Millimeter-wave recombination lines from radio-bright H II regions

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/167148· OSTI ID:6018319

Gordon, M A

This paper presents new observations of radio recombination lines in the millimeter-wavelength regime from the radio-bright H II regions W3 Main, NGC 1976, NGC 2024, Sgr B2, M17, W49A, and W75/DR21. Mean values for the electron temperature and density averaged along the lines of sight are obtained, and the (He+)/(H+) ratio is measured as a function of galactocentric distance. Excluding NGC 2024, an average value and a galactocentric radius for (He+)/(H+) of 0.103 + or - 0.031 and 0.00924/kpc, respectively, are found. 52 references.

• Research Organization: National Radio Astronomy Observatory, Tucson, AZ (USA)
• OSTI ID: 6018319
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 337; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CATIONS
CHARGED PARTICLES
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
DISTANCE
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
ELECTRON TEMPERATURE
H2 REGIONS
HELIUM IONS
HYDROGEN IONS
IONS
QUANTUM NUMBERS
RADIATIONS
RADIOWAVE RADIATION
ULTRAVIOLET RADIATION