Origin of the S Stars in the Galactic Center

Abstract

Over the last 15 years, around a hundred very young stars have been observed in the central parsec of our Galaxy. While the presence of young stars forming one or two stellar disks at approx. 0.1 pc from the supermassive black hole (SMBH) can be understood through star formation in accretion disks, the origin of the S stars observed a factor of 10 closer to the SMBH has remained a major puzzle. Here we show the S stars to be a natural consequence of dynamical interaction of two stellar disks at larger radii. Due to precession and Kozai interaction, individual stars achieve extremely high eccentricities at random orientation. Stellar binaries on such eccentric orbits are disrupted due to close passages near the SMBH, leaving behind a single S star on a much tighter orbit. The remaining star may be ejected from the vicinity of the SMBH, thus simultaneously providing an explanation for the observed hypervelocity stars in the Milky Way halo.

4 pages, 4 figures, accepted for publication in ApJ Letters; final version, minor changes only

References in corpus (10)

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Cited by in corpus (9)

• Dynamical evolution of the young stars in the Galactic center: N-body simulations of the S-stars
• S62 and S4711: Indications of a population of faint fast moving stars inside the S2 orbit -- S4711 on a 7.6 year orbit around Sgr~A*
• Binary dynamics near a massive black hole
• The Anisotropic Spatial Distribution of Hypervelocity Stars
• Characterizing the High-Velocity Stars of RAVE: The Discovery of a Metal-Rich Halo Star Born in the Galactic Disk
• Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei
• The Effectiveness of the Kozai Mechanism in the Galactic Centre
• The properties of hypervelocity stars and S-stars originating from an eccentric disc around a supermassive black hole
• Sculpting the Stellar Cusp in the Galactic Center