The surface composition of Jupiter Trojans: Visible and near-infrared survey of dynamical families

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2006.02.012 Byline: E. Dotto (a), S. Fornasier (b), M.A. Barucci (c), J. Licandro (d)(e), H. Boehnhardt (f), O. Hainaut (g), F. Marzari (h), C. de Bergh (c), F. De Luise (a) Keywords: Asteroids; Photometry; Spectroscopy Abstract: Asteroid dynamical families are supposed to be formed from the collisional disruption of parent bodies. As a consequence, the investigation of the surface properties of small and large family members may give some hints on the nature of the dynamical group, the internal composition of the parent body, and the role played by space weathering processes in modifying the spectral behavior of the members' surfaces. In this work we present visible-near-infrared observations of 24 Jupiter Trojans belonging to seven dynamical families of both the L4 and L5 swarms. The most important characteristics we found is the uniformity of the Trojans population. All the investigated Trojans have featureless spectra and a spectral behavior typical of the primitive P and D taxonomic classes. In particular, no signatures of water ice have been found on the spectra of these primordial bodies. From our investigation, the L4 and L5 clouds appear to be compositionally indistinguishable. Tentative models of the surface composition, based on the Hapke theory, are presented and discussed. Author Affiliation: (a) INAF, Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone (Roma), Italy (b) Department of Astronomy, University of Padova, Vicolo dell'Osservatorio 2, I-35122 Padova, Italy (c) LESIA, Observatoire de Paris-Meudon, 5 Place Jules Janssen, 92195 Meudon, France (d) Isaac Newton Group of Telescopes, P.O. Box 321, E-38700 Santa Cruz de la Palma, Tenerife, Spain (e) Instituto de Astrofisica de Canarias, c/Via Lactea s/n, E-38200 La Laguna, Tenerife, Spain (f) Max Planck Institute for Solar System Research, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau, Germany (g) European Southern Observatory, Casilla 19001, Santiago, Chile (h) Department of Physics, University of Padova, Via Marzolo 8, I-35131 Padova, Italy Article History: Received 27 June 2005; Revised 14 February 2006 Article Note: (footnote) [star] Based on observations carried out at the European Southern Observatory (ESO), La Silla, Chile, ESO proposals 69.C-0524 and 71.C-0650, and at the Telescopio Nazionale Galileo, La Palma, Canary Island, proposals TAC06 (AOT7) and TAC705 (AOT6).