Bibcode
Díaz-Luis, J. J.; García-Hernández, D. A.; Kameswara Rao, N.; Manchado, A.; Cataldo, F.
Bibliographical reference
Memorie della Societa Astronomica Italiana, v.87, p.295 (2016)
Advertised on:
2016
Citations
0
Refereed citations
0
Description
The short transition phase between asymptotic giant branch stars (AGB;
when circumstellar envelopes rich in small organic molecules are
efficiently created) and planetary nebulae (PNe) represents a most
active phase of molecular synthesis. Different complex organic molecules
- e.g., polycyclic aromatic hydrocarbons and fullerenes - have been
proposed as carriers of the enigmatic diffuse interstellar bands (DIBs).
If the DIBs arise from such large carbon-based molecules, then they are
also expected to be present in the circumstellar shells around C-rich
AGB descendants; i.e., post-AGB stars and young PNe. Diffuse
circumstellar bands (DCBs) in absorption have been unsuccessfully search
for more than 40 years; the main difficulty being to distinguish the
DCBs from the DIBs. Here we present a detailed DIB radial velocity
analysis and a complete search of diffuse bands towards three young PNe
(Tc 1, M 1-20, and IC 418) containing fullerenes. Interestingly, we
report the first possible detection of two DCBs at 4428 and 5780 Å
in the fullerene-rich circumstellar environment around PN Tc 1. This
possible detection of DCBs in an environment rich in fullerenes and
fullerene-related molecules could provide a link between fullerene
compounds and some of the DIB carriers.