19-23 October 2020
Europe/Prague timezone
Please, give us your feedback in the Survey

Missing bright red giants in the Galactic center: A fingerprint of its once active state?

19 Oct 2020, 15:25


Dr Michal Zajaček (Center for Theoretical Physics, Polish Academy of Sciences)


The observations in the near-infrared domain revealed that old bright late-type stars have a flat to a decreasing surface-density profile, which is in contrast to the cusp-like distribution of young OB/Wolf-Rayet stars. The core-like distribution of bright red giants is apparent from the decrease in the strength of the CO bandhead as well as from the stellar number counts. More recently, it was found that faint late-type stars exhibit a cusp-like distribution. Hence, a certain mechanism must have taken place that led to the preferential depletion of bright late-type stars, leaving fainter giants intact. Here we propose that the interactions of large red giants with the Galactic center nuclear jet during its active phases led to the effective ablation of bright late-type stars. Several thousand star-jet passages led to the drop in the infrared luminosity, which resulted in the flattening of the original cusp-like profile. The red giant - jet interactions were the most efficient within the inner ~0.04 pc (S cluster). On larger scales, the mechanism was complemented by the star-accretion disc collisions up to ~0.5 pc, while on the smallest milliparsec scales tidal stripping operated.

Primary authors

Dr Michal Zajaček (Center for Theoretical Physics, Polish Academy of Sciences) Dr Anabella Araudo (ELI Beamlines, Institute of Physics, Czech Academy of Sciences) Prof. Vladimir Karas (Astronomical Institute, Czech Academy of Sciences) Prof. Bozena Czerny (Center for Theoretical Physics, Polish Academy of Sciences) Prof. Andreas Eckart (First Institute of Physics, University of Cologne)

Presentation Materials