Data Set Overview : This dataset identifies asteroid dynamical clusters identified by Mothe-Diniz et al. 2005 using the Hierarchical Clustering Method (HCM) in the space of proper elements. The proper elements are those of the AstDys data base (Knezevic and Milani 2000,2003) as of November 2003, including 120,000 asteroids.  The data are divided by region into Inner (semimajor axis from 2.0 to 2.5 A.U.), Middle (from 2.5 to 2.8 A.U.) and Outer (from 2.8 to 3.3 A.U.). For each region, there is one file for each dynamical family identified, containing the proper elements of all its members, and one additional file containing all the clumps also identified by the method. In addition, for each dynamical family with a minimum of three objects classified, there is a file containing the taxonomic classification of the family members, as well as a file containing the taxonomic classification of the background members. Filenames incorporate the number and name of the principal member of the family.  Subdirectories of the data directory include:  INNER, MIDDLE, and OUTER - containing one file for each dynamical family, listing the family members. (18 data files)  TAXONOMY - containing one file for each family with at least three members, giving the taxonomic class of each member. (18 data files)  BACKGROUND - containing files giving taxonomic classes for the background objects for each family. (18 files)  CLUMPS - containing the membership of clumps identified by the method. (3 data files) Note: The paper included only clumps with 12 or more members. In these files, some additional clumps with fewer members are also included.  The taxonomic classification method adopted is that of Bus and Binzel 2002b, and is based on visible reflectance spectra obtained by the SMASS (Xu et al. 1995), SMASSII (Bus et al. 2002b) and S3OS2 (Lazzaro et al. 2004) surveys and on the spectra of the Eos family members kindly supplied by Alain Douressoundiram.  The taxonomic classifications and the spectra on which it is based are available in the following PDS data sets: EAR-A-5-DDR-TAXONOMY-V5.0 EAR-A-M3SPEC-3-RDR-SMASS-V2.1 EAR-A-I0028-4-SBN0001/SMASSII-V1.0 (The S3OS2 spectra are yet to be included in the archive.)  Modification History:  The data set was updated in early 2012 from V1.0 to V1.1 to add a column for family name to the data files in the inner, middle, and outer subdirectories. This was done to facilitate loading the data into the SBN Data Ferret.  References:  Bendjoya, Ph., and V. Zappala, Asteroid Family Identification, in 'Asteroids III', W.F. Bottke et al., Eds., pp. 613-618, 2002. [BENDJOYA&ZAPPALA2002]  Bus, S.J. and R.P. Binzel, Phase II of the small main-belt asteroid spectroscopic survey: A feature-based taxonomy, Icarus 158, 146- 177, 2002. [BUS&BINZEL2002B]  Knezevic, Z., and A. Milani, Synthetic proper elements for outer main belt asteroids, Celest. Mech. Dynam. Astron. 78, 17-46, 2000. [KNESEVIC&MILANI2000]  Knezevic, Z., and A. Milani, Proper element catalogs and asteroid families, Astron. Astrophys.403, 1165-1173, 2003. [KNEZEVIC&MINLANI2003]  Lazzaro, D., C.A. Angeli, J.M. Carvano, T. Mothe-Diniz, R. Duffard, and M. Florczak, S3OS2: The visible spectroscopic survey of 820 asteroids, Icarus 172, 179-220, 2004. [LAZARROETAL2004]  Mothe-Diniz, T., F. Roig, and J.M. Carvano, Reanalysis of Asteroid Families Structure Through Visible Spectroscopy, Icarus 174, 45-80, 2005. [MOTHE-DINIZETAL2005]  Xu, Shui, R.P. Binzel, T.H. Burbine, and S.J. Bus, Small Main-Belt Asteroid Spectroscopic Survey: Initial results, Icarus, 115, 1-35, 1995. [XUETAL1995]

Confidence Level Overview : The determination of asteroid families using the Hierarchical Clustering Method is affected by two major limitations: (i) the accuracy of the dataset of proper elements used and (ii) the definition of the cutoff level. Concerning the first limitation, we have to bear in mind that the present determination is based on the dataset of analytic proper elements available at AstDyS (http://hamilton.dm.unipi.it/astdys). It is well known that analytic proper elements are poorly estimated for high-eccentric or high-inclined orbits as well as for near-resonant orbits. Therefore, the results for such kind of asteroids must be carefully interpreted. Concerning the second limitation, the user may refer to Mothe-Diniz et al. 2005.  1)Data coverage and quality:  Only the families in the main asteroid belt (a : 2.5 to 3.3 AU) have been determined. Recall that it is not expected to find any asteroid families outside this range since the number of asteroids decreases significantly. The determination has been done using a dataset of proper elements for numbered and multi-oppositional asteroids known by November, 2003. As the number of such asteroids increase in the databases we may expect slight changes in the family members, especially for small clumps.  2)Limitations:  The intrinsic limitations of the HCM and comparison to other methods are well described in Bendjoya and Zappala 2002, and references therein.