Optical spectrum of proflavine
with Goranka Bilalbegovic
First diffuse interstellar bands (DIBs) were discovered in the beginning of 20th century. Today there are more than 300 known DIBs found in different lines of sight throughout the Galaxy, but their origins are still unknown. During the years of research many different carriers were suggested, analyzed, and often completely or partially rejected. Among these are: processes on surfaces of dust grains, excited states of carbon chains, fullerens and other nanostructures and molecules. We examine the possibility that proflavine molecule is connected to some DIBs. Proflavine is chemically similar to a widely researched naphthalene molecule, but contains three nitrogen atoms, in addition to carbon and hydrogen.
Optical spectra of proflavine and its ions in vacuum were calculated using the time-dependent density functional theory. All spectra are characterized with two strong absorption lines: the first one in the optical, the second one in the near-UV part of the spectrum. The optical line of a neutral proflavine lies within FWHM of a known DIB, which makes proflavine a potential DIB carrier. A special importance of this result comes from the possibility that molecules in this class of up until now scarcely investigated compounds, which besides carbon and hydrogen also contain nitrogen, are connected with the origin of diffuse interstellar bands.
More information:
Optical spectrum of proflavine and its ions
(ADS | Arxiv)
Bonaca, A., and Bilalbegovic, G., 2010, CPL, 493, 33
Electronic absorption spectra of hydrogenated protonated naphthalene and proflavine
(ADS | Arxiv)
Bonaca, A., and Bilalbegovic, G., 2011, MNRAS, 416, 1509