An astronomical 2175 angstrom feature in interplanetary dust particles.
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.
Bradley
John
J
Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. jbradley@igpp.ucllnl.org
Dai
Zu Rong
ZR
Erni
Rolf
R
Browning
Nigel
N
Graham
Giles
G
Weber
Peter
P
Smith
Julie
J
Hutcheon
Ian
I
Ishii
Hope
H
Bajt
Sasa
S
Floss
Christine
C
Stadermann
Frank
F
Sandford
Scott
S
D002244:Carbon; D019443:Cosmic Dust; D006838:Hydrocarbons; D008670:Metals; D046529:Microscopy, Electron, Transmission; D009930:Organic Chemicals; D010100:Oxygen; D017640:Silicates; D013056:Spectrophotometry, Ultraviolet; D013057:Spectrum Analysis; D014466:Ultraviolet Rays
D019443:Cosmic Dust; D006838:Hydrocarbons; D008670:Metals; D009930:Organic Chemicals; D017640:Silicates; D002244:Carbon; D010100:Oxygen