distribution of the visible matter. It possibly stems from a new law of physics. I list the theoretical aspects of MOND, its achievements and problems. MOND has been tested mainly in disc galaxies so far. Its tests in elliptical galaxies are rare because the MOND effects are small for them in the parts observable by the conventional methods. In the thesis, I explain the methods and ideas I developed for testing MOND in the ellipticals using stellar shells. Moreover, the shells enable us to test MOND for stars in radial orbits for the first time. The shells are results of galactic interactions. I discuss the shell formation mechanisms and summarize the findings from shell observations and simulations.
|
|
|
Shell galaxies - "sticky particles" hydrodynamical simulations
Zimandl, Martin ; Jungwiert, Bruno (advisor) ; Šolc, Martin (referee)
Shell galaxies are usually ellipticals with concentric faint arc-like stellar structures with sharp outer edges. They originate from galactic collisions (so called mergers). According to observations, some galaxies has also gaseous structures, that can be associated with stellar shells. We carry out a few numerical simulations, in which we recreate gaseous shells throug radial collisions of small and large elliptical galaxies. Then we analyze the differences between stellar and gaseous shells. Our simulations are based on earlier models, which describes gas by using so called "sticky-particles" hydrodynamics. This approach was so far quite succesful in resolving origin of gaseous shells. Our conclusion is, that gas in preset galaxies is not sufficient to make any difference. Higher quantities on the other hand has significant effect. Powered by TCPDF (www.tcpdf.org)
|
guest ::
