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Naoki Watanabe, Dr.
Professor

Tel: +81-11-706-5501, Fax: +81-11-706-7142
Email: watanabe@lowtem.hokudai.ac.jp

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Research areas: Atomic and molecular physics, Astrochemistry, Surface chemistry

I earned a doctoral degree in atomic and molecular physics from Tokyo Metropolitan University in 1993, and worked on the photoionization processes of highly-charged ions and molecules in gas phase using synchrotron radiation as a postdoctoral researcher at The Institute of Physical and Chemical Research (RIKEN) until 1996. During 2000/2001, I was a visiting researcher at University College London. Since becoming a permanent staff at Institute of Low Temperature Science Hokkaido University in 1996, I have tackled surface physics and chemistry on solid water at very low temperatures, relevant to chemical evolution on cosmic dust.

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Invited talks (after 2005)


Recent Publications


  • "Determination of the Branching Ratio of CH3OH + OH Reaction on Water Ice Surface at 10 K"
    A. Ishibashi, H. Hidaka, W. M. C. Sameera, Y. Oba, N. Watanabe
    Astrophys. J. 960, 90 (2023)

  • "Modelling deuterated isotopologues of methanol towards the pre-stellar core L1544"
    W. Riedel, O. Sipilä, E. Redaelli, P. Caselli, A. I. Vasyunin, F. Duliu, N. Watanabe
    Astron. Astrophys. 680, A87 (2023)

  • "Surface diffusion of carbon atoms as a driver of interstellar organic chemistry"
    M. Tsuge, G. Molpeceres, Y. Aikawa, N. Watanabe
    Nature Astronomy 7, 1351 (2023)

  • "A systematic mechanistic survey on the reactions between OH radical and CH3OH on ice"
    W. M. C. Sameera, Avo P. Jayaweera, Atsuki Ishibashi, Hiroshi Hidaka, Yasuhiro Oba, Naoki Watanabe
    Faraday Discussion 245, 508 (2023)

  • "Methanol Formation through Reaction of Low-energy CH3+ Ions with an Amorphous Solid Water Surface at Low Temperature"
    Y. Nakai, W. M. C. Sameera, K. Furuya, H. Hidaka, A. Ishibashi, N. Watanabe
    Astrophys. J. 953, 162 (2023)

  • "Radical reactions on interstellar icy dust grains: Experimental investigations of elementary processes"
    M. Tsuge, N. Watanabe
    Proc. Jpn. Acad., Ser. B99 (2023)

  • "Surface Reaction of Methyl Mercaptan (CH3SH) with Hydrogen Atoms on Amorphous Solid Water"
    T. Nguyen, Y. Oba, W. M. C. Sameera, K. Furuya, A. Kouchi, N. Watanabe
    Astrophys. J. 944, 219(14pp) (2023)

  • "Direct Determination of the Activation Energy for Diffusion of OH Radicals on Water Ice"
    A. Miyazaki, M. Tsuge, H. Hidaka, N. Nakai, N. Watanabe
    Astrophys. J. Lett. 940, L2 (2022)

  • "Penetration of Nonenergetic Hydrogen Atoms into Amorphous Solid Water and their Reaction with Embedded Benzene and Naphthalene"
    M. Tsuge, A. Kouchi, N. Watanabe
    Astrophys. J. 933, 138(9pp) (2022)

  • "Diffusion Activation Energy and Desorption Activation Energy for Astrochemically Relevant Species on Water Ice show No Clear Relation"
    K. Furuya, T. Hama, Y. Oba, A. Kouchi, N. Watanabe, Y. Aikawa
    Astrophys. J. Lett. 933, L16 (2022)

  • "Hydrogen abstraction reactions in formic and thioformic acid isomers by hydrogen and deuterium atoms"
    G. Molpeceres, I. Jiménez-Serra, Y. Oba, T. Nguyen, N. Watanabe, J. García de la Concepción, B. Maté, R. Oliveira, J. Kästner
    Astron. Astrophys. 663, A41 (2022)

  • "Modelling the Radical Chemistry on Ice Surfaces: An Integrated Quantum Chemical and Experimental Approach"
    W. M. C. Sameera, B. Senevirathne, T. Nguyen, Y. Oba, A. Ishibashi, M. Tsuge, H. Hidaka, N. Watanabe
    Front. Astron. Space Sci. 9, 890161 (2022)

