Carbon in the Universe

Abstract

Carbon is a major player in the evolutionary scheme of the universe because of its abundance and its ability to form complex species. It is also a key element in the evolution of prebiotic molecules. The different forms of cosmic carbon are reviewed ranging from carbon atoms and carbon-bearing molecules to complex, solid-state, carbonaceous structures. The current state of knowledge is assessed on the observational and laboratory fronts. Fundamental astrophysical implications are examined as well as the impact of these studies on the hitherto poorly understood physical and chemical properties of carbon materials in space.

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

“…Carbonaceous materials are observed throughout many different regions in space (Henning & Salama 1998;Ehrenfreund & Charnley 2000). The diverse environment conditions thus met for carbon chemistry lead to original questions dealing not only with the structure of these carbonaceous particles (e.g.…”

Observations and modelling of CO and [C i] in protoplanetary disks

“…Carbon is one of the most abundant elements in the Universe; it is central to interstellar and terrestrial chemistry and to planetary climate (Henning & Salama 1998;Unterborn et al 2014). The carbon content of planets is determined by chemical and physical processes before and during the protoplanetary disk stage.…”

Defective Carbon Onions in Interstellar Space as the Origin of the Optical Extinction Bump at 217.5 Nanometers

“…The observations reviewed by Fitzpatrick & Massa (1990) established that the extinction maximum of the bump remains constant in position, while its width varies by more than 30% along one line of sight to another. There has been only a general agreement that the 4.6 m À1 feature is associated with carbonaceous dust in interstellar space (Henning & Salama 1998). Many models of the carbonaceous dust particles have already been constructed to account for this feature, e.g., a size distribution of graphitic particles (Mathis et al 1977); a mixture of spheres composed of graphite, amorphous carbon, and silicate (Aannestad 1995;Mathis & Whiffen 1989); an irregular or fractal arrangement of graphite and amorphous carbon (Perrin & Sivan 1991;Wright 1987); polycyclic aromatic hydrocarbons (Lee & Wdoviak 1993); and natural coal (Papoular et al 1996).…”