Advances in Astronomy and Space Physics, Volume 12, Issue 1-2, PP. 18-24 (2022)
doi: 10.17721/2227-1481.12.18-24
Kinematic characteristics of the Milky Way globular clusters based on Gaia DR2 data
1Taras Shevchenko National University of Kyiv, Glushkova ave. 4, 03127 Kyiv, Ukraine
2Institut d'Astrophysique de Paris, CNRS - Sorbonne Universite, 98bis boulevard Arago, 75014 Paris, France
3Main Astronomical Observatory of NAS of Ukraine, 27 Akademika Zabolotnoho str., 03143 Kyiv, Ukraine
4Fesenkov Astrophysical Institute, Observatory 23, 050020 Almaty, Kazakhstan
5Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
6GEPI, Observatoire de Paris, Université PSL, CNRS, 5 Place Jules Janssen, 92190 Meudon, France
7Astronomisches Rechen-Institut, Zentrum für Astronomie, University of Heidelberg, Mönchhofstrasse 12-14, 69120 Heidelberg, Germany
8Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), MTA Centre of Excellence, Konkoly Thege Miklóns út 15-17, 1121 Budapest, Hungary
2Institut d'Astrophysique de Paris, CNRS - Sorbonne Universite, 98bis boulevard Arago, 75014 Paris, France
3Main Astronomical Observatory of NAS of Ukraine, 27 Akademika Zabolotnoho str., 03143 Kyiv, Ukraine
4Fesenkov Astrophysical Institute, Observatory 23, 050020 Almaty, Kazakhstan
5Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
6GEPI, Observatoire de Paris, Université PSL, CNRS, 5 Place Jules Janssen, 92190 Meudon, France
7Astronomisches Rechen-Institut, Zentrum für Astronomie, University of Heidelberg, Mönchhofstrasse 12-14, 69120 Heidelberg, Germany
8Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), MTA Centre of Excellence, Konkoly Thege Miklóns út 15-17, 1121 Budapest, Hungary
Abstract
Using the data from Gaia (ESA) Data Release 2 we performed the orbital calculations of globular clusters (GCs) of the Milky Way. To explore possible close encounters (or collisions) between the GCs, using our own developed high-order φ-GRAPE code, we integrated backward and forward orbits of 119 objects with reliable positions and proper motions. In the calculations, we adopted a realistic axisymmetric Galactic potential (bulge + disk + halo). Using different impact conditions, we found four pairs of six GCs that may have experienced an encounter within twice the sum of the half-mass radii ('collisions') over the last 5 Gyr: Terzan 3 — NGC 6553, Terzan 3 — NGC 6218, Liller 1 — NGC 6522 and Djorg 2 — NGC 6553.
Keywords:
Galaxy: globular clusters: general - Galaxy: kinematics and dynamics - methods: numerical