Abstract
We present an updated size distribution for the nuclei of Jupiter-Family
Comets, based on observations of nuclei at large heliocentric distances.
The data set used includes our own recently published work and that of
others published since the comprehensive review by Lamy et al. (2004, in
Comets II), in addition to older measurements from the refereed
literature that were included in that compilation. We apply a new
approach to make a rigorous assessment of the uncertainty on the size
distribution power law slope, taking into account all unknown factors
and sources of uncertainty. We include: 1) the uncertainty on the
original photometry; 2) the difference between the measured effective
radius from snap-shot observations and the mean effective radius for
observations at unknown rotational phase of a nucleus with unknown pole
orientation and axial ratio; 3) the unknown solar phase function; and 4)
the unknown albedo. We use a Monte Carlo technique to look at how the
size distribution changes when allowing individual size measurements to
vary within these uncertainties. We find the cumulative size
distribution can be fit by a power law, N( > r) r^{-a}, where r is
the radius and the slope, a = 1.86 ± 0.15. This work was funded
in part by the NASA Planetary Astronomy Program and was performed in
part at the Jet Propulsion Laboratory under contract with NASA.
Original language | English |
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Publication status | Published - 01 Sept 2009 |
Externally published | Yes |