Naslov
Hydrocarbon nanoparticles as a diffuse ISM analog: morphology and infrared absorption in 2000 cm-1 - 500 cm-1 region

Autori
Kovačević, Eva ; Stefanović, Ilija ; Berndt, Johannes ; Pendleton, Yvonne J. ; Winter, Jörg

Izvornik
Plasma physics and controlled fusion (0741-3335) 47 (2005), 4; 11-20

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
plasma; dust; TEM; dust growth; interstellar; buffer gas

Sažetak
In this paper we analysed morphology and chemistry of carbonaceous dust particles proposed as a candidate analog material for dust in diffuse interstellar media. The particles were polymerised in a low pressure capacitively coupled rf discharge in mixtures of argon/acetylene and helium/acetylene. Infrared spectra of our dust particles reveal the strong presence of aliphatic features, both stretching and bending, very similar to astronomical data from diffuse interstellar media. The comparison between the infrared spectra obtained in argon and in helium as buffer gas reveals in the case of helium a strong presence of C=C double bonds (skeletal modes). The presence of these skeletal modes is clearly visible through the broad absorption feature at 1600 cm-1, present in observational data of interstellar PAH’ s , but until now not observed in observational data for the dust in diffuse interstellar media or in spectra of interstellar analog materials. The origin of this new/strenghtened feature can be connected with the change in the plasma parameters due to the change of buffer gas in the same discharge conditions.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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