  • "Thermal Desorption of Interstellar Ices: A Review on the Controlling Parameters and Their Implications from Snowlines to Chemical Complexity"
    M. Minissale, Y. Aikawa, E. Bergin, M. Bertin, W. A. Brown, S. Cazaux, S. B. Charnley, A. Coutens, H. M. Cuppen, V. Guzman, H. Linnartz, M. R. S. McCoustra, A.Rimola, J.G.M. Schrauwen, C. Toubin, P. Ugliengo, N. Watanabe, V. Wakelam, F. Dulieu
    ACS Earth Space Chem. 6, 597-630 (2022)

  • "FAUST III. Misaligned rotations of the envelope, outflow, and disks in the multiple protostellar system of VLA4 1623-2417"
    S. Ohashi et al.
    Astrophysical J. 927, 54 (22pp) (2022)

  • "Measurements of Ortho-to-para Nuclear Spin Conversion of H2 on Low-temperature Carbonaceous Grain Analogs: Diamond-like Carbon and Graphite"
    M. Tsuge, A. Kouchi, N. Watanabe
    Astrophys. J. 923, 71(8pp), (2021)

  • "UV-Induced Formation of Ice XI Observed Using an Ultra-High Vacuum Cryogenic Transmission Electron Microscope and its Implications for Planetary Science"
    A. Kouchi, Y. Kimura, K. Kitajima, H. Katsuno, H. Hidaka, Y. Oba, M. Tsuge, T. Yamazaki, K. Fujita, T. Hama, Y. Takahashi, S. Nakatsunbo, N. Watanabe
    Frontier in Chemistry 9, 799851, (2021)

  • "Successive H-atom Addition to Solid OCS on Compact Amorphous Solid Water"
    T. Nguyen, Y. Oba, W. M. C. Sameera, A. Kouchi, N. Watanabe
    Astrophys. J. 922, 146(13pp), (2021)

  • "Efficient formation pathway of methyl formate: the role of OH radicals on ice dust"
    A. Ishibashi, H. Hidaka, Y. Oba, A. Kouchi, N. Watanabe
    Astrophys. J. Lett. 921, L13(9pp), (2021)

  • "Experimental and computational studies on the physico-chemical behavior of phosphine induced by reactions with H and D atoms on interstellar ice grains"
    T. Nguyen, Y. Oba, W. M. C. Sameera, A. Kouchi, N. Watanabe
    Astrophys. J. 918, 73(15pp), (2021)

  • "Transmission Electron Microscopy Study of the Morphology of Ices Composed of H2O, CO2, and CO on Refractory Grains"
    A. Kouchi, M. Tsuge, T. Hama, Y. Oba, S. Okuzumi, S. Sirono, M. Momose, N. Nakatani, K. Furuya, T. Shimonishi, T. Yamazaki, H. Hidaka, Y. Kimura, K. Murata, K. Fujita, S. Nakatsubo, S. Tachibana, and N. Watanabe
    Astrophys. J. 918, 45, (2021)

  • "Formation of chiral CO polyhedral crystals on icy interstellar grains"
    A. Kouchi, M. Tsuge, T. Hama, H. Niinomi, N. Nakatani, T. Shimonishi, Y. Oba, Y. Kimura, S. Sirono, S. Okuzumi, M. Momose, K. Furuya and N. Watanabe
    MNRAS 505, 1530-1542 (2021)

  • "Binding energies and sticking coefficients of H2 on crystalline and amorphous CO ice"
    G. Molpeceres, V. Zaverkin, N. Watanabe, J. Kästner
    Astron. Astrophys, 648, A84, (2021)

  • "FAUST II. Discovery of a secondary outflow in IRAS 15398-3359: Variability in outflow direction during the earliest stage of star formation?"
    Y. Okoda et al.
    Astrophysical Journal,910, 11(13pp) (2021)

  • "Rapid Ortho-to-para Nuclear Spin Conversion of H2 on a Silicate Dust Surface"
    M. Tsuge, T. Namiyoshi, K. Furuya, T. Yamazaki, A. Kouchi, N. Watanabe
    Astrophys. J. 908, 234 (2021)

  • "Behavior of Hydroxyl Radicals on Water Ice at Low Temperatures"
    M. Tsuge, N. Watanabe
    Acc. Chem. Res. 54, 471 (2021)

  • "CH3O Radical Binding on Hexagonal Water Ice and Amorphous Solid Water"
    W. M. C. Sameera, S. Bethmini, S. Andersson, M. Al-Ibadi, H. Hidaka, A. Kouchi, G. Nyman, N. Watanabe
    J. Phys. Chem. A 125, 387 (2021)

  • "Delivery of Electrons by Proton-Hole Transfer in Ice at 10 K: Role of Surface OH Radicals"
    K. Kitajima, Y. Nakai, W. M. C. Sameera, M. Tsuge, A. Miyazaki, H. Hidaka, A. Kouchi, N. Watanabe
    J. Phys. Chem. Lett. 12, 704 (2021)

