Do the nuclear-spin temperatures of cometary molecules reflect the temperature of their birth place?

2013 Fiscal Year Final Research Report

• Project/Area Number: 24740329
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Space and upper atmospheric physics
• Research Institution: Hokkaido University
• Principal Investigator: HAMA Tetsuya 北海道大学, 低温科学研究所, 助教 (20579172)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: 彗星 / 原子核スピン温度 / アモルファス氷

Research Abstract

The nuclear-spin temperatures of molecules such as H2O have often been observed in cometary comae, because they have been suggested to reflect the temperature of their birth place. However, laboratory investigation to support this hypothesis is not thus far reported, and the real meaning of the observed nucelar-spin temperature in cometary comae remains a topic of debate. Here I studied nuclear-spin temperature of photodesorbed H2O molecules from water ice at 8 K using 532 nm laser photo-stimulated desorption and resonance-enhanced multiphoton ionization (PSD-REMPI). The PSD-REMPI spectra of H2O molecules imply that the nuclear spin temperature is higher than 8 K. On the basis of the present and previous experimental studies, the hypothesis that the nuclear-spin temperatures of cometary molecules reflect the temperature of their birth place appears unlikely.

Research Products

• [Journal Article] Surface Processes on Interstellar Amorphous Solid Water : Adsorption, Diffusion, Tunneling, Reaction, and Nuclear-Spin Conversion (2013)
  • Author(s): T. Hama, and N. Watanabe
  • Journal Title: Chemical Reviews Volume: 113, 12 Pages: 8783-8839
  • DOI: 10.1021/cr4000978
• [Journal Article] Nuclear spin temperatures of hydrogen and water molecules on amorphous solid water (2013)
  • Author(s): N. Watanabe, T. Hama, and A. Kouchi
  • Journal Title: AIP Conference Proceedings Volume: 1543 Pages: 308-316
  • DOI: 10.1063/1.4812625
• [Journal Article] Photochemical reaction processes during vacuum-ultraviolet irradiation of water ice (2013)
  • Author(s): A. Yabushita, T. Hama, and M. Kawasaki
  • Journal Title: Journal of Photochemistry and Photobiology C : Photochemistry Reviews Volume: 16 Pages: 46-61
  • DOI: 10.1016/j.jphotochemrev.2013.01.001
• [Journal Article] The mechanism of surface diffusion of H and D atoms on amorphous solid water : Existence of various potential sites (2012)
  • Author(s): T. Hama, K. Kuwahata, N. Watanabe, A. Kouchi, Y. Kimura. T. Chigai, and V. Pirronello
  • Journal Title: Astrophys. J. Volume: 757, 185 Pages: 12
  • DOI: 10.1088/0004-637X/757/2/185
• [Journal Article] Water formation through a quantum tunneling surface reaction, OH + H_2, at 10 K (2012)
  • Author(s): Y. Oba, N. Watanabe, T. Hama, K. Kuwahata, H. Hidaka, and A. Kouchi
  • Journal Title: Astrophys. J. Volume: 749, 67 Pages: 12
  • DOI: 10.1088/0004-637X/749/1/67
• [Journal Article] 星間分子雲での微粒子表面における水素の化学物理過程, Physicochemical Processes of Hydrogen on Cosmic Dust in Molecular Clouds (2012)
  • Author(s): 渡部直樹, 香内晃, 羽馬哲也, 日高宏, 大場康弘, 千貝健
  • Journal Title: 表面科学 Volume: 33(12), 2012年12月号 Pages: 662-668
  • DOI: 10.1380/jsssj.33.662
• [Presentation] Development of an ultrahigh vacuum transmission electron mircoscope for in-situ observation of ice (2014)
  • Author(s): A. Kouchi, N. Watanabe, H. Hidaka, T. Hama, S. Nakatsubo, K. Fujita, K. Sinbori, and M. Ikeda
  • Organizer: 13^<th> International Conference on the Physics and Chemistry of Ice(PCI-2014)
  • Place of Presentation: Thayer School of Engineering at Dartmauth, Hanover, US.
