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Bertin M, Basalgète R, Ocaña AJ, Féraud G, Romanzin C, Philippe L, Michaut X, Fillion JH. Vacuum UV photodesorption of organics in the interstellar medium: an experimental study of formic acid HCOOH and methyl formate HCOOCH 3-containing ices. Faraday Discuss 2023; 245:488-507. [PMID: 37309601 DOI: 10.1039/d3fd00004d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Being a potential process that could explain gas phase abundances of so-called complex organic molecules (COMs) in the cold interstellar medium (ISM), the UV photon-induced desorption from organics-containing molecular ices has been experimentally studied. In this work, we focused on the observation of the photodesorbed products and the measurement of the associated photodesorption yields from pure and mixed molecular ices, each containing organic molecules whose detection has been achieved in the gas phase of the cold ISM, namely formic acid HCOOH and methyl formate HCOOCH3. Each molecule, in pure ice or in ice mixed with CO or water, was irradiated at 15 K with monochromatic vacuum UV photons in the 7-14 eV range using synchrotron radiation from the SOLEIL synchrotron facility, DESIRS beamline. Photodesorption yields of the intact molecules and of the photoproducts were derived as a function of the incident photon energy. Experiments have revealed that the desorbing species match the photodissociation pattern of each isolated molecule, with little influence of the kind of ice (pure or mixed in CO or H2O-rich environment). For both species, the photodesorption of the intact organics is found to be negligible in our experimental conditions, resulting in yields typically below 10-5 ejected molecules per incident photon. The results obtained on HCOOH and HCOOCH3-containing ices are similar to what has already been found for methanol-containing ices, but contrast with the case of another complex molecule, CH3CN, photodesorption of which has been recently studied. Such experimental results may be linked to the observation of COMs in protoplanetary disks, in which CH3CN is commonly observed whereas HCOOH or methanol are detected only in some sources, HCOOCH3 not being detected at all.
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Affiliation(s)
- Mathieu Bertin
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Romain Basalgète
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Antonio J Ocaña
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Géraldine Féraud
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Claire Romanzin
- Univ. Paris-Saclay, CNRS UMR 8000, ICP, F-91405, Orsay, France
| | - Laurent Philippe
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Xavier Michaut
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
| | - Jean-Hugues Fillion
- Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, F-75005, Paris, France.
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Herczku P, Mifsud DV, Ioppolo S, Juhász Z, Kaňuchová Z, Kovács STS, Traspas Muiña A, Hailey PA, Rajta I, Vajda I, Mason NJ, McCullough RW, Paripás B, Sulik B. The Ice Chamber for Astrophysics-Astrochemistry (ICA): A new experimental facility for ion impact studies of astrophysical ice analogs. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:084501. [PMID: 34470410 DOI: 10.1063/5.0050930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
The Ice Chamber for Astrophysics-Astrochemistry (ICA) is a new laboratory end station located at the Institute for Nuclear Research (Atomki) in Debrecen, Hungary. The ICA has been specifically designed for the study of the physico-chemical properties of astrophysical ice analogs and their chemical evolution when subjected to ionizing radiation and thermal processing. The ICA is an ultra-high-vacuum compatible chamber containing a series of IR-transparent substrates mounted on a copper holder connected to a closed-cycle cryostat capable of being cooled down to 20 K, itself mounted on a 360° rotation stage and a z-linear manipulator. Ices are deposited onto the substrates via background deposition of dosed gases. The ice structure and chemical composition are monitored by means of FTIR absorbance spectroscopy in transmission mode, although the use of reflectance mode is possible by using metallic substrates. Pre-prepared ices may be processed in a variety of ways. A 2 MV Tandetron accelerator is capable of delivering a wide variety of high-energy ions into the ICA, which simulates ice processing by cosmic rays, solar wind, or magnetospheric ions. The ICA is also equipped with an electron gun that may be used for electron impact radiolysis of ices. Thermal processing of both deposited and processed ices may be monitored by means of both FTIR spectroscopy and quadrupole mass spectrometry. In this paper, we provide a detailed description of the ICA setup as well as an overview of the preliminary results obtained and future plans.
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Affiliation(s)
- Péter Herczku
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - Duncan V Mifsud
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - Sergio Ioppolo
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Zoltán Juhász
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - Zuzana Kaňuchová
- Astronomical Institute, Slovak Academy of Sciences, Tatranská Lomnica SK-059 60, Slovakia
| | - Sándor T S Kovács
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - Alejandra Traspas Muiña
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Perry A Hailey
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, United Kingdom
| | - István Rajta
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - István Vajda
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
| | - Nigel J Mason
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury CT2 7NH, United Kingdom
| | - Robert W McCullough
- Department of Physics and Astronomy, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Béla Paripás
- Department of Physics, Faculty of Mechanical Engineering and Informatics, University of Miskolc, Miskolc H-3515, Hungary
| | - Béla Sulik
- Institute for Nuclear Research (Atomki), PO Box 51, Debrecen H-4026, Hungary
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Arumainayagam CR, Garrod RT, Boyer MC, Hay AK, Bao ST, Campbell JS, Wang J, Nowak CM, Arumainayagam MR, Hodge PJ. Extraterrestrial prebiotic molecules: photochemistryvs.radiation chemistry of interstellar ices. Chem Soc Rev 2019; 48:2293-2314. [DOI: 10.1039/c7cs00443e] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Photochemistry and radiation chemistry of interstellar ices lead to the synthesis of prebiotic molecules which may be delivered to planets by meteorites and/or comets.
