Spectroscopic surface brightness fluctuations : probing bright evolved stars in unresolved stellar populations Galaxies evolve on cosmological timescales and to study this evolution we can either study the stellar populations tracing the star formation and chemical enrichment or the dynamics tracing interactions and mergers of galaxies as well as accretion. In the last decades this field has become one of the most active research areas in modern astrophysics and especially the use of integral field spectrographs furthered our understanding. This work is based on data of NGC 5102 obtained with the panoramic integral field spectrograph MUSE. The data are analysed with two separate and complementary approaches: In the first part standard methods are used to measure the kinematics and than model the gravitational potential using these exceptionally high quality data. In the second part I develop the new method of surface brightness fluctuation spectroscopy and quantitatively explore its potential to investigate the bright evolved stellar population. Measuring the kinematics of NGC 5102 I discover that this low luminosity S0 galaxy hosts ...