On the Formation of Compact Stellar Disks Around Sgr A*

Abstract

The recent identification of one or two sub-parsec disks of young, massive stars orbiting the ~4e6 solar mass black hole Sgr A* has prompted an "in-situ" scenario for star formation in disks of gas formed from a cloud captured from the Galactic center environment. To date there has been no explanation given for the low angular momentum of the disks relative to clouds passing close to the center. Here we show that the partial accretion of extended Galactic center clouds, such as the 50 km/s giant molecular cloud, that temporarily engulf Sgr A* during their passage through the central region of the Galaxy provide a natural explanation for the angular momentum and surface density of the the observed stellar disks. The captured cloud material is gravitationally unstable and forms stars as it circularizes, potentially explaining the large eccentricity and range of inclinations of the observed stellar orbits. The application of this idea to the formation of the circumnuclear ring is also discussed.

12 pages, 2 figs, minor changes, ApJ Letters accepted

References in corpus (6)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Simulations of star formation in a gaseous disc around sgr A* - a failed AGN
• Self-gravitating accretion disk in Sgr A* few million years ago: was Sgr A* a failed quasar?
• Evidence for a Long-Standing Top-Heavy IMF in the Central Parsec of the Galaxy
• The proper motion of the Arches cluster with Keck Laser-Guide Star Adaptive Optics
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• Massive Star Formation in the Molecular Ring Orbiting the Black Hole at the Galactic Center
• On the evolution of gas clouds exposed to AGN radiation. I. Three-dimensional radiation hydrodynamic simulations
• Molecular Gas Feeding the Circumnuclear Disk of the Galactic Center
• The Galactic Center as a laboratory for theories of gravity and dark matter
• ALMA Detection of Bipolar Outflows: Evidence for Low Mass Star Formation within 1pc of Sgr A*
• Physical Contact between the +20 km/s Cloud and the Galactic Circumnuclear Disk
• The apparent tail of the Galactic center object G2/DSO
• Predicted Stellar Kinematics of a Kiloparsec-Scale Nuclear Disc (or Ring) in the Milky Way
• Millimeter-wave Spectral Line Surveys toward the Galactic Circumnuclear Disk and Sgr A*
• Evolution of eccentric stellar disks around supermassive black holes: the complex disk disruption dynamics and the milliparsec stars
• The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic structure
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• Red giant - jet collisions in galactic nuclei I: 3D hydrodynamical model of a few stellar orbits
• Mass flows in the Galactic Center by supernovae of the circumnuclear disk