Díaz-Luis, J. J.; García-Hernández, D. A.; Kameswara Rao, N.; Manchado, A.; Cataldo, F.
Bibliographical reference
Astronomy and Astrophysics, Volume 573, id.A97, 14 pp.
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1
2015
Journal
Citations
25
Refereed citations
18
Description
Large fullerenes and fullerene-based molecules have been proposed as
carriers of diffuse interstellar bands (DIBs). The recent detection of
the most common fullerenes (C60 and C70) around
some planetary nebulae (PNe) now enable us to study the DIBs towards
fullerene-rich space environments. We search DIBs in the optical spectra
towards three fullerene-containing PNe (Tc 1, M 1-20, and IC 418).
Special attention is given to DIBs which are found to be unusually
intense towards these fullerene sources. In particular, an unusually
strong 4428 Å absorption feature is a common charateristic of
fullerene PNe. Similar to Tc 1, the strongest optical bands of neutral
C60 are not detected towards IC 418. Our high-quality (S/N
> 300) spectra for PN Tc 1, together with its large radial velocity,
permit us to search for the presence of diffuse bands of circumstellar
origin, which we refer to as diffuse circumstellar bands (DCBs). We
report the first tentative detection of two DCBs at 4428 and 5780
Å in the fullerene-rich circumstellar environment around the PN Tc
1. Laboratory and theoretical studies of fullerenes in their
multifarious manifestations (carbon onions, fullerene clusters, or even
complex species formed by fullerenes and other molecules like PAHs or
metals) may help solve the mystery of some of the diffuse band carriers.
Appendix A is available in electronic form at http://www.aanda.org
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