Abundances and kinematics of K giants in the galactic nuclear bulge

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6696424

Rich, R M

Spectroscopy and photometry were obtained for 100 K giants in Baade's Window at l = 1/sup 0/, b = -4/sup 0/. The abundance distribution of the nuclear bulge K giants was derived relative to 45 stars of known abundance. The abundances run from -1 to nearly +1 dex, with a peak at 0.3 dex, or twice the solar abundance. Of the 88 stars with derived abundances, 22% exceeded the abundance of the most metal rich local K giants; 50% exceeded the solar abundance, and 10% were metal poor (< -0.6 dex). Radial velocities were measured for 53 nuclear bulge K giants which also have derived abundances. Their velocity dispersion is 104 km/sec. The mean velocity is -19 +/- 14 km/sec; within 1 sigma of the solar Pi velocity of -10 km/sec. When this sample is divided into 3 subsets based on the abundances, the subset of 21 stars > 0.3 dex has sigma = 92 +/- 14 km/sec and the metal poor subset of 16 stars <-0.3 dex has J = 126 +/- 22 km/sec. An intermediate set of 16 stars has sigma = 97 +/- 17 km/sec. The most metal rich stars may have a bulk velocity of -38 +/- 14 km/sec, 1sigma less than the -19 km/sec of the metal poor stars. No evidence was found that either the metal rich or metal poor stars follow the galactic rotation curve; hence, neither population appears to be rotation supported. Optical and infrared photometry is presented for nuclear bulge K giants. The colors of these stars are shown to be too hot for their derived metal abundances.

• Research Organization: California Inst. of Tech., Pasadena (USA)
• OSTI ID: 6696424
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
640105 -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
COLOR
ELECTROMAGNETIC RADIATION
ELEMENT ABUNDANCE
ELEMENTS
GALAXIES
GIANT STARS
INFRARED RADIATION
KINETICS
METALS
MILKY WAY
MOTION
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
RADIAL VELOCITY
RADIATIONS
ROTATION
SPECTROSCOPY
STARS
VELOCITY
VISIBLE RADIATION