1
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Dyrek A, Min M, Decin L, Bouwman J, Crouzet N, Mollière P, Lagage PO, Konings T, Tremblin P, Güdel M, Pye J, Waters R, Henning T, Vandenbussche B, Ardevol Martinez F, Argyriou I, Ducrot E, Heinke L, van Looveren G, Absil O, Barrado D, Baudoz P, Boccaletti A, Cossou C, Coulais A, Edwards B, Gastaud R, Glasse A, Glauser A, Greene TP, Kendrew S, Krause O, Lahuis F, Mueller M, Olofsson G, Patapis P, Rouan D, Royer P, Scheithauer S, Waldmann I, Whiteford N, Colina L, van Dishoeck EF, Östlin G, Ray TP, Wright G. SO 2, silicate clouds, but no CH 4 detected in a warm Neptune. Nature 2024; 625:51-54. [PMID: 37967578 DOI: 10.1038/s41586-023-06849-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 11/08/2023] [Indexed: 11/17/2023]
Abstract
WASP-107b is a warm (approximately 740 K) transiting planet with a Neptune-like mass of roughly 30.5 M⊕ and Jupiter-like radius of about 0.94 RJ (refs. 1,2), whose extended atmosphere is eroding3. Previous observations showed evidence for water vapour and a thick, high-altitude condensate layer in the atmosphere of WASP-107b (refs. 4,5). Recently, photochemically produced sulfur dioxide (SO2) was detected in the atmosphere of a hot (about 1,200 K) Saturn-mass planet from transmission spectroscopy near 4.05 μm (refs. 6,7), but for temperatures below about 1,000 K, sulfur is predicted to preferably form sulfur allotropes instead of SO2 (refs. 8-10). Here we report the 9σ detection of two fundamental vibration bands of SO2, at 7.35 μm and 8.69 μm, in the transmission spectrum of WASP-107b using the Mid-Infrared Instrument (MIRI) of JWST. This discovery establishes WASP-107b as the second irradiated exoplanet with confirmed photochemistry, extending the temperature range of exoplanets exhibiting detected photochemistry from about 1,200 K down to about 740 K. Furthermore, our spectral analysis reveals the presence of silicate clouds, which are strongly favoured (around 7σ) over simpler cloud set-ups. Furthermore, water is detected (around 12σ) but methane is not. These findings provide evidence of disequilibrium chemistry and indicate a dynamically active atmosphere with a super-solar metallicity.
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Affiliation(s)
- Achrène Dyrek
- Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM, Gif-sur-Yvette, France.
| | - Michiel Min
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
| | - Leen Decin
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | - Jeroen Bouwman
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | - Nicolas Crouzet
- Leiden Observatory, Leiden University, Leiden, The Netherlands
| | - Paul Mollière
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | - Pierre-Olivier Lagage
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | | | - Pascal Tremblin
- Université Paris-Saclay, UVSQ, CNRS, CEA, Maison de la Simulation, Gif-sur-Yvette, France
| | - Manuel Güdel
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
- Department of Astrophysics, University of Vienna, Vienna, Austria
- Institute for Particle Physics and Astrophysics, ETH Zürich, Zürich, Switzerland
| | - John Pye
- Space Research Centre, School of Physics & Astronomy, University of Leicester, Leicester, UK
| | - Rens Waters
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
- Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands
- HFML-FELIX, Radboud University, Nijmegen, The Netherlands
| | - Thomas Henning
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | | | - Francisco Ardevol Martinez
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
- Kapteyn Astronomical Institute, University of Groningen, Groningen, The Netherlands
- Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | | | - Elsa Ducrot
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - Linus Heinke
- Institute of Astronomy, KU Leuven, Leuven, Belgium
- Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | | | | | - David Barrado
- Centro de Astrobiología (CAB), CSIC-INTA, Madrid, Spain
| | - Pierre Baudoz
- LESIA, Observatoire de Paris, CNRS, Université Paris Cité, Sorbonne Université, Meudon, France
| | - Anthony Boccaletti
- LESIA, Observatoire de Paris, CNRS, Université Paris Cité, Sorbonne Université, Meudon, France
| | - Christophe Cossou
- Département d'Electronique des Détecteurs et d'Informatique pour la Physique, Université Paris-Saclay, CEA, Gif-sur-Yvette, France
| | - Alain Coulais
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
- LERMA, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS, Paris, France
| | - Billy Edwards
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
| | - René Gastaud
- Département d'Electronique des Détecteurs et d'Informatique pour la Physique, Université Paris-Saclay, CEA, Gif-sur-Yvette, France
| | - Alistair Glasse
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
| | - Adrian Glauser
- Institute for Particle Physics and Astrophysics, ETH Zürich, Zürich, Switzerland
| | - Thomas P Greene
- Space Science and Astrobiology Division, NASA's Ames Research Center, Moffett Field, CA, USA
| | - Sarah Kendrew
- European Space Agency, Space Telescope Science Institute, Baltimore, MD, USA
| | - Oliver Krause
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | - Fred Lahuis
