Back to Search
Start Over
On the absorption properties of metallic needles
- Source :
- Monthly Notices of the Royal Astronomical Society. 498:3560-3564
- Publication Year :
- 2020
- Publisher :
- Oxford University Press (OUP), 2020.
-
Abstract
- Needle-like metallic particles have been suggested to explain a wide variety of astrophysical phenomena, ranging from the mid-infrared interstellar extinction to the thermalization of starlight to generate the cosmic microwave background. These suggestions rely on the amplitude and the wavelength dependence of the absorption cross sections of metallic needles. On the absence of an exact solution to the absorption properties of metallic needles, their absorption cross sections are often derived from the antenna approximation. However, it is shown here that the antenna approximation is not an appropriate representation since it violates the Kramers-Kronig relation. Stimulated by the recent discovery of iron whiskers in asteroid Itokawa and graphite whiskers in carbonaceous chondrites, we call for rigorous calculations of the absorption cross sections of metallic needle-like particles, presumably with the discrete dipole approximation. We also call for experimental studies of the formation and growth mechanisms of metallic needle-like particles as well as experimental measurements of the absorption cross sections of metallic needles of various aspect ratios over a wide wavelength range to bound theoretical calculations.<br />5 pages, 1 figure; accepted for publication in MNRAS
- Subjects :
- Physics
Opacity
Whiskers
Extinction (astronomy)
Cosmic microwave background
FOS: Physical sciences
Astronomy and Astrophysics
Discrete dipole approximation
Astrophysics - Astrophysics of Galaxies
Molecular physics
Wavelength
Thermalisation
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Absorption (electromagnetic radiation)
Subjects
Details
- ISSN :
- 13652966 and 00358711
- Volume :
- 498
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi.dedup.....7a6bb8167324fbb18aeb4b4f6e00dd33