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oai:uvadoc.uva.es:10324/610532025-12-01T11:24:49Zcom_10324_1186com_10324_931com_10324_894col_10324_1404

Sanz Novo, Miguel Rivilla, Víctor M. Jiménez Serra, Izaskun Martín Pintado, Jesús Colzi, Laura Zeng, Shaoshan Megías, Andrés López Gallifa, Álvaro Martínez Henares, Antonio Massalkhi, Sarah Tercero, Belén Vicente, Pablo de Martín, Sergio Andrés, David San Requena Torres, Miguel A. 2023-08-24T08:47:25Z 2023-08-24T08:47:25Z 2023 The Astrophysical Journal, 2023, Volume 954, Number 1 0004-637X https://uvadoc.uva.es/handle/10324/61053 10.3847/1538-4357/ace523 3 1 The Astrophysical Journal 954 1538-4357 Producción Científica A quarter century after the detection of the last interstellar carboxylic acid, acetic acid (CH3COOH), we report the discovery of a new one, the cis-trans form of carbonic acid (HOCOOH), toward the Galactic center molecular cloud G+0.693–0.027. HOCOOH stands as the first interstellar molecule containing three oxygen atoms and the third carboxylic acid detected so far in the interstellar medium. Albeit the limited available laboratory measurements (up to 65 GHz), we have also directly identified several pairs of unblended lines in the astronomical data (between 75 and 120 GHz), which allowed us to slightly improve the set of spectroscopic constants. We derive a column density for cis-trans HOCOOH of N = (6.4 ± 0.4) × 1012 cm−2, which yields an abundance with respect to molecular H2 of 4.7 × 10−11. Meanwhile, the extremely low dipole moment (about 15 times lower) of the lower-energy conformer, cis-cis HOCOOH, precludes its detection. We obtain an upper limit to its abundance with respect to H2 of ≤1.2 × 10−9, which suggests that cis-cis HOCOOH might be fairly abundant in interstellar space, although it is nearly undetectable by radio astronomical observations. We derive a cis-cis/cis-trans ratio of ≤25, consistent with the smaller energy difference between both conformers compared with the relative stability of trans- and cis-formic acid. Finally, we compare the abundance of these acids in different astronomical environments, further suggesting a relationship between the chemical content found in the interstellar medium and the chemical composition of the minor bodies of the solar system, which could be inherited during the star formation process. Ministerio de Universidades (MIU) / Universidad de Valladolid: contrato postdoctoral Margarita Salas Víctor Manuel Rivilla Ministerio de Ciencia e Innovación (PID2020-117742GB-I00) Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación (proyectos RYC2020-029387-I y PID2019-105552RB-C41) Centro de Astrobiología (CAB) (proyecto 20225AT015) Ministerio de Ciencia e Innovación (proyecto PID2019-107115GB-C21. B.T.) Ministerio de Ciencia e Innovación (PID2019-106235GB-I00) application/pdf eng IOP Publishing American Astronomical Society info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ © 2023 The Authors Atribución 4.0 Internacional Ácido carbónico (HOCOOH) Carbonic acid (HOCOOH) Interstellar molecule Molécula interestelar 21 Astronomía y Astrofísica Discovery of the Elusive Carbonic Acid (HOCOOH) in Space info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion https://iopscience.iop.org/article/10.3847/1538-4357/ace523 SI