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
| | - Michael Mueller
- Kapteyn Astronomical Institute, University of Groningen, Groningen, The Netherlands
| | - Goran Olofsson
- Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, Sweden
| | - Polychronis Patapis
- Institute for Particle Physics and Astrophysics, ETH Zürich, Zürich, Switzerland
| | - Daniel Rouan
- Centro de Astrobiología (CAB), CSIC-INTA, Madrid, Spain
| | - Pierre Royer
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | | | - Ingo Waldmann
- Department of Physics and Astronomy, University College London, London, UK
| | - Niall Whiteford
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
| | - Luis Colina
- Centro de Astrobiología (CAB), CSIC-INTA, Madrid, Spain
| | | | - Göran Östlin
- Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM, Gif-sur-Yvette, France
- Department of Astronomy, Oskar Klein Centre, Stockholm University, Stockholm, Sweden
| | - Tom P Ray
- School of Cosmic Physics, Dublin Institute for Advanced Studies, Dublin, Ireland
| | - Gillian Wright
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
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2
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Barrado D, Mollière P, Patapis P, Min M, Tremblin P, Ardevol Martinez F, Whiteford N, Vasist M, Argyriou I, Samland M, Lagage PO, Decin L, Waters R, Henning T, Morales-Calderón M, Guedel M, Vandenbussche B, Absil O, Baudoz P, Boccaletti A, Bouwman J, Cossou C, Coulais A, Crouzet N, Gastaud R, Glasse A, Glauser AM, Kamp I, Kendrew S, Krause O, Lahuis F, Mueller M, Olofsson G, Pye J, Rouan D, Royer P, Scheithauer S, Waldmann I, Colina L, van Dishoeck EF, Ray T, Östlin G, Wright G. 15NH 3 in the atmosphere of a cool brown dwarf. Nature 2023; 624:263-266. [PMID: 37931645 DOI: 10.1038/s41586-023-06813-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/31/2023] [Indexed: 11/08/2023]
Abstract
Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical1,2. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios3. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity4. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System5-7. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks8,9. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope10, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.
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Affiliation(s)
- David Barrado
- Centro de Astrobiología (CAB), CSIC-INTA, Madrid, Spain.
| | - Paul Mollière
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | - Polychronis Patapis
- Institute of Particle Physics and Astrophysics, ETH Zurich, Zürich, Switzerland
| | - Michiel Min
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
| | - Pascal Tremblin
- Université Paris-Saclay, UVSQ, CNRS, CEA, Gif-sur-Yvette, France
| | - Francisco Ardevol Martinez
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
- Kapteyn Institute of Astronomy, University of Groningen, Groningen, The Netherlands
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
- Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK
| | - Niall Whiteford
- Department of Astrophysics, American Museum of Natural History, New York, NY, USA
| | | | | | | | - Pierre-Olivier Lagage
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
| | - Leen Decin
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | - Rens Waters
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
- Department of Astrophysics/IMAPP, Radboud University, Nijmegen, The Netherlands
| | - Thomas Henning
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | | | - Manuel Guedel
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
- Institute of Particle Physics and Astrophysics, ETH Zurich, Zürich, Switzerland
- Department of Astrophysics, University of Vienna, Vienna, Austria
| | | | | | - Pierre Baudoz
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
| | - Anthony Boccaletti
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
| | - Jeroen Bouwman
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | | | - Alain Coulais
- Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, Gif-sur-Yvette, France
- LERMA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Paris, France
| | - Nicolas Crouzet
- Leiden Observatory, Leiden University, Leiden, The Netherlands
| | - René Gastaud
- Université Paris-Saclay, CEA, IRFU, Gif-sur-Yvette, France
| | - Alistair Glasse
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
| | - Adrian M Glauser
- Institute of Particle Physics and Astrophysics, ETH Zurich, Zürich, Switzerland
| | - Inga Kamp
- Kapteyn Institute of Astronomy, University of Groningen, Groningen, The Netherlands
| | - Sarah Kendrew
- European Space Agency, Space Telescope Science Institute, Baltimore, MD, USA
| | - Oliver Krause
- Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany
| | - Fred Lahuis
- SRON Netherlands Institute for Space Research, Leiden, The Netherlands
| | - Michael Mueller
- Kapteyn Institute of Astronomy, University of Groningen, Groningen, The Netherlands
| | - Göran Olofsson
- Department of Astronomy, Stockholm University, AlbaNova University Center, Stockholm, Sweden
| | - John Pye
- School of Physics & Astronomy, Space Research Centre, Space Park Leicester, University of Leicester, Leicester, UK
