PAHs and the Universe最新文献_第2页

Experimental Studies of the Dissociative Recombination Processes for the C6D+ 6 and C6D+ 7 Ions C6D+ 6和C6D+ 7离子解离重组过程的实验研究

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146026

M. Hamberg, E. Vigren, R. Thomas, V. Zhaunerchyk, M. Zhang, S. Trippel, M. Kamińska, I. Kashperka, M. A. Ugglas, A. Källberg, A. Simonsson, A. Paál, J. Semaniak, M. Larsson, W. Geppert

{"title":"Experimental Studies of the Dissociative Recombination Processes for the C6D+\u0000 6 and C6D+\u0000 7 Ions","authors":"M. Hamberg, E. Vigren, R. Thomas, V. Zhaunerchyk, M. Zhang, S. Trippel, M. Kamińska, I. Kashperka, M. A. Ugglas, A. Källberg, A. Simonsson, A. Paál, J. Semaniak, M. Larsson, W. Geppert","doi":"10.1051/EAS/1146026","DOIUrl":"https://doi.org/10.1051/EAS/1146026","url":null,"abstract":"We have investigated the dissociative recombination (DR) of the\u0000 C 6 D 6 + and C 6 D 7 + ions using the CRYRING heavy-ion storage ring at Stockholm University, Sweden. The\u0000 dissociative recombination branching ratios were determined at minimal collision energy, showing that the DR of both ions was dominated by pathways keeping the carbon atoms\u0000 together in one product. The absolute reaction cross sections for the titular ions are\u0000 best fitted by σ (E cm [eV]) = 1.3 ± 0.4 × 10 -15 (E cm [eV]) −1.19 ± 0.02 cm 2 (C 6 D 6 + )\u0000 and σ (E cm [eV]) = 1.1 ± 0.3 × \u0000 10 -15 (E cm [eV]) −1.33 ± 0.02 cm 2 (C 6 D 7 + )\u0000 in the intervals 3-300 meV and 3-200 meV respectively. The thermal rate constants of the\u0000 titular reactions are best described by:\u0000 k(T) = 1.3 ± 0.4 × 10 -6 (T/300) −0.69 ± 0.02 cm 3 s -1 for C 6 D 6 + and k(T) = 2.0 ± 0.6 × 10 -6 (T/300) −0.83 ± 0.02 cm 3 s -1 for C 6 D 7 + .\u0000 These expressions correlates well with earlier flowing afterglow studies on the same\u0000 process.","PeriodicalId":197011,"journal":{"name":"PAHs and the Universe","volume":"187 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122773365","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: 3

Modeling the Anharmonic Infrared Emission Spectra of PAHs: Application to the Pyrene Cation 多环芳烃的非谐波红外发射光谱建模:在芘阳离子中的应用

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146009

M. Basire, P. Parneix, T. Pino, P. Bréchignac, F. Calvo

引用次数: 9

Spectroscopy of Protonated and Deprotonated PAHs 质子化和去质子化多环芳烃的光谱分析

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146038

M. Hammonds, A. Candian

引用次数: 5

Dialectics of the PAH Abundance Trend with Metallicity 多环芳烃丰度趋势与金属丰度的辩证关系

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146004

F. Galliano

引用次数: 0

VUV Photochemistry of PAHs Trapped in Interstellar Water Ice 星际水冰中多环芳烃的紫外光化学研究

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146027

J. Bouwman, H. Cuppen, L. Allamandola, H. Linnartz

引用次数: 1

PAHs and Astrobiology 多环芳烃与天体生物学

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146032

L. Allamandola

引用次数: 13

PAH in Vectorized Three Dimensional Monte Carlo Dust Radiative Transfer Models 矢量三维蒙特卡罗尘埃辐射传输模型中的多环芳烃

