Discovery of two new magnesium-bearing species in IRC+10216: MgC3N and MgC4H
| Autor: | G. Quintana-Lacaci, José Cernicharo, Yasuki Endo, M. Guelin, Juan R. Pardo, L. Velilla-Prieto, F. Tercero, Juan Daniel Gallego, José Pablo Fonfría, Carlos Cabezas, Marcelino Agúndez, J. A. López-Pérez, Celina Bermúdez |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Swedish Research Council, Ministerio de Economía y Competitividad (España) |
| Rok vydání: | 2019 |
| Předmět: |
Astrochemistry
Line: identification Astrophysics 01 natural sciences Molecular physics 0103 physical sciences Molecule identification [Line] Spectroscopy 010303 astronomy & astrophysics Stars: individual: IRC+10216 Dissociative recombination Physics 010304 chemical physics Molecular data Polyatomic ion individual: IRC+10216 [Stars] Astronomy and Astrophysics Circumstellar matter Diatomic molecule 3. Good health Stars: carbon Space and Planetary Science Rotational spectroscopy Ground state carbon [Stars] |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 10 pags., 5 figs., 7 tabs., 5 apps. We report on the detection of two series of harmonically related doublets in IRC+10216. From the observed frequencies, the rotational constant of the first series is B = 1380.888 MHz and that of the second series is B = 1381.512 MHz. The two series correspond to two species with a 2Σ electronic ground state. After considering all possible candidates, and based on quantum chemical calculations, the first series is assigned to MgC3N and the second to MgC4H. For the latter species, optical spectroscopy measurements support its identification. Unlike diatomic metal-containing molecules, the line profiles of the two new molecules indicate that they are formed in the outer layers of the envelope, as occurs for MgNC and other polyatomic metal-cyanides. We also confirm the detection of MgCCH that was previously reported from the observation of two doublets. The relative abundance of MgC3N with respect to MgNC is close to one while that of MgC4H relative to MgCCH is about ten. The synthesis of these magnesium cyanides and acetylides in IRC+10216 can be explained in terms of a two-step process initiated by the radiative association of Mg+ with large cyanopolyynes and polyynes followed by the dissociative recombination of the ionic complexes. The Spanish authors thank the Ministerio de Ciencia Innovación y Universidades for funding support from the CONSOLIDER-Ingenio program “ASTROMOL” CSD 2009-00038, AYA2012-32032, AYA2016-75066-C2-1-P. We also thank ERC for funding through grant ERC-2013-Syg610256-NANOCOSMOS. MA thanks the Ministerio de Ciencia Innovación y Universidades for the Ramón y Cajal grant RyC-2014-16277. CB thanks the Ministerio de Ciencia Innovación y Universidades for the Juan de la Cierva grant FJCI-2016-27983. LVP acknowledges support from the Swedish Research Council and from ERC consolidator grant 614 |
| Databáze: | OpenAIRE |
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