On the origin of the B-stars in the Galactic center

Abstract

We present a new directly-observable statistic which uses sky position and proper motion of stars near the Galactic center massive black hole to identify populations with high orbital eccentricities. It is most useful for stars with large orbital periods for which dynamical accelerations are difficult to determine. We apply this statistic to a data set of B-stars with projected radii 0."1 < p < 25" (~0.004 - 1 pc) from the massive black hole in the Galactic center. We compare the results with those from N-body simulations to distinguish between scenarios for their formation. We find that the scenarios favored by the data correlate strongly with particular K-magnitude intervals, corresponding to different zero-age main-sequence (MS) masses and lifetimes. Stars with 14 < mK < 15 (15 - 20 solar masses, t_{MS} = 8-13 Myr) match well to a disk formation origin, while those with mK > 15 (<15 solar masses, t_{MS} >13 Myr), if isotropically distributed, form a population that is more eccentric than thermal, which suggests a Hills binary-disruption origin.

Updated paper. 21 pages, 28 figures, 6 tables, ApJ accepted

References in corpus (12)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Starbursts near supermassive black holes: young stars in the Galactic Center, and gravitational waves in LISA band
• The structure of the nuclear stellar cluster of the Milky Way
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• Star Formation Around Super-Massive Black Holes
• Clues to Nuclear Star Cluster Formation from Edge-on Spirals
• Self-gravitating accretion disk in Sgr A* few million years ago: was Sgr A* a failed quasar?
• Kinematics of the old stellar population at the Galactic Center
• Dynamical evolution of the young stars in the Galactic center: N-body simulations of the S-stars
• On the nature of the fast moving star S2 in the Galactic Center
• On the Formation of Compact Stellar Disks Around Sgr A*
• 3D stellar kinematics at the Galactic center: measuring the nuclear star cluster spatial density profile, black hole mass, and distance

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• Comparing hypervelocity star populations from the Large Magellanic Cloud and the Milky Way
• Constraints on the Galactic Centre environment from \textit{Gaia} hypervelocity stars III: Insights on a possible companion to Sgr A*
• Constraints on the Galactic Centre environment from Gaia hypervelocity stars II: The evolved population
• Random Forest Classification of Stars in the Galactic Centre
• Evolution of eccentric stellar disks around supermassive black holes: the complex disk disruption dynamics and the milliparsec stars
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• Quadrupole stellar oscillations: The impact of gravitational waves from the Galactic Center
• Double progenitor origin of the S-star cluster
• Short and long term evolution of a stellar disk around a massive black hole: The role of binaries, the cusp and stellar evolution
• Accelerations of stars in central 2-7 arcsec from Sgr A*