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The Differing Magnitude Distributions of the Two Jupiter Trojan Color Populations

Wong, Ian and Brown, Michael E. and Emery, Joshua P. (2014) The Differing Magnitude Distributions of the Two Jupiter Trojan Color Populations. Astronomical Journal, 148 (6). Art. No. 112. ISSN 0004-6256. doi:10.1088/0004-6256/148/6/112.

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The Jupiter Trojans are a significant population of minor bodies in the middle solar system that have garnered substantial interest in recent years. Several spectroscopic studies of these objects have revealed notable bimodalities with respect to near-infrared spectra, infrared albedo, and color, which suggest the existence of two distinct groups among the Trojan population. In this paper, we analyze the magnitude distributions of these two groups, which we refer to as the red and less red color populations. By compiling spectral and photometric data from several previous works, we show that the observed bimodalities are self-consistent and categorize 221 of the 842 Trojans with absolute magnitudes in the range into the two color populations. We demonstrate that the magnitude distributions of the two color populations are distinct to a high confidence level (%) and fit them individually to a broken power law, with special attention given to evaluating and correcting for incompleteness in the Trojan catalog as well as incompleteness in our categorization of objects. A comparison of the best-fit curves shows that the faint-end power-law slopes are markedly different for the two color populations, which indicates that the red and less red Trojans likely formed in different locations. We propose a few hypotheses for the origin and evolution of the Trojan population based on the analyzed data.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Wong, Ian0000-0001-9665-8429
Brown, Michael E.0000-0002-8255-0545
Additional Information:© 2014 American Astronomical Society. Received 10 December 2013, accepted for publication 28 July 2014; published 30 October 2014. This work had its inception at the “In Situ Science and Instrumentation for Primitive Bodies” study funded by the W. M. Keck Institute for Space Studies. The authors were supported by NASA Grant NNX09AB49G. The authors also thank an anonymous reviewer for constructive comments that helped to improve the manuscript.
Group:Keck Institute for Space Studies
Funding AgencyGrant Number
Keck Institute for Space Studies (KISS)UNSPECIFIED
Subject Keywords:minor planets, asteroids: general
Issue or Number:6
Record Number:CaltechAUTHORS:20141219-112548515
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Official Citation:The Differing Magnitude Distributions of the Two Jupiter Trojan Color Populations Ian Wong et al. 2014 The Astronomical Journal 148 112
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:53043
Deposited On:20 Dec 2014 00:05
Last Modified:10 Nov 2021 19:47

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