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Affiliation(s)
| | - Robin T. Garrod
- University of Virginia
- Astronomy & Chemistry
- Charlottesville
- USA
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Agúndez M, Roueff E, Le Petit F, Le Bourlot J. The chemistry of disks around T Tauri and Herbig Ae/Be stars. ASTRONOMY AND ASTROPHYSICS 2018; 616:A19. [PMID: 30185991 PMCID: PMC6120683 DOI: 10.1051/0004-6361/201732518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
CONTEXT Infrared and (sub-)mm observations of disks around T Tauri and Herbig Ae/Be stars point to a chemical differentiation between both types of disks, with a lower detection rate of molecules in disks around hotter stars. AIMS To investigate the underlying causes of the chemical differentiation indicated by observations we perform a comparative study of the chemistry of T Tauri and Herbig Ae/Be disks. This is one of the first studies to compare chemistry in the outer regions of these two types of disks. METHODS We developed a model to compute the chemical composition of a generic protoplanetary disk, with particular attention to the photochemistry, and applied it to a T Tauri and a Herbig Ae/Be disk. We compiled cross sections and computed photodissociation and photoionization rates at each location in the disk by solving the FUV radiative transfer in a 1+1D approach using the Meudon PDR code and adopting observed stellar spectra. RESULTS The warmer disk temperatures and higher ultraviolet flux of Herbig stars compared to T Tauri stars induce some differences in the disk chemistry. In the hot inner regions, H2O, and simple organic molecules like C2H2, HCN, and CH4 are predicted to be very abundant in T Tauri disks and even more in Herbig Ae/Be disks, in contrast with infrared observations that find a much lower detection rate of water and simple organics toward disks around hotter stars. In the outer regions, the model indicates that the molecules typically observed in disks, like HCN, CN, C2H, H2CO, CS, SO, and HCO+, do not have drastic abundance differences between T Tauri and Herbig Ae disks. Some species produced under the action of photochemistry, like C2H and CN, are predicted to have slightly lower abundances around Herbig Ae stars due to a narrowing of the photochemically active layer. Observations indeed suggest that these radicals are somewhat less abundant in Herbig Ae disks, although in any case the inferred abundance differences are small, of a factor of a few at most. A clear chemical differentiation between both types of disks concerns ices. Owing to the warmer temperatures of Herbig Ae disks, one expects snowlines lying farther away from the star and a lower mass of ices compared to T Tauri disks. CONCLUSIONS The global chemical behavior of T Tauri and Herbig Ae/Be disks is quite similar. The main differences are driven by the warmer temperatures of the latter, which result in a larger reservoir or water and simple organics in the inner regions and a lower mass of ices in the outer disk.
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Affiliation(s)
- Marcelino Agúndez
- Instituto de Física Fundamental, CSIC, C/ Serrano 123, E-28006 Madrid, Spain
| | - Evelyne Roueff
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190 Meudon, France
| | - Franck Le Petit
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190 Meudon, France
| | - Jacques Le Bourlot
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190 Meudon, France
- Université Paris-Diderot, Sorbonne Paris-Cité, F-75013 Paris, France
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Öberg KI. Photochemistry and Astrochemistry: Photochemical Pathways to Interstellar Complex Organic Molecules. Chem Rev 2016; 116:9631-63. [DOI: 10.1021/acs.chemrev.5b00694] [Citation(s) in RCA: 255] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karin I. Öberg
- Harvard-Smithsonian Center for Astrophysics, 60
Garden St., Cambridge, Massachusetts 02138, United States
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Marchione D, McCoustra MRS. Electrons, excitons and hydrogen bonding: electron-promoted desorption from molecular ice surfaces. Phys Chem Chem Phys 2016; 18:29747-29755. [DOI: 10.1039/c6cp05814k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Desorption of benzene from methanol and diethyl ether ices during irradiation with 250 eV electrons is reported and compared with our previous work on benzene/water ices to highlight the role of hydrogen bonding in excitation transport.
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Thrower JD, Ioppolo S, Walsh C. Highlights from Faraday Discussion 168: Astrochemistry of Dust, Ice and Gas, Leiden, The Netherlands, April 2014. Chem Commun (Camb) 2014; 50:13636-44. [DOI: 10.1039/c4cc90397h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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