  • "Photostimulated desorption of OH radicals from amorphous solid water: Evidence for the interaction of visible light with an OH-ice complex"
    A. Miyazaki, N. Watanabe, W. M. C. Sameera, Y. Nakai, M. Tsuge, T. Hama, H. Hidaka, and A. Kouchi
    Phys. Rev. A 102, 052822, (2020)

  • "UV-ray irradiation never causes amorphization of crystalline CO2: A transmission electron microscopy study"
    Masashi Tsuge, Thanh Nguyen, Yasuhiro Ob, Tetsuya Hama, Akira Kouchi, Naoki Watanabe
    Chem. Phys. Lett. 760, 137999 (2020)

  • "FAUST I. The hot corino at the heart of the prototypical Class I protostar L1551 IRS5"
    E. Bianchi et al.
    Mon. Not. R. Astron. Soc. 498, L87 (2020)

  • "Diffusive hydrogenation reactions of CO embedded in amorphous solid water at elevated temperatures ~70 K"
    Masashi Tsuge, Hiroshi Hidaka, Akira Kouchi, Naoki Watanabe
    Astrophys. J. 900, 187(7pp) (2020)

  • "Quantitative Anisotropic Analysis of Molecular Orientation in Amorphous N2O at 6 K by Infrared Multiple-Angle Incidence Resolution Spectrometry"
    T. Hama, A. Ishibashi, A. Kouchi, N. Watanabe, N. Shioya, T. Shimoaka, T. Hasegawa
    J. Phys. Chem. Lett. 11, 7857 (2020)

  • "An Experimental Study of Chemical Desorption for Phosphine in Interstellar Ice"
    Thanh Nguyen, Yasuhiro Oba, Takashi Shimonishi, Akira Kouchi, Naoki Watanabe
    Astrophys. J. Lett. 898, L52(6pp),(2020)

  • "In vivo characterization of the structures of films of a fatty acid and an alcohol adsorbed on the skin surface"
    T. Hama, A. Kouchi, N. Watanabe, N. Shioya, T. Shimoaka, T. Hasegawa
    Biophys. Chem. 166, 106459 (2020)

  • "Precometary organic matter: A hidden reservoir of water inside the snow line"
    H. Nakano, N. Hirakawa, Y. Matsubara, S. Yamashita, T. Okuchi, K. Asahina, R. Tanaka, N.i Suzuki, H. Naraoka, Y. Takano, S. Tachibana, T. Hama, Y. Oba, Y. Kimura, N. Watanabe, A. Kouchi
    Scientific Reports 10, 7755 (2020)

  • "Direct Measurements of Activation Energies for Surface Diffusion of CO and CO2 on Amorphous Solid Water Using In Situ Transmission Electron Microscopy"
    Akira Kouchi, Kenji Furuya, Tetsuya Hama, Takeshi Chiga, Takashi Kozasa, and Naoki Watanabe
    Astrophys. J. Lett. 891, L22(7pp) (2020)

  • "Experimental Approach to Physicochemical Hydrogen Processes on Cosmic Ice Dust"
    N. Watanabe, M. Tsuge
    J. Phys. Soc. Jpn 89, 051015 (2020)

  • "Ultraviolet-photon exposure stimulates negative current conductivity in amorphous ice below 50 K"
    N. Watanabe, W. M. C. Sameera, H. Hidaka, A. Miyazaki, A. Kouchi
    Chem. Phys. Lett. 737, 136820 (2019)

  • "Nucleobase synthesis in interstellar ices"
    Y. Oba, Y. Takano, H. Naraoka, N. Watanabe and A. Kouchi
    Nature Communications, 10,4413 (2019)

  • "H2 Ortho.Para Spin Conversion on Inhomogeneous Grain Surfaces"
    Kenji Furuya, Yuri Aikawa, Tetsuya Hama, Naoki Watanabe
    Astrophys. J. 882, 172 (11pp) (2019)

  • "Probing the Molecular Structure and Orientation of the Leaf Surface of Brassica oleracea L. by Polarization Modulation-Infrared Reflection-Absorption Spectroscopy"
    T. Hama, K. Seki, A. Ishibashi, A. Miyazaki, A. Kouchi, N. Watanabe, T. Shimoaka, T. Hasegawa
    Plant Cell Physiol 60, 1567 (2019)

  • "Physico-chemical Behavior of Hydrogen Sulfide Induced by Reactions with H and D Atoms on Different Types of Ice Surfaces at Low Temperature"
    Yasuhiro Oba, Takuto Tomaru, Akira Kouchi, and Naoki Watanabe
    Astrophys. J. 874, 124 (8pp) (2019)

