منابع مشابه
On the Excitation and Formation of Circumstellar Fullerenes
We compare and analyze the Spitzer mid-infrared spectrum of three fullerene-rich planetary nebulae in the Milky Way and the Magellanic Clouds; Tc1, SMP SMC 16, and SMP LMC 56. The three planetary nebulae share many spectroscopic similarities. The strongest circumstellar emission bands correspond to the infrared active vibrational modes of the fullerene species C60 and little or no emission is p...
متن کاملOrigin and Evolution of Dust in Circumstellar and Interstellar Environments
Astronomical observations and analysis of stardust isolated from meteorites have revealed a highly diverse interstellar and circumstellar grain inventory, including both amorphous materials and highly crystalline compounds (oxides, silicates and carbonaceous). This dust is highly processed during its sojourn from its birthsite (stellar outflows and supernova explosions) to its incorporation int...
متن کاملHydrocarbon anions in interstellar clouds and circumstellar envelopes
The recent detection of the hydrocarbon anion C6H − in the interstellar medium has led us to investigate the synthesis of hydrocarbon anions in a variety of interstellar and circumstellar environments. We find that the anion/neutral abundance ratio can be quite large, on the order of at least a few percent, once the neutral has more than five carbon atoms. Detailed modeling shows that the colum...
متن کاملTop-down formation of fullerenes in the interstellar medium.
Fullerenes have been recently detected in various circumstellar and interstellar environments, raising the question of their formation pathway. It has been proposed that they can form at the low densities found in the interstellar medium by the photo-chemical processing of large polycyclic aromatic hydrocarbons (PAHs). Following our previous work on the evolution of PAHs in the NGC 7023 reflect...
متن کاملSurvivability of Fullerenes under Γ-irradiation in the Interstellar Medium
Introduction: Although the presence of fullere-nes in the interstellar medium remains a subject for considerable discussion and waits for an unambiguous experimental confirmation, it is generally assumed that the large spherical carbon clusters can be generated within circumstellar envelopes of mass-losing carbon-rich stars [1-14]. The detection of fullerenes in carbo-naceous chondrites, in the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2018
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921319004691