Article
Astronomy & Astrophysics
N. Tieppo, F. Pauzat, O. Parisel, Y. Ellinger
Summary: This study finds that in the interstellar medium, the conversion of CO to CH3OH can occur without any energy barriers when using [H...(H2O)(n)] complexes as hydrogenation vectors on water ice surfaces. This simplified synthetic approach could be generalized for studying important atomic hydrogenations on ices in the interstellar medium.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Gwenaelle Dufour, Steven B. Charnley, Johan E. Lindberg
Summary: We study gas-grain chemical models of interstellar clouds to investigate non-linear dynamical evolution. We propose a method to produce oscillatory solutions in the presence of bistable solutions in gas-phase chemistry and demonstrate the existence of limit cycle and relaxation oscillation solutions. As these solutions are common to all models of interstellar chemistry, their occurrence should be widespread. We briefly discuss the implications for interpreting molecular cloud composition using time-dependent models and suggest some future directions for this approach.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Xia Zhang, Donghui Quan, Runxia Li, Jarken Esimbek, Long-Fei Chen, Guoming Zhao, Yan Zhou
Summary: Cyanamide and carbodiimide, which are considered key prebiotic molecules in the study of the origin of life, can form adenine in the interstellar medium (ISM) through a series of reactions. Using the NAUTILUS chemical code, we investigated their formation and destruction in different physical environments. Our simulated results indicate that these molecules primarily come from surface chemistry and are then released back to the gas phase. We speculate that forming a tautomer of adenine starting from cyanacetylene, cyanamide, and carbodiimide in ISM is an inefficient process.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Qingkuan Meng, Qiang Chang, Gang Zhao, Donghui Quan, Masashi Tsuge, Xia Zhang, Yong Zhang, Xiao-Hu Li
Summary: In this study, we quantitatively explain the relationship between the desorption energy of hydrogen on a diamond-like carbon surface and the surface coverage through experiments and calculations. We derived a mathematical formula to calculate the effective desorption energy of hydrogen, which depends on the desorption energy of hydrogen on the substrate and the ratio of diffusion barrier to desorption energy. By recalculating these parameters based on experimental data, we achieved good agreement between theoretical and experimental results.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. Megias, I Jimenez-Serra, J. Martin-Pintado, A. Vasyunin, S. Spezzano, P. Caselli, G. Cosentino, S. Viti
Summary: Recent observations of L1544 and L1498 show enhanced complex organic molecules (COMs) in the gas phase towards their outer and intermediate-density shells. High-sensitivity observations of L1517B reveal lower detection and abundance of COMs and COM precursors compared to L1544 and L1498. The chemical complexity in these starless cores seems to increase over time, with N-bearing molecules forming first followed by O-bearing COMs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Long-Fei Chen, Qiang Chang, Yao Wang, Di Li
Summary: This study investigates the roles of stochastic grain heating in the formation of complex organic molecules (COMs) in cold cores. The research finds that grain coagulation can affect the formation of certain gas-phase species in cold core environments, and COMs formed on stochastically heated grains may help explain the observed abundances of gas-phase COMs in cold cores.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Johannes Heyl, Thanja Lamberts, Serena Viti, Jonathan Holdship
Summary: The impact of including reactions of C and CH with molecular hydrogen in a gas-grain network is evaluated through a sensitivity analysis. By varying the efficiency for the reaction, the cosmic ray ionization rate, and the final density of the collapsing dark cloud, a grid of 12 models is used to investigate the effect of these parameters on the final molecular abundances of the chemical network. It is found that including reactions with molecular hydrogen alters the hydrogen economy of the network, leading to changes in the abundances of different species.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Lisa Giani, Cecilia Ceccarelli, Luca Mancini, Eleonora Bianchi, Fernando Pirani, Marzio Rosi, Nadia Balucani
Summary: This article presents a revised reaction network for the formation of methyl cyanide in the gas phase and explores the chemical link between methyl cyanide and methanol. The study identifies two new reactions that play a significant role in the formation of methyl cyanide and confirms the importance of a radiative association and electron recombination reaction in both cold and warm environments.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ritika, T. J. Dhilip Kumar