  • "Measurements of the Activation Energies for Atomic Hydrogen Diffusion on Pure Solid C0"
    Y. Kimura, M. Tsuge, V. Pirronello, A. Kouchi, N. Watanabe
    Astrophys. J. Lett. 858, L23 (2018)

  • "The Ortho-to-para Ratio of Water Molecules Desorbed from Ice Made from Para-water Monomers at 11K"
    T. Hama, A. Kouchi, N. Watanabe
    Astrophys. J. Lett. 857, L13 (2018)

  • "An infrared measurement of chemical desorption from interstellar ice analogues"
    Y. Oba, T. Tomaru, T. Lamberts, A. Kouchi, N. Watanabe,
    Nature Astronomy, 2, 228-232 (2018)

  • "Deuterium Fractionation upon the Formation of Hexamethylenetetramines through Photochemical Reactions of Interstellar Ice Analogs Containing Deuterated Methanol Isotopologues"
    Y. Oba, Y. Takano, H. Naraoka, A. Kouchi, N. Watanabe,
    Astrophys. J. Lett. 849, 122 (2017)

  • "H2 formation on interstellar dust grains: The viewpoints of theory, experiments, models and observations"
    V. Wakelam, E. Bron, S. Cazaux, F. Dulieu, C. Gry, P. Guillard, E. Habart, L. Hornekær, S. Morisset, G. Nyman, V. Pirronello, S. D. Price, V. Valdivia, G. Vidali, N. Watanabe
    Molecular Astrophysics 9, 1, (2017)

  • "Laboratory Studies of Methane and Its Relationship to Prebiotic Chemistry"
    K. Kobayashi, W. D. Geppert, N. Carrasco, N. G. Holm, O. Mousis, M. E. Palumbo, J. H. Waite, N. Watanabe, L. M. Ziurys
    Astrobiology 17, 786, (2017)

  • "Liquid-like behavior of UV-irradiated interstellar ice analog at low temperatures"
    S. Tachibana, A. Kouchi, T. Hama, Y. Oba, L. Piani, I. Sugawara, Y. Endo, H. Hidaka, Y. Kimura, K. Murata, H. Yurimoto, N. Watanabe,
    Science Advances 3, eaao2538 (2017)

  • "Fast crystalline ice formation at extremely low temperature through water/neon matrix sublimation"
    T. Hama, S. Ishizuka, T. Yamazaki, Y. Kimura, A. Kouchi, N. Watanabe, T. Sugimoto, V. Pirronello,
    Phys. Chem. Chem. Phys. 19, 17677 (2017)

  • "Hydrogenation and Deuteration of C2H2 and C2H4 on Cold Grains: A Clue to the Formation Mechanism of C2H6 with Astronomical Interest"
    Hitomi Kobayashi, Hiroshi Hidaka, Thanja Lamberts, Tetsuya Hama, Hideyo Kawakita, Johannes Kastner, Naoki Watanabe
    Astrophys. J. 837, 155 (2017)

  • "Simulations and Spectra of Water in CO Matrices"
    R. Escribano, E. Artacho, A. Kouchi, T. Hama, Y. Kimura, H. Hidaka, and N Watanabe
    Physical Chemistry Chemical Physics 19, 7280-7287 (2017)

  • "In Situ Nondestructive Analysis of Kalanchoe pinnata Leaf Surface Structure by Polarization-Modulation Infrared Reflection Absorption Spectroscopy"
    T. Hama, A. Kouchi, N. Watanabe, S. Enami, T. Shimoaka, T. Hasegawa
    J. Phys. Chem. B 121, 11124 (2017)

  • "Matrix sublimation method for the formation of high-density amorphous ice"
    A. Kouchi, T. Hama, Y. Kimura, H. Hidaka, R. Escribano, N. Watanabe
    Chemical Physics Letters 658, 287-292 (2016)

  • "Deuterium Fractionation during Amino Acid Formation by Photolysis of Interstellar Ice Analogs Containing Deuterated Methanol"
    Y. Oba, Y. Takano, N. Watanabe, A. Kouchi
    Astrophys. J. Lett. 827, L18 (2016)

  • "Negative catalytic effect of water on the reactivity of hydrogen abstraction from the C.H bond of dimethyl ether by deuterium atoms through tunneling at low temperatures"
    Y. Oba, N. Watanabe, A. Kouchi
    Chem. Phys. Lett. 662, 14 (2016)

  • "Hydrogen.deuterium substitution in solid ethanol by surface reactions at low temperatures"
    Y. Oba, K. Osaka, T. Chigai, A. Kouchi, N. Watanabe
    Mon. Not. Roy. Astron. Soc. 462, 689 (2016)

