scholarly journals Systems Astrochemistry: A New Doctrine for Experimental Studies

2021 ◽  
Vol 8 ◽  
Author(s):  
Nigel J. Mason ◽  
Perry A. Hailey ◽  
Duncan V. Mifsud ◽  
James S. Urquhart
Keyword(s):  
Experimental Design ◽  
Interstellar Medium ◽  
Laboratory Experiments ◽  
Organic Molecules ◽  
Prebiotic Chemistry ◽  
Experimental Studies ◽  
Experimental Parameter ◽  
Complex Organic ◽  
Insight Into ◽  
Reductionist Approach

Laboratory experiments play a key role in deciphering the chemistry of the interstellar medium (ISM) and the formation of complex organic molecules (COMs) relevant to life. To date, however, most studies in experimental astrochemistry have made use of a reductionist approach to experimental design in which chemical responses to variations in a single parameter are investigated while all other parameters are held constant. Although such work does afford insight into the chemistry of the ISM, it is likely that several important points (e.g., the possible influence of experimental parameter interaction) remain ambiguous. In light of this, we propose the adoption of a new “systems astrochemistry” approach for experimental studies and present the basic tenants and advantages of this approach in this perspective article. Such an approach has already been used for some time now and to great effect in the field of prebiotic chemistry, and so we anticipate that its application to experimental astrochemistry will uncover new data hitherto unknown which could aid in better linking laboratory work to observations and models.

Thermal and photochemical study of CH3OH and CH3OH–O2 astrophysical ices

2020 ◽  
Vol 500 (1) ◽  
pp. 1188-1200
Author(s):  
Killian Leroux ◽  
Lahouari Krim
Keyword(s):  
Interstellar Medium ◽  
Organic Compounds ◽  
Organic Molecules ◽  
Uv Light ◽  
Hydrogen Abstraction ◽  
Insertion Reaction ◽  
Abstraction Reaction ◽  
Uv Photons ◽  
Astrophysical Ices ◽  
Complex Organic

ABSTRACT Methanol, which is one of the most abundant organic molecules in the interstellar medium, plays an important role in the complex grain surface chemistry that is believed to be a source of many organic compounds. Under energetic processing such as ultraviolet (UV) photons or cosmic rays, methanol may decompose into CH4, CO2, CO, HCO, H2CO, CH3O and CH2OH, which in turn lead to complex organic molecules such as CH3OCHO, CHOCH2OH and HOCH2CH2OH through radical recombination reactions. However, although molecular oxygen and its detection, abundance and role in the interstellar medium have been the subject of many debates, few experiments on the oxidation of organic compounds have been carried out under interstellar conditions. The present study shows the behaviour of solid methanol when treated by UV light and thermal processing in oxygen-rich environments. Methanol has been irradiated in the absence and presence of O2 at different concentrations in order to study how oxidized complex organic molecules may form and also to investigate the O-insertion reaction in the C–H bound to form methanediol HOCH2OH through a CH3OH + O(1D) solid-state reaction. The adding of O2 in the thermal and photochemical reaction of solid methanol leads to the formation of O3, H2O and HO2, in addition to three main organics, HCOOH, CHOCHO and HOCH2OH. We show that in an O2-rich environment, species such as CO, CH4, HCO, CH3OH and CHOCH2OH are oxidized into CO2, CH3OH, HC(O)OO, HOCH2OH and CHOCHO, respectively, while HCOOH might be formed through the H2CO + O(3P) → (OH + HCO)cage → HCOOH hydrogen-abstraction reaction.

scholarly journals Prebiologically Important Interstellar Molecules

2004 ◽  
Vol 213 ◽  
pp. 185-188
Author(s):  
Y.-J. Kuan ◽  
H.-C. Huang ◽  
S. B. Charnley ◽  
W.-L. Tseng ◽  
L. E. Snyder ◽  
...  
Keyword(s):  
Amino Acid ◽  
Organic Molecules ◽  
Prebiotic Chemistry ◽  
Interstellar Space ◽  
Central Question ◽  
Dna And Rna ◽  
The Galaxy ◽  
Molecular Complexity ◽  
Cloud Cores ◽  
Complex Organic