PAHs and the Universe Pub Date : 2020-11-04 DOI: 10.1051/EAS/1146030

R. Siebenmorgen, F. Heymann, E. Krügel

{"title":"PAH in Vectorized Three Dimensional Monte Carlo Dust Radiative Transfer Models","authors":"R. Siebenmorgen, F. Heymann, E. Krügel","doi":"10.1051/EAS/1146030","DOIUrl":"https://doi.org/10.1051/EAS/1146030","url":null,"abstract":"We present a Monte Carlo (MC) radiative transfer code for complex three dimensional dust distributions and include transiently heated PAH. The correctness of the code is confirmed by comparison with benchmark results. The method makes use of the parallelization capabilities of modern vectorized computing units like graphic cards. The computational speed grows linearly with the number of graphical processing units (GPU). On a conventional desktop PC, our code is up to a factor 100 faster when compared to other MC algorithms. As an example, we compute the dust emission of proto-planetary disks. We simulate how a mid-IR instrument mounted at a future 42 m ELT will detect such disks. Two cases are distinguished: a homogeneous disk and a disk with an outward migrating planet, producing a gap and a spiral density wave. We find that the resulting mid-IR spectra of both disks are almost identical. However, they can be distinguished at those wavelengths by coronographic, dual-band imaging. Finally, the emission of PAHs exposed to different radiation fields is computed. We demonstrate that PAH emission depends not only on the strength but also strongly on the hardness of the radiation, a fact which has often been neglected in previous models. We find that hard photons (>20 eV) easily dissociate all PAHs in the disks of T Tauri stars. To explain the low, but not negligible detection rate (<10%) of PAHs in T Tau disks, we suggest that turbulent motions act as a possible path for PAH survival.","PeriodicalId":197011,"journal":{"name":"PAHs and the Universe","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115240117","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: 0

Astronomical Models of PAHs and Dust 多环芳烃和尘埃的天文模型

PAHs and the Universe Pub Date : 2011-12-01 DOI: 10.1051/EAS/1146003

B. Draine

引用次数: 12

Search for far-IR PAH Bands with Herschel: Modelling and Observational Approaches 用赫歇尔搜索远红外多环芳烃波段:建模和观测方法

PAHs and the Universe Pub Date : 2011-12-01 DOI: 10.1051/EAS/1146013

C. Joblin, G. Mulas, G. Malloci, E. Bergin

引用次数: 7

Atypical Dust Species in the Ejecta of Classical Novae 经典新星喷出物中的非典型尘埃

PAHs and the Universe Pub Date : 2011-12-01 DOI: 10.1051/EAS/1146042

L. Helton, A. Evans, C. Woodward, R. Gehrz

{"title":"Atypical Dust Species in the Ejecta of Classical Novae","authors":"L. Helton, A. Evans, C. Woodward, R. Gehrz","doi":"10.1051/EAS/1146042","DOIUrl":"https://doi.org/10.1051/EAS/1146042","url":null,"abstract":"A classical nova outburst arises from a thermonuclear run- away in the hydrogen-rich material accreted onto the surface of a white dwarf in a binary system. These explosions can produce copious amounts of heavy element enriched material that are ejected violently into the surrounding interstellar medium. In some novae, conditions in the ejecta are suitable for the formation of dust of various compositions, including silicates, amorphous carbon, silicon carbide, and hydrocar- bons. Multiple dust grain types are sometimes produced in the same system. CO formation in novae may not reach saturation, thus in- validating the usual paradigm in which the C:O ratio determines the dust species. A few novae, such as V705 Cas and DZ Cru, have ex- hibited emission features near 6, 8, and 11 µm that are similar to \"Unidentified Infrared\" (UIR) features, but with significant differences in position and band structure. Here, we present Spitzer IRS spectra of two recent dusty novae, V2361 Cyg and V2362 Cyg, that harbor similar peculiar emission structures superimposed on features arising from carbonaceous grains. In other astronomical objects, such as star forming regions and young stellar objects, emission peaks at 6.2, 7.7, and 11.3 µm have been associated with polycyclic aromatic hydro- carbon (PAH) complexes. We suggest that hydrogenated amorphous carbon (HAC) may be the source of these features in novae based upon the spectral behavior of the emission features and the conditions under which the dust formed.","PeriodicalId":197011,"journal":{"name":"PAHs and the Universe","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128600299","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: 9