What is the reason for the lack of cool evolved stars near the center of the Galaxy?

The observed deficit of bright late-type giants in the central parsec of the Milky Way remains an open problem. We investigate whether repeated passages of red giants (RGs) through a past jet from Sgr A* can modify their envelopes and apparent spectral types. Three-dimensional hydrodynamical simulations follow a 1,M, 100,R RG through up to ten jet crossings at 10-3, pc, using jet kinetic luminosities of 10 42, 10 44, and 10 48, erg, s-1. Each passage produces shocks, envelope ablation, and an asymmetric downstream tail. For jet luminosities up to 10 44, erg, s-1, the cumulative ablated mass evolves approximately as ΔM proportional to t 1/2 and reaches about 10-4,M over a 10 5, yr active phase. Repeated heating also raises the surface temperature from about 3600 to 8500, K during the first ten passages, potentially making an M-type giant appear as an A-type source. Jet feedback may therefore contribute to the apparent depletion of cool giants and the excess of hot stars in galactic nuclei (GN).