ORIGIN OF THE GALACTIC CENTER S-STARS: GRAVITATIONAL TORQUES FROM LIN-SHU-TYPE SPIRAL DENSITY WAVES

Journal Article · Mon Feb 01 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/709/2/597· OSTI ID:21392311

Griv, Evgeny ^[1]

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1. Department of Physics, Ben-Gurion University, P.O. Box 653, Beer-Sheva 84105 (Israel)

The supermassive approx4 x 10{sup 6} M{sub sun} black hole at the Galactic center is surrounded by a parsec-scale star disk, with several thousands of dynamically relaxed, evolved, late-type CO absorption line stars and a small approx100 population of luminous O and Wolf-Rayet stars which move in approximately circular Keplerian orbits. These bluish in color massive O and Wolf-Rayet stars are very young with an estimated age of 6 +- 2 Myr. Another small group of roughly 20 young (<10 Myr) blue B stars with the orbital periods as short as 15 years ('S-stars') follow eccentric, randomly oriented orbits well inside the disk stars. A model is proposed to explain the S-stars. Accordingly, the stars formed originally in the parsec-scale disk through Jeans' gravitational fragmentation of gas. The newly formed S-stars then migrated inward to the Galactic center via the torques exerted by Lin-Shu-type spiral density waves on the stars at an inner Lindblad resonance. The model explains both the number of observed S-stars orbiting the Galactic black hole within the nuclear (<0.05 pc) star cluster and the key property of the S-star orbits, namely, their high eccentricities.

• OSTI ID: 21392311
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 709; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
BLACK HOLES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COLOR
GALAXIES
MAIN SEQUENCE STARS
OPTICAL PROPERTIES
ORBITS
ORGANOLEPTIC PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SORPTION
STAR CLUSTERS
STARS
TORQUE
WOLF-RAYET STARS