scholarly journals Synthesis of solid-state complex organic molecules through accretion of simple species at low temperatures

2019 ◽  
Vol 15 (S350) ◽  
pp. 46-50
Author(s):  
D. Qasim ◽  
G. Fedoseev ◽  
K.-J. Chuang ◽  
V. Taquet ◽  
T. Lamberts ◽  
...  
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Organic Molecules ◽  
Primary Alcohol ◽  
Major Product ◽  
Activation Barriers ◽  
Upper Limit ◽  
Complex Organic

AbstractComplex organic molecules (COMs) have been detected in the gas-phase in cold and lightless molecular cores. Recent solid-state laboratory experiments have provided strong evidence that COMs can be formed on icy grains through ‘non-energetic’ processes. In this contribution, we show that propanal and 1-propanol can be formed in this way at the low temperature of 10 K. Propanal has already been detected in space. 1-propanol is an astrobiologically relevant molecule, as it is a primary alcohol, and has not been astronomically detected. Propanal is the major product formed in the C2H2 + CO + H experiment, and 1-propanol is detected in the subsequent propanal + H experiment. ALMA observations towards IRAS 16293-2422B are discussed and provide a 1-propanol:propanal upper limit of < 0.35–0.55, which are complemented by computationally-derived activation barriers in addition to the performed laboratory experiments.

scholarly journals Laboratory data in support of JWST observations of interstellar ices

2019 ◽  
Vol 15 (S350) ◽  
pp. 420-421
Author(s):  
Marina G. Rachid ◽  
Jeroen Terwisscha van Scheltinga ◽  
Daniël Koletzki ◽  
Giulia Marcandalli ◽  
Ewine F. van Dishoeck ◽  
...  
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Organic Molecules ◽  
Methyl Formate ◽  
Laboratory Data ◽  
Protoplanetary Disks ◽  
Theoretical Studies ◽  
James Webb Space Telescope ◽  
Complex Organic ◽  
Experimental And Theoretical Studies

AbstractExperimental and theoretical studies have shown that Complex Organic Molecules (COMs) can be formed on icy dusty grains in molecular clouds and protoplanetary disks. The number of astronomical detections of solid COMs, however, is very limited. With the upcoming launch of the James Webb Space Telescope (JWST) this should change, but in order to identify solid state features of COMs, accurate laboratory data are needed. Here we present high resolution (0.5 cm–1) infrared ice spectra of acetone (C3H6O) and methyl formate (HCOOCH3), two molecules already identified in astronomical gas phase surveys, whose interstellar synthesis is expected to follow solid state pathways.

scholarly journals Dust and molecules in extra-galactic planetary nebulae

2015 ◽  
Vol 11 (A29B) ◽  
Author(s):  
D. A. García-Hernández
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Organic Molecules ◽  
Local Group ◽  
Planetary Nebulae ◽  
Circumstellar Envelopes ◽  
The Galaxy ◽  
Models Comparison ◽  
Polycyclic Aromatic ◽  
Complex Organic

AbstractExtra-galactic planetary nebulae (PNe) permit the study of dust and molecules in metallicity environments other than the Galaxy. Their known distances lower the number of free parameters in the observations vs. models comparison, providing strong constraints on the gas-phase and solid-state astrochemistry models. Observations of PNe in the Galaxy and other Local Group galaxies such as the Magellanic Clouds (MC) provide evidence that metallicity affects the production of dust as well as the formation of complex organic molecules and inorganic solid-state compounds in their circumstellar envelopes. In particular, the lower metallicity MC environments seem to be less favorable to dust production and the frequency of carbonaceous dust features and complex fullerene molecules is generally higher with decreasing metallicity. Here, I present an observational review of the dust and molecular content in extra-galactic PNe as compared to their higher metallicity Galactic counterparts. A special attention is given to the level of dust processing and the formation of complex organic molecules (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene precursors) depending on metallicity.