  • Year and Date: 20140317-20
• [Presentation] Role of quantum tunneling for the formation of H_2O by reaction of H_<2 >with OH on interstellar grains (2014)
  • Author(s): Y. Oba, N. Watanabe, T. Hama, K. Kuwahata, H. Hidaka, and A. Kouchi
  • Organizer: 247th ACS Chemistry & Materials for Energy
  • Place of Presentation: The Dallas convention center, Dallas, USA
  • Year and Date: 20140316-20
• [Presentation] Diffusion of hydrogen atom on amorphous solid water : Thermal or tunneling? (2014)
  • Author(s): N. Watanabe, K. Kuwahata, T. Hama, and A. Kouchi
  • Organizer: 247th ACS National Meeting & Exposition
  • Place of Presentation: The Dallas convention center, Dallas, USA
  • Year and Date: 20140316-20
• [Presentation] 分子雲有機物の生成・分析にむけた光化学反応実験装置の開発 (2013)
  • Author(s): 羽馬哲也
  • Organizer: 「宇宙における分子進化:星間雲から原始惑星系へ」平成25年度研究集会
  • Place of Presentation: 北海道大学(北海道)
  • Year and Date: 20131127-28
• [Presentation] 氷表面における水素原子の熱拡散およびトンネル拡散の実験研究 (2013)
  • Author(s): 桑畑和明, 羽馬哲也, 日高宏, 香内晃, 渡部直樹
  • Organizer: 第38回原子衝突学会年会
  • Place of Presentation: 理化学研究所(和光)鈴木梅太郎記念ホール(埼玉県)
  • Year and Date: 20131116-17
• [Presentation] 氷表面において水素原子はトンネル拡散するか? (2013)
  • Author(s): 桑畑和明, 羽馬哲也, 日高宏, 香内晃, 渡部直樹
  • Organizer: 第34回原子衝突若手の会秋の学校
  • Place of Presentation: 熱海姫の沢自然の家(静岡県)
  • Year and Date: 20131012-14
• [Presentation] 氷の表面でおきる化学反応とその天文学における意義 (2013)
  • Author(s): 羽馬哲也
  • Organizer: 第34回原子衝突若手の会秋の学校
  • Place of Presentation: 熱海姫の沢自然の家(静岡県)
  • Year and Date: 20131012-14
• [Presentation] 低温アモルファス氷上での水素原子表面拡散の同位体効果 (2013)
  • Author(s): 桑畑和明, 羽馬哲也, 日高宏, 香内晃, 渡部直樹
  • Organizer: 日本物理学会2013年秋季大会
  • Place of Presentation: 徳島大学常三島キャンパス(徳島県)
  • Year and Date: 20130925-28
• [Presentation] The Ortho-Para Ratio of H_2O Desorbed from Ice : Implications for Cometary Coma (2013)
  • Author(s): T. Hama, A. Kouchi, and N. Watanabe
  • Organizer: Goldschmidt2013
  • Place of Presentation: Firenze Fiera Congress & Exhibition Center, Florence, Italy
  • Year and Date: 20130825-30
• [Presentation] 氷でおきる化学反応 (2013)
  • Author(s): 羽馬哲也
  • Organizer: 衛星系研究会:衛星観測から探る衛星形成環境
  • Place of Presentation: 定山渓温泉渓流荘(札幌)
  • Year and Date: 20130807-09
• [Presentation] Surface number density of physisorbed H and D atoms on water ice during continuous atomic deposition (2013)
  • Author(s): K. Kuwahata, T. Hama, A. Kouchi, and N. Watanabe
  • Organizer: 29th Symposium on Chemical Kinetics and Dynamics
  • Place of Presentation: Katahira Sakura Hall, Tohoku Univ., Sendai
  • Year and Date: 20130605-07
• [Presentation] Experimental study of quantum-tunneling surface reaction OH + H_<2 >→H_2O+ H at 10 K (2013)
  • Author(s): Y. Oba, N. Watanabe, T. Hama, H. Hidaka., K. Kuwahata, and A. Kouchi
  • Organizer: 29th Symposium on Chemical Kinetics and Dynamics
  • Place of Presentation: Katahira Sakura Hall, Tohoku Univ., Sendai
  • Year and Date: 20130605-07
• [Presentation] Ortho-to-para Ratio of Water Molecules Thermally Desorbed from Ice (2013)
  • Author(s): T. Hama
  • Organizer: Workshop on Ice and Water Films