Understanding the organic chemistry of molecular clouds, particularly the formation of biologically important molecules, is fundamental to the study of the processes which lead to the origin, evolution and distribution of life in the Galaxy. Determining the level of molecular complexity attainable in the clouds, and the nature of the complex organic material available to protostellar disks and the planetary systems that form from them, requires an understanding of the possible chemical pathways and is therefore a central question in astrochemistry. We have thus searched for prebiologically important molecules in the hot molecular cloud cores: Sgr B2(N-LMH), W51 e1/e2 and Orion-KL. Among the molecules searched: Pyrimidine is the unsubstituted ring analogue for three of the DNA and RNA bases. 2H-Azirine and Aziridine are azaheterocyclic compounds. And Glycine is the simplest amino acid. Detections of these interstellar organic molecular species will thus have important implications for Astrobiology. Our preliminary results indicate a tentative detection of interstellar glycine. If confirmed, this will be the first detection of an amino acid in interstellar space and will greatly strengthen the thesis that interstellar organic molecules could have played a pivotal role in the prebiotic chemistry of the early Earth.

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.

scholarly journals SUBMARINE MASS FAILURE: WAVE GENERATION BY GRANULAR SLIDES

2018 ◽  
pp. 47
Author(s):  
Frederic M. Evers ◽  
Helge Fuchs ◽  
David Vetsch ◽  
Robert M. Boes
Keyword(s):  
Laboratory Experiments ◽  
Numerical Models ◽  
Experimental Studies ◽  
Wave Generation ◽  
Data Set ◽  
Ongoing Research ◽  
Tsunami Waves ◽  
Potential Source ◽  
Submarine Mass Failure ◽  
Insight Into

Submarine mass failures (SMF) are a potential source of hazardous tsunamis. While the link between seismic events and the magnitude of tsunami waves has been extensively studied and corresponding approaches are included in numerical tsunami warning models, the basic implementation of SMF generated waves is subject to ongoing research. In this context, laboratory experiments are essential for the validation of numerical schemes. Most experimental studies apply rigid slide models whereas only few include granular slides (e.g. Watts 1997, Ataie-Ashtiani & Najafi-Jilani 2008, Grilli et al. 2017). The objective of this study is to gain a better insight into the hydraulic processes related to wave generation by submarine granular slides based on experiments as well as establishing a comprehensive data set for the validation of numerical models.

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.

scholarly journals Chemical complexity in the Horsehead photodissociation region

2014 ◽  
Vol 168 ◽  
pp. 103-127 ◽  
Author(s):  
Viviana V. Guzmán ◽  
Jérôme Pety ◽  
Pierre Gratier ◽  
Javier R. Goicoechea ◽  
Maryvonne Gerin ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Gas Phase ◽  
Thermal Desorption ◽  
Organic Molecules ◽  
Dense Core ◽  
High Spectral Resolution ◽  
Complex Molecules ◽  
Chemical Complexity ◽  
Clean Environment ◽  
Complex Organic

