Abundances of argon, sulfur, and neon in six galactic H II regions from infrared forbidden lines

Journal Article · Sun Nov 01 04:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159361· OSTI ID:5729033

Herter, T; Helfer, H L; Pipher, J L; Forrest, W J; McCarthy, J; Houck, J R; Willner, S P; Puetter, R C; Rudy, R J; Soifer, B T

Airborne measurements of the (Ar II) (6.99 ..mu..m) and (S III) (18.71 ..mu..m) lines for six compact H II regions are presented, as well as ground-based 2--4 ..mu..m and 8--13 ..mu..m spectroscopy if not already published. From these data and radio data, we deduce lower limits to the elemental abundances of Ar, Ne, and S. G29.9--0.0 at 5 kpc from the galactic center is overabundant in all these elements. The other five regions (at distances 6--13 kpc from the center) mainly appear to be consistent with standard abundances, with the exception of G75.84 +- 0.4 at 10 kpc from the galactic center, which is overabundant in S. However, our preliminary results on G12.8--0.2 at 6 kpc from the galactic center suggest a possible underabundance. We feel that a large statistical sample of H II regions is required in order to determine if there is a radial gradient in the heavy element abundances in our Galaxy.

• Research Organization: University of Rochester
• OSTI ID: 5729033
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 250:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ARGON
CHARGED PARTICLES
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
ELEMENTS
ENERGY-LEVEL TRANSITIONS
FINE STRUCTURE
FLUIDS
FORBIDDEN TRANSITIONS
GALAXIES
GASES
H2 REGIONS
INFRARED SPECTRA
IONS
MILKY WAY
NEBULAE
NEON
NONMETALS
RADIATION FLUX
RARE GASES
SPECTRA
SULFUR