Title: The AKARI IRC asteroid flux catalogue: updated diameters and albedos,
Abstract: The AKARI IRC All-sky survey provided more than twenty thousand thermal
infrared observations of over five thousand asteroids. Diameters and albedos
were obtained by fitting an empirically calibrated version of the standard
thermal model to these data. After the publication of the flux catalogue in
October 2016, our aim here is to present the AKARI IRC all-sky survey data and
discuss valuable scientific applications in the field of small-body physical
properties studies. As an example, we update the catalogue of asteroid
diameters and albedos based on AKARI using the near-Earth asteroid thermal
model (NEATM). We fit the NEATM to derive asteroid diameters and, whenever
possible, infrared beaming parameters. We obtained a total of 8097 diameters
and albedos for 5170 asteroids, and we fitted the beaming parameter for almost
two thousand of them. When it was not possible to fit the beaming parameter, we
used a straight line fit to our sample's beaming parameter-versus-phase angle
plot to set the default value for each fit individually instead of using a
single average value. Our diameters agree with stellar-occultation-based
diameters well within the accuracy expected for the model. They also match the
previous AKARI-based catalogue at phase angles lower than 50 degrees, but we
find a systematic deviation at higher phase angles, at which near-Earth and
Mars-crossing asteroids were observed. The AKARI IRC All-sky survey provides
observations at different observation geometries, rotational coverages and
aspect angles. For example, by comparing in more detail a few asteroids for
which dimensions were derived from occultations, we discuss how the multiple
observations per object may already provide three-dimensional information about
elongated objects even based on an idealised model like the NEATM.