The interstellar medium is known to be chemically complex. Organic molecules with up to 11 atoms have been detected in the interstellar medium, and are believed to be formed on the ices around dust grains. The ices can be released into the gas-phase either through thermal desorption, when a newly formed star heats the medium around it and completely evaporates the ices; or through non-thermal desorption mechanisms, such as photodesorption, when a single far-UV photon releases only a few molecules from the ices. The first mechanism dominates in hot cores, hot corinos and strongly UV-illuminated PDRs, while the second dominates in colder regions, such as low UV-field PDRs. This is the case of the Horsehead were dust temperatures are ≃20–30 K, and therefore offers a clean environment to investigate the role of photodesorption. We have carried out an unbiased spectral line survey at 3, 2 and 1mm with the IRAM-30m telescope in the Horsehead nebula, with an unprecedented combination of bandwidth, high spectral resolution and sensitivity. Two positions were observed: the warm PDR and a cold condensation shielded from the UV field (dense core), located just behind the PDR edge. We summarize our recently published results from this survey and present the first detection of the complex organic molecules HCOOH, CH2CO, CH3CHO and CH3CCH in a PDR. These species together with CH3CN present enhanced abundances in the PDR compared to the dense core. This suggests that photodesorption is an efficient mechanism to release complex molecules into the gas-phase in far-UV illuminated regions.

Extraterrestrial Molecules: Present and Future Observations from Space

1979 ◽  
Vol 47 ◽  
pp. 439-456
Author(s):  
Cristiano Batalli Cosmovici
Keyword(s):  
Interstellar Medium ◽  
Interdisciplinary Research ◽  
Organic Molecules ◽  
Space Astronomy ◽  
Cool Stars ◽  
Infrared Studies ◽  
The Galaxy ◽  
Molecular Astrophysics ◽  
Complex Organic ◽  
Atmospheric Windows

AbstractIn the last ten years Molecular Astrophysics has become an extremely interesting field of interdisciplinary research as a result of unexpected discoveries of complex organic molecules made by radioastronomy in many regions and objects of the Galaxy. Since not all molecules have detectable transitions through the atmospheric windows, the development of UV and IR space astronomy will allow us to study new important molecular transitions in the interstellar medium and in the atmospheres of cool stars and comets. In this paper the present status of molecular astrophysics will be described and special emphasis will be devoted to the importance of IR space astronomy for the future knowledge of molecular species in the interstellar medium and in the atmospheres of Carbon stars where the low temperatures are particularly, suitable for infrared studies

Formaldehyde chemistry in cometary ices: the case of HOCH2OH formation

2014 ◽  
Vol 16 (44) ◽  
pp. 24200-24208 ◽  
Author(s):  
F. Duvernay ◽  
A. Rimola ◽  
P. Theule ◽  
G. Danger ◽  
T. Sanchez ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Organic Molecules ◽  
Complex Organic ◽  
The Universe

Laboratory experiments devoted to simulate the chemistry occurring in interstellar and cometary ice analogues are of paramount importance to understand the formation of complex organic molecules that are detected throughout the universe.

scholarly journals Interstellar Methanol from the Lab to Protoplanetary Disks

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
Maria N. Drozdovskaya ◽  
Catherine Walsh ◽  
Ruud Visser ◽  
Daniel Harsono ◽  
Ewine F. van Dishoeck
Keyword(s):  
Organic Molecules ◽  
Disk Formation ◽  
Chemical Complexity ◽  
Chemical Models ◽  
Collapse Model ◽  
Low Mass ◽  
Grain Surface ◽  
Physical And Chemical ◽  
Complex Organic ◽  
Insight Into

Interstellar methanol is thought to be the precursor of larger, more complex organic molecules. It holds a central role in many astrochemical models (e.g., Garrod & Herbst 2006). Methanol has also been the focus of several laboratory studies (e.g., Watanabe et al. 2004, Fuchs et al. 2009), in an effort to gain insight into grain-surface chemistry, which potentially builds chemical complexity already in the cold, dark prestellar phase. The case of methanol is a prime example of experimental work having implications on astronomical scales. Drozdovskaya et al. (2014) unified physical and chemical models to simulate infalling material during the birth of a low-mass protostar. An axisymmetric 2D semi-analytic collapse model (Visser et al. 2009), wavelength-dependent radiative transfer calculations with RADMC3D (Dullemond & Dominik 2004) and a comprehensive gas-grain chemical network (Walsh et al. 2014) were used to study two modes of protoplanetary disk formation.

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