scholarly journals Infrared spectra of complex organic molecules in astronomically relevant ice matrices

2019 ◽  
Vol 15 (S350) ◽  
pp. 356-357
Author(s):  
J. Terwisscha van Scheltinga ◽  
N. F. W. Ligterink ◽  
A. C. A. Boogert ◽  
E. F. van Dishoeck ◽  
H. Linnartz
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Organic Molecules ◽  
Laboratory Studies ◽  
Astronomical Observations ◽  
James Webb Space Telescope ◽  
Circumstellar Gas ◽  
Complex Organic ◽  
Recent Laboratory

AbstractThe identification of complex organic molecules, COMs, in inter- and circumstellar gas phase environments is steadily increasing. The formation of such COMs takes largely place on the icy dust grains, as has been shown in recent laboratory studies. Until now solid state features of smaller molecular species have been directly identified in these environments. The presented work on acetaldehyde (CH3CHO), ethanol (CH3CH2OH), and dimethyl ether (CH3OCH3) in different astronomically relevant ice environments and for temperatures in the range 15 to 160 Kelvin, provides the necessary tools to guide or interpret astronomical observations, specifically for upcoming James Webb Space Telescope observations.

scholarly journals Mapping observations of complex organic molecules around Sagittarius B2 with the ARO 12 m telescope

2020 ◽  
Vol 492 (1) ◽  
pp. 556-565
Author(s):  
Juan Li ◽  
Junzhi Wang ◽  
Haihua Qiao ◽  
Donghui Quan ◽  
Min Fang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gas Phase ◽  
Low Temperatures ◽  
Organic Molecules ◽  
Methyl Formate ◽  
Surface Reactions ◽  
High Sensitivity ◽  
Methyl Amine ◽  
Grain Surface ◽  
Complex Organic

ABSTRACT We have performed high-sensitivity mapping observations of several complex organic molecules around Sagittarius B2 with the ARO 12 m telescope at 3 mm wavelength. Based on their spatial distribution, molecules can be classified as either ‘extended’, those detected not only in Sgr B2(N) and Sgr B2(M), or ‘compact’, those only detected toward or near Sgr B2(N) and Sgr B2(M). The ‘extended’ molecules include glycolaldehyde (CH2OHCHO), methyl formate (CH3OCHO), formic acid (t-HCOOH), ethanol (C2H5OH) and methyl amine (CH3NH2), while the ‘compact’ molecules include dimethyl ether (CH3OCH3), ethyl cyanide (C2H5CN), and amino acetonitrile (H2NCH2CN). These ‘compact’ molecules are likely produced under strong UV radiation, while the ‘extended’ molecules are likely formed at low temperatures, via gas-phase or grain-surface reactions. The spatial distribution of ‘warm’ CH2OHCHO at 89 GHz differs from the spatial distribution of ‘cold’ CH2OHCHO observed at 13 GHz. We found evidence for an overabundance of CH2OHCHO compared to that expected from the gas-phase model, which indicates that grain-surface reactions are necessary to explain the origin of CH2OHCHO in Sagittarius B2. Grain-surface reactions are also needed to explain the correlation between the abundances of ‘cold’ CH2OHCHO and C2H5OH. These results demonstrate the importance of grain-surface chemistry in the production of complex organic molecules.

scholarly journals Synthetic Approaches to Complex Organic Molecules in the Cold Interstellar Medium

2022 ◽  
Vol 8 ◽  
Author(s):  
Eric Herbst ◽  
Robin T. Garrod
Keyword(s):  
Low Temperature ◽  
Interstellar Medium ◽  
Gas Phase ◽  
Low Temperatures ◽  
Organic Molecules ◽  
High Energy ◽  
Interstellar Space ◽  
Interstellar Clouds ◽  
Millimeter And Submillimeter Waves ◽  
Complex Organic

