The Antennae Galaxies
The Antennae galaxies (NGC 4038/39) are the nearest and best-studied major\nmerger of two gas-rich spirals in the local Universe. They are\nnamed after the characteristic pair of tidal tails that protrude out of their\nmain galactic disks. Due to their proximity the\nAntennae are extremely well sampled by modern high-resolution observations\nover an enormous wavelength range, from radio to X-ray. This allows for\na comprehensive multiwavelength approach to the present-day morphology\nand dynamical history of the system. The goal of this Thesis is to test the available high-quality multiwavelength data against new high-resolution merger simulations as a key to improve our understanding of several\nmerger-induced physical processes, such as starbursts and the\nformation of young star clusters. These processes are expected to have\nbeen even more important in the formation and early evolution of\ngalaxies.\nFirst of all, accurate initial conditions for the interaction orbit\nand the initial galaxy models need to be constrained. To this end,\nwe perform an extended parameter search in order to obtain a suitable\nmatch to the Antennae galaxies.\nUsing these new initial conditions, we are able to present the\nfirst high-resolution numerical simulations that successfully\nmatch the detailed large- and small-scale morphology and kinematics of the Antennae\ngalaxies. Moreover, the spatial\ndistribution of star-forming regions as well as the \ntotal star formation rate are reproduced in excellent quantitative\nagreement, in particular, if we adopt a very weak stellar feedback.\nWe find that the Antennae are currently in a special\nphase of their evolution, shortly after the second pericenter. They\nwill merge soon within the next ~50 Myr.\nIn addition, we compare the star formation histories of all\npublished hydrodynamical Antennae simulations with the observed \ncluster age distribution. The latter is well approximated by a\npower-law dN/dt ~ t^gamma, declining as gamma =\n1. Under the assumption that clusters form at rates proportional to\nthe total star formation, it is found that the variations in the\nsimulated formation histories alone cannot account for most of the\nsteep decline in the observed age distribution. This provides strong\nevidence for efficient, prolonged cluster disruption in the Antennae,\nsimilar to more quiescent galaxies.\nFinally, we address the question of whether the Antennae will\nevolve into a typical elliptical galaxy. We find that\nthe virialized merger remnant resembles an oblate, fast-rotating early-type\nwith surface brightness profile well fitted by a Sersic function of\nindex n ~ 5. For high metallicities (Z > Z_sun) the\nstellar remnant of the Antennae may add to a population of present-day\nellipticals after secular evolution of another ~2.5 -3 Gyr.\nWithin this Thesis, we present an improved numerical\nmodel for the interacting Antennae galaxies that may serve as a \ntest-bed for further investigations of this archetypal\nmerger. As next steps, we plan to investigate the extended hot gas\ncomponent found in X-ray observations of the Antennae, and test our\npresent results in a code comparison project.