Stratified Distribution of Organic Molecules at the Planet-Formation Scale in the HH 212 Disk Atmosphere

Abstract

Formamide (NH2CHO) is considered an important prebiotic molecule because of its potential to form peptide bonds. It was recently detected in the atmosphere of the HH 212 protostellar disk on the Solar-System scale where planets will form. Here we have mapped it and its potential parent molecules HNCO and H2CO, along with other molecules CH3OH and CH3CHO, in the disk atmosphere, studying its formation mechanism. Interestingly, we find a stratified distribution of these molecules, with the outer emission radius increasing from ~ 24 au for NH2CHO and HNCO, to 36 au for CH3CHO, to 40 au for CH3OH, and then to 48 au for H2CO. More importantly, we find that the increasing order of the outer emission radius of NH2CHO, CH3OH, and H2CO is consistent with the decreasing order of their binding energies, supporting that they are thermally desorbed from the ice mantle on dust grains. We also find that HNCO, which has much lower binding energy than NH2CHO, has almost the same spatial distribution, kinematics, and temperature as NH2CHO, and is thus more likely a daughter species of desorbed NH2CHO. On the other hand, we find that H2CO has a more extended spatial distribution with different kinematics from NH2CHO, thus questioning whether it can be the gas-phase parent molecule of NH2CHO.

22 pages, 5 figures

References in corpus (22)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The ALMA-PILS survey: Inventory of complex organic molecules towards IRAS 16293-2422 A
• Seeds Of Life In Space (SOLIS): The organic composition diversity at 300--1000 au scale in Solar-type star forming regions
• Seeds of Life in Space (SOLIS) III. Formamide in protostellar shocks: evidence for gas-phase formation
• Binding energies of interstellar molecules on crystalline and amorphous models of water ice by ab-initio calculations
• ALMA discovery of a rotating SO/SO${}_2$ flow in HH212. A possible MHD disk wind?
• Formation and Atmosphere of Complex Organic Molecules of the HH 212 Protostellar Disk
• The ALMA view of the protostellar system HH212 - The wind, the cavity, and the disk
• Complex organics in IRAS 4A revisited with ALMA and PdBI: Striking contrast between two neighbouring protostellar cores
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• Interstellar formamide (NH${}_2$CHO), a key prebiotic precursor
• Discovery of a Hot Corino in the Bok Globule B335
• Formation of the prebiotic molecule NH${}_2$CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations
• Quantum mechanical simulations of the radical-radical chemistry on icy surfaces
• First Abundance Measurement of Organic Molecules in the Atmosphere of HH 212 Protostellar Disk
• Hydrogenation at low temperatures does not always lead to saturation: the case of HNCO
• What Produces Dust Polarization in the HH 212 Protostellar Disk at 878 μm: Dust Self-Scattering or Dichroic Extinction?
• First Detection of Interaction between a Magnetic Disk Wind and an Episodic Jet in a Protostellar System
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Hot Corino Survey toward Protostellar Cores in the Orion Cloud
• Ammonia snow-lines and ammonium salts desorption
• First measurement of the 14N/15N ratio in the analogue of the Sun progenitor OMC-2 FIR4
• Inferring (Sub)millimeter Dust Opacities and Temperature Structure in Edge-on Protostellar Disks From Resolved Multi-Wavelength Continuum Observations: The Case of the HH 212 Disk

Cited by in corpus (11)

• An overview of desorption parameters of Volatile and Complex Organic Molecules: A systematic dig on experimental literature
• Modest dust settling in the IRAS04302+2247 Class I protoplanetary disk
• Digging into the Interior of Hot Cores with ALMA (DIHCA). III: The Chemical Link between NH${}_2$CHO, HNCO, and H${}_2$CO
• ALMA-IMF XI: The sample of hot core candidates A rich population of young high-mass proto-stars unveiled by the emission of methyl formate
• ALMA reveals thermal and non-thermal desorption of methanol ice in the HD 100546 protoplanetary disk
• FAUST XX. The chemical structure and temperature profile of the IRAS 4A2 hot corino at 20-50 au
• Peptide Bonds in the Interstellar Medium: Facile Autocatalytic Formation from Nitriles on Water-Ice Grains
• FAUST XV. A disk wind mapped by CH${}_3$OH and SiO in the inner 300 au of the NGC 1333 IRAS 4A2 protostar
• Hidden under a warm blanket: If planets existed in protostellar disks, they would hardly produce observable substructures
• Correlations among complex organic molecules around protostars: Effects of physical structure
• HOPS-288: A Laboratory for Complex Organics in Proto-multiple Systems