The observation and synthesis of organic molecules in interstellar space is one of the most exciting and rapidly growing topics in astrochemistry. Spectroscopic observations especially with millimeter and submillimeter waves have resulted in the detection of more than 250 molecules in the interstellar clouds from which stars and planets are ultimately formed. In this review, we focus on the diverse suggestions made to explain the formation of Complex Organic Molecules (COMs) in the low-temperature interstellar medium. The dominant mechanisms at such low temperatures are still a matter of dispute, with both gas-phase and granular processes, occurring on and in ice mantles, thought to play a role. Granular mechanisms include both diffusive and nondiffusive processes. A granular explanation is strengthened by experiments at 10 K that indicate that the synthesis of large molecules on granular ice mantles under space-like conditions is exceedingly efficient, with and without external radiation. In addition, the bombardment of carbon-containing ice mantles in the laboratory by cosmic rays, which are mainly high-energy protons, can lead to organic species even at low temperatures. For processes on dust grains to be competitive at low temperatures, however, non-thermal desorption mechanisms must be invoked to explain why the organic molecules are detected in the gas phase. Although much remains to be learned, a better understanding of low-temperature organic syntheses in space will add both to our understanding of unusual chemical processes and the role of molecules in stellar evolution.

scholarly journals Precursors of complex organic molecules: NH3 and CH3OH in the ices surrounding low-mass protostars

2008 ◽  
Vol 4 (S251) ◽  
pp. 105-110 ◽  
Author(s):  
Sandrine Bottinelli ◽  
Adwin C. A. Boogert ◽  
Ewine F. van Dishoeck ◽  
Martha Beckwith ◽  
Jordy Bouwman ◽  
...  
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Organic Molecules ◽  
High Sensitivity ◽  
Young Stellar Objects ◽  
Stellar Objects ◽  
Space Telescope ◽  
Low Mass ◽  
Complex Organic

AbstractNH3 and CH3OH are key molecules in the chemical networks leading to the formation of complex N- and O-bearing organic molecules. However, despite a number of recent studies, there is still a lot to learn about their abundances in the solid state and how they relate to those of other N/O-bearing organic molecules or to NH3 and CH3OH abundances in the gas phase. This is particularly true in the case of low-mass young stellar objects (YSOs), for which only the recent advent of the Spitzer Space Telescope has allowed high sensitivity observations of the ices in their enveloppes. We present a combined study of Spitzer data (obtained within the Legacy program “From Molecular Cores to Planet-Forming Disks”, c2d) and laboratory spectra, leading to the detections of NH3 and CH3OH in the ices of low-mass protostars. We investigate correlations with other ice features and conclude with prospects on further studies linking these two precursors of complex organic molecules with their gas-phase products.

scholarly journals Aldehydes and sugars from evolved precometary ice analogs: Importance of ices in astrochemical and prebiotic evolution

2015 ◽  
Vol 112 (4) ◽  
pp. 965-970 ◽  
Author(s):  
Pierre de Marcellus ◽  
Cornelia Meinert ◽  
Iuliia Myrgorodska ◽  
Laurent Nahon ◽  
Thomas Buhse ◽  
...  
Keyword(s):  
Gas Phase ◽  
Molecular Clouds ◽  
Room Temperature ◽  
Laboratory Experiments ◽  
Organic Residue ◽  
Organic Residues ◽  
Flight Mass Spectrometry ◽  
The Earth ◽  
Planetary Environment ◽  
Complex Organic

Evolved interstellar ices observed in dense protostellar molecular clouds may arguably be considered as part of precometary materials that will later fall on primitive telluric planets, bringing a wealth of complex organic compounds. In our laboratory, experiments reproducing the photo/thermochemical evolution of these ices are routinely performed. Following previous amino acid identifications in the resulting room temperature organic residues, we have searched for a different family of molecules of potential prebiotic interest. Using multidimensional gas chromatography coupled to time-of-flight mass spectrometry, we have detected 10 aldehydes, including the sugar-related glycolaldehyde and glyceraldehyde—two species considered as key prebiotic intermediates in the first steps toward the synthesis of ribonucleotides in a planetary environment. The presence of ammonia in water and methanol ice mixtures appears essential for the recovery of these aldehydes in the refractory organic residue at room temperature, although these products are free of nitrogen. We finally point out the importance of detecting aldehydes and sugars in extraterrestrial environments, in the gas phase of hot molecular clouds, and, more importantly, in comets and in primitive meteorites that have most probably seeded the Earth with organic material as early as 4.2 billion years ago.

