Millimeter/submillimeter spectroscopy of Tio (X{sup 3}Δ{sub r}): the rare titanium isotopologues
Pure rotational spectra of the rare isotopologues of titanium oxide, {sup 46}TiO, {sup 47}TiO, {sup 49}TiO, and {sup 50}TiO, have been recorded using a combination of Fourier transform millimeter-wave (FTmmW) and millimeter/submillimeter direct absorption techniques in the frequency range 62–538 GHz. This study is the first complete spectroscopic characterization of these species in their X {sup 3}Δ{sub r} ground electronic states. The isotopologues were created by the reaction of N{sub 2}O or O{sub 2} and titanium vapor, produced either by laser ablation or in a Broida-type oven, and observed in the natural Ti isotopic abundances. Between 10 and 11 rotational transitions J + 1 ↔ J were measured for each species, typically in all 3 spin–orbit ladders Ω = 1, 2, and 3. For {sup 47}TiO and {sup 49}TiO, hyperfine structure was resolved, originating from the titanium-47 and titanium-49 nuclear spins of I = 5/2 and 7/2, respectively. For the Ω = 1 and 3 components, the hyperfine structure was found to follow a classic Landé pattern, while that for Ω = 2 appeared to be perturbed, likely a result of mixing with the nearby isoconfigurational a {sup 1}Δ state. The spectra were analyzed with a case (a) Hamiltonian, and rotational, spin–orbit, and spin–spin parameters were determined for each species, as well as magnetic hyperfine and electric quadrupole constants for the two molecules with nuclear spins. The most abundant species, {sup 48}TiO, has been detected in circumstellar envelopes. These measurements will enable other titanium isotopologues to be studied at millimeter wavelengths, providing Ti isotope ratios that can test models of nucleosynthesis.
- OSTI ID:
- 22868395
- Journal Information:
- Astrophysical Journal, Vol. 833, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Hyperfine interactions in the ground states of titanium monoxide and mononitride
Hyperfine structure and Zeeman tuning of the A {sup 2}PI-X {sup 2}SIGMA{sup +}(0,0) band system of the odd isotopologue of strontium monofluoride {sup 87}SrF
Related Subjects
74 ATOMIC AND MOLECULAR PHYSICS
ABLATION
ABSORPTION
FOURIER TRANSFORMATION
HAMILTONIANS
HYPERFINE STRUCTURE
ISOTOPE RATIO
L-S COUPLING
MOLECULES
NUCLEOSYNTHESIS
ORBITS
QUADRUPOLES
SPECTRA
SPECTROSCOPY
TITANIUM 46
TITANIUM 47
TITANIUM 49
TITANIUM 50
TITANIUM OXIDES