6533b7defe1ef96bd12769e5
RESEARCH PRODUCT
The hyperfine structure in the rotational spectrum of CF+
Pierre GratierMaryvonne GerinViviana V. GuzmánEvelyne RoueffJérôme PetyD. TeyssierJürgen GaussJavier R. Goicoecheasubject
AstrochemistryFOS: Physical sciencesContext (language use)Astrophysics010402 general chemistryRotation01 natural sciencesISM: clouds0103 physical sciencesSpin (physics)010303 astronomy & astrophysicsHyperfine structureAstrophysics::Galaxy AstrophysicsLine (formation)PhysicsNebularadio lines: ISMastrochemistryAstronomy and AstrophysicsAstrophysics - Astrophysics of GalaxiesISM: molecules0104 chemical sciences[PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]Space and Planetary ScienceAstrophysics of Galaxies (astro-ph.GA)ISM: individual objects: Horsehead nebula[SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]Atomic physicsBar (unit)description
Context. CF+ has recently been detected in the Horsehead and Orion Bar photo-dissociation regions. The J=1-0 line in the Horsehead is double-peaked in contrast to other millimeter lines. The origin of this double-peak profile may be kinematic or spectroscopic. Aims. We investigate the effect of hyperfine interactions due to the fluorine nucleus in CF+ on the rotational transitions. Methods. We compute the fluorine spin rotation constant of CF+ using high-level quantum chemical methods and determine the relative positions and intensities of each hyperfine component. This information is used to fit the theoretical hyperfine components to the observed CF+ line profiles, thereby employing the hyperfine fitting method in GILDAS. Results. The fluorine spin rotation constant of CF+ is 229.2 kHz. This way, the double-peaked CF+ line profiles are well fitted by the hyperfine components predicted by the calculations. The unusually large hyperfine splitting of the CF+ line therefore explains the shape of the lines detected in the Horsehead nebula, without invoking intricate kinematics in the UV-illuminated gas.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-12-01 |