A new infrared band in the Interstellar and Circumstellar Clouds: C_4 or C_4H?
| Autor: | Cernicharo, J., Goicoechea, J. R., Benilan, Y. |
|---|---|
| Přispěvatelé: | Universidad Autónoma de Madrid |
| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
individual (CRL 618
CRL 2688 IRC +10216 NGC 7027) [Stars] Line: identification Astrophysics (astro-ph) FOS: Physical sciences Astrophysics ISM: molecules ISM: lines and bands Infrared: general individual (Sagittarius B2) [ISM] general [Infrared] Stars: individual (CRL 618 CRL 2688 IRC +10216 NGC 7027) ISM: individual (Sagittarius B2) lines and bands [ISM] identification [Line] molecules [ISM] |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | We report on the detection with the Infrared Space Observatory (ISO) of a molecular band at 57.5 microns (174 cm^{-1}) in carbon-rich evolved stars and in Sgr B2. Taking into account the chemistry of these objects the most likelihood carrier is a carbon chain. We tentatively assign the band to the nu_5 bending mode of C_4 for which a wavenumber of 170-172.4 cm^{-1} has been derived in matrix experiments (Withey et al. 1991). An alternate carrier might be C_4H, although the frequency of its lowest energy vibrational bending mode, nu_7, is poorly known (130-226 cm^{-1}). If the carrier is C_4, the derived maximum abundance is nearly similar to that found for C_3 in the interstellar and circumstellar media by Cernicharo, Goicoechea & Caux (2000). Hence, tetra-atomic carbon could be one of the most abundant carbon chain molecules in these media. We thank Spanish DGES and PNIE for funding support undergrants ESP98-1351-E and PANAYA2000-1784. J. R. G. ac-knowledges Universidad Auto ́ noma de Madrid for a predoctoralfellowship |
| Databáze: | OpenAIRE |
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