The Surfaces of Resonant TNOs in grz

The colors of Trans-Neptunian Objects (TNOs) in the optical and near-infrared (NIR) provide a useful tool for determining surface classification and understanding the evolutionary history of these objects. The Colours of the Outer Solar System Origins Survey (Col-OSSOS) has found that the current cold classical TNOs have FaintIR surfaces, or surfaces which have reduced IR reflectivity relative to their optical reflectivity. We have acquired photometry in g, r, and z bands in order to measure the optical and NIR reflectivity of TNOs in the 3:2 and 2:1 resonances and classified them using the FaintIR and BrightIR system. The presence of a significant number of resonant FaintIR objects, which we infer originally formed in the same region as the cold classical objects, would indicate an efficient capture process during Neptune’s outward migration, such as a period of smooth resonance sweeping over the primordial FaintIR population. A FaintIR fraction similar to the general excited Kuiper belt would imply that scattering capture was the dominant population mechanism for these resonances.