Authors: Moran, Jose R.; Cabezas, Carlos; Hussain, Farha S.; Perez, Cristobal; Cernicharo, Jose; Steber, Amanda L.; Pena, Isabel
Journal: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Publication date: 2025/03/24
Abstract: The recent interstellar detection of individual polycyclic aromatic hydrocarbons (PAHs) in the Taurus Molecular Cloud (TMC-1) brings with it interest in related species that could be present in this astronomical environment. The interstellar PAHs detected in TMC-1 consist of a few pure PAHs while the majority that have been detected are their cyano-derivative counterparts due to their larger dipole moment components. Bowl-shaped PAHs, such as sumanene (C21H12), represent another important target for radio astronomy as they are very polar species, in spite of their high symmetry, increasing their chances of detection. Here, we present the laboratory rotational spectroscopic study of the PAH sumanene, characterized in the gas-phase using a chirped-pulse Fourier-transform microwave spectrometer operating between 2 and 8 GHz. Accurate spectroscopic parameters are derived from the spectral analysis and compared to those obtained for corannulene. These parameters have been employed to achieve reliable frequency predictions for their astronomical search in TMC-1. We do not detect either sumanene or corannulene in our QUIJOTE line survey of TMC-1 but upper limits to their abundance in this source are derived.
