An observational study of millimeter-wave recombination lines
Creators
- 1. Max-Planck-Institut fuer Radioastronomie, Bonn (Germany, F.R.)
- 2. National Radio Astronomy Observatory, Tucson, AZ (USA)
Description
Observations of H36-alpha, He36-alpha, H40-alpha, He40-alpha, H44-beta, He44-beta, H45-beta, H50-beta, H50-gamma, H56-delta, H57-gamma, and H60-epsilon radio recombination lines in the 2 and 3 mm telluric windows made with the IRAM 30 m telescope on Pico Veleta, Spain are presented. Sources observed were the H II regions W3, NGC 1976, NGC 2024, Sgr B2, M17, W49, and DR 21. The observations are consistent with non-LTE models based upon centimeter-wave observations. The millimeter-wave recombination lines show no substantive indication of excitation by Lyman line radiation from nearby exciting stars so that conventional departure coefficients may be used with confidence. However, small departures from the expected line ratios have been found in some cases which merit additional investigation. 32 refs
Additional details
Publishing Information
- Journal Title
- Astrophysical Journal
- Journal Volume
- 365
- Series
- Astrophys. J.
- Journal Page Range
- 606-614
- ISSN
- 0004-637X
- CODEN
- ASJOA
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 22040371
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
- Descriptors DEI
- BALMER LINES; COMPARATIVE EVALUATIONS; COSMIC RADIO SOURCES; EMISSION SPECTRA; EXCITATION; H2 REGIONS; INTERSTELLAR SPACE; RADIOASTRONOMY; RECOMBINATION
- Descriptors DEC
- ASTRONOMY; ENERGY-LEVEL TRANSITIONS; EVALUATION; SPACE; SPECTRA