Abstract
The band has been identified and measured in the laboratory spectrum of the CD molecule for the first time. The emission from the discharge was observed with a high accuracy dispersive optical spectroscopy technique using a plane-grating spectrograph and recorded by a photomultiplier tube. In total, 99 ro-vibronic frequencies were measured with an absolute accuracy of about
cm
. In the following work, we present the results of the combined analysis of the current experimental data and the
(0−0) [Szajna et al., J. Mol. Spectrosc. 324, 48–52 (2016)] and
(0−0) [Herzberg and Johns, Astrophys. J. 158, 399–417 (1969)] bands of CD. The resulting data, compared to those from the earlier measurements, present more accurate molecular constants for the v = 0 vibrational level of the
and
states. The parameters of the Λ-doubling (p, q) of the
(v = 0) level were obtained for the first time. The current observations and analysis have become a basis to discuss the possible detection of the CD radical in the interstellar medium by the
,
+
and
spectral lines of the
band in the 3880 Å region.
GRAPHICAL ABSTRACT
![](/cms/asset/2a91cade-2690-4473-be9d-13ab4af6c147/tmph_a_2128459_uf0001_oc.jpg)
Acknowledgements
We dedicate this work to Professor Wim Ubachs (Vrije Universiteit) on the occasion of his 65th birthday and in recognition of his outstanding contribution to laser and molecular spectroscopy as well as metrology leading into physics beyond the Standard Model.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Correction Statement
This article has been corrected with minor changes. These changes do not impact the academic content of the article.
Notes
1 Originally the lines were numbered by N value rather than by J value.