The high resolution infrared spectrum of HCl$^+$

TL;DR

This paper provides accurate infrared rovibrational transition data and an improved global fit of spectroscopic data for HCl$^+$, aiding future astronomical observations and analysis of this interstellar molecule.

Contribution

It introduces a comprehensive set of infrared transition wavenumbers and an enhanced global spectroscopic fit for HCl$^+$, integrating IR data with existing UV and mm-wave data.

Findings

Accurate rovibrational transition wavenumbers for HCl$^+$ provided.

Improved global fit of spectroscopic data achieved.

Supports future infrared astronomical observations of HCl$^+$.

Abstract

The chloroniumyl cation, HCl$^+$, has been recently identified in space from Herschel's spectra. A joint analysis of extensive vis-UV spectroscopy emission data together with a few high resolution and high accuracy mm-wave data provided the necessary rest frequencies to support the astronomical identification. Nevertheless, the analysis did not include any infrared vibration-rotation data. Furthermore, with the end of the Herschel mission, infrared observations from ground may be one of the few available means to further study this ion in space. In this work we provide a set of accurate rovibrational transition wavenumbers as well as a new and improved global fit of vis-UV, IR and mm-wave spectroscopy laboratory data, that will aid in future studies of this molecule.