Activation of extended red emission photoluminescence in carbon solids by exposure to atomic hydrogen and UV radiation

1993 ◽  
Vol 415 ◽  
pp. L51 ◽  
Author(s):  
Douglas G. Furton ◽  
Adolf N. Witt
Keyword(s):  
Uv Radiation ◽  
Atomic Hydrogen ◽  
Red Emission ◽  
Extended Red Emission

scholarly journals Are the Carriers of Diffuse Interstellar Bands and Extended Red Emission the same?

2020 ◽  
Author(s):  
Thomas S-Y Lai ◽  
Adolf N Witt ◽  
Carlos Alvarez ◽  
Jan Cami
Keyword(s):  
Molecular Ions ◽  
Ionization Front ◽  
Stellar Spectrum ◽  
Red Emission ◽  
Large Molecules ◽  
Radiation Fields ◽  
Diffuse Interstellar Bands ◽  
Vibrational Levels ◽  
Extended Red Emission ◽  
Photodissociation Region

Abstract We report the first spectroscopic observations of a background star seen through the region between the ionization front and the dissociation front of the nebula IC 63. This photodissociation region (PDR) exhibits intense extended red emission (ERE) attributed to fluorescence by large molecules/ions. We detected strong diffuse interstellar bands (DIB) in the stellar spectrum, including an exceptionally strong and broad DIB at λ4428. The detection of strong DIBs in association with ERE could be consistent with the suggestion that the carriers of DIBs and ERE are identical. The likely ERE process is recurrent fluorescence, enabled by inverse internal conversions from highly excited vibrational levels of the ground state to low-lying electronic states with subsequent transitions to ground. This provides a path to rapid radiative cooling for molecules/molecular ions, greatly enhancing their ability to survive in a strongly irradiated environment. The ratio of the equivalent widths (EW) of DIBs λ5797 and λ5780 in IC 63 is the same as that observed in the low-density interstellar medium with UV interstellar radiation fields (ISRF) weaker by at least two orders of magnitude. This falsifies suggestions that the ratio of these two DIBs can serve as a measure of the UV strength of the ISRF. Observations of the nebular spectrum of the PDR of IC 63 at locations immediately adjacent to where DIBs were detected failed to reveal any presence of sharp emission features seen in the spectrum of the Red Rectangle nebula. This casts doubts upon proposals that the carriers of these features are the same as those of DIBs seen at slightly shorter wavelengths.

The extended red emission filaments in NGC 2023

1989 ◽  
Vol 347 ◽  
pp. L25 ◽  
Author(s):  
Adolf N. Witt ◽  
David F. Malin
Keyword(s):  
Red Emission ◽  
Extended Red Emission

scholarly journals Quenched carbonaceous composite (QCC) as a carrier of the extended red emission and blue luminescence in the red rectangle

2008 ◽  
Vol 4 (S251) ◽  
pp. 417-424
Author(s):  
S. Wada ◽  
Y. Mizutani ◽  
T. Narisawa ◽  
A. T. Tokunaga
Keyword(s):  
Quantum Yield ◽  
Laboratory Data ◽  
Blue Luminescence ◽  
Peak Wavelength ◽  
Gaseous State ◽  
Red Emission ◽  
Polycyclic Aromatic ◽  
Solid Film ◽  
Large Width ◽  
Extended Red Emission

AbstractFilmy-QCC is an organic material synthesized in the laboratory, and it exhibits red photoluminescence (PL). The peak wavelength of the PL ranges from 650 to 690 nm, depending on the mass distribution of polycyclic aromatic hydrocarbon (PAH) molecules, and the emission profile is a good match for that of the extended red emission in the Red Rectangle nebula. The quantum yield of the PL ranges from 0.009 to 0.04. When filmy-QCC is dissolved in cyclohexane, it exhibits blue PL in the wavelength range of 400–500 nm with a quantum yield of 0.12–0.16. The large width of the red PL and the large wavelength difference between the PL of the filmy-QCC as a solid film and in a solution indicate that there is a strong interaction between the components of filmy-QCC. The major components of filmy-QCC are PAHs up to 500 atomic mass units. Our laboratory data suggest that the blue luminescence observed in the Red Rectangle nebula is probably caused by small PAHs in a gaseous state, and the extended red emission is caused by larger PAHs in dust grains.

ON THE CARRIER OF THE EXTENDED RED EMISSION AND BLUE LUMINESCENCE

2008 ◽  
Vol 690 (1) ◽  
pp. 111-119 ◽  
Author(s):  
S. Wada ◽  
Y. Mizutani ◽  
T. Narisawa ◽  
A. T. Tokunaga
Keyword(s):  
Blue Luminescence ◽  
Red Emission ◽  
Extended Red Emission
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