SEMINARIO
Sala Consiglio - Martedì 17 Maggio, ore 11:00

Rafal Hakalla
Material and Spectroscopic Research Department
University of Rzeszów
Poland

Spectroscopy of the rare 12C17O and 13C17O isotopologues and deperturbation analysis of the A1Π state

Carbon monoxide is the second most abundant molecular species in the Universe. CO
is used as a physicochemical benchmark in many astronomical environments, such as:
interstellar clouds, circumstellar discs, as well as planetary and exoplanetary atmospheres.
It has become crucial to obtain precise values of the molecular parameters of various CO
isotopologues, as they facilitate study of the chemical evolution of low-mass star formation
and solar nebula and protoplanetary discs as well as planetary nebulae. The research
of 12C17O and 13C17O is of significant importance for inter alia explanation of the so-called
depth optical effect in interstellar absorption as well as for precise determination of the
[12C]/[13C] and [16O]/[17O]/[18O] ratios, which are used, among others, to determine
relationship between the processes of stellar nucleosynthesis of the first and second
generation [1]. From a pure spectroscopy perspective, the CO molecule is a benchmark
species for the investigation of perturbations in the spectroscopy of diatomic molecules.
In particular the energy level structure of the first excited singlet state of CO, i.e. A1Π,
exhibits a wealth of perturbations in all CO isotopologues.
In the framework of this lecture I would like to present the first investigations of the
VIS Ångström (B1Σ+ - A1Π) and Herzberg (C1Σ+ - A1Π) systems as well as VUV Hopfield-Birge
(B1Σ+ - X1Σ+, C1Σ+ - X1Σ+) systems in the rare 12C17O and 13C17O isotopologues by means of the
high-resolution methods of high-precision optical dispersion spectroscopy (HADOS, Rzeszów)
as well as Fourier-transform spectroscopy of VIS region (Bruker 125 HR spectrometer,
Rzeszów) and VUV region (SOLEIL synchrotron, St. Aubin, France). The first deperturbation
analysis of the unique A1Π state in 12C17O and 13C17O will be also presented [2, 3].

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