“TNOs are Cool”: A survey of the trans-Neptunian region

XV. Physical characteristics of 23 resonant trans-Neptunian and scattered disk objects

¹ Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege 15-17, 1121 Budapest, Hungary
e-mail: farkas.aniko@csfk.mta.hu
² Eötvös University, Faculty of Science, Pázmány P. sétány 1/A, 1171 Budapest, Hungary
³ ELTE Eötvös Loránd University, Institute of Phyiscs, Pázmány P. sétány 1/A, 1171 Budapest, Hungary
⁴ Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
⁵ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
⁶ Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff, AZ 86001, USA
⁷ Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA
⁸ Observatoire de Paris, Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique (LESIA), 5 Place Jules Janssen, 92195 Meudon Cedex, France
⁹ Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, UK

Received: 26 June 2019
Accepted: 2 March 2020

Abstract

The goal of this work is to determine the physical characteristics of resonant, detached and scattered disk objects in the trans-Neptunian region, observed mainly in the framework of the “TNOs are Cool” Herschel open time key programme. Based on thermal emission measurements with the Herschel/PACS and Spitzer/MIPS instruments, we determine size, albedo, and surface thermal properties for 23 objects using radiometric modeling techniques. This is the first analysis in which the physical properties of objects in the outer resonances are determined for a notable sample. In addition to the results for individual objects, we compared these characteristics with the bulk properties of other populations of the trans-Neptunian region. The newly analyzed objects show a large variety of beaming factors, indicating a diversity of thermal properties, and in general they follow the albedo-color clustering identified earlier for Kuiper belt objects and Centaurs, further strengthening the evidence for a compositional discontinuity in the young Solar System.