| 1. |
- Algaba, Juan-Carlos, et al.
(författare)
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Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
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Forskningsöversikt (refereegranskat)abstract
- In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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| 2. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Armand, M., et al.
(författare)
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Review-Development of Huckel Type Anions: From Molecular Modeling to Industrial Commercialization. A Success Story
- 2020
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 167:7
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Forskningsöversikt (refereegranskat)abstract
- This paper reviews the battery electrolyte technologies involving Huckel-type salts as a major electrolyte component. The concept was initially proposed by M. Armand in 1995 and then explored by several research groups. In the present review studies on the optimization of the electrolyte composition starting from molecular modeling through enhancing the yield of the salt synthesis to structural characterization and electrochemical performance are described. Furthermore, the use of the optimized electrolytes in a variety of lithium-ion and post-lithium batteries is presented and discussed. Finally, the commercialization of the up to date technology by Arkema is discussed as well as the performance of the present Huckel anion based electrolytes as compared to other marketed electrolyte technologies.
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| 4. |
- Scheers, Johan, 1979, et al.
(författare)
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Benzimidazole and imidazole lithium salts for battery electrolytes
- 2010
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 195:18, s. 6081-6087
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Konferensbidrag (refereegranskat)abstract
- The intrinsic anion oxidation potential (Delta E-v) and lithium ion pair dissociation energy (Delta E-d) are two important properties for predicting the potential use of new lithium salts for battery electrolytes. In this work several cyano substituted fluoroalkylated benzimidazole and imidazole anions have been investigated computationally to obtain Delta E-v and Delta E-d. Varying the number and position of cyano substituents results in large effects on the electrochemical stability of the anion and on the possible lithium ion pair configurations. The lengthening of the fluoroalkyl group introduces several new stable ion pair configurations and a small increase in anion oxidation stability. The most promising fluoroalkylated anions in the present work are the 4,5,6,7-tetracyano-2-fluoroalkylated benzimidazolides (TTB and PTB), with oxidation potentials suitable for high voltage Li-ion battery applications (
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