  • URL: http://cmd.snu.ac.kr/IceWorkshop.htm
  • Place of Presentation: Mogam Hall, Seoul National Univ., Seoul, South Korea
  • Year and Date: 20130506-08
• [Presentation] 表面への水素・重水素原子照射による吸着原子数密度の同位体依存性 (2013)
  • Author(s): 桑畑和明, 羽馬哲也, 日高宏, 香内晃, 渡部直樹
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学(広島県)
  • Year and Date: 20130326-29
• [Presentation] Physics and chemistry of hydrogen on cosmic dust : diffusion, spin temperatures, and water formation (2013)
  • Author(s): N. Watanabe, T. Hama, H. Hidaka, Y. Kimura, A. Kouchi, Y. Oba, and V. Pirronello
  • Organizer: First Workshop on Experimental Laboratory Astrophysics
  • Place of Presentation: Sheraton Kauai, Poipu, Kauai, Hawaii
  • Year and Date: 20130225-27
• [Presentation] Development of an ultrahigh vacuum low temperature transmission electron microscope for in situ observation of ice (2013)
  • Author(s): A. Kouchi, N. Watanabe, H. Hidaka, T. Hama, S. Nakatsubo, K. Fujita, K. Sinbori, and M. Ikeda
  • Organizer: First Workshop on Experimental Laboratory Astrophysics
  • Place of Presentation: Sheraton Kauai, Poipu, Kauai, Hawaii
  • Year and Date: 20130225-27
• [Presentation] Experimental measurements of nuclear-spin temperature of thermally desorbed water molecules from ice (2013)
  • Author(s): T. Hama, N. Watanabe, and A. Kouchi.
  • Organizer: First Workshop on Experimental Laboratory Astrophysics
  • Place of Presentation: Sheraton Kauai, Poipu, Kauai, Hawaii
  • Year and Date: 20130225-27
• [Presentation] Surface diffusion mechanism of H and D atoms on amorphous solid water (2013)
  • Author(s): K. Kuwahata, T. Hama, N. Watanabe, A. Kouchi, Y. Kimura, and V. Pirronello
  • Organizer: First Workshop on Experimental Laboratory Astrophysics
  • Place of Presentation: Sheraton Kauai, Poipu, Kauai, Hawaii
  • Year and Date: 20130225-27
• [Presentation] 固体ベンゼンの水素原子トンネル付加反応によるシクロヘキサン生成 (2013)
  • Author(s): 羽馬哲也, 植田寛和, 渡部直樹, 香内晃
  • Organizer: 第38回原子衝突学会年会
  • Place of Presentation: 理化学研究所(和光)鈴木梅太郎記念ホール(埼玉県)
  • Year and Date: 20130116-17
• [Presentation] 水素分子-氷表面相互作用研究のための分子線装置開発 (2013)
  • Author(s): 植田寛和, 羽馬哲也, 中坪俊一, 森章一, 藤田和之, 齋藤史明, 香内晃, 渡部直樹
  • Organizer: 第19回低温科学研究所技術部技術報告会
  • Place of Presentation: 北海道大学低温科学研究所(北海道)
  • Year and Date: 2013-12-13
• [Presentation] 天文学におけるオルトーパラ分子比の意義と実験研究によるアプローチ (2013)
  • Author(s): 羽馬哲也
  • Organizer: 第2回卓越拠点物理化学若手ワークショップ 核スピン異性体(オルト-パラ)分子科学の新展開～孤立分子から凝縮相・天体観測への応用～
  • Place of Presentation: 京都大学理学部6号館(京都府)
  • Year and Date: 2013-03-05
• [Presentation] 低温アモルファス氷表面に物理吸着した水素原子の拡散 (2012)
  • Author(s): 羽馬哲也, 桑畑和明, 渡部直樹, 香内晃, 千貝健
  • Organizer: 第3回真空・表面科学若手勉強会
  • Place of Presentation: 甲南大学ポートアイランドキャンパス(兵庫県)
  • Year and Date: 20121112-13
• [Presentation] Laboratory measurements of spin temperature of water molecules from ice in thermal desorption (2012)
  • Author(s): T. Hama, N. Watanabe, and K. Kouchi
  • Organizer: Workshop on Interstellar Matter 2012
  • Place of Presentation: Hokkaido Univ. Sapporo
  • Year and Date: 20121017-19
