Prebiotic precursors of the primordial RNA world in space: Detection of NH${}_2$OH

Abstract

One of the proposed scenarios for the origin of life is the primordial RNA world, which considers that RNA molecules were likely responsible for the storage of genetic information and the catalysis of biochemical reactions in primitive cells, before the advent of proteins and DNA. In the last decade, experiments in the field of prebiotic chemistry have shown that RNA nucleotides can be synthesized from relatively simple molecular precursors, most of which have been found in space. An important exception is hydroxylamine, NH${}_2$OH, which, despite several observational attempts, it has not been detected in space yet. Here we present the first detection of NH${}_2$OH in the interstellar medium towards the quiescent molecular cloud G+0.693-0.027 located in the Galactic Center. We have targeted the three groups of transitions from the $J$=2$-$1, 3$-$2, and 4$-$3 rotational lines, detecting 5 transitions that are unblended or only slightly blended. The derived molecular abundance of NH${}_2$OH is (2.1$\pm$0.9)$\times$10${}^{-10}$. From the comparison of the derived abundance of NH${}_2$OH and chemically related species, with those predicted by chemical models and measured in laboratory experiments, we favor the formation of NH${}_2$OH in the interstellar medium via hydrogenation of NO on dust grain surfaces, with possibly a contribution of ice mantle NH${}_3$ oxidation processes. Further laboratory studies and quantum chemical calculations are needed to completely rule out the formation of NH${}_2$OH in the gas phase.

Accepted in the Astrophysical Journal Letters

References in corpus (11)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• The largest oxigen bearing organic molecule repository
• Tracing shocks and photodissociation in the Galactic center region
• ALMA and ROSINA detections of phosphorus-bearing molecules: the interstellar thread between star-forming regions and comets
• The Survey of Water and Ammonia in the Galactic Center (SWAG): Molecular Cloud Evolution in the Central Molecular Zone
• Phosphorus-bearing molecules in the Galactic Center
• Efficient Surface Formation Route of Interstellar Hydroxylamine through NO Hydrogenation II: the multilayer regime in interstellar relevant ices
• Seeding the Pregenetic Earth: Meteoritic Abundances of Nucleobases and Potential Reaction Pathways
• Formation of hydroxylamine on dust grains via ammonia oxidation
• Nitrogen oxide in protostellar envelopes and shocks: the ASAI survey