| | - Daniel Rouan
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France
| | - Pierre Royer
- Institute of Astronomy, KU Leuven, Leuven, Belgium
| | | | - Ingo Waldmann
- Department of Physics and Astronomy, University College London, London, UK
| | - Luis Colina
- Centro de Astrobiología (CAB), CSIC-INTA, Madrid, Spain
| | | | - Tom Ray
- School of Cosmic Physics, Dublin Institute for Advanced Studies, Dublin, Ireland
| | - Göran Östlin
- Department of Astronomy, Oskar Klein Centre, Stockholm University, Stockholm, Sweden
| | - Gillian Wright
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK
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3
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van Dishoeck EF, Grant S, Tabone B, van Gelder M, Francis L, Tychoniec L, Bettoni G, Arabhavi AM, Gasman D, Nazari P, Vlasblom M, Kavanagh P, Christiaens V, Klaassen P, Beuther H, Henning T, Kamp I. The diverse chemistry of protoplanetary disks as revealed by JWST. Faraday Discuss 2023; 245:52-79. [PMID: 37366333 DOI: 10.1039/d3fd00010a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Early results from the James Webb Space Telescope-Mid-InfraRed Instrument (JWST-MIRI) guaranteed time programs on protostars (JOYS) and disks (MINDS) are presented. Thanks to the increased sensitivity, spectral and spatial resolution of the MIRI spectrometer, the chemical inventory of the planet-forming zones in disks can be investigated with unprecedented detail across stellar mass range and age. Here, data are presented for five disks, four around low-mass stars and one around a very young high-mass star. The mid-infrared spectra show some similarities but also significant diversity: some sources are rich in CO2, others in H2O or C2H2. In one disk around a very low-mass star, booming C2H2 emission provides evidence for a "soot" line at which carbon grains are eroded and sublimated, leading to a rich hydrocarbon chemistry in which even di-acetylene (C4H2) and benzene (C6H6) are detected. Together the data point to an active inner disk gas-phase chemistry that is closely linked to the physical structure (temperature, snowlines, presence of cavities and dust traps) of the entire disk and which may result in varying CO2/H2O abundances and high C/O ratios >1 in some cases. Ultimately, this diversity in disk chemistry will also be reflected in the diversity of the chemical composition of exoplanets.
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Affiliation(s)
- Ewine F van Dishoeck
- Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
| | - S Grant
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
| | - B Tabone
- Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, 91405, Orsay, France
| | - M van Gelder
- Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
| | - L Francis
- Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
| | - L Tychoniec
- European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
| | - G Bettoni
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
| | - A M Arabhavi
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, P. O. Box 800, 9700 AV Groningen, The Netherlands
| | - D Gasman
- Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - P Nazari
- Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
| | - M Vlasblom
- Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands.
| | - P Kavanagh
- Dublin Institute for Advanced Studies, Astronomy & Astrophysics Section, 31 Fitzwilliam Place, Dublin 2, Ireland
| | - V Christiaens
- STAR Institute, Université de Liège, Allée du Six Août 19c, 4000 Liège, Belgium
| | - P Klaassen
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
| | - H Beuther
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Th Henning
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - I Kamp
- Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, P. O. Box 800, 9700 AV Groningen, The Netherlands
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4
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Bianchi E, Brünken S, Ceccarelli C, Cordiner M, Flint A, Garrod RT, Gudipati MS, Gupta D, Heard DE, Herbst E, Huang KY, Kamp I, Li J, Madhusudhan N, Martin Domenech R, McCoustra MRS, Meijer A, Milam S, Millar TJ, Plakitina K, Sims I, van Dishoeck EF, Viti S, Walker N, Wiesenfeld L, Wilkins OH. Observational astrochemistry in the age of ALMA, NOEMA, JWST and beyond!: general discussion. Faraday Discuss 2023; 245:199-220. [PMID: 37668601 DOI: 10.1039/d3fd90024j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
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5
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Bromley ST, Brünken S, Ceccarelli C, Cordiner M, Darnell K, Dufour G, Flint A, Garrod RT, Gudipati MS, Halpern J, Herbst E, Huang KY, Kamp I, Madhusudhan N, McCoustra MRS, Suits AG, Van de Sande M, van Dishoeck EF, Viti S, Wiesenfeld L. Computational astrochemistry: general discussion. Faraday Discuss 2023; 245:620-637. [PMID: 37667846 DOI: 10.1039/d3fd90027d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
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6
