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

doi:10.1086/590531

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

Research output: Contribution to journal › Article › peer-review

25 Citations (Scopus)

Abstract

We demonstrate experimentally that photodissociation of amorphous solid water at 100 K results in formation of H₂ molecules with an ortho/para ratio of g_OPR = 3. Two distinct mechanisms can be identified: endothermic abstraction of a hydrogen atom from H₂O by a photolytically produced H atom yields vibrationally cold H₂ products, whereas exothermic recombination of two H-atom photoproducts yields translationally and internally hot H₂. These results are in accord with predictions by molecular dynamics calculations and their astrophysical implications are discussed.

Original language	English
Pages (from-to)	L69-L72
Journal	Astrophysical Journal
Volume	682
Issue number	1 PART 2
DOIs	https://doi.org/10.1086/590531
Publication status	Published - 2008
Externally published	Yes

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1086/590531

Cite this

@article{734ccb05853647878163d4ce75fb09ec,

title = "Measurements of energy partitioning in H2 formation by photolysis of amorphous water ice",

abstract = "We demonstrate experimentally that photodissociation of amorphous solid water at 100 K results in formation of H2 molecules with an ortho/para ratio of gOPR = 3. Two distinct mechanisms can be identified: endothermic abstraction of a hydrogen atom from H2O by a photolytically produced H atom yields vibrationally cold H2 products, whereas exothermic recombination of two H-atom photoproducts yields translationally and internally hot H2. These results are in accord with predictions by molecular dynamics calculations and their astrophysical implications are discussed.",

author = "Akihiro Yabushita and Tetsuya Hama and Daisuke Iida and Noboru Kawanaka and Masahiro Kawasaki and Naoki Watanabe and Ashfold, {Michael N.R.} and Loock, {Hans Peter}",

year = "2008",

doi = "10.1086/590531",

language = "English",

volume = "682",

pages = "L69--L72",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "1 PART 2",

}

TY - JOUR

T1 - Measurements of energy partitioning in H2 formation by photolysis of amorphous water ice

AU - Yabushita, Akihiro

AU - Hama, Tetsuya

AU - Iida, Daisuke

AU - Kawanaka, Noboru

AU - Kawasaki, Masahiro

AU - Watanabe, Naoki

AU - Ashfold, Michael N.R.

AU - Loock, Hans Peter

PY - 2008

Y1 - 2008

N2 - We demonstrate experimentally that photodissociation of amorphous solid water at 100 K results in formation of H2 molecules with an ortho/para ratio of gOPR = 3. Two distinct mechanisms can be identified: endothermic abstraction of a hydrogen atom from H2O by a photolytically produced H atom yields vibrationally cold H2 products, whereas exothermic recombination of two H-atom photoproducts yields translationally and internally hot H2. These results are in accord with predictions by molecular dynamics calculations and their astrophysical implications are discussed.

AB - We demonstrate experimentally that photodissociation of amorphous solid water at 100 K results in formation of H2 molecules with an ortho/para ratio of gOPR = 3. Two distinct mechanisms can be identified: endothermic abstraction of a hydrogen atom from H2O by a photolytically produced H atom yields vibrationally cold H2 products, whereas exothermic recombination of two H-atom photoproducts yields translationally and internally hot H2. These results are in accord with predictions by molecular dynamics calculations and their astrophysical implications are discussed.

UR - http://www.scopus.com/inward/record.url?scp=56249109558&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=56249109558&partnerID=8YFLogxK

U2 - 10.1086/590531

DO - 10.1086/590531

M3 - Article

AN - SCOPUS:56249109558

SN - 0004-637X

VL - 682

SP - L69-L72

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1 PART 2

ER -

Measurements of energy partitioning in H₂ formation by photolysis of amorphous water ice

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this