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Astrophysics, Gravitation and Cosmology Seminar - Sebastiano von Fellenberg (Max Planck Radioastronomy) "Young Stars in the Galactic Center"

Event Type
Department of Physics
Loomis 464
Mar 22, 2023   12:00 pm  
Sebastiano von Fellenberg
Brandy Koebbe
Originating Calendar
Physics - Astrophysics, Gravitation, and Cosmology Seminar

I will present a large ∼30'' × 30'' spectroscopic survey of the Galactic Center using the SINFONI IFU at the VLT. Combining observations of the last two decades we compile spectra of over 2800 stars. Using the Bracket-γ absorption lines, we identify 195 young stars, extending the list of known young stars by 79. We calculate the angular momentum space as a function of projected separation from Sgr A*. We find that the observed young star distribution is substantially different from an isotropic cluster. We identify the previously reported feature of the clockwise disk and find that its angular momentum changes as a function of separation from the black hole and thus confirm a warp of the clockwise disk (p ∼ 99.2%). At large separations, we discover three prominent overdensities of the angular momentum. One overdensity has been reported previously, the counterclockwise disk. The other two are new. Determining the likely members of these structures, we find that as many as 75% of stars can be associated with one of these features. Stars belonging to the warped clockwise disk show a top-heavy K-band luminosity function, while stars belonging to the larger separation features do not. Our observations are in good agreement with the predictions of simulations of in situ star formation and argue for the common formation of these structures.

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