  • "Surface Temperature Dependence of Hydrogen Ortho-Para Conversion on Amorphous Solid Water"
    H. Ueta, N. Watanabe, T. Hama, A. Kouchi
    Phys. Rev. Lett. 116, 253201 (2016)

  • "Stepwise formation of H3O+(H2O)n in an ion drift tube: Empirical effective temperature of association/dissociation reaction equilibrium in an electric field"
    Y, Nakai, H. Hidaka, N. Watanabe, T. M. Kojima
    J. Chem. Phys. 144, 224306 (2016)

  • "Statistical ortho-to-para ratio ofwater desorbed from ice at 10 kelvin"
    T. Hama, A. Kouchi, and N. Watanabe
    Science 351, 65 (2016)

  • "Signaturte of Quantum-Tunneling Diffusion of Hydrogen Atoms on Water Ice at 10 K"
    K. Kuwahata, T. Hama, A. Kouchi, and N. Watanabe
    Phys. Rev. Lett. 115, 133201 (2015)

  • "Chiral glycine formation on cold interstellar grains by quantumtunneling hydrogen.deuterium substitution reactions"
    Y. Oba, N. Watanabe, Y. Osamura, and A. Kouchi
    Chem. Phys. Lett. 634, 53-59 (2015)

  • "Quantum Tunneling Observed without its Characteristic Large Kinetic Isotope Effects"
    T. Hama, H. Ueta, A. Kouchi, and N. Watanabe
    PNAS 112, 7438-7443 (2015)

  • "Quantum Tunneling Hydrogenation of Solid Benzene and Its Control via Surface Structure"
    T. Hama, H. Ueta, A. Kouchi, N. Watanabe, and H. Tachikawa
    The Journal of Physical Chemistry Letters 5, 3843-3848 (2014)

  • "Reaction kinetics and isotope effect of water formation by the surface reaction of solid H2O2 with H atoms at low temperatures"
    Yasuhiro Oba, Kazuya Osaka, Naoki Watanabe, Takeshi Chigai and Akira Kouchi
    Faraday Discussion 168, 185-204 (2014)

  • "Surface Processes on Interstellar Amorphous Solid Water: Adsorption, Diffusion, Tunneling Reactions, and Nuclear-Spin Conversion"
    Tetsuya Hama, Naoki Watanabe
    Chem. Rev. 113, 8783 (2013)

  • "Hydrogen isotopic substitution of solid methylamine through atomic surface reactions at low temperatures: A potential contribution to the D/H ratio of methylamine in molecular clouds",
    Yasuhiro OBA,Takeshi CHIGAI, Yoshihiro OSAMURA, Naoki WATANABE, Akira KOUCH
    Meteoritics & Planetary Science 1-16 (2013):DOI: 10.1111/maps.12096

  • hThe Mechanism of Surface Diffusion of H and D Atoms on Amorphous Solid Water: Existence of Various Potential Sitesh,
    T. Hama, K. Kuwahata, N. Watanabe, A. Kouchi, Y. Kimura. T. Chigai, V. Pirronello
    Astrophys. J. 757, 185 (2012)

  • gWater Formation Through a Quantum Tunneling Surface Reaction, OH + H2, at 10 K", Y. Oba, N. Watanabe, T. Hama, K. Kuwahata, H. Hidaka, A. Kouchi, Astrophys. J. 749:67 (2012)

  • "Spin temperature of water molecules desorbed from the surfaces of amorphous solid water, vapor-deposited and produced from photolysis of a CH4/O2 solid mixture", T. Hama, N. Watanabe, A. Kouchi, and M. Yokoyama, Astrophys. J. Lett. 738, L15 (2011)

  • "FTIR study of ammonia formation via the successive hydrogenation of N atoms trapped in a solid N2 matrix at low temperatures", H. Hidaka, M. Watanabe, A. Kouchi and N. Watanabe, Phys. Chem. Chem. Phys. 13, 15798 (2011)

  • "Experimental studies of surface reactions among OH radicals that yield H2O and CO2 at 40-60 K",Y. Oba, N. Watanabe, A. Kouchi, T. Hama, and V. Pirronello, Phys. Chem. Chem. Phys. 13, 15792 (2011)

  • "Surface abundance change in vacuum ultraviolet photodissociation of CO2 and H2O mixture ices", T. Kinugawa, A. Yabushita, M. Kawasaki, T. Hama, and N. Watanabe, Phys. Chem. Chem. Phys. 13,  15785 (2011)

