Molecular Astrophysics最新文献_第6页

Binding energies: New values and impact on the efficiency of chemical desorption 结合能:新的数值及其对化学解吸效率的影响

Molecular Astrophysics Pub Date : 2017-03-01 DOI: 10.1016/j.molap.2017.01.002

V. Wakelam , J.-C. Loison , R. Mereau , M. Ruaud

引用次数: 117

Inelastic cross sections and rate coefficients for collisions between CO and H2 CO和H2碰撞的非弹性截面和速率系数

Molecular Astrophysics Pub Date : 2017-03-01 DOI: 10.1016/j.molap.2017.01.003

Christina Castro , Kyle Doan , Michael Klemka , Robert C. Forrey , Benhui Yang , Phillip C. Stancil , N. Balakrishnan

{"title":"Inelastic cross sections and rate coefficients for collisions between CO and H2","authors":"Christina Castro , Kyle Doan , Michael Klemka , Robert C. Forrey , Benhui Yang , Phillip C. Stancil , N. Balakrishnan","doi":"10.1016/j.molap.2017.01.003","DOIUrl":"10.1016/j.molap.2017.01.003","url":null,"abstract":"<div>A five-dimensional coupled states (5D-CS) approximation is used to compute cross sections and rate coefficients for CO+H2 collisions. The 5D-CS calculations are benchmarked against accurate six-dimensional close-coupling (6D-CC) calculations for transitions between low-lying rovibrational states. Good agreement between the two formulations is found for collision energies greater than 10cm−1. The 5D-CS approximation is then used to compute two separate databases which include highly excited states of CO that are beyond the practical limitations of the 6D-CC method. The first database assumes an internally frozen H2 molecule and allows rovibrational transitions for v ≤ 5 and j ≤ 30, where v and j are the vibrational and rotational quantum numbers of the initial state of the CO molecule. The second database allows H2 rotational transitions for initial CO states with v ≤ 5 and j ≤ 10. The two databases are in good agreement with each other for transitions that are common to both basis sets. Together they provide data for astrophysical models which were previously unavailable.</div>","PeriodicalId":44164,"journal":{"name":"Molecular Astrophysics","volume":"6 ","pages":"Pages 47-58"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molap.2017.01.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77479718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Weakly bound molecular complexes in the laboratory and in the interstellar medium: A lost interest? 实验室和星际介质中的弱结合分子复合物:失去了兴趣?

Molecular Astrophysics Pub Date : 2017-03-01 DOI: 10.1016/j.molap.2017.01.001

Alexey Potapov

引用次数: 17

13C-substituted C60+: Predictions of the rotational spectra 13c取代C60+:旋转光谱的预测

Molecular Astrophysics Pub Date : 2017-03-01 DOI: 10.1016/j.molap.2016.12.001

Koichi M.T. Yamada , Stephen C. Ross , Fumiyuki Ito

引用次数: 3

The Possibility of Forming Propargyl Alcohol in the Interstellar Medium 在星际介质中形成丙炔醇的可能性

Molecular Astrophysics Pub Date : 2017-03-01 DOI: 10.1016/j.molap.2017.01.004

Prasanta Gorai , Ankan Das , Liton Majumdar , Sandip Kumar Chakrabarti , Bhalamurugan Sivaraman , Eric Herbst

{"title":"The Possibility of Forming Propargyl Alcohol in the Interstellar Medium","authors":"Prasanta Gorai , Ankan Das , Liton Majumdar , Sandip Kumar Chakrabarti , Bhalamurugan Sivaraman , Eric Herbst","doi":"10.1016/j.molap.2017.01.004","DOIUrl":"10.1016/j.molap.2017.01.004","url":null,"abstract":"<div>Propargyl alcohol (HC2CH2OH, PA) has yet to be observed in the interstellar medium (ISM) although one of its stable isomers, propenal (CH2CHCHO), has already been detected in Sagittarius B2(N) with the 100-meter Green Bank Telescope in the frequency range <math><mrow><mn>18</mn><mo>−</mo><mn>26</mn></mrow></math> GHz. In this paper, we investigate the formation of propargyl alcohol along with one of its deuterated isotopomers, HC2CH2OD (OD-PA), in a dense molecular cloud. Various pathways for the formation of PA in the gas and on ice mantles surrounding dust particles are discussed. We use a large gas-grain chemical network to study the chemical evolution of PA and its deuterated isotopomer. Our results suggest that gaseous HC2CH2OH can most likely be detected in hot cores or in collections of hot cores such as the star-forming region Sgr B2(N). A simple LTE (Local thermodynamic equilibrium) radiative transfer model is employed to check the possibility of detecting PA and OD-PA in the millimeter-wave regime. In addition, we have carried out quantum chemical calculations to compute the vibrational transition frequencies and intensities of these species in the infrared for perhaps future use in studies with the James Webb Space Telescope (JWST).</div>","PeriodicalId":44164,"journal":{"name":"Molecular Astrophysics","volume":"6 ","pages":"Pages 36-46"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molap.2017.01.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90277927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

