The fate of formamide in a fragmenting protoplanetary disc

Abstract

Recent high-sensitivity observations carried out with ALMA have revealed the presence of complex organic molecules (COMs) such as methyl cyanide (CH${}_3$CN) and methanol (CH${}_3$OH) in relatively evolved protoplanetary discs. The behaviour and abundance of COMs in earlier phases of disc evolution remains unclear. Here we combine a smoothed particle hydrodynamics simulation of a fragmenting, gravitationally unstable disc with a gas-grain chemical code. We use this to investigate the evolution of formamide (NH${}_2$CHO), a pre-biotic species, in both the disc and in the fragments that form within it. Our results show that formamide remains frozen onto grains in the majority of the disc where the temperatures are $<$100 K, with a predicted solid-phase abundance that matches those observed in comets. Formamide is present in the gas-phase in three fragments as a result of the high temperatures ($\ge$200\,K), but remains in the solid-phase in one colder ($\le$150 K) fragment. The timescale over which this occurs is comparable to the dust sedimentation timescales, suggesting that any rocky core which is formed would inherit their formamide content directly from the protosolar nebula.

arXiv comment10 pages, 5 figures, accepted for publication in ApJ

References in corpus (25)

• The UMIST database for astrochemistry 2012
• Modelling Accretion in Protobinary Systems
• Evaporation of ices near massive stars: models based on laboratory TPD data
• The cometary composition of a protoplanetary disk as revealed by complex cyanides
• Complex organic molecules in protoplanetary disks
• Binding energies: new values and impact on the efficiency of chemical desorption
• First detection of gas-phase methanol in a protoplanetary disk
• Dust as interstellar catalyst I. Quantifying the chemical desorption process
• First detection of water vapor in a pre-stellar core
• The chemical history of molecules in circumstellar disks. II. Gas-phase species
• UCLCHEM: A Gas-Grain Chemical Code
• Complex organic molecules in comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy): detection of ethylene glycol and formamide
• Chemical modelling of complex organic molecules with peptide-like bonds in star-forming regions
• Towards a population synthesis model of self-gravitating disc fragmentation and tidal downsizing II: The effect of fragment-fragment interactions
• Cometary ices in forming protoplanetary disc midplanes
• Introducing a Hybrid Method of Radiative Transfer for Smoothed Particle Hydrodynamics
• Water delivery from cores to disks: deuteration as a probe of the prestellar inheritance of H2O
• Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability
• Dawes Review. The tidal downsizing hypothesis of planet formation
• The chemistry of protoplanetary fragments formed via gravitational instabilities
• Chemistry in a gravitationally unstable protoplanetary disc
• Identifying and Analysing Protostellar Disc Fragments in Smoothed Particle Hydrodynamics Simulations
• Gravitational instabilities in a protosolar-like disc I: dynamics and chemistry
• Warm Cores around Regions of Low-Mass Star Formation
• Chemistry in a forming protoplanetary disk: main accretion phase

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• Modelling methanol and hydride formation in the JWST Ice Age era
• Photoprocessing of formamide ice: route towards prebiotic chemistry in space
• Searching for wide-orbit gravitational instability protoplanets with ALMA in the dust continuum
• Constraining protoplanetary disc mass using the GI wiggle