Summary: This study investigates the non-reactive collisions between NCCP and He at low temperatures. The rotational cross-sections of NCCP-He collisions are calculated using a new ab initio potential energy surface. Resonances are observed at low energies due to quasi-bound states of the NCCP-IIe complex. The rate coefficients among the rotational levels of NCCP are determined by thermal averaging the cross-sections at low temperatures.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Satyam Srivastav, Milan Sil, Prasanta Gorai, Amit Pathak, Bhalamurugan Sivaraman, Ankan Das
Summary: Straight-chain and branched-chain alkyl cyanides have been discovered in massive star-forming regions, indicating the presence of key amino acids in similar regions. The research shows that branching is more favorable for higher order alkyl cyanides, and realistic binding energy values can significantly change the abundance of these species.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Danilo R. Campanha, Edgar Mendoza, Mateus X. Silva, Paulo F. G. Velloso, Miguel Carvajal, Valentine Wakelam, Breno R. L. Galvao
Summary: The impact of the Si + SO2 reaction on the abundances of astrochemically relevant molecules is investigated and it is found that only SO and SiO are produced as products. No other reaction pathways leading to the abundance of SiS have been identified. Furthermore, it is discovered that SiS is stable in collisions with O-2, and other reactions involving Si and S-bearing molecules are examined.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Azrael A. von Prochazka, T. J. Millar
Summary: The study reveals that the abundances of NH3 in both gas phase and solid state are sensitive to gas-grain cycling within the system, and the degree of chemical complexity achievable at later stages of the cloud's chemical evolution is indeed influenced by the manner in which the gas-grain cycling occurs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
J. Garcia de la Concepcion, I. Jimenez-Serra, J. C. Corchado, G. Molpeceres, A. Martinez-Henares, V. M. Rivilla, L. Colzi, J. Martin-Pintado
Summary: This study investigates the difference in abundance ratios between isomers of an organic molecule in the interstellar medium (ISM) and provides valuable information about the chemistry, physics, and history of molecular clouds. The presence of cis-formic acid (c-HCOOH) at only 6% abundance compared to the trans isomer (t-HCOOH) in cold cores is explained through a cyclic process involving HCOOH, HCO+, and NH3. The proposed sequential acid-base (SAB) mechanism is a new approach to understanding the isomerism of organic molecules in the ISM.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. Garcia de la Concepcion, I. Jimenez-Serra, V. M. Rivilla, L. Colzi, J. Martin-Pintado
Summary: The formation of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium has been a topic of interest for astrophysicists. Through simulated reactions in molecular clouds, it was found that the reaction between the propargyl radical and the vinyl radical may occur under interstellar conditions, yielding the cyclopentadienyl radical, which could be an important precursor for the formation of more complex polycyclic hydrocarbons and simple PAHs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Carlos Cabezas, Isabel Pena, Jose Cernicharo
Summary: The recent detection of cyanonaphthalenes in interstellar space has sparked interest in exploring other aromatic molecular species that may be present in similar environments. This study focuses on ethynyl derivatives of naphthalene as potential candidates to be observed in the Taurus Molecular Cloud (TMC-1), where cyanonaphthalenes, as well as cyano- and ethynyl-derivatives of cyclopentadiene and benzene, have already been found. The researchers have successfully observed the rotational spectra of 1- and 2-ethynylnaphthalene species for the first time, providing accurate spectroscopic parameters that will aid in future astronomical searches.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
R. Martinez, A. Agnihotri, E. F. da Silveira, M. E. Palumbo, G. Strazzulla, P. Boduch, A. Domaracka, H. Rothard
Summary: Silicates are widely present in space and play a significant role in the surfaces of planets and small bodies. Irradiation by energetic cosmic particles induces structural changes and sputtering effects, affecting the physical and chemical properties of planetary surfaces. Experimental studies on irradiated silicates provide insights into the interaction between galactic cosmic rays, solar wind, solar energetic particles, and planetary surfaces.
Article
Physics, Atomic, Molecular & Chemical
D. Mifsud, Z. Kanuchova, S. Ioppolo, P. Herczku, A. Traspas Muina, T. A. Field, P. A. Hailey, Z. Juhasz, S. T. S. Kovacs, N. J. Mason, R. W. McCullough, S. Pavithraa, K. K. Rahul, B. Paripas, B. Sulik, S-L Chou, J- Lo, A. Das, B-M Cheng, B. N. Rajasekhar, A. Bhardwaj, B. Sivaraman
Summary: The astrochemistry of CO2 ice analogues has been extensively studied due to its prevalence in the interstellar medium and the Solar System. This study investigates the spectroscopic characteristics and chemical changes of pure CO2 ice at different temperatures, as well as the products of electron irradiation. The results indicate that temperature plays a crucial role in determining the spectroscopic properties and chemical reactions of CO2 ice.
