A Subaru Pencil-beam Search for m_R~27 Trans-neptunian bodies

TL;DR

This study used Subaru archival data to discover 20 new Trans-neptunian objects at faint magnitudes, providing the most precise measurement of the TNO luminosity function break and insights into their size distribution.

Contribution

It presents the first detailed measurement of the TNO luminosity function break at R~25, with new TNO discoveries and refined size distribution parameters.

Findings

Discovered 20 new TNOs with R=24-27

Measured the break in the TNO luminosity function at R~25

Estimated the size distribution break at D=90+-30 km

Abstract

We present the results of an archival search for Trans-neptunian objects (TNOs) in an ecliptic field observed with Subaru in 2002. The depth of the search allowed us to find 20 new TNOs with magnitudes between R=24 and 27. We fit a double power law model to the data; the most likely values for the bright and faint power law exponents are alpha_1=0.73_{-0.09}^{+0.08} and alpha_2=0.20_{-0.14}^{+0.12}; the differential number density at R=23 is sigma_{23}=1.46_{-0.12}^{+0.14} and the break magnitude is R_{eq}=25.0_{-0.6}^{+0.8}. This is the most precise measurement of the break in the TNO luminosity function to date. The break in the size distribution corresponds to a diameter of D = 90+-30 km assuming a 4% albedo.