scholarly journals Detection of glyceraldehyde and glycerol in VUV processed interstellar ice analogues containing formaldehyde: a general formation route for sugars and polyols

2020 ◽  
Vol 496 (4) ◽  
pp. 5292-5307
Author(s):  
Y Layssac ◽  
A Gutiérrez-Quintanilla ◽  
T Chiavassa ◽  
F Duvernay
Keyword(s):  
Laboratory Experiments ◽  
Organic Molecules ◽  
General Scheme ◽  
Star Forming ◽  
Star Forming Regions ◽  
Vuv Photolysis ◽  
Different Temperatures ◽  
Low Mass ◽  
Species Production ◽  
Complex Organic

ABSTRACT Complex organic molecules (COMs) have been identified toward high- and low-mass protostars as well as molecular clouds. Among them, sugar-like and polyol two carbon-bearing molecules such as glycolaldehyde (GA) and ethylene glycol (EG) are of special interest. Recent laboratory experiments have shown that they can efficiently be formed via atom addition reactions between accreting H-atoms and CO molecules or via energetic processes (UV, electrons) on ice analogues containing methanol or formaldehyde. In this study, we report new laboratory experiments on the low-temperature solid state formation of complex organic molecules – the first sugar glyceraldehyde and its saturated derivative glycerol – through VUV photolysis performed at three different temperatures (15, 50, and 90 K) of astrochemically relevant ices composed of water and formaldehyde. We get evidence that the species production depends on the ice temperature during photolysis. The results presented here indicate that a general scheme of aldose and polyol formation is plausible and that heavier COMs than GA and EG could exist in interstellar environments. We propose a general pathway involving radical-formaldehyde reactions as common initiation step for aldose and polyol formation. Future telescope observations may give additional clues on their presence in star-forming regions as observations are currently limited because of the detection thresholds.

Formation of complex organic molecules in astrophysical environments: Sugars and derivatives

2019 ◽  
Vol 15 (S350) ◽  
pp. 123-126
Author(s):  
Michel Nuevo ◽  
George Cooper ◽  
John M. Saunders ◽  
Christina E. Buffo ◽  
Scott A. Sandford
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Laboratory Experiments ◽  
Organic Molecules ◽  
Formation Mechanisms ◽  
Sugar Alcohols ◽  
Amphiphilic Compounds ◽  
Uv Photons ◽  
Sugar Derivatives ◽  
Complex Organic

AbstractCarbonaceous meteorites contain a large variety of complex organic molecules, including amino acids, nucleobases, sugar derivatives, amphiphiles, and other compounds of astrobiological interest. Photoprocessing of ices condensed on cold grains with ultraviolet (UV) photons was proposed as an efficient way to form such complex organics in astrophysical environments. This hypothesis was confirmed by laboratory experiments simulating photo-irradiation of ices containing H2O, CH3OH, CO, CO2, CH4, H2CO, NH3, HCN, etc., condensed on cold (~10–80 K) substrates. These experiments resulted in the formation of amino acids, nucleobases, sugar derivatives, amphiphilic compounds, and other organics comparable to those identified in carbonaceous meteorites. This work presents results for the formation of sugars, sugar alcohols, sugar acids, and their deoxy variants from the UV irradiation of ices containing H2O and CH3OH in relative proportions 2:1, and their comparison with meteoritic data. The formation mechanisms of these compounds and the astrobiological implications are also discussed.

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