2015/07/10 by D. Massari, Davide Massari, E. Dalessandro +7
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Bulge #Galaxy #Globular cluster #Hubble space telescope #Kinematics #Orbit (dynamics) #Stars #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/810/1/69
25 pages, 14 figures, accepted for publication by ApJ
arxiv created 2015/07/10 · openalex publication_date 2015/09/01 · openalex created_date 2016/06/24 · arxiv updated 2017/12/06 · openalex updated_date 2026/08/05
By exploiting two sets of high-resolution images obtained with the Hubble Space Telescope Advanced Camera for Surveys/Wide Field Channel over a baseline of ∼10 years, we have measured relative proper motions (PMs) of ∼70,000 stars in the stellar system Terzan 5. The results confirm the membership of the three subpopulations with different iron abundances discovered in the system. The orbit of the system has been derived from a first estimate of its absolute PM, obtained by using bulge stars as a reference. The results of the integration of this orbit within an axisymmetric Galactic model exclude any external accretion origin for this cluster. Terzan 5 is known to have chemistry similar to the Galactic bulge; our findings support a kinematic link between the cluster and the bulge, further strengthening the possibility that Terzan 5 is the fossil remnant of one of the pristine clumps that originated the bulge.