CFHT UM2025 - Presentation Details
Abstract Details
Title: TNO Absolute Magnitude Distributions for H=7-10
Presenter: Justine Obidowski
Abstract:
The transneptunian object (TNO) absolute magnitude distribution is tied to the size distribution (with variations possible depending on albedo). In the cold classical Kuiper belt, it seems likely that this distribution is unevolved and preserves the planet formation epoch's size distribution, while the hot population is different in that it built objects all the way up to dwarf planet scale. The OSSOS survey presented precise and absolutely calibrated H magnitude distributions for the hot and cold populations down to about H=8.5. We present our progress on an analysis of the CLASSY survey's exploration of the H magnitude distribution, which pushes deeper than OSSOS, and explores the H=7-10 range by using deep imaging stacks on CFHT to push down to apparent magnitudes of ~26.5. We have linked detections across several month arcs in order to obtain heliocentric distances accurate to ~1%, which confines the absolute magnitude uncertainty to the photometric precision and allows us to obtain enough orbital information to calculate accurate free orbital inclinations. We are then able to separate the hot and cold populations in this sample and show that the two populations continue to follow exponential taper functional forms (of the kind generated in streaming instability models of planetesimal formation) for fainter (smaller) objects as found by OSSOS. CLASSY is thus directly probing planetesimal formation physics. This 30-300 km TNO diameter range will provide a critical bridge to even fainter studies (eg. JWST) of the magnitude distribution and is beyond the detection capabilities of LSST.