EPSC Abstracts Vol. 13, EPSC-DPS2019-289-1, 2019 EPSC-DPS Joint Meeting 2019 c Author(s) 2019. CC Attribution 4.0 license. The use of Multiple large-scale Surveys in Astrocladistics: The Jovian Trojans Timothy R. Holt (1), Jonathan Horner (1), David Nesvorný (2), Rachel King (1), Brad Carter(1) and Christopher Tylor (1) (1) Center of Astrophysics, University of Southern Queensland, Queensland, Australia, (2) Department of Space Studies, Southwest Research Institute, Boulder, CO. USA. ([email protected]) Abstract 2. Astrocladistical methodology Cladistics is a multivariate analysis technique most of- Astrocladistical methodology begins with the creation ten used in the biological sciences. Recent advances of a 2D matrix. In the rows are the objects of inter- have brought this method to Astronomy, forming a est, in this case the Jovian Trojans, with each column new discipline, Astrocladistics. The technique uses representing a specific characteristic. The characteris- clustering analysis to link closely related objects, and tics are the dynamical proper elements (∆a, e & sin-i) presents the resulting hypothetical relationships based [8], calculated librations, geometric albedo and col- on their characteristics. We apply Astrocladistics to ors from three surveys, WISE [3], SDSS [7] and Gaia the Jovian Trojans, a population known to contain at DR2 [12]. Characteristics for each Trojan are binned least six collisional families, to further demonstrate the and coded, with incomplete data accounted for with a technique in the planetary sciences. Through this anal- ?. In total there are 349 L4 Trojans and 351 L5 Trojans ysis, we can incorporate dynamical information, as analysed, selected for having data in at least one of the well as datasets from three surveys, WISE, SDSS and surveys. Once constructed, a block of 10,000 equally Gaia DR2, without truncating datasets. The resulting parsimonious trees are generated using TNT [2]. A dendritic trees identify members of existing collisional consensus of the trees [9] then represents the hypothe- families, and can be compared with other taxonomic sised relationships between the Jovian Trojans. systems. This is preparation for the future datasets, including the release of Gaia DR3 and other next gen- 3. L4 and L5 Trees eration surveys, such as LSST. In each of the L4 and L5 consensus trees, the respec- tive identified families can be seen. We show the ex- 1. Introduction ample of the extended Eurybates family in figure 1. The core family is identified, with the rest of the ex- Modern cladistics began in the mid 20th century [4] tended family shown. Within this extended family, and rapidly became the methodology of choice for bi- new groupings may be seen, for example around 9817 ological taxonomy. Today, the discipline has expanded Thersander, that have not been previously identified. to include genetic analysis, with large datasets giv- ing us a clear understanding of the ‘Tree of Life’ [6]. There have been recent efforts to expand the cladisti- 4. Future Work cal technique into Astronomy, collectively called ‘As- Astrocladistics can be used to combine the analysis of trocladistics’ [1]. These works include investigations disparate survey databases. As we move into the new into the satellite systems of Jupiter and Saturn [5]. In era of large sky surveys, the technique could be used order to expand the use of Astrocladistics