Depletion of Bright Red Giants in the Galactic Center during Its Active Phases

0539781 - ASÚ 2021 RIV US eng J - Journal Article
Zajaček, M. - Araudo, Anabella - Karas, Vladimír - Czerny, B. - Eckart, A.
Depletion of Bright Red Giants in the Galactic Center during Its Active Phases.
Astrophysical Journal. Roč. 903, č. 2 (2020), č. článku 140. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA ČR(CZ) GA20-19854S
Institutional support: RVO:67985815
Keywords : galactic center * red giant stars * relativistic jets
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.877, year: 2020
Method of publishing: Limited access
https://doi.org/10.3847/1538-4357/abbd94

Observations in the near-infrared domain showed the presence of the flat core of bright late-type stars inside similar to 0.5 pc from the Galactic center supermassive black hole (Sgr A*), while young massive OB/Wolf-Rayet stars form a cusp. Several dynamical processes were proposed to explain this apparent paradox of the distribution of the Galactic center stellar populations. Given the mounting evidence on the significantly increased activity of Sgr A* during the past million years, we propose a scenario based on the interaction between the late-type giants and a nuclear jet, whose past existence and energetics can be inferred from the presence of gamma-ray Fermi bubbles and bipolar radio bubbles. Extended, loose envelopes of red giant stars can be ablated by the jet with kinetic luminosity in the range of L-j 10(41)-10(44) erg s(-1) within the inner similar to 0.04 pc of Sgr A* (S-cluster region), which would lead to their infrared luminosity decrease after several thousand jet-star interactions. The ablation of the atmospheres of red giants is complemented by the process of tidal stripping that operates at distances of less than or similar to 1 mpc, and by the direct mechanical interaction of stars with a clumpy disk at greater than or similar to 0.04 pc, which can explain the flat density profile of bright late-type stars inside the inner half parsec from Sgr A*.
Permanent Link: http://hdl.handle.net/11104/0317479