Knowledge Bank

Thermal emission apectrum of YbF molecule has been photographed for the first time in the apectral region $\lambda \lambda 3600-4600$ {\AA} at a reciprocal linear dispersion of 7.3 A/mm. The study reveals the presence of 103 single and double headed violet degraded bands which have been attributed into two systems viz. C-X and D-X. The system C-X is entirely new and consists of 92 double headed bands while the, already reported, system D-X comprises of 11 single headed bands. The vibrational analysis has been performed and it was found that both the systems arose form the ground state $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$. The detailed an analysis shows that system C-X involves the transition $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi -\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$; while D-X system depicts the feature of $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma -\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$ transition. The following vibrational constants have been determined for the different systems: