Discovery of interstellar phenalene (

Year: 2025

Type: article

Abstract: We present the discovery of the unsubstituted polycyclic aromatic hydrocarbon (PAH) phenalene (C13H10) in TMC-1 as part of the QUIJOTE line survey. In spite of the low dipole moment of this three-ring PAH, we managed to identify a total of 267 rotational transitions with quantum numbers J and Ka up to 34 and 14, respectively, corresponding to 71 independent frequencies. The identification of this new PAH from our survey was based on the agreement between the rotational parameters derived from the analysis of the lines and those obtained by quantum chemical calculations. Our subsequent chemical synthesis of this PAH and investigation of its laboratory microwave spectrum unequivocally support our identification. We report the column density of phenalene in TMC-1 as (2.8 ± 1.6) × 1013 cm−2.

Source: Springer Link (Chiba Institute of Technology)

DOI: 10.1051/0004-6361/202556687/pdf

Authors: C. Cabezas, M. Agúndez, C. Pérez, D. Villar-Castro, G. Molpeceres, D. Pérez, A. L. Steber, R. Fuentetaja, B. Tercero, N. Marcelino, A. Lesarri, P. de Vicente, J. Cernicharo

Institutions: Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Universidad de Valladolid, Universidade de Santiago de Compostela, Centro Singular de Investigación en Química Biológica y Materiales Moleculares, Yebes Observatory, Spanish National Observatory

Language: English

Topic: Astrophysics and Star Formation Studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Xunta de Galicia, European Regional Development Fund, Agencia Estatal de Investigación, European Social Fund

OpenAlex ID: W7080180676