5 research outputs found
Searching for the first Near-Earth Object family
We report on our search for genetically related asteroids amongst the
near-Earth object (NEO) population - families of NEOs akin to the well known
main belt asteroid families. We used the technique proposed by Fu et al. (2005)
supplemented with a detailed analysis of the statistical significance of the
detected clusters. Their significance was assessed by comparison to identical
searches performed on 1,000 'fuzzy-real' NEO orbit distribution models that we
developed for this purpose. The family-free 'fuzzy-real' NEO models maintain
both the micro and macro distribution of 5 orbital elements (ignoring the mean
anomaly). Three clusters were identified that contain four or more NEOs but
none of them are statistically significant at \geq 3{\sigma}. The most
statistically significant cluster at the \sim 2{\sigma} level contains 4
objects with H < 20 and all members have long observational arcs and
concomitant good orbital elements. Despite the low statistical significance we
performed several other tests on the cluster to determine if it is likely a
genetic family. The tests included examining the cluster's taxonomy,
size-frequency distribution, consistency with a family-forming event during
tidal disruption in a close approach to Mars, and whether it is detectable in a
proper element cluster search. None of these tests exclude the possibility that
the cluster is a family but neither do they confirm the hypothesis. We conclude
that we have not identified any NEO families.Comment: 36 pages, 3 tables, 9 figures, accepted for publicatio