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

Journal Article · Mon Feb 01 00:00:00 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, Vol. 709, Issue 2; Other Information: DOI: 10.1088/0004-637X/709/2/597; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

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