Abstract
The pure rotational spectrum of the MgH radical (X 2Σ+) in its ground state v = 0 and v = 1 vibrational modes has been observed in the laboratory using millimeter/submillimeter direct absorption spectroscopy. The rotational spectra of two isotopically substituted species, MgD and 26MgH, have been detected as well. These free radicals were produced by the reaction of magnesium, vaporized in a Broida-type oven, with hydrogen atoms generated in a microwave discharge. All six hyperfine components of the N = 0 → 1 transition of MgH in its v = 0 and v = 1 states have been directly measured to an accuracy of ± 50 kHz, and five components have been observed for 26MgH. The N = 0 → 1 and N = 1 → 2 transitions of MgD have also been detected. Rotational, fine structure, and hyperfine constants were determined for all species from a nonlinear least-squares fit to the data using a 2Σ Hamiltonian. Measurement of these frequencies for MgH should greatly aid in establishing its presence in interstellar space.
Original language | English (US) |
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Pages (from-to) | L21-L24 |
Journal | Astrophysical Journal |
Volume | 402 |
Issue number | 1 PART 2 |
DOIs | |
State | Published - Jan 1 1993 |
Keywords
- ISM: molecules
- Line: identification
- Molecular data
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science