Confirming Interstellar C60
 + Using the Hubble Space Telescope

Cordiner, Martin; Linnartz, H.; Cox, N. L. J.; Cami, J.; Najarro, F.; Proffitt, Charles; Lallement, R.; Ehrenfreund, P.; Foing, B. H.; Gull, Theodore R.; Sarre, P. J.; Charnley, S. B.

doi:10.3847/2041-8213/ab14e5

Cited by 114 publications

(85 citation statements)

References 33 publications

(57 reference statements)

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“…For tetracene, the fragmentation pattern exhibits the typical bi-modal structure as in the case of triphenylene. [29][30][31] and very recently in diffuse ISM with a robust confirmation from the Hubble telescope [32]. A key difference between fullerenes and the PAHs discussed above is the presence of 5-membered rings in fullerenes.…”

Section: Pyrene (C 16 H +mentioning

confidence: 79%

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

et al. 2020

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When exposed to a thermal beam of hydrogen atoms, gas-phase coronene cations C24H12+ can be sequentially hydrogenated. This process is accompanied by a gradual transition of the electronic structure from aromatic to aliphatic. The planar very stable coronene structure transforms into the significantly weaker corrugated structure, typical for aliphatic molecules. In this study, we have investigated the hydrogenation of 5 smaller polycyclic aromatic hydrocarbon cations using a combination of radiofrequency ion trapping with time-of-flight mass spectrometry. Anthracene (C14H10+), pyrene (C16H10+), triphenylene (C18H12+), tetracene (C18H12+) and 8-9-benzofluoranthene (C20H12+) only cover a small mass range, but differ in carbon/hydrogen ratio, number of outer-edge sites and overall structure. We have observed qualitatively similar initial hydrogenation patterns for all 5 molecular ions, with odd hydrogenation states being dominant. Strong quantitative differences in hydrogenation and in attachment-induced fragmentation were found. For the case of pyrene cations, we have also investigated exposure to atomic D. Clear lines of evidence for HD/D2 abstraction reactions of Eley–Rideal type were found, as previously observed for coronene cations. Graphical abstract

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Section: Pyrene (C 16 H +mentioning

confidence: 79%

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

et al. 2020

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“…Initially identified in a young planetary nebula, they are now seen in a wide variety of sources. Interstellar C + 60 , originally proposed by Foing & Ehrenfreund (1994), is now firmly detected at optical wavelenths (Cordiner et al 2019). In fact, there is now good observational evidence for the transformation of PAHs to fullerenes under the influence of UV radiation, a process that is also understood theoretically (Berné & Tielens 2012) and simulated experimentally (Zhen et al 2014).…”

Section: Molecular Physics: Pahs Fullerenesmentioning

confidence: 82%

Laboratory astrophysics: Key to understanding the Universe

Dishoeck

2019

Proc. IAU

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This brief overview stresses the importance of laboratory data and theory in analyzing astronomical observations and understanding the physical and chemical processes that drive the astrophysical phenomena in our Universe. This includes basic atomic and molecular data such as spectroscopy and collisional rate coefficients, but also an improved understanding of nuclear, plasma and particle physics, as well as reactions and photoprocesses in the gaseous and solid state that lead to chemical complexity and building blocks for life. Systematic laboratory collision experiments have provided detailed insight into the steps that produce pebbles, bricks and ultimately planetesimals starting from sub-μ-sized grains. Sample return missions and meteoritic studies benefit from increasingly sophisticated laboratory machines to analyze materials and provide compositional images on nanometer scales. Prioritization of future data requirements will be needed to cope with the increasing data streams from a diverse range of future astronomical facilities within a constrained laboratory astrophysics budget.

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“…[71] García-Hernández et al presented evidence that that fullerenes and PAHs coexist in the circumstellar ejecta of low-excitation and H-containing planetary nebula in our galaxy and in the Small Magellanic Cloud. [72] Based on Hubble Space Telescope data, combined with ground-based observations, in a 2019 report Cordiner et al [73] conclusively confirmed the presence of C 60 + in low-density, strongly-irradiated environments of interstellar space. To explain how the C 60 fullerene could form in the ISM, several "top-down" schemes have been proposed where larger carbon clusters shrink to reach C 60 .…”

Section: Proposed Routes To Fullerenes In the Ismmentioning

confidence: 93%

Fullerenes and PAHs: A Novel Model Explains their Formation via Sequential Cycloaddition Reactions Involving C2 Dimers

Smadja¹

2019

Preprint

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Based on a new understanding of the nature of the bonding in the C2 dimer, a novel bottom-up model is offered that can explain the growth processes of fullerenes and polycyclic aromatic hydrocarbons (PAHs). It is shown how growth sequences involving C2 dimers, that take place in carbon vapor, combustion systems, and the ISM, could give rise to a variety of bare carbon clusters. Among the bare carbon clusters thus formed, some could lead to fullerenes, while others, after hydrogenation, could lead to PAHs. We propose that the formation of hexagonal rings present in these bare carbon clusters are the result of [2+2+2] and [4+2] cycloaddition reactions that involve C2 dimers. In the C60 and C70 fullerenes, each of the twelve pentagons is surrounded by five hexagons and thereby “isolated” from each other. To explain why, we suggest that in bowl-shaped clusters the pentagons can form as the consequence of closures of “cove regions” that exist between hexagonal rings, and that they can also form during cage-closure, which results in the creation of six “isolated” pentagonal rings, and five hexagonal rings. The proposed growth mechanisms can account for the formation of fullerene isomers without the need to invoke the widely used Stone-Wales rearrangement. Considering processes that take place in combustion systems, it is proposed that soot particle inception can result from oligomerization of the bare carbon clusters that originated from cycloadditions involving C2 dimers. In future work, the insights offered in this article could provide a better understanding of nanotube growth, with or without defects.

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Confirming Interstellar C₆₀ ⁺ Using the Hubble Space Telescope

Cited by 114 publications

References 33 publications

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

Laboratory astrophysics: Key to understanding the Universe

Fullerenes and PAHs: A Novel Model Explains their Formation via Sequential Cycloaddition Reactions Involving C2 Dimers

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Confirming Interstellar C60 + Using the Hubble Space Telescope

Cited by 114 publications

References 33 publications

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

Atomic hydrogen interactions with small polycyclic aromatic hydrocarbons cations

Laboratory astrophysics: Key to understanding the Universe

Fullerenes and PAHs: A Novel Model Explains their Formation via Sequential Cycloaddition Reactions Involving C2 Dimers

Contact Info

Product

Resources

About

Confirming Interstellar C₆₀ ⁺ Using the Hubble Space Telescope