Fullerenes and fullerene-related molecules have been proposed as explanations for unidentified astronomical features such as the intense UV absorption band at 217 nm and the enigmatic diffuse interstellar bands (DIBs), In order to shed light on the a long-standing DIB’s problem, we search high-resolution and high-quality VLT/UVES optical spectra of the hot R Coronae Borealis (RCB) star DY Cen for electronic transitions of the neutral C60 fullerene molecule and DIBs. We report the non-detection of the strongest C60 electronic transitions (e.g., those at ∼376, 398, and 402 nm). DIBs towards DY Cen are normal for its reddening; the only exception is the DIB at 628 nm (possibly also the 722 nm DIB) that is found to be unusually strong. We also report the detection of a new broad (FWHM∼2 Å) and unidentified feature centered at∼400 nm. The non detection of neutral C60 in the high-quality VLT/UVES DY Cen’s spectrum may support recent experimental work, showing that the∼7.0, 8.5, 17.4, and 18.8 micron IR features seen in sources with polycyclic aromatic hydrocarbon (PAH)-like dominated spectra have to attributed to proto-fullerenes rather than to neutral C60. In addition, the new 400 nm DIB reported here (possibly also the carriers of the classical 628 nm and 722 nm DIBs) may be related to fullerene precursors; an organic compound containing pentagonal rings. These pentagonal carbon rings are usually present in hydrogenated amorphous carbon (HAC) nanoparticles and nanotubes, suggesting that they may be intimately related with the formation process of fullerenes.
Advertised on
References
The Astrophysical Journal Letters, 2012, 759, L21
It may interest you
-
The universality of the stellar initial mass function (IMF) is one of the most widespread assumptions in modern Astronomy and yet, it might be flawed. While observations in the Milky Way generally support an IMF that is invariant with respect to the local conditions under which stars form, measurements of massive early-type galaxies systematically point towards a non-universal IMF. To bridge the gap between both sets of evidence, in this work we measured for the first time the low-mass end of the IMF from the integrated spectra of a Milky Way-like galaxy, NGC3351. We found that the slope ofAdvertised on
-
Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbourAdvertised on
-
The formation and evolution of the disk of our Galaxy, the Milky Way, remains an enigma in astronomy. In particular, the relationship between the thick disk and the thin disk —two key components of the Milky Way— is still unclear. Understanding the chemical and dynamical properties of the stars within these disks is crucial, especially in the parameter spaces where their characteristics overlap, such the metallicity regime around [Fe/H] ~ -0.7, which marks the metal-poor end of the thin disk, higher than that of the thick disk. This is often interpreted as an indication that the thin diskAdvertised on