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Balucani N, Brann M, Brünken S, Ceccarelli C, Cordiner M, Crump EM, Douglas KM, Fleisher AJ, Flint A, Fulker J, Garrod RT, Gudipati MS, Gupta D, Halpern J, Heard DE, Herbst E, Hockey EK, Huang KY, Jacovella U, Kamp I, Lemmens AK, Madhusudhan N, McCoustra MRS, McGuire B, Meijer A, Puzzarini C, Rap DB, Sims IR, Stockett MH, Sturm A, Suits AG, van Dishoeck EF, Viti S, Walker N, Widicus Weaver S, Wiesenfeld L, Wilkins OH. Laboratory astrochemistry of the gas phase: general discussion. Faraday Discuss 2023; 245:391-445. [PMID: 37671500 DOI: 10.1039/d3fd90025h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
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7
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Kamp I, Henning T, Arabhavi AM, Bettoni G, Christiaens V, Gasman D, Grant SL, Morales-Calderón M, Tabone B, Abergel A, Absil O, Argyriou I, Barrado D, Boccaletti A, Bouwman J, Caratti O Garatti A, van Dishoeck EF, Geers V, Glauser AM, Güdel M, Guadarrama R, Jang H, Kanwar J, Lagage PO, Lahuis F, Mueller M, Nehmé C, Olofsson G, Pantin E, Pawellek N, Perotti G, Ray TP, Rodgers-Lee D, Samland M, Scheithauer S, Schreiber J, Schwarz K, Temmink M, Vandenbussche B, Vlasblom M, Waelkens C, Waters LBFM, Wright G. The chemical inventory of the inner regions of planet-forming disks - the JWST/MINDS program. Faraday Discuss 2023; 245:112-137. [PMID: 37462069 DOI: 10.1039/d3fd00013c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
The understanding of planet formation has changed recently, embracing the new idea of pebble accretion. This means that the influx of pebbles from the outer regions of planet-forming disks to their inner zones could determine the composition of planets and their atmospheres. The solid and molecular components delivered to the planet-forming region can be best characterized by mid-infrared spectroscopy. With Spitzer low-resolution (R = 100, 600) spectroscopy, this approach was limited to the detection of abundant molecules, such as H2O, C2H2, HCN and CO2. This contribution will present the first results of the MINDS (MIRI mid-INfrared Disk Survey, PI:Th Henning) project. Due do the sensitivity and spectral resolution provided by the James Webb Space Telescope (JWST), we now have a unique tool to obtain the full inventory of chemistry in the inner disks of solar-type stars and brown dwarfs, including also less-abundant hydrocarbons and isotopologues. The Integral Field Unit (IFU) capabilities will enable at the same time spatial studies of the continuum and line emission in extended sources such as debris disks, the flying saucer and also the search for mid-IR signatures of forming planets in systems such as PDS 70. These JWST observations are complementary to ALMA and NOEMA observations of outer-disk chemistry; together these datasets will provide an integral view of the processes occurring during the planet-formation phase.
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Affiliation(s)
- Inga Kamp
- Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands.
| | - Thomas Henning
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Aditya M Arabhavi
- Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands.
| | - Giulio Bettoni
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
| | | | - Danny Gasman
- Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - Sierra L Grant
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
| | - Maria Morales-Calderón
- Centro de Astrobiología (CAB), CSIC-INTA, ESAC Campus, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
| | - Benoît Tabone
- Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, 91405, Orsay, France
| | - Alain Abergel
- Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, 91405, Orsay, France
| | - Olivier Absil
- STAR Institute, Université de Liège, Allée du Six Août 19c, 4000 Liège, Belgium
| | - Ioannis Argyriou
- Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - David Barrado
- Centro de Astrobiología (CAB), CSIC-INTA, ESAC Campus, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
| | - Anthony Boccaletti
- LESIA, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 Place Jules Janssen, 92195 Meudon, France
| | - Jeroen Bouwman
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Alessio Caratti O Garatti
- INAF - Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Napoli, Italy
- Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, D02 XF86 Dublin, Ireland
| | - Ewine F van Dishoeck
- Max-Planck Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1, 85748, Garching, Germany
- Leiden Observatory, Leiden University, 2300 RA Leiden, The Netherlands
| | - Vincent Geers
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
| | - Adrian M Glauser
- ETH Zürich, Institute for Particle Physics and Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
| | - Manuel Güdel
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
- ETH Zürich, Institute for Particle Physics and Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
- Dept. of Astrophysics, University of Vienna, Türkenschanzstr 17, A-1180 Vienna, Austria
| | - Rodrigo Guadarrama
- Dept. of Astrophysics, University of Vienna, Türkenschanzstr 17, A-1180 Vienna, Austria
| | - Hyerin Jang
- Department of Astrophysics, IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
| | - Jayatee Kanwar
- Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands.
