Ensemble Properties of Comets in the Sloan Digital Sky Survey

TL;DR

This study analyzes 31 comets observed by SDSS, examining their colors, sizes, and dust production, revealing a power-law luminosity function and uniform color distribution similar to Jupiter Trojans.

Contribution

It provides the first statistical analysis of SDSS-observed comets, detailing their ensemble properties and luminosity function.

Findings

Luminosity function follows a power law with different slopes for bright and faint comets.

Comets exhibit a narrow color distribution similar to Jupiter Trojans.

No correlation found between comet colors and other physical or dynamical parameters.

Abstract

We present the ensemble properties of 31 comets (27 resolved and 4 unresolved) observed by the Sloan Digital Sky Survey (SDSS). This sample of comets represents about 1 comet per 10 million SDSS photometric objects. Five-band (u,g,r,i,z) photometry is used to determine the comets' colors, sizes, surface brightness profiles, and rates of dust production in terms of the Af{\rho} formalism. We find that the cumulative luminosity function for the Jupiter Family Comets in our sample is well fit by a power law of the form N(< H) \propto 10(0.49\pm0.05)H for H < 18, with evidence of a much shallower fit N(< H) \propto 10(0.19\pm0.03)H for the faint (14.5 < H < 18) comets. The resolved comets show an extremely narrow distribution of colors (0.57 \pm 0.05 in g - r for example), which are statistically indistinguishable from that of the Jupiter Trojans. Further, there is no evidence of correlation between color and physical, dynamical, or observational parameters for the observed comets.