in planetary to analyse even larger datasets. Gaia DR3, which is sciences, we chose the Jovian Trojans as a test case to be released in late 2021, will incorporate more col- for the technique. The Jovian Trojans are a population ors and a wider range of Solar system objects. LSST of approximately 7000 known small bodies, located at [11], which is to gain first light in 2020 will provide a the L4 and L5 Lagrange points of Jupiter. Within the plethora of information regarding estimations of mil- two swarms, six collisional families have been iden- lions of Solar system objects. Astrocladistics, being tified [10], four in the L4 swarm and two in the L5 parallelizable on HPC systems [2], is well suited to swarm. these large forms of data analysis. Outgroup 1 1 1 1 1 4902 Thessandrus (1989 AN2) 1 1 1 1 1 15436 (1998 VU30) 2260 Neoptolemus (1975 WM1) 1 1 1 1 1 5284 Orsilocus (1989 CK2) 0 0 0 0 0 . 20729 (1999 XS143) 1 1 . 1 1 1 .9 .9 9 9 9 1 1 1 9 9 1 1 9 9 9 161024 (2002 FM7) 0 0 0 0 0 0 0 0 0 0 9 . 9 . 9 9 .9 .9 9 9 9 9 162822 (2001 BD49) 9 9 9 9 9 1 1 1 1 1 0 0 0 0 0 0 0 5126 Achaemenides (1989 CH2) 0 1 1 0 0 1 1 1 9 9 9 9 . 9 . 9 9 9 9 9 38050 (1998 VR38) 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 . 41340 (1999 YO14) . 9 9 9 .9 .9 9 9 9 9 9 9 9 9 9 9 15663 Periphas (4168 T-2) 0 0 0 0 0 0 0 0 0 0 0 0 0 9 0 0 9 . 9 9 9 .9 .9 9 . 24587 Kapaneus (4613 T-2) 9 9 .6 .6 6 6 6 9 9 9 9 9 5 5 5 5 5 0 0 0 4833 Meges (1989 AL2) 0 0 9 9 9 1 1 9 9 9 1 9 9 1 1 0 0 9 9 0 5 50 0 5 5 5 . 23970 (1998 YP6) .6 .6 6 6 6 6 6 6 6 6 22014 (1999 XQ96) 2 2 2 2 2 5 5 5 5 5 37299 (2001 CN21) 24501 (2001 AN37) 0 0 0 0 0 . 111819 (2002 DD1) . 6 6 6 6 6 1 1 1 1 1 0 0 6 6 6 0 6 6 0 0 2146 Stentor (1976 UQ) . 8 8 8 8 8 .6 .6 6 6 6 4 4 4 4 4 0 0 4 4 4 0 0 0 4 4 83983 (2002 GE39) 0 0 0 0 0 . 7 7 7 . 9 9 7 7 9 . 9 9 .6 .6 3 3 6 3 6 6 3 3 9 9 9 5264 Telephus (1991 KC) 9 9 2 2 2 2 2 0 0 0 0 0 2 2 2 1 1 2 2 1 9 9 9 1 1 9799 (1996 RJ) 9 9 1 1 1 1 1 7641 (1986 TT6) 0 0 0 0 0 88225 (2001 BN27) . 9 9 9 0 0 9 9 0 0 0 0 0 0 0 0 1 1 1 . 1 1 42187 (2001 CS32) .6 .6 . 6 6 6 .9 .9 8 8 9 8 8 8 9 9 3 3 3 3 3 2 9 9 9 2 2 2 2 20424 (1998 VF30) 9 9 7 7 7 7 7 0 0 0 0 0 1 1 1 1 1 9 9 9 9 9 23958 (1998 VD30) 0 0 0 0 0 5254 Ulysses (1986 VG1) . 9 9 1 1 9 9 9 1 1 1 24519 (2001 CH) 7 7 7 7 7 6 6 6 6 6 0 0 0 0 0 5 5 38610 (2000 AU45) 5 5 5 . 9 9 0 0 9 0 9 9 0 0 9 . 9 9 13385 (1998 XO79) 9 9 .6 .6 6 6 6 9 9 9 9 9 6 6 6 6 6 4 4 4 11396 (1998 XZ77) 4 4 2 2 0 0 2 0 0 0 0 0 0 2 2 0 0 8 . 8 8 . 1 1 . 8 9 9 1 8 9 .9 .9 1 1 0 0 9 9 9 0 16099 (1999 VQ24) 9 9 0 0 6 6 6 . 9 9 9 . 6 6 .6 .6 9 9 6 6 6 5 5 5 9 9 0 0 5 5 9 0 21599 (1998 WA15) 9 9 5 5 0 0 5 5 5 4 4 4 4 . 4 4 4 4 . 4 3 3 .6 .6 4 3 6 3 3 6 6 8 168364 (1996 TZ19) 8 9 9 8 9 8 8 9 9 0 0 7 7 0 0 0 7 7 7 . 1 1 . 5 5 1 5652 Amphimachus (1992 HS3) 1 1 .9 .9 5 5 5 9 9 9 9 9 9 9 9 1 1 1 1 1 20144 (1996 RA33) 9 9 9 9 9 4 4 1 1 1 4 4 4 1 1 2148 Epeios (1976 UW) 37710 (1996 RD12) 0 0 0 0 0 0 0 0 0 0 . .9 9 . 9 13387 Irus (1998 YW6) 9 9 .6 .6 6 6 6 9 9 9 9 9 0 0 0 0 7 7 7 0 0 0 0 0 0 7 7 9 9 9 24486 (2000 YR102) 9 . 9 . 0 0 . 0 . 9 9 9 9 0 0 9 9 9 9 4 4 9 9 4 4 4 7 7 7 8 9 7 8 8 9 9 7 8 9 0 0 8 9 0 63265 (2001 CP12) 0 0 6 6 9 9 . 6 9 . 6 6 9 9 .9 .9 9 9 9 3 3 4 3 4 4 3 3 4 0 0 4 9 0 83975 (2002 AD184) 9 9 0 0 9 9 . 9 .9 9 .9 9 9 9 9 9 9 0 0 4 4 9 0 21284 Pandion (1996 TC51) 4 9 0 0 9 4 4 9 9 . 9 . 9 9 .9 9 9 9 9 9 9 0 0 4 9 0 15521 (1999 XH133) 4 9 0 0 4 9 4 9 4 9 .