PAH chemistry at eV internal energies. 1. H-shifted isomers eV内能下的多环芳烃化学。1. h移同分异构体

Molecular Astrophysics Pub Date : 2017-02-14 DOI: 10.1016/j.molap.2017.02.001

G. Trinquier, A. Simon, M. Rapacioli, F. X. Gad'ea

引用次数: 16

PAH chemistry at eV internal energies. 2. Ring alteration and dissociation eV内能下的多环芳烃化学。2. 环的改变和分离

Molecular Astrophysics Pub Date : 2017-02-13 DOI: 10.1016/j.molap.2017.02.002

G. Trinquier, A. Simon, M. Rapacioli, F. X. Gad'ea

引用次数: 17

Ion-neutral reaction of C2H2N+ with CH4: An experimental and theoretical study C2H2N+与CH4离子中性反应的实验与理论研究

Molecular Astrophysics Pub Date : 2016-11-01 DOI: 10.1016/j.molap.2016.07.001

P. Fathi , W.D. Geppert , F. Lindén , A. Cernuto , D. Ascenzi

引用次数: 4

Photo-fragmentation behavior of methyl- and methoxy-substituted derivatives of hexa-peri-hexabenzocoronene (HBC) cations 六-邻六苯并冠烯(HBC)阳离子甲基和甲氧基取代衍生物的光断裂行为

Molecular Astrophysics Pub Date : 2016-11-01 DOI: 10.1016/j.molap.2016.08.001

Junfeng Zhen , Pablo Castellanos , Harold Linnartz , Alexander G.G.M. Tielens

{"title":"Photo-fragmentation behavior of methyl- and methoxy-substituted derivatives of hexa-peri-hexabenzocoronene (HBC) cations","authors":"Junfeng Zhen , Pablo Castellanos , Harold Linnartz , Alexander G.G.M. Tielens","doi":"10.1016/j.molap.2016.08.001","DOIUrl":"10.1016/j.molap.2016.08.001","url":null,"abstract":"<div>A systematic study, using ion trap time-of-flight mass spectrometry, is presented for the photo-fragmentation of methyl- and methoxy-substituted derivatives of HBC cations, (OCH3)6HBC<math><msup><mrow></mrow><mo>+</mo></msup></math> and (CH3)4(OCH3)2HBC<math><msup><mrow></mrow><mo>+</mo></msup></math>. Both substituted HBC cations fragment through sequential loss of CH3CO units upon laser (595nm) irradiation, resulting in a PAH-like derivative C36H12<math><msup><mrow></mrow><mo>+</mo></msup></math> and a methyl-substituted PAH derivative C44H24<math><mrow><msup><mrow></mrow><mo>+</mo></msup><mo>,</mo></mrow></math> respectively. Upon ongoing irradiation, these species further fragment. For lower laser energy C44H24<math><msup><mrow></mrow><mo>+</mo></msup></math> dehydrogenates and photo-fragments through CH3 and CHCH2 unit losses; for higher laser energy isomerization takes place, yielding a regular PAH-like configuration, and both stepwise dehydrogenation and C2/C2H2 loss pathways are found. C36H12<math><msup><mrow></mrow><mo>+</mo></msup></math> follows largely this latter fragmentation scheme upon irradiation.It is concluded that the photo-dissociation mechanism of the substituted PAH cations studied here is site selective in the substituted subunit. This work also shows experimental evidence that photo-fragmentation of substituted PAHs may contribute to the formation in space of smaller species that are normally considered to form by merging atoms and molecules.</div>","PeriodicalId":44164,"journal":{"name":"Molecular Astrophysics","volume":"5 ","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molap.2016.08.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83937614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Methylacetylene (CH3CCH) and propene (C3H6) formation in cold dense clouds: A case of dust grain chemistry 甲基乙炔(CH3CCH)和丙烯(C3H6)在冷致密云中的形成:一个尘埃颗粒化学的例子

Molecular Astrophysics Pub Date : 2016-04-01 DOI: 10.1016/j.molap.2016.03.001

Kevin M. Hickson , Valentine Wakelam , Jean-Christophe Loison

引用次数: 30