Bibcode
Durech, J.; Hanus, Josef; Delbo, Marco; Ali-Lagoa, V.; Carry, Benoit
Referencia bibliográfica
American Astronomical Society, DPS meeting #46, #509.11
Fecha de publicación:
11
2014
Número de citas
0
Número de citas referidas
0
Descripción
Convex shape models and spin vectors of asteroids are now routinely
derived from their disk-integrated lightcurves by the lightcurve
inversion method of Kaasalainen et al. (2001, Icarus 153, 37). These
shape models can be then used in combination with thermal infrared data
and a thermophysical model to derive other physical parameters - size,
albedo, macroscopic roughness and thermal inertia of the surface. In
this classical two-step approach, the shape and spin parameters are kept
fixed during the thermophysical modeling when the emitted thermal flux
is computed from the surface temperature, which is computed by solving a
1-D heat diffusion equation in sub-surface layers. A novel method of
simultaneous inversion of optical and infrared data was presented by
Durech et al. (2012, LPI Contribution No. 1667, id.6118). The new
algorithm uses the same convex shape representation as the lightcurve
inversion but optimizes all relevant physical parameters simultaneously
(including the shape, size, rotation vector, thermal inertia, albedo,
surface roughness, etc.), which leads to a better fit to the thermal
data and a reliable estimation of model uncertainties. We applied this
method to selected asteroids using their optical lightcurves from
archives and thermal infrared data observed by the Wide-field Infrared
Survey Explorer (WISE) satellite. We will (i) show several examples of
how well our model fits both optical and infrared data, (ii) discuss the
uncertainty of derived parameters (namely the thermal inertia), (iii)
compare results obtained with the two-step approach with those obtained
by our method, (iv) discuss the advantages of this simultaneous approach
with respect to the classical two-step approach, and (v) advertise the
possibility to use this approach to tens of thousands asteroids for
which enough WISE and optical data exist.