The latest catalogue of the satellite Gaia contains astrometric data on the three-dimensional positions and two-dimensional transverse velocities, as well as radial velocities of 33 million stars. The aim of this master’s thesis is to use this incredible amount of high-quality measurements to determine the rotation curve of our Galaxy’s disk. By using astrometric, photometric, and spectroscopic data, and relying on an analytical model of the Galaxy from the literature, we work on calculating the circular velocity of stars in the disk as accurately as possible at various distances from the Galactic centre, ranging from a radius of 0 kpc to 24 kpc. Moreover, we analyse the spatial distribution of red giants and main sequence stars and explore the characteristics of the velocity distribution of the entire sample. During the analysis, we identify remnants of the Milky Way’s last major merger with a satellite galaxy, and detect the influence of a nearby spiral arm in the rotation curve.
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