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An astronomical 2175 Å feature in
interplanetary dust particles.
Bradley J., Dai Z. R., Erni R., Browning N., Graham G.,
Weber P., Smith J., Hutcheon I., Ishii H., Bajt S., Floss
C., Stadermann F., and Sandford S. (2005)
Science 307, 244-247.
doi:
10.1126/science.1106717
ABSTRACT
The 2175 angstrom extinction feature is the strongest
(visible-ultraviolet) spectral signature of dust in the
interstellar medium. Forty years after its discovery, the
origin of the feature and the nature of the carrier(s)
remain controversial. Using a transmission electron
microscope, we detected a 5.7 electron volt (2175 angstrom)
feature in interstellar grains embedded within
interplanetary dust particles (IDPs). The carriers are
organic carbon and amorphous silicates that are abundant in
IDPs and in the interstellar medium. These multiple carriers
may explain the enigmatic invariant central wavelength and
variable bandwidth of the astronomical 2175 angstrom
feature.
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