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Dwarf galaxies with active galactic nucleus
Adamcová, Barbora ; Svoboda, Jiří (advisor) ; Grossová, Romana (referee)
Title: Dwarf galaxies with active galactic nucleus Author: Barbora Adamcová Institute: Astronomical Institute of the Charles University in Prague Supervisor: RNDr. Jiří Svoboda, Ph.D., Astronomical Institute of the Czech Academy of Sciences Abstract: This masters's thesis deals with star-forming dwarf galaxies with an enhanced X-ray luminosity based on the predictions from star-formation processes. We constructed a sample of dwarf galaxies observed with the SDSS telescope in optical light and with the ESA XMM-Newton observatory in X-rays. We compared different methods to predict the X-ray luminosity from star formation processes and compared it to the observed values. We investigated whether the X-ray excess is related to any physical properties of the studied galaxies, such as stellar population, metallicity or specific star formation rate, or can be attributed to active galactic nucleus. We also processed the first X-ray observations of 7 Blueberry galaxies, which are analogues of high redshift galaxies. We found, that their X-ray luminosities are lower than expected, with only 1 source having an X-ray excess, 1 source being detected and for the rest only the upper limits could be constrained. We discuss possible sources for the measured X-ray excess in the dwarf galaxy sample, as well as the implications...
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The concept of leadership in Aristotle's Politics and Plato's Republic
Adamcová, Barbora ; Jirsa, Jakub (advisor) ; Thein, Karel (referee)
In this bachelor thesis titled "The Meaning of Leadership in Plato's Republic and Aristotle's Politics ", I offer a comparison of the respective passages in the Republic and the Politics that are central to understand the role of a leader. I have focused not only on understanding a leader's personality, motivations, and their role in the polis, but I have also considered the polis and its citizens. Despite the relative complexity and breath of both works, the question of leadership is not explicitly addressed in either. Therefore, I have systematically analysed related terms and topics that touch upon the subject of leadership in order to distil the insights relevant for the subject of my inquiry. Correspondingly, the structure of the thesis logically proceeds from the general and rather uncontested, to the particular and complex. I have relied on a wide range of acclaimed interpreters of both Plato and Aristotle to shed further light on the challenging passages. The result of this effort is a structured comparison of Plato's and Aristotle's respective views on leadership as recorded in two of their key texts.
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X-ray emission of star-forming dwarf galaxies
Adamcová, Barbora ; Svoboda, Jiří (advisor) ; Jáchym, Pavel (referee)
Title: X-ray emission of star-forming dwarf galaxies Author: Barbora Adamcová Institute: Astronomical Institute of the Charles University in Prague Supervisor: RNDr. Jiří Svoboda, Ph.D., Astronomical Institute of the Czech Academy of Sciences Abstract: This bachelor's thesis deals with star-forming dwarf galaxies that were proposed to host an Active Galactic Nucleus (AGN) based on the measured X-ray excess over the prediction from star-formation processes. For the studied sample, we compared different methods of X-ray luminosity calculations from the star formation rate (SFR). From the optical emission line measurements, we estimated the galaxy metallicities using three distinct methods to include the metallicity effects in the X-ray luminosity predictions. We found that the galaxy metallicities are on average sub-solar, but not sufficiently low to explain the measured X-ray luminosity. We compared the studied sample with other similar galaxies in the luminosity-SFR-metallicity plane showing their different position from purely star-forming galaxies. We discuss possible sources for the measured X-ray excess as well as the implication of the found results on the AGN diagnostics in dwarf galaxies. Keywords: Dwarf galaxies, star formation, X-ray astronomy 1
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How quickly do resolutions subside? Case of the fitness attendance after the New Year's Eve
Adamcová, Barbora ; Rotschedl, Jiří (advisor) ; Čermáková, Klára (referee)
Aim of this thesis was to investigate the effect of New Year's resolutions on the gym attendance and period, during which people abandon their set resolution. Analysis was performed by ordinary least squares method using data obtained from Hamr -- Sport, a.s. and it proved a positive effect of the resolutions on the attendance of the fitness center situated in Záběhlice compound. The thesis also analyzes influence of the weather, precipitation, days of week and moths of the year on the level of attendance. According to the results of the econometric model estimation, New Year's resolutions last on average for three months. In order to verify this period a robustness test was conducted, which confirmed the result. In a questionnaire survey respondents most frequently reported, that they managed to follow their latest resolution for three months (40 %). The questionnaire also revealed that people seem to leave their long term plans most often due to their own laziness and lack of willpower, but most of them do not use any motivational tools to solve the problem of self-control (or they just rely on their will and abilities).
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