Selina Nitschai

Selina Nitschai   (Germany)

nitschai @

The formation history of omega Centauri

Omega Centauri (ω Cen) is the brightest, most massive globular cluster in the Milky Way and it has been suspected to be a stripped nucleus of a galaxy that has merged with the Milky Way a long time ago. Evidence for that is the complexity in its stellar populations, multiple sequences in its color-magnitude diagram, showing a large spread in metallicity and
possibly also in age. In addition, the recent Gaia observations have strengthened the evidence that ω Cen is related to one of the most significant merger events that the Milky Way hasencountered in its entire history.
In my work, we will try to investigate the formation and interaction history of ω Cen by mapping the kinematics, abundances, and ages of individual stars out to its half-light radius (4.65´) in a large MUSE mosaic. We will extract a large number of individual stars (~ 110 000) and use the individually extracted stellar spectra to measure metallicities and estimate the ages of individual stars. By connecting the spatial information to the kinematics, abundances, and stellar ages, we will be able to clearly identify member stars of ω Cen and get valuable information on its formation history.

Supervisor:    Nadine Neumayer   (MPIA)