Highlights of Astronomy, Volume 16 XXVIIIth IAU General Assembly, August 2012 T. Montmerle, ed. c  International Astronomical Union 2015 doi:10.1017/S1743921314013052 Laboratory Analogues of the Carbonaceous Dust: Synthesis of Soot-like Materials and their Properties T. Pino 1 , Y. Carpentier 1 †, G. F´ eraud 1 , Ph. Br´ echignac 1 , R. Brunetto 2 , L. d’Hendecourt 2 , E. Dartois 2 and J.-N. Rouzaud 3 1 Institut des Sciences Mol´ eculaires d’Orsay, CNRS - Univ Paris-Sud, F91405 Orsay Cedex, France email: thomas.pino@u-psud.fr 2 Institut d’Astrophysique Spatiale, CNRS - Univ Paris-Sud, F91405 Orsay Cedex, France 3 Laboratoire de G´ eologie, Ecole Normale Sup´ erieure, F75231 Paris Cedex 5, France Abstract. Carbonaceous cosmic dust is observed through infrared spectroscopy either in ab- sorption or in emission and the details of the spectral features are believed to shed some light on its structure and finally enable the study of its life cycle. Other spectral domains also contain some information, as does the UV bump at 217 nm. In order to progress on the understanding of these spectral features, many laboratory works are devoted to the production and character- ization of laboratory analogues. Generally several analytical tools are used in combination to better analyse the intimate structure of the analogues and the influence of the nanostructuration on the spectral properties. In this proceeding We will focus on the elaboration of new spectral parameters that enables the nanostructuration of the carriers of the AIBs to be traced. Keywords. ISM: general, astrochemistry, (ISM:) dust, extinction, infrared: ISM 1. Introduction Carbonaceous materials are observed in many objects in space (Henning & Salama 1998, Ehrenfreund & Charnley 2000) through their specific spectral features. Some are found in the visible to UV range (D´ esert et al. 1990, Draine 2003, Zubko et al. 2004), but most of the spectral information is obtained in the infrared range of wavelength. In particular, the aromatic infrared bands (AIBs) (Gillett et al. 1973) trace carbonaceous particles whose inferred size vary from large molecules, the polycyclic aromatic hydro- carbons (PAHs), to nanoparticles of a few nanometers (L´ eger & Puget 1984, Crawford et al. 1985, Tielens 2008). Three main classes A, B and C of astrophysical spectra have been proposed based on the observed spectral characteristics in the 6 to 9 μm wavelength region (Peeters et al. 2002). If the band positions, in most sources, are clearly attributed to aromatic materials (Goto et al. 2007), however, the exact nature of the emitters still escape. In the case of the class A emitters, the carbonaceous species emit through their vibrational bands thanks to the stochastic heating mechanism (Puget & L´ eger 1989, Al- lamandola et al. 1989, Draine & Li 2001). In the other cases, thermal emission may occur, particularly for the class C objects. In order to study these materials, many laboratory astrophysics works are perfomed on various analogues. At Orsay (France), we focus on the polyaromatic carbons with a special emphasize on the soot-like nanoparticles. Such materials provide interesting laboratory analogues of cosmic dust. The soot samples are † Present address: Laboratoire de Physique des Laser, Atomes et Mol´ ecules, Bˆat P5 - USTL, F-59655 Villeneuve d’Ascq cedex, France 717 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1743921314013052 Downloaded from https://www.cambridge.org/core. IP address: 18.206.13.133, on 11 Jun 2020 at 00:51:20, subject to the Cambridge Core terms of use, available at