First detections of the key prebiotic molecule PO in star-forming regions

Phosphorus is a crucial element in biochemistry, especially the P-O bond, which is key for the formation of the backbone of the deoxyribonucleic acid. So far, PO has only been detected towards the envelope of evolved stars, and never towards star-forming regions. We report the first detections of PO...

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Detalles Bibliográficos
Autores: Rivilla, V. M., Fontani, F., Beltrán, M. T., Vasyunin, A., Caselli, P., Martín-Pintado, J., Cesaroni, R.
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2016
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/415778
Acceso en línea:http://hdl.handle.net/10261/415778
http://arxiv.org/abs/1605.06109v2
Access Level:acceso abierto
Palabra clave:astro-ph.SR
astrobiology
astrochemistry
ISM: molecules
line: identification
molecular data
stars: formation
astro-ph.GA
Descripción
Sumario:Phosphorus is a crucial element in biochemistry, especially the P-O bond, which is key for the formation of the backbone of the deoxyribonucleic acid. So far, PO has only been detected towards the envelope of evolved stars, and never towards star-forming regions. We report the first detections of PO towards two massive star-forming regions, W51 e1/e2 and W3(OH), using data from the IRAM 30m telescope. PN has also been detected towards the two regions. The abundance ratio PO/PN is 1.8 and 3 for W51 and W3(OH), respectively. Our chemical model indicates that the two molecules are chemically related and are formed via gas-phase ion-molecule and neutral-neutral reactions during the cold collapse. The molecules freeze out onto grains at the end of the collapse and desorb during the warm-up phase once the temperature reaches 35 K. Similar abundances of the two species are expected during a period of 5x10^{4} yr at the early stages of the warm-up phase, when the temperature is in the range 35-90 K. The observed molecular abundances of 10^{-10} are predicted by the model if a relatively high initial abundance of 5x10^{-9} of depleted phosphorus is assumed.