JOURNAL OF MOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Stephane Coussan, Jennifer A. Noble, Herma M. Cuppen, Britta Redlich, Sergio Ioppolo
Summary: Amorphous solid water is one of the most widely studied solid phase systems, and understanding the nature of inter- and intramolecular forces in ASW is crucial for interpreting its catalytic role in environments. Experiments with mid-infrared radiation demonstrated the selective effects of vibrational energy injection on both the surface and bulk of pASW.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Astronomy & Astrophysics
Olivier Berne, Emilie Habart, Els Peeters, Alain Abergel, Edwin A. Bergin, Jeronimo Bernard-Salas, Emeric Bron, Jan Cami, Emmanuel Dartois, Asuncion Fuente, Javier R. Goicoechea, Karl D. Gordon, Yoko Okada, Takashi Onaka, Massimo Robberto, Markus Rollig, Alexander G. G. M. Tielens, Silvia Vicente, Mark G. Wolfire, Felipe Alarcon, C. Boersma, Amelie Canin, Ryan Chown, Daniel Dicken, David Languignon, Romane Le Gal, Marc W. Pound, Boris Trahin, Thomas Simmer, Ameek Sidhu, Dries Van de Putte, Sara Cuadrado, Claire Guilloteau, Alexandros Maragkoudakis, Bethany R. Schefter, Thiebaut Schirmer, Stephanie Cazaux, Isabel Aleman, Louis Allamandola, Rebecca Auchettl, Giuseppe Antonio Baratta, Salma Bejaoui, Partha P. Bera, Goranka Bilalbegovic, John H. Black, Francois Boulanger, Jordy Bouwman, Bernhard Brandl, Philippe Brechignac, Sandra Brunken, Andrew Burkhardt, Alessandra Candian, Jose Cernicharo, Marin Chabot, Shubhadip Chakraborty, Jason Champion, Sean W. J. Colgan, Ilsa R. Cooke, Audrey Coutens, Nick L. J. Cox, Karine Demyk, Jennifer Donovan Meyer, Cecile Engrand, Sacha Foschino, Pedro Garcia-Lario, Lisseth Gavilan, Maryvonne Gerin, Marie Godard, Carl A. Gottlieb, Pierre Guillard, Antoine Gusdorf, Patrick Hartigan, Jinhua He, Eric Herbst, Liv Hornekaer, Cornelia Jaeger, Eduardo Janot-Pacheco, Christine Joblin, Michael Kaufman, Francisca Kemper, Sarah Kendrew, Maria S. Kirsanova, Pamela Klaassen, Collin Knight, Sun Kwok, Alvaro Labiano, Thomas S-Y Lai, Timothy J. Lee, Bertrand Lefloch, Franck Le Petit, Aigen Li, Hendrik Linz, Cameron J. Mackie, Suzanne C. Madden, Joelle Mascetti, Brett A. McGuire, Pablo Merino, Elisabetta R. Micelotta, Karl Misselt, Jon A. Morse, Giacomo Mulas, Naslim Neelamkodan, Ryou Ohsawa, Alain Omont, Roberta Paladini, Maria Elisabetta Palumbo, Amit Pathak, Yvonne J. Pendleton, Annemieke Petrignani, Thomas Pino, Elena Puga, Naseem Rangwala, Mathias Rapacioli, Alessandra Ricca, Julia Roman-Duval, Joseph Roser, Evelyne Roueff, Gael Rouille, Farid Salama, Dinalva A. Sales, Karin Sandstrom, Peter Sarre, Ella Sciamma-O'Brien, Kris Sellgren, Matthew J. Shannon, Sachindev S. Shenoy, David Teyssier, Richard D. Thomas, Aditya Togi, Laurent Verstraete, Adolf N. Witt, Alwyn Wootten, Nathalie Ysard, Henning Zettergren, Yong Zhang, Ziwei E. Zhang, Junfeng Zhen
Summary: Massive stars disrupt the molecular cloud material through radiative and mechanical feedback processes, impacting the evolution of interstellar matter. Observations of Photo-Dissociation Regions (PDRs) provide insights into physical and chemical processes in interstellar and circumstellar media. PDR emission dominates infrared spectra of star-forming galaxies and will be a focus of observations with the James Webb Space Telescope (JWST).
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
(2022)
Article
Astronomy & Astrophysics
Julia C. Santos, Ko-Ju Chuang, Thanja Lamberts, Gleb Fedoseev, Sergio Ioppolo, Harold Linnartz
Summary: Research shows that the formation of methanol in interstellar ices is an important pathway through the CH3O-induced abstraction reaction, rather than just the gradual addition of H atoms to CO. Experimental results and analytical techniques support this theory, while the isotope effect hinders the progress of another reaction pathway to some extent.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Lidia Mezzina, Angelo Nicosia, Giuseppe Antonio Baratta, Maria Elisabetta Palumbo, Carlotta Scire, Placido Giuseppe Mineo
Summary: As space exploration missions become more frequent, the effects of space radiation on polymers, which are versatile and suitable for advanced applications, are not yet fully understood.
