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arXiv · 1808.07891

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

Víctor M. Rivilla·Francesco Fontani·Maite Beltrán·Anton Vasyunin·Paola Caselli·Jesús Martín-Pintado·Riccardo Cesaroni
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Abstract

Phosphorus is a crucial element in prebiotic chemistry, especially the P$-$O bond, which is key for the formation of the backbone of the deoxyribonucleic acid. So far, PO had only been detected towards the envelope of evolved stars, and never towards star-forming regions. We report the first detection 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 $\sim$35 K. The observed molecular abundances of 10$^{-10}$ are predicted by the model if a relatively high initial abundance of phosphorus, 5$\times$10$^{-9}$, is assumed.

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Víctor M. Rivilla, Francesco Fontani, Maite Beltrán, Anton Vasyunin, Paola Caselli, Jesús Martín-Pintado, Riccardo Cesaroni. 2018-08-23. The first detections of the key prebiotic molecule PO in star-forming regions. https://doi.org/10.1017/s1743921317008729

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