The Size Distributions of Asteroid Families in the SDSS Moving Object Catalog 4

By A. Parker, Željko Ivezic´, Mario Juric, Robert Lupton, M. Sekora, A. Kowalski. 2008

179 citations recorded by the source corpus.

Asteroid families, traditionally defined as clusters of objects in orbital parameter space, often have distinctive optical colors. We show that the separation of family members from background interlopers can be improved with the aid of SDSS colors as a qualifier for family membership. Based on an ∼88,000 object subset of the Sloan Digital Sky Survey Moving Object Catalog 4 with available proper orbital elements, we define 37 statistically robust asteroid families with at least 100 members (12 families have over 1000 members) using a simple Gaussian distribution model in both orbital and color space. The interloper rejection rate based on colors is typically ∼10% for a given orbital family definition, with four families that can be reliably isolated only with the aid of colors. About 50% of all objects in this data set belong to families, and this fraction varies from about 35% for objects brighter than an H magnitude of 13 and rises to 60% for objects fainter than this. The fraction of C-type objects in families decreases with increasing H magnitude for H>13, while the fraction of S-type objects above this limit remains effectively constant. This suggests that S-type objects require a shorter timescale for equilibrating the background and family size distributions via collisional processing. The size distribution varies significantly among families, and is typically different from size distributions for background populations. The size distributions for 15 families display a well-defined change of slope and can be modeled as a “broken” double power-law. Such “broken” size distributions are twice as likely for S-type familes than for C-type families (73% vs. 36%), and are dominated by dynamically old families. The remaining families with size distributions that can be modeled as a single power law are dominated by young families (<1 Gyr). When size distribution requires a double power-law model, the two slopes are correlated and are steeper for S-type families. No such slope–color correlation is discernible for families whose size distribution follows a single power law. For several very populous families, we find that the size distribution varies with the distance from the core in orbital-color space, such that small objects are more prevalent in the family outskirts. This “size sorting” is consistent with predictions based on the Yarkovsky effect.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/c93d3250859cf11fabd1fe46882853bfc0469543

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In Astronomy and Astrophysics

Citations in the corpus

Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations (2012, unknown): “Parker et al. (2008) compared Johnson V data derived from the photometric measurements from the Sloan Digital Sky Survey (SDSS) Moving Object Catalog 4 for a sample of about 64,000 asteroids observed at solar phases between 3 (cid”
PRELIMINARY RESULTS FROM NEOWISE: AN ENHANCEMENT TO THE WIDE-FIELD INFRARED SURVEY EXPLORER FOR SOLAR SYSTEM SCIENCE (2011, methodology): “This will facilitate study of the distribution of sizes and albedos within dynamical families (Hirayama 1918) as has been done with multiband optical photometry (Parker et al. 2008; Ivezic et al. 2002).”
Asteroid Catalog Using AKARI: AKARI/IRC Mid-Infrared Asteroid Survey (2011, methodology): “There are several survey catalogs of asteroids: the 2MASS Asteroid Catalog (Sykes et al. 2000) compiles near-infrared colors of 1054 asteroids based on the Two Micron All Sky Survey; the Subaru Main Belt Asteroid Survey (SMBAS: Yoshida & Nakamura 2007) gives the size and color distributions of 1838 ”
Differentiated Planetesimals and the Parent Bodies of Chondrites (2013, background): “As a result, the assumption of spectral homogeneity is now routinely used to identify family members from a background of compositionally distinct objects with similar orbital elements (Parker et al. 2008).”
LSST: From Science Drivers to Reference Design and Anticipated Data Products (2008, methodology): “26) and size; size distributions of asteroid families (Parker et al. 2008) and their correlations with age (Jedicke et al. 2004; Nesvorný et al. 2005); dynamical effects (Bottke et al. 2001); and studies of object shapes and spin states using light curve inversion techniques (Pravec & Harris 2000;…”
MAIN BELT ASTEROIDS WITH WISE/NEOWISE. I. PRELIMINARY ALBEDOS AND DIAMETERS (2011, background): “MBAs have been previously shown to cluster in color-space (Ivezić et al. 2002; Parker et al. 2008) and show similar reflectance spectra (e.g. Binzel & Xu 1993; Cellino et al. 2001, etc.) indicative of the common origin of members of families, which are the result of a catastrophic breakup of a…”
The taxonomic distribution of asteroids from multi-filter all-sky photometric surveys (2013, background): “The homogeneity in surface reflectance and albedo of asteroids pertaining to dynamical families (e.g., Ivezić et al., 2002; Cellino et al., 2002; Parker et al., 2008; Carruba et al., 2013) however suggest that most asteroids have an interior composition similar to their surface composition.”
SDSS-based taxonomic classification and orbital distribution of main belt asteroids (2010, methodology): “Recent works that use SDSS colors to study families (Parker et al. 2008) also tend to report color homogeneity in the families, although it should be noted that they use the SDSS colors as a criterion to define the family membership.”
The Compositional Structure of the Asteroid Belt (2015, unknown): “, Parker, A. H. (2015) Asteroid Family Physical Properties.”