• [Presentation] Water formation by OH + H_<2 > on grain surfaces at 10 K : large isotope effects by quantum tunneling (2012)
  • Author(s): Y. Oba, N. Watanabe, T. Hama, K. Kuwahata, H. Hidaka, and A. Kouchi
  • Organizer: Workshop on Interstellar Matter 2012
  • Place of Presentation: Hokkaido Univ. Sapporo
  • Year and Date: 20121017-19
• [Presentation] The surface diffusion mechanism of hydrogen atom on interstellar ice (2012)
  • Author(s): K. Kuwahata, T. Hama, N. Watanabe, A.Kouchi, and Y. Kimura
  • Organizer: Workshop on Interstellar Matter 2012
  • Place of Presentation: Hokkaido Univ. Sapporo
  • Year and Date: 20121017-19
• [Presentation] Spin temperature of water molecules desorbed from ice produced by photolysis of a CH_4/O_2 solid mixture and its implication in a cometary coma (2012)
  • Author(s): T. Hama
  • Organizer: Gordon Research Conference on Radiation Chemistry
  • Place of Presentation: Proctor Academy, Andover, New Hampshire, USA
  • Year and Date: 20120729-0803
• [Presentation] The diffusion mechanism of H atom on the surface of amorphous solid water : quantum tunneling or thermal hopping (2012)
  • Author(s): T. Hama, K. Kuwahata, A. Kouchi, and N. Watanabe
  • Organizer: 第28回化学反応討論会 28^<th> Symposium on Chemical Kinetics and Dynamics
  • Place of Presentation: 九州大学筑紫キャンパス(福岡県春日市)
  • Year and Date: 20120606-08
• [Presentation] 彗星コマの水分子の核スピン温度は彗星氷の生成温度を反映しているか?Does nuclear-spin temperature of water molecules in comet coma reflect the formation temperature of the cometary ice? (2012)
  • Author(s): 羽馬哲也, 渡部直樹, 香内晃
  • Organizer: 日本地球惑星科学連合2012年大会
  • Place of Presentation: 幕張メッセ国際会議場(千葉県)
  • Year and Date: 20120520-25
• [Presentation] 星間塵表面での水分子とその重水素置換体生成, Formation of H_2O and its isotopologues on interstellar grains(2012) (2012)
  • Author(s): 大場康弘, 渡部直樹, 羽馬哲也, 桑畑和明, 日高宏, 香内晃
  • Organizer: 日本地球惑星科学連合2012年大会
  • Place of Presentation: 幕張メッセ国際会議場(千葉県)
  • Year and Date: 20120520-25
• [Presentation] Nuclear-Spin Temperature of Water Molecules Thermally Desorbed from Ice : A Laboratory Study (2012)
  • Author(s): T. Hama, N. Watanabe, and A. Kouchi
  • Organizer: ACM2012 (Asteroid, Comets, Meteors(2012))
  • Place of Presentation: Niigata Toki Messe (Niigata Convention Center), Niigata
  • Year and Date: 20120516-20
• [Presentation] Surface Chemical Reactions to the Formation of Solid H_2O and its Isotopologues on Interstellar Grains at 10K (2012)
  • Author(s): Y. Oba, N. Watanabe, H. Hama, K. Kuwahata, H. Hidaka, and A. Kouchi
  • Organizer: ACM2012 (Asteroid, Comets, Meteors(2012))
  • Place of Presentation: Niigata Toki Messe (Niigata Convention Center), Niigata
  • Year and Date: 20120516-20
• [Presentation] Chemical Reaction on Interstellar Grain Surfaces (星間塵表面でおきる化学反応) (2012)
  • Author(s): T. Hama
  • Organizer: The 76th Seminar on Formation of Stars & Planets (第76回「星・惑星形成」ゼミ)
  • Place of Presentation: 名古屋大(愛知県)
  • Year and Date: 2012-05-26
• [Remarks]
  • URL: http://www.lowtem.hokudai.ac.jp/astro/index.html