Science and Exploration

A Search Of The Full Six Years Of The Dark Energy Survey For Outer Solar System Objects

By Keith Cowing
Press Release
September 8, 2021
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A Search Of The Full Six Years Of The Dark Energy Survey For Outer Solar System Objects
Semi-major axes, eccentricities and inclinations of the 816 TNOs (excluding the object found in a cometary orbit) found in this search, color-coded by dynamical class. The dotted lines represent constant perihelion q = a(1 ? e), and the vertical dashed lined the approximate locations of some p:q mean motion resonances. Since many of these have similar a, we do not indicate all occupied resonances. The solid circles represent objects with secure dynamical classifications, and the triangles objects whose classification is insecure (including resonant candidates). Table 4 presents the number of objects found in each dynamical class.

We present the results of a search for outer Solar System objects in the full six years of data (Y6) from the Dark Energy Survey (DES).
The DES covered a contiguous 5000 deg2 of the southern sky with ?80,000 3 deg2 exposures in the grizY optical/IR filters between 2013 and 2019. This search yielded 815 trans-Neptunian objects (TNOs), one Centaur and one Oort cloud comet, with 461 objects reported for the first time in this paper. We present methodology that builds upon our previous search carried out on the first four years of data. Here, all DES images were reprocessed with an improved detection pipeline that leads to an average completeness gain of 0.47 mag per exposure, as well as an improved transient catalog production and optimized algorithms for linkage of detections into orbits.

All objects were verified by visual inspection and by computing the sub-threshold significance, the total signal-to-noise ratio in the stack of images in which the object’s presence is indicated by the orbit fit, but no detection was reported. This yields a highly pure catalog of TNOs complete to r?23.8 mag and distances 29 < d <2500 au. The Y6 TNOs have minimum (median) of 7 (12) distinct nights' detections and arcs of 1.1 (4.2) years, and will have grizY magnitudes available in a further publication. We present software for simulating our observational biases that enable comparisons of population models to our detections. Initial inferences demonstrating the statistical power of the DES catalog are: the data are inconsistent with the CFEPS-L7 model for the classical Kuiper Belt; the 16 ``extreme'' TNOs (a>150 au, q>30 au) are consistent with the null hypothesis of azimuthal isotropy; and non-resonant TNOs with q>38 au, a>50 au show a highly significant tendency to be sunward of the major mean motion resonances, whereas this tendency is not present for q<38 au. Pedro H. Bernardinelli, Gary M. Bernstein, Masao Sako, Brian Yanny, M. Aguena, S. Allam, F. Andrade-Oliveira, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, C. Conselice, M. Costanzi, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, J. P. Dietrich, P. Doel, K. Eckert, S. Everett, I. Ferrero, B. Flaugher, P. Fosalba, J. Frieman, J. Garcia-Bellido, D. W. Gerdes, D. Gruen, R. A. Gruendl, J. Gschwend, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. J. James, S. Kent, K. Kuehn, N. Kuropatkin, O. Lahav, M. A. G. Maia, M. March, F. Menanteau, R. Miquel, R. Morgan, J. Myles, R. L. C. Ogando, A. Palmese, F. Paz-Chinchon, A. Pieres, A. A. Plazas Malagon, A. K. Romer, A. Roodman, E. Sanchez, V. Scarpine, M. Schubnell, S. Serrano, I. Sevilla-Noarbe, M. Smith, M. Soares-Santos, E. Suchyta, M. E. C. Swanson, G. Tarle, C. To, T. N. Varga, A. R. Walker (the DES collaboration) Comments: 29 pages, submitted to AAS journals. Survey simulation software and table of objects will be made available post peer review. Abstract abridged Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM) Report number: FERMILAB-PUB-21-390-AE Cite as: arXiv:2109.03758 [astro-ph.EP] (or arXiv:2109.03758v1 [astro-ph.EP] for this version) Submission history From: Pedro Bernardinelli [v1] Wed, 8 Sep 2021 16:29:18 UTC (3,855 KB)

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