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, A-8042 Graz, Austria
| | - Pierre-Olivier Lagage
- Université Paris-Saclay, Université de Paris, CEA, CNRS, AIM, F-91191 Gif-sur-Yvette, France
| | - Fred Lahuis
- SRON Netherlands Institute for Space Research, PO Box 800, 9700 AV, Groningen, The Netherlands
| | - Michael Mueller
- Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands.
| | - Cyrine Nehmé
- CEA, DSM, Irfu, Service d'Astrophysique - Laboratoire AIM, France
| | - Göran Olofsson
- Department of Astronomy, Stockholm University, AlbaNova University Center, 10691 Stockholm, Sweden
| | - Eric Pantin
- IRFU, DAp Département D'Astrophysique CE Saclay, Gif-sur-Yvette, France
| | - Nicole Pawellek
- Dept. of Astrophysics, University of Vienna, Türkenschanzstr 17, A-1180 Vienna, Austria
- Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly-Thege Miklós út 15-17, H-1121 Budapest, Hungary
| | - Giulia Perotti
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Tom P Ray
- Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, D02 XF86 Dublin, Ireland
| | - Donna Rodgers-Lee
- Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, D02 XF86 Dublin, Ireland
| | - Matthias Samland
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Silvia Scheithauer
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Jürgen Schreiber
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Kamber Schwarz
- Max-Planck-Institut für Astronomie (MPIA), Königstuhl 17, 69117 Heidelberg, Germany
| | - Milou Temmink
- Leiden Observatory, Leiden University, 2300 RA Leiden, The Netherlands
| | - Bart Vandenbussche
- Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - Marissa Vlasblom
- Leiden Observatory, Leiden University, 2300 RA Leiden, The Netherlands
| | | | - L B F M Waters
- Department of Astrophysics, IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
- SRON Netherlands Institute for Space Research, Niels Bohrweg 4, NL-2333 CA Leiden, The Netherlands
| | - Gillian Wright
- UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
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8
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Kruijssen JMD, Schruba A, Chevance M, Longmore SN, Hygate APS, Haydon DT, McLeod AF, Dalcanton JJ, Tacconi LJ, van Dishoeck EF. Fast and inefficient star formation due to short-lived molecular clouds and rapid feedback. Nature 2019; 569:519-522. [PMID: 31118525 PMCID: PMC6544524 DOI: 10.1038/s41586-019-1194-3] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/12/2019] [Indexed: 11/18/2022]
Abstract
The physics of star formation and the deposition of mass, momentum, and energy into the interstellar medium by massive stars (‘feedback’) are the main uncertainties in modern cosmological simulations of galaxy formation and evolution1, 2. These processes determine the properties of galaxies3, 4, but are poorly understood on the ≲100 pc scale of individual giant molecular clouds (GMCs)5, 6 resolved in modern galaxy formation simulations7, 8. The key question is why the timescale for depleting molecular gas through star formation in galaxies (tdep ≈ 2 Gyr)9, 10 exceeds the dynamical timescale of GMCs by two orders of magnitude11. Either most of a GMC’s mass is converted into stars over many dynamical times12, or only a small fraction turns into stars before the GMC is dispersed on a dynamical timescale13, 14. Here we report our observation that molecular gas and star formation are spatially decorrelated on GMC scales in the nearby flocculent spiral galaxy NGC300, contrary to their tight correlation on galactic scales5. We demonstrate that this de-correlation implies rapid evolutionary cycling between GMCs, star formation, and feedback. We apply a novel statistical method15, 16 to quantify the evolutionary timeline and find that star formation is regulated by efficient stellar feedback, driving GMC dispersal on short timescales (~1.5 Myr) due to radiation and stellar winds, prior to supernova explosions. This feedback limits GMC lifetimes to about one dynamical timescale (~10 Myr), with integrated star formation efficiencies of only 2–3%. Our findings reveal that galaxies consist of building blocks undergoing vigorous, feedback-driven lifecycles, that vary with the galactic environment and collectively define how galaxies form stars. Systematic applications of this multi-scale analysis to large galaxy samples will provide key input for a predictive, bottom-up theory of galaxy formation and evolution.
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Affiliation(s)
- J M Diederik Kruijssen
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany. .,Max-Planck Institut für Astronomie, Heidelberg, Germany.
| | - Andreas Schruba
- Max-Planck Institut für Extraterrestrische Physik, Garching, Germany
| | - Mélanie Chevance
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany
| | - Steven N Longmore
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK
| | - Alexander P S Hygate
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany.,Max-Planck Institut für Astronomie, Heidelberg, Germany
| | - Daniel T Haydon
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany
| | - Anna F McLeod
- Department of Astronomy, University of California Berkeley, Berkeley, CA, USA.,Department of Physics and Astronomy, Texas Tech University, Lubbock, TX, USA
| | | | - Linda J Tacconi
- Max-Planck Institut für Extraterrestrische Physik, Garching, Germany
| | - Ewine F van Dishoeck
- Max-Planck Institut für Extraterrestrische Physik, Garching, Germany.,Leiden Observatory, Leiden University, Leiden, The Netherlands
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9
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Affiliation(s)
- Marc C. van Hemert
- Leiden
Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg
55, 2333 CC Leiden, The Netherlands
| | - Junko Takahashi
- Faculty
of Law, Meiji Gakuin University, 1518 Kamikurata-cho, Totsuka-ku, Yokohama 244-8539, Japan
| | - Ewine F. van Dishoeck
- Leiden
Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
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10
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Abstract
A brief introduction and overview of the astrochemistry of dust, ice and gas and their interplay is presented. The importance of basic chemical physics studies of critical reactions is illustrated through a number of recent examples. Such studies have also triggered new insight into chemistry, illustrating how astronomy and chemistry can enhance each other. Much of the chemistry in star- and planet-forming regions is now thought to be driven by gas–grain chemistry rather than pure gas-phase chemistry, and a critical discussion of the state of such models is given. Recent developments in studies of diffuse clouds and PDRs, cold dense clouds, hot cores, protoplanetary disks and exoplanetary atmospheres are summarized, both for simple and more complex molecules, with links to papers presented in this volume. In spite of many lingering uncertainties, the future of astrochemistry is bright: new observational facilities promise major advances in our understanding of the journey of gas, ice and dust from clouds to planets.
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Affiliation(s)
- Ewine F. van Dishoeck
- Leiden Observatory
- Leiden University
- 2300 RA Leiden, the Netherlands
- Max-Planck-Institute für Extraterrestrische Physik
- Garching, Germany
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11
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Affiliation(s)
- Xiaohu Li
- Leiden
Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
| | - Carina Arasa
- Leiden
Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Marc C. van Hemert
- Leiden
Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Ewine F. van Dishoeck
- Leiden
Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
- Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
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12
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13
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Qi C, Öberg KI, Wilner DJ, D’Alessio P, Bergin E, Andrews SM, Blake GA, Hogerheijde MR, van Dishoeck EF. Imaging of the CO Snow Line in a Solar Nebula Analog. Science 2013; 341:630-2. [DOI: 10.1126/science.1239560] [Citation(s) in RCA: 225] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Chunhua Qi
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - Karin I. Öberg
- Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - David J. Wilner
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - Paola D’Alessio
- Centro de Radioastronomõa y Astrofisica, Universidad Nacional Autonoma de Mexico (UNAM), 58089 Mexico City, Mexico
| | - Edwin Bergin
- Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sean M. Andrews
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - Geoffrey A. Blake
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | | | - Ewine F. van Dishoeck
- Leiden Observatory, Leiden University, 2300 RA Leiden, Netherlands
- Max Planck Institute for Extraterrestrial Physics, 85748 Garching, Germany
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14
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Benz AO, Bruderer S, van Dishoeck EF, Stäuber P, Wampfler SF. Neutral and Ionized Hydrides in Star-Forming Regions. Observations with Herschel/HIFI. J Phys Chem A 2013; 117:9840-7. [DOI: 10.1021/jp312813a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Arnold O. Benz
- Institute for Astronomy, ETH Zurich, 8093
Zürich, Switzerland
| | - Simon Bruderer
- Max Planck Institut für extraterrestrische Physik, Giessenbachstrasse
1, 85748 Garching, Germany
| | | | - Pascal Stäuber
- Institute for Astronomy, ETH Zurich, 8093
Zürich, Switzerland
| | - Susanne F. Wampfler
- Centre
for Star and Planet Formation,
Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, DK-1350 København K, Denmark
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15
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van der Marel N, van Dishoeck EF, Bruderer S, Birnstiel T, Pinilla P, Dullemond CP, van Kempen TA, Schmalzl M, Brown JM, Herczeg GJ, Mathews GS, Geers V. A Major Asymmetric Dust Trap in a Transition Disk. Science 2013; 340:1199-202. [PMID: 23744942 DOI: 10.1126/science.1236770] [Citation(s) in RCA: 443] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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16
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Lis DC, Bergin EA, Schilke P, van Dishoeck EF. Ortho-to-Para Ratio in Interstellar Water on the Sightline toward Sagittarius B2(N). J Phys Chem A 2013; 117:9661-5. [DOI: 10.1021/jp312333n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Dariusz C. Lis
- Cahill Center
for Astronomy
and Astrophysics 301-17, California Institute of Technology, Pasadena, California 91125, United States
| | - Edwin A. Bergin
- Department of Astronomy, University of Michigan, 933 Dennison Building, Ann
Arbor, Michigan 48109, United States
| | - Peter Schilke
- I. Physicalisches Institut der Universität zu Köln, Zülpicher
Straße 77, 50937 Köln, Germany
| | - Ewine F. van Dishoeck
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The
Netherlands and Max Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
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17
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Abstract
In this paper, we discuss the astronomical search for water vapour in order to understand the disposition of water in all its phases throughout the processes of star and planet formation. Our ability to detect and study water vapour has recently received a tremendous boost with the successful launch and operation of the Herschel Space Observatory. Herschel spectroscopic detections of numerous transitions in a variety of astronomical objects, along with previous work by other space-based observatories, will be threaded throughout this paper. In particular, we present observations of water tracing the earliest stage of star birth where it is predominantly frozen as ice. When a star is born, the local energy release by radiation liberates ices in its surrounding envelope and powers energetic outflows that appear to be water factories. In these regions, water plays an important role in the gas physics. Finally, we end with an exploration of water in planet-forming discs surrounding young stars. The availability of accurate molecular data (frequencies, collisional rate coefficients and chemical reaction rates) is crucial to analyse the observations at each of these steps.
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Affiliation(s)
- Edwin A Bergin
- Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48197, USA.
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18
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Hogerheijde MR, Bergin EA, Brinch C, Cleeves LI, Fogel JKJ, Blake GA, Dominik C, Lis DC, Melnick G, Neufeld D, Panić O, Pearson JC, Kristensen L, Yıldız UA, van Dishoeck EF. Detection of the Water Reservoir in a Forming Planetary System. Science 2011; 334:338-40. [PMID: 22021851 DOI: 10.1126/science.1208931] [Citation(s) in RCA: 234] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Michiel R. Hogerheijde
- Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands
| | - Edwin A. Bergin
- Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Christian Brinch
- Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands
| | | | | | - Geoffrey A. Blake
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Carsten Dominik
- Astronomical Institute Anton Pannekoek, University of Amsterdam, 1098 XH Amsterdam, Netherlands
| | - Dariusz C. Lis
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA
| | - Gary Melnick
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - David Neufeld
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Olja Panić
- European Southern Observatory, 85748 Garching, Germany
| | - John C. Pearson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - Lars Kristensen
- Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands
| | - Umut A. Yıldız
- Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands
| | - Ewine F. van Dishoeck
- Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands
- Max-Planck-Institut für Extraterrestrische Physik, 85748 Garching, Germany
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19
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Abstract
When interstellar clouds collapse to form new stars and planets, the surrounding gas and dust become part of the infalling envelopes and rotating disks, thus providing the basic material from which new solar systems are formed. Instrumentation to probe the chemistry in low-mass star-forming regions has only recently become available. The results of a systematic program to study the abundances in solar-mass protostellar and protoplanetary regions are presented. Surveys at submillimeter and infrared wavelengths reveal a rich chemistry, including simple and complex (organic) gases, ices, polycyclic aromatic hydrocarbons, and silicates. Each of these species traces different aspects of the physical and chemical state of the objects as they evolve from deeply embedded protostars to pre-main sequence stars with planet-forming disks. Quantitative information on temperatures, densities, and abundances is obtained through molecular excitation and radiative transfer models as well as from analysis of solid-state line profiles. The chemical characteristics are dominated by freeze-out in the coldest regions and ice evaporation in the warmer zones. In the surface layers of disks, UV radiation controls the chemistry. The importance of complementary laboratory experiments and calculations to obtain basic molecular data is emphasized.
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20
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Andersson S, Al-Halabi A, Kroes GJ, van Dishoeck EF. Molecular-dynamics study of photodissociation of water in crystalline and amorphous ices. J Chem Phys 2006; 124:64715. [PMID: 16483237 DOI: 10.1063/1.2162901] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present the results of classical dynamics calculations performed to study the photodissociation of water in crystalline and amorphous ice surfaces at a surface temperature of 10 K. A modified form of a recently developed potential model for the photodissociation of a water molecule in ice [S. Andersson et al., Chem. Phys. Lett. 408, 415 (2005)] is used. Dissociation in the top six monolayers is considered. Desorption of H(2)O has a low probability (less than 0.5% yield per absorbed photon) for both types of ice. The final outcome strongly depends on the original position of the photodissociated molecule. For molecules in the first bilayer of crystalline ice and the corresponding layers in amorphous ice, desorption of H atoms dominates. In the second bilayer H atom desorption, trapping of the H and OH fragments in the ice, and recombination of H and OH are of roughly equal importance. Deeper into the ice H atom desorption becomes less important and trapping and recombination dominate. Motion of the photofragments is somewhat more restricted in amorphous ice. The distribution of distances traveled by H atoms in the ice peaks at 6-7 Angstroms with a tail going to about 60 Angstroms for both types of ice. The mobility of OH radicals is low within the ice with most probable distances traveled of 2 and 1 Angstrom for crystalline and amorphous ices, respectively. OH is, however, quite mobile on top of the surface, where it has been found to travel more than 80 Angstroms. Simulated absorption spectra of crystalline ice, amorphous ice, and liquid water are found to be in very good agreement with the experiments. The outcomes of photodissociation in crystalline and amorphous ices are overall similar, but with some intriguing differences in detail. The probability of H atoms desorbing is 40% higher from amorphous than from crystalline ice and the kinetic-energy distribution of the H atoms is on average 30% hotter for amorphous ice. In contrast, the probability of desorption of OH radicals from crystalline ice is much higher than that from amorphous ice.
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21
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Fuchs GW, Acharyya K, Bisschop SE, Oberg KI, van Broekhuizen FA, Fraser HJ, Schlemmer S, van Dishoeck EF, Linnartz H. Comparative studies of O2and N2in pure, mixed and layered CO ices. Faraday Discuss 2006; 133:331-45; discussion 347-74, 449-52. [PMID: 17191456 DOI: 10.1039/b517262b] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present laboratory data on pure, layered and mixed CO and O2 ices relevant for understanding the absence of gaseous O2 in space. Experiments have been performed on interstellar ice analogues under ultra high vacuum conditions by molecular deposition at 14 K on a gold surface. A combination of reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) is used to derive spectroscopic and thermodynamic properties of the ices. It is found that for pure ices the desorption energy of O2 is larger than that of CO and N2. TPD spectra reveal similar desorption processes for all examined CO-O2 ice morphologies. The different amorphous and crystalline components of pure 13CO RAIR spectra are analyzed. The RAIRS data of the 13CO stretching vibration show a significant difference between layered and mixed CO-O2 ices: layered CO-O2 ices resemble that of pure 13CO whereas the spectra of mixed ices are broadened. The experiments also show that the sticking probabilities of O2 on CO and O2 on O2 are close to unity. These new results are compared with recently analyzed data of CO-N2 ices. The differences in the TPD and RAIRS spectra of the CO-N2 and CO-O2 ice systems are explained by differences in quadrupole intermolecular interactions and by different crystallization processes of these ices.
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Affiliation(s)
- Guido W Fuchs
- Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, Postbus 9513, 2300 RA, The Netherlands.
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22
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Abstract
Circumstellar disks are exposed to intense ultraviolet (UV) radiation from the young star. In the inner disks, the UV radiation can be enhanced by more than seven orders of magnitude compared with the average interstellar radiation field, resulting in a physical and chemical structure that resembles that of a dense photon-dominated region (PDR). This intense UV field affects the chemistry, the vertical structure of the disk, and the gas temperature, especially in the surface layers. The parameters which make disks different from more traditional PDRs are discussed, including the shape of the UV radiation field, grain growth, the absence of PAHs, the gas/dust ratio and the presence of inner holes. Illustrative infrared spectra from the Spitzer Space Telescope are shown. New photodissociation cross sections for selected species, including simple ions, are presented. Also, a summary of cross sections at the Lyman alpha 1216 A line, known to be strong for some T Tauri stars, is made. Photodissociation and ionization rates are computed for different radiation fields with color temperatures ranging from 30000 to 4000 K and grain sizes up to a few microm. The importance of a proper treatment of the photoprocesses is illustrated for the transitional disk toward HD 141569A which includes grain growth.
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23
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24
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25
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Koch A, van Hemert MC, van Dishoeck EF. Photodissociation of the HCO+ ion. I. Two‐dimensional calculations through the I 1Π state. J Chem Phys 1995. [DOI: 10.1063/1.470327] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Beärda RA, van Hemert MC, van Dishoeck EF. Photodissociation of CH2. V. Three‐dimensional adiabatic potential energy surfaces and transition dipole moments. J Chem Phys 1995. [DOI: 10.1063/1.468947] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Beärda RA, Kroes G, van Hemert MC, Heumann B, Schinke R, van Dishoeck EF. Photodissociation of CH2. III. Two‐dimensional dynamics of the dissociation of CH2, CD2, and CHD through the first excited triplet state. J Chem Phys 1994. [DOI: 10.1063/1.466643] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Offer AR, Hemert MCV, Dishoeck EFV. Rotationally inelastic and hyperfine resolved cross sections for OH–H2 collisions. Calculations using a new ab initio potential surface. J Chem Phys 1994. [DOI: 10.1063/1.466950] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alison R. Offer
- Sterrewacht Leiden, Huygens Laboratory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
| | - Marc C. van Hemert
- Chemistry Department, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Ewine F. van Dishoeck
- Sterrewacht Leiden, Huygens Laboratory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
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29
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Kroes G, van Dishoeck EF, Beärda RA, van Hemert MC. Photodissociation of CH2. II. Three‐dimensional wave packet calculations on dissociation through the first excited triplet state. J Chem Phys 1993. [DOI: 10.1063/1.465800] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Beärda RA, van Hemert MC, van Dishoeck EF. Photodissociation of CH2. I. Potential energy surfaces of the dissociation into CH and H. J Chem Phys 1992. [DOI: 10.1063/1.463395] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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33
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van Dishoeck EF, van Hemert MC, Allison AC, Dalgarno A. Resonances in the photodissociation of OH by absorption into coupled2Π states: Adiabatic and diabatic formulations. J Chem Phys 1984. [DOI: 10.1063/1.447622] [Citation(s) in RCA: 110] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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35
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36
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37
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38
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Langhoff SR, van Dishoeck EF, Wetmore R, Dalgarno A. Radiative lifetimes and dipole moments of the A 2Σ+, B 2Σ+, and C 2Σ+ states of OH. J Chem Phys 1982. [DOI: 10.1063/1.443962] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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