Article
Astronomy & Astrophysics
M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, Fengwu Sun, Tracy L. Beck, A. C. A. Boogert, W. A. Brown, P. Caselli, S. B. Charnley, Herma M. Cuppen, H. Dickinson, M. N. Drozdovskaya, E. Egami, J. Erkal, H. Fraser, R. T. Garrod, D. Harsono, S. Ioppolo, I. Jimenez-Serra, M. Jin, J. K. Jorgensen, L. E. Kristensen, D. C. Lis, M. R. S. McCoustra, Brett A. McGuire, G. J. Melnick, Karin I. Oberg, M. E. Palumbo, T. Shimonishi, J. A. Sturm, E. F. van Dishoeck, H. Linnartz
Summary: Icy grain mantles in interstellar clouds are important reservoirs of volatile elements that connect chemical processes with planet formation and atmospheric composition. Results from the Ice Age program using the James Webb Space Telescope reveal the rich composition of these dense cloud ices, showing the detection of weak ice features and complex organic molecules. The study suggests that simple and complex molecules can form early in ice-rich environments and JWST can trace the molecules seen in planetary atmospheres back to their origins in interstellar clouds.
Article
Physics, Atomic, Molecular & Chemical
Duncan V. Mifsud, Peter Herczku, Bela Sulik, Zoltan Juhasz, Istvan Vajda, Istvan Rajta, Sergio Ioppolo, Nigel J. Mason, Giovanni Strazzulla, Zuzana Kanuchova
Summary: The organic chemistry in interstellar environments plays a crucial role in the formation of complex molecules relevant to the origins of life. This study investigates the irradiation of CH4:H2O ice mixtures using 1 MeV protons and 2 keV electrons at 20 K. The results show the formation of various new products, including simple and complex molecules such as C2H6, C3H8, C2H2, CH3OH, CO, CO2, and potentially H2CO. Interestingly, proton irradiation leads to a higher abundance of radiolytic daughter molecules compared to electron irradiation, despite a lower radiation dose administered. These findings are important for understanding radiation astrochemistry in interstellar clouds and Solar System objects.
Article
Astronomy & Astrophysics
J. C. Santos, K. J. Chuang, J. G. M. Schrauwen, A. Traspas Muina, J. Zhang, H. M. Cuppen, B. Redlich, H. Linnartz, S. Ioppolo
Summary: In this study, the behavior of interstellar relevant CO and CH3OH ice analogs following resonant vibrational excitation using tunable IR radiation was systematically investigated. The dissipation of vibrational energy was found to be highly dependent on the excited mode and the chemical environment of the ice. Both pure CO and CH3OH ices showed IR-induced photodesorption, with interstellar photodesorption efficiencies comparable to or higher than UV-induced counterparts.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
G. Strazzulla, M. E. Palumbo, P. Boduch, H. Rothard
Summary: An essential requirement for life on Earth is the continuous cycling of key atoms and molecules. This study investigates the cycling of certain species in the icy moons of Jupiter, which are exposed to energetic particles from the planet's magnetosphere. The results show that carbon, nitrogen, oxygen, and sulfur atoms go through various cycles on the icy surfaces of these moons. These findings have implications for future space observations conducted by the JWST telescope and the JUICE spacecraft.
EARTH MOON AND PLANETS
(2023)
Article
Astronomy & Astrophysics
J. A. Sturm, M. K. Mcclure, C. J. Law, D. Harsono, J. B. Bergner, E. Dartois, M. N. Drozdovskaya, S. Ioppolo, K. I. Oberg, M. E. Palumbo, Y. J. Pendleton, W. R. M. Rocha, H. Terada, R. G. Urso
Summary: Observations of edge-on disks play an important role in understanding protoplanetary disk properties. However, current models struggle to reproduce both the spectral energy distributions and scattered light observations due to differences in geometry and dust properties at different wavelengths. In this study, the authors successfully constrained the geometry and characteristics of the protoplanetary disk HH 48 NE using a parameterized dust model and a Monte Carlo framework. The findings provide insights into the physical structure and icy chemistry of this disk.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Chemistry, Physical
Duncan V. Mifsud, Peter Herczku, K. K. Rahul, Ragav Ramachandran, Pavithraa Sundararajan, Sandor T. S. Kovacs, Bela Sulik, Zoltan Juhasz, Richard Racz, Sandor Biri, Zuzana Kanuchova, Robert W. Mccullough, Bhalamurugan Sivaraman, Sergio Ioppolo, Nigel J. Mason
Summary: The use of mid-infrared spectroscopy is important for understanding the chemistry of icy environments in space. Laboratory data is crucial for comparative analysis.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)