Deutsche Übersetzung des Titels: Struktur und Dyamik wechselwirkender Galaxien

Englische Übersetzung des Titels: Structure and dynamics of interacting galaxies

Vorschau

PDF, Englisch Download (9MB) | Nutzungsbedingungen

Übersetzung des Abstracts (Englisch)

According to the ``merger hypothesis'', elliptical galaxies form by mergers of spiral galaxies. To test this hypothesis, simulations of collisionless mergers between disk galaxies with different mass ratios and orbital geometries were performed. Every merger remnant was investigated with respect to its photometric and kinematic properties. The methods used to determine the characteristic properties were developed to resemble the methods used by observational astronomers. Therefore a self-consistent comparison between simulated data and observations was possible. 1:1 merger remnants are triaxial, rotate slowly, are supported by anisotropic velocity dispersions, have significant minor-axis rotation and show predominantly boxy iosphotes in good agreement with observations of bright, boxy, giant elliptical galaxies. 3:1 and 4:1 remnants are oblate isoptropic, fast rotators, show a small amount of minor-axis rotation and have disky isophotes in perfect agreement with observations of faint, disky, giant elliptical galaxies. 2:1 remnants show intermediate properties. Projection effects lead to a large spread in the data in good agreement with observations. They do not change the fundamental differences between 1:1 and 3:1 merger remnants. The effect of the merger geometry on the properties of the remnants is discussed. The shape of the LOSVD of the simulated remnants does in general not agree with observations. An additional stellar disk component with 15 of the total stellar mass and a scale length of the order of the effective radius, artificially added to the merger remnants, can solve this problem. The results lead to the conclusion that collisionless merging of disk galaxies cannot explain the formation of observed elliptical galaxies. The progenitor galaxies must have contained a significant amount of gas.