Velocity dispersion and the stellar population in the central 1. 2 parsecs of the Galaxy

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169039· OSTI ID:6550585

Sellgren, K; Mcginn, M T; Becklin, E E; Hall, D N ^[1]

---

1. Hawaii Univ., Honolulu (USA)

New observations of the 2.3 micron absorption band head of CO in integrated stellar light in the central 1.2 pc of the Galaxy are presented. These data confirm that the velocity dispersion of the stars increases toward the Galactic center and totally dominates their systematic rotation at small radii. The velocity dispersion is constant an average value of 125 km/s within about 30 arcsec projected diameter central region. The strength of the CO features decreases in the integrated faint light within the same region. These observations are all consistent with the hypothesis that both the diffuse 2 micron light and the bright 2 micron point sources in the central region are dominated by sources that have little or no CO absorption feature. The observed CO feature at projected distances less than 0.6 pc thus actually arises in stars that are at true radii greater than 0.6 pc. The mass distribution at radius between 3.7 and 0.6 pc from IRS 16 is strong evidence for an increasing mass/2 micron radiation ratio toward the Galactic center. 24 refs.

• OSTI ID: 6550585
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 359; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
DISTRIBUTION
GALAXIES
GALAXY NUCLEI
INFRARED SPECTRA
MASS
MASS DISTRIBUTION
MILKY WAY
MOTION
OXIDES
OXYGEN COMPOUNDS
ROTATION
SPATIAL DISTRIBUTION
SPECTRA
VELOCITY