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Las bandas infrarrojas interestelares no identificadas: ¿los HAP como portadores?
S Schlemmer1, D J Cook, J A Harrison
1Department of Chemistry, University of California, Berkeley 94720-1460, USA.
Science (New York, N.Y.)
|September 16, 1994
Resumen
Los espectros infrarrojos de laboratorio del naftaleno y el pireno no coinciden con las observaciones astronómicas. Esto sugiere que los pequeños hidrocarburos aromáticos policíclicos no son responsables de las bandas de emisión infrarrojas no identificadas en el espacio.
Área de la Ciencia:
- La astroquímica es astroquímica.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Los objetos astronómicos exhiben bandas de emisión infrarrojas no identificadas.
- Los hidrocarburos aromáticos policíclicos (HAP) son portadores potenciales de estas bandas.
- El naftaleno y el pireno son HAP representativos pequeños y no sustituidos.
Objetivo del estudio:
- Para medir los espectros de emisión infrarrojos del naftaleno y el pireno en fase gaseosa.
- Para comparar espectros de laboratorio con observaciones astronómicas de bandas de emisión infrarrojas no identificadas.
- Para determinar si los HAP pequeños y no sustituidos pueden explicar las observaciones astronómicas.
Principales métodos:
- Se midieron los espectros de emisión infrarrojos para el naftaleno y el pireno en fase gaseosa.
- Las mediciones se llevaron a cabo en el rango de 3 a 7,5 micrómetros.
- Se emplearon la desorción-excitación por láser ultravioleta y la espectroscopia infrarroja de conteo de un solo fotón.
Principales resultados:
- Se observaron discrepancias significativas entre los espectros de laboratorio y los datos astronómicos.
- Las longitudes de onda y las intensidades relativas de las características espectrales no coincidían.
- Los espectros de emisión de laboratorio de naftaleno y pireno no replicaron las bandas astronómicas observadas.
Conclusiones:
- Es poco probable que los hidrocarburos aromáticos policíclicos pequeños, neutrales y no sustituidos sean portadores de las bandas de emisión infrarrojas no identificadas.
- El origen de las bandas de emisión infrarrojas no identificadas en objetos astronómicos sigue siendo desconocido.
- Se necesita más investigación para identificar las moléculas responsables de estas características espectrales.
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