Аннотация
This study addresses thermal modeling of asteroids with a new derivation of
the Near Earth Asteroid Thermal (NEATM) model which correctly accounts for the
presence of reflected sunlight in short wave IR bands. Kirchhoff's law of
thermal radiation applies to this case and has important implications. New
insight is provided into the eta parameter in the NEATM model and it is
extended to thermal models besides NEATM. The role of surface material
properties on eta is examined using laboratory spectra of meteorites and other
asteroid compositional proxies; the common assumption that emissivity e=0.9 in
asteroid thermal models may not be justified and can lead to misestimating
physical parameters. In addition, indeterminacy in thermal modeling can limit
its ability to uniquely determine temperature and other physical properties. A
new curve fitting approach allows thermal modeling to be done independent of
visible band observational parameters such as the absolute magnitude H. These
new thermal modeling techniques are applied to observational data for selected
asteroids from the WISE/NEOWISE mission. The previous NEOWISE analysis assumes
Kirchhoff's law does not apply. It also deviates strongly from established
statistical practice and systematically underestimates the sampling error
inherent in observing potentially irregular asteroids from a finite sample of
observations. As a result, the new analysis finds asteroid diameter and other
physical properties that have large differences from published NEOWISE results,
with greatly increased error estimates. NEOWISE results have a claimed +/-10\%
accuracy for diameter estimates, but this is unsupported by any calculations
and undermined because NEOWISE results for 102 asteroids appear to have had the
diameter from prior radar and occultation studies simply copied rather than
being due to NEOWISE thermal modeling. ABSTRACT CONTINUED IN PDF...
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