Detalles de publicación
PP 07014
FULLERENES AND THE \lambda 4430 DIFFUSE INTERSTELLAR BAND
IAC
The photoabsorption spectra of single-shell icosahedral fullerenes is investigated in the region of the strongest diffuse interstellar band at 4430 \AA. According to Hückel and Pariser-Parr-Pople models several fullerenes (C_80, C_240, C_320 and C_540) present transitions in the vicinity of this band. The same semiempirical models also predict a high density of transitions
in the UV that may explain the 2175 \AA~ bump in the extinction curve of the interstellar medium (Iglesias-Groth 2004). It appears that fullerenes could be responsible of these two major features of interstellar absorption. Using the theoretical cross sections and available empirical data on the 4430 \AA~ band we estimate for these fullerenes abundances of $\sim$0.05 molecules per million hydrogen atoms in regions of the interstellar medium with excess color index of E(B-V)=0.1.
in the UV that may explain the 2175 \AA~ bump in the extinction curve of the interstellar medium (Iglesias-Groth 2004). It appears that fullerenes could be responsible of these two major features of interstellar absorption. Using the theoretical cross sections and available empirical data on the 4430 \AA~ band we estimate for these fullerenes abundances of $\sim$0.05 molecules per million hydrogen atoms in regions of the interstellar medium with excess color index of E(B-V)=0.1.