  • "Translational and rotational energy measurements of desorbed water molecules in their vibrational ground state following 157 nm irradiation of amorphous solid water", T. Hama, M. Yokoyama, A. Yabushita, M. Kawasaki, & N. Watanabe,Nucl. Instr. Methods B 269, 1011-1015 (2011)

  • "Formation of Carbonic Acid by Surface Reactions of Non-energetic OH Radicals with CO Molecules at Low Temperatures", Y. Oba, N. Watanabe, A. Kouchi, T. Hama, V. Pirronello, Astrophys. J. 722, 1598-1606 (2010)

  • "Direct measurements of hydrogen atom diffusion and the spin temperature of nascent H2 molecule on amorphous solid water", N. Watanabe, Y. Kimura, A. Kouchi, T. Chigai, T. Hama, & V. Pirronello, Astrophys. J. Lett. 714, L233 (2010)

  • "A desorption mechanism of water following vacuum-ultraviolet irradiation on amorphous solid water at 90 K", T. Hama, M. Yokoyama, A. Yabushita, M. Kawasaki, S. Andersson, C.M. Western, M.N.R. Ashfold, R.N. Dixon, & N. Watanabe, J. Chem. Phys. 132, 164508 (2010)

  • "Direct evidence for ammonium ion formation in ice through ultraviolet-induced acid-base reaction of NH3 with H3O+", E-S. Moon, H. Kang, Y. Oba, N. Watanabe, & A. Kouchi, Astrophys. J. 713, 906 (2010)

  • "Experimental study of CO2 formation by surface reactions of non-energetic OH radicals with CO moleculesh, Y. Oba, N. Watanabe, A. Kouchi, T. Hama, & V. Pirronello, Astrophys. J. Lett. 712, L174 (2010)

  • "Nonenergetic reactions between atomic hydrogen and molecules on interstellar grain surfaces", N. Watanabe, A. Kouchi, H. Hidaka, Y. Oba, & N. Miyauchi, J. Phys.: Conf. Ser. 194, 012044 (2009)

  • "Hydrogen isotope exchange and H(D) atom addition reaction of solid formaldehyde on amorphous solid water at low temperatures", H. Hidaka, M. Watanabe, A. Kouchi, & N. Watanabe, J. Phys.: Conf. Ser. 194, 132024 (2009)

  • "Formation mechanisms of oxygen atoms in the O(3PJ) state from the 157 nm photoirradiation of amorphous water ice at 90 K", Tetsuya Hama, Akihiro Yabushita, Masaaki Yokoyama, Masahiro Kawasaki, & Naoki Watanabe, J. Chem. Phys. 131, 114511 (2009)

  • "Formation mechanisms of oxygen atoms in the O(1D2) state from the 157 nm photoirradiation of amorphous water ice at 90 K", Tetsuya Hama, Akihiro Yabushita, Masaaki Yokoyama, Masahiro Kawasaki, & Naoki Watanabe,J. Chem. Phys. 131, 114510 (2009)

  • "Reaction routes in the CO-H2CO-dn-CH3OH-dm system clarified from H(D) exposure of solid formaldehyde at low temperatures", H. Hidaka, M.Watanabe, A. Kouchi & N. Watanabe, Astrophys. J. 702, 291 (2009)

  • "Formation of compact amorphous H2O ice by codeposition of hydrogen atoms with oxygen molecules on grain surfaces", Y. Oba, N. Miyauchi, H. Hidaka, T. Chigai, N. Watanabe & A. Kouchi, Astrophys. J. 701, 464 (2009)

  • "Translational and Rotational Energy Measurements of Photodesorbed Water Molecules in Their Vibrational Ground State from Amorphous Solid Water", Akihiro Yabushita, Tetsuya Hama, Masaaki Yokoyama, Masahiro Kawasaki, Stefan Andersson, Richard N. Dixon, Michael N. R. Ashfold, & Naoki Watanabe, Astrophys. J. Lett. 699, L80-L83, (2009)

  • "Ice surface reactions: A key to chemical evolution in space", Naoki Watanabe & Akira Kouchi, Prog. Surf. Sci., 83, 439-489 (2008)

  • "Release of hydrogen molecules from the photodissociation of amorphous solid water and polycrystalline ice at 157 and 193 nm", Akihiro Yabushita, Tetsuya Hama, Daisuke Iida, Noboru Kawanaka, Masahiro Kawasaki, Naoki Watanabe, Michael N. R. Ashfold, & Hans-Peter Loock, J. Chem. Phys., 129, 044501 (2008)

  • "Measurements of energy partitioning in H2 formation by photolysis of amorphous water ice", Akihiro Yabushita, Tetsuya Hama, Daisuke Iida, Noboru Kawanaka, Masahiro Kawasaki, Naoki Watanabe, Michael N. R. Ashfold, & Hans-Peter Loock, Astrophys. J. Lett., 682, L69 (2008)

  • "Structural effects of ice grain surfaces on the hydrogenation of CO at low temperatures",H. Hidaka, N. Miyauchi, A. Kouchi, & N. Watanabe, Chem. Phys. Lett., 456, 36 (2008)

  • "Formation of hydrogen peroxide and water from the reaction of cold H atoms with solid O2 at 10 K", N. Miyauchi, H. Hidaka, T. Chigai, A. Nagaoka, N. Watanabe, & A. Kouchi, Chem. Phys. Lett., 456, 27 (2008)

  • "Laboratory Simulation of Competition between Hydrogenation and Photolysis in the Chemical Evolution of H2O-CO Ice Mixtures"; N. Watanabe, O. Mouri, A. Nagaoka, T. Chigai, A. Kouchi & V. Pirronell, Astrophys. J., 668, 1001 (2007)

  • "Temperature, composition, and hydrogen isotope effect in the hydrogenation of CO at 10 - 20 K", H. Hidaka, A. Kouchi & N. Watanabe, J. Chem. Phys., 126, 204707 (2007)

  • "Effective rate constants for the surface reaction between solid methanol and deuterium atoms at 10 K", A. Nagaoka, N. Watanabe, & Akira Kouchi, J. Phys. Chem. A, 111, 3016 (2007)

  • "Dependence of the effective rate constants for the hydrogenation of CO on the temperature and composition of the surface", N. Watanabe, A. Nagaoka, H. Hidaka, T. Shiraki, T. Chigai, & A. Kouchi, Planetary and Space Science, 54, 1107 (2006)

  • "Formation and Deuterium Fractionation of Organic Molecules on Grain Surfaces", Naoki Watanabe, in Astrochemistry: Recent Successes and Current@Challenges, eds. D.C. Lis, G.A. Blake & E. Herbst, Cambridge University Press, (2006)

  • "H-D substitution in interstellar solid methanol : a key route for D enrichment", Akihiro Nagaoka, Naoki Watanabe, & Akira Kouchi, Astrophys. J. Lett. 624, 29 (2005)

  • "Observation of resonance structures in 4d photoionization of Eu+", Takao M. Kojima, Fanfu Chen, Masashi Kitajima, Tetsuo Koizumi, Yoichi Nakai, Hitoshi Yamaoka, & Naoki Watanabe,@Journal of Electron Spectroscopy and Related Phenomena, 144-147, 71-74 (2005)

  • "Hydrogenation of CO on pure solid CO and CO-H2O mixed ice", Naoki Watanabe, Akihiro Nagaoaka, Takahiro Shiraki, & Akira Kouchi, Astrophys. J. 616, 638 (2004)

  • "Conversion of H2CO to CH3OH by reactions of cold atomichydrogen on ice surfaces below 20 K", H. Hidaka, N. Watanabe, T. Shiraki, A. Nagaoka, and A. Kouchi, Astrophys. J.614, 1124 (2004)

  • "The dependence of H2CO and CH3OH formation on temperature and thickness of H2O-CO ice during successive hydrogenation of CO", Naoki Watanabe, Takahiro Shiraki, and Akira Kouchi, Astrophys. J. Lett. 588, 121 (2003)

  • "An apparatus to determine the rovibrational distribution of molecular hydrogen formed by the heterogeneous recombination of H atoms on cosmic dust analogues", J.S.A. Perry, J.M. Gingell, K.A. Newson, J. To, N. Watanabe, and S.D. Price, Meas. Sci. Technol. 13, 1414 (2002)

  • "Efficient formation of formaldehyde and methanol by the addition of hydrogen atoms to CO in H2O-CO ice at 10K", Naoki Watanabe and Akira Kouchi, Astrophys. J. Lett. 571, 173 (2002)

  • "Rapid Growth of Asteroids Owing to Very Sticky Interstellar Organic Grains", Akira Kouchi, Tatsuyuki Kudo, Hideyuki Nakano, Masahiko Arakawa, Naoki Watanabe, Sin-iti Sirono, Michiya Higa, and Norikazu Maeno, Astrophys. J. Lett. 566, 121 (2002)

  • "Measurements of conversion rates of CO to CO2 in UV induced reaction of D2O/CO amorphous ice", Naoki Watanabe and Akira Kouchi, Astrophys. J. 567, 651-655 (2002)

  • "Absolute photoionization cross section measurements of Xe+ ions in the 4d threshold energy region", Y. Itoh, A. Ito, M. Kitajima, T. Koizumi, T. M. Kojima, H. Sakai, M. Sano and N. Watanabe, J. Phys. B: At. Mol. Opt. Phys.34, 3493-3499 (2001)

  • "Measurements of D2 yields from D2O amorphous ice by ultraviolet irradiation at 12K", N. Watanabe, T. Horii, and A. Kouchi, Astrophys. J. 541, 772-779 (2000)

  • "Photoion-yield spectra of Xe2+ in the 4d-threshold energy region", N. Watanabe, Y. Awaya, A. Fujino, Y. Itoh, M. Kitajima, T. M. Kojima, M. Oura , R. Okuma, M. Sano, T. Sekioka and T. Koizumi, J. Phys. B : At. Mol. Opt. Phys.31, 4137-4141 (1998)

  • "Diret Determination of Partial Wave Contributions in σ* Shape Resonance of CO Molecules", E. Shigemasa, J. Adachi, K. Soejima, N. Watanabe, A. Yagishita, and N.A. Cherepkov, Phys. Rev. Lett. 80, 1622-1625 (1998)

  • "Dynamic Properties of N and O 1s-1σu* shape resonances in N2 and CO2 molecules", A.A.Pavlychev, N.G. Forminykh, N. Watanabe, K. Soejima, E. Shigemasa,and A. Yagishita, Phys. Rev. Lett. 81, 3623-3626 (1998)

  • "Photoion yield spectroscopy in the 4d photoionization of Eu+", T.M.Kojima, M.Oura, Y.Itoh, T.Koizumi, M.Sano, T.Sekioka, N.Watanabe, H.Yamaoka, and Y.Awaya, J. Phys. B: At. Mol. Opt. Phys.31, 1463-1468 (1998)

  • "4d Photionization of singly-charged ions", T.M.Kojima, M.Oura, N.Watanabe, Y.Awaya, Y.Itoh, T.Koizumi, M.Sano, and F.Koike, Journal of the Korean Physical Society 32, 273-279 (1998)

  • "Fixed-molecule 1sσg,u photoelectron angular distributions as a probe of σg* and σu* shape resonances of CO2", N. Watanabe, J. Adachi, K. Soejima, E. Shigemasa, A. Yagishita, N. G. Fominykh, and A. A.Pavlychev, Phys. Rev. Lett.78, 4910 (1997)

  • "Feasibility of the photoionization of multi-chrged ions and first test ofa PHOton Beam Ion Source (PHOBIS) with RIKEN EBIS (REBIS)", S.D.Kravis, N.Watanabe, Y.Awaya, M.Kimura, T.Kojima, K.Okuno, and M.Oura, Physica Scripta T71 121-126 (1997)

  • "Recoil-ion momentum distribution of single-electron capture to the ground and excited states in 0.5-1MeV/u B4+,5+ + He collisions", T.Kambara, A.Igarashi, N.Watanabe, Y.Nakai, T.M.Kojima, and Y.Awaya, J. Phys. B : At. Mol. Opt. Phys. 30, 1251 (1997)

  • "4d Photoionization of Multiply Charged Xeq+ (q=1-3) Ions", T. Koizumi, Y. Awaya, A. Fujino, T. Itoh, M. Kitajima, T.M. Kojima, M. Oura M. Sano, T. Sekioka, N. Watanabe, and F. Koike, Physica Scripta T73, 131-132 (1997)

  • "Reaction of carbon-silicon binary cluster", Y.Negishi, N.Watanabe, H.Shiromaru, Y.Achiba, and N.Kobayashi, Surf. Rev. Lett. 3, 661-665 (1996)

  • "Photoionization of 4d-electrons in singly-charged Xe ions", M.Sano, Y.Itoh, T.Koizumi, T.M.Kojima, S.D.Kravis, M.Oura, T.Sekioka, N.Watanabe, Y.Awaya, and F.Koike, J. Phys. B 29, 5305-5313 (1996)

  • "4d photoionization of singly-charged Xe, Ba, and Eu ions", T.Koizumi, Y.Awaya, M.Gonno, Y.Itoh, M.Kiura, T.M.Kojima, S.Kravis, M.Oura, M.Sano, Naoki Watanabe, H.Yamaoka, and F.Koike, J. Electron Spectrosc. Relat. Phenom. 79, 289-292 (1996)

  • "Single ionization of He by low-velocity protons and C6+: Ejected electron momentum distributions", Kravis SD, Abdallah M, Cocke CL, Lin CD, Stockli M, Walch B, Wang YD, Olson RE, Rodriguez VD, Wu W, Pieksma M, Watanabe N, Phys. Rev. A 54, 1394-1403 (1996)