TY - JOUR
T1 - Thermophysical Modeling of Asteroid Surfaces Using Ellipsoid Shape Models
AU - Maclennan, Eric M.
AU - Emery, Joshua P.
N1 - Funding Information:
E.M.M. greatly appreciates support from the NASA Earth and Space Sciences Fellowship (#NNX14AP21H). This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration.
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2019/1
Y1 - 2019/1
N2 - Thermophysical Models (TPMs), which have proven to be a powerful tool in the interpretation of the infrared emission of asteroid surfaces, typically make use of shape models and spin axes obtained a priori for use as input boundary conditions. We test and then employ a TPM approach - under an assumption of an ellipsoidal shape - that exploits the combination of thermal multi-wavelength observations obtained at pre- and post-opposition. Thermal infrared data, when available at these observing circumstances, are inherently advantageous in constraining thermal inertia and sense of spin, among other physical traits. We show that, despite the lack of a priori knowledge mentioned above, the size, albedo, and thermal inertia of an object are well-constrained with precision comparable to that of previous techniques. Useful estimates of the surface roughness, shape, and spin direction can also be made, to varying degrees of success. Applying the method to Wide-Field infrared Survey Explorer observations, we present best-fit size, albedo, thermal inertia, surface roughness, shape elongation and sense of spin direction for 21 asteroids. We explore the thermal inertia's correlation with asteroid diameter, after accounting for its dependence on the heliocentric distance.
AB - Thermophysical Models (TPMs), which have proven to be a powerful tool in the interpretation of the infrared emission of asteroid surfaces, typically make use of shape models and spin axes obtained a priori for use as input boundary conditions. We test and then employ a TPM approach - under an assumption of an ellipsoidal shape - that exploits the combination of thermal multi-wavelength observations obtained at pre- and post-opposition. Thermal infrared data, when available at these observing circumstances, are inherently advantageous in constraining thermal inertia and sense of spin, among other physical traits. We show that, despite the lack of a priori knowledge mentioned above, the size, albedo, and thermal inertia of an object are well-constrained with precision comparable to that of previous techniques. Useful estimates of the surface roughness, shape, and spin direction can also be made, to varying degrees of success. Applying the method to Wide-Field infrared Survey Explorer observations, we present best-fit size, albedo, thermal inertia, surface roughness, shape elongation and sense of spin direction for 21 asteroids. We explore the thermal inertia's correlation with asteroid diameter, after accounting for its dependence on the heliocentric distance.
KW - methods: numerical
KW - methods: observational
KW - methods: statistical
KW - minor planets, asteroids: general
KW - surveys
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U2 - 10.3847/1538-3881/aaed47
DO - 10.3847/1538-3881/aaed47
M3 - Article
AN - SCOPUS:85060132384
SN - 0004-6256
VL - 157
JO - Astronomical Journal
JF - Astronomical